FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Cane, HV Erickson, WC Prestage, NP AF Cane, HV Erickson, WC Prestage, NP TI Solar flares, type III radio bursts, coronal mass ejections, and energetic particles SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE particles; flares; radio bursts; CMEs ID INTERPLANETARY SHOCKS; FILAMENT ERUPTIONS; ACCELERATION; EVENTS; WAVES; ELECTRONS; EMISSION; SPECTRA; PROTONS AB [1] In this correlative study between >20 MeV solar proton events, coronal mass ejections (CMEs), flares, and radio bursts it is found that essentially all of the proton events are preceded by groups of type III bursts and all are preceded by CMEs. These type III bursts (that are a flare phenomenon) usually are long-lasting, intense bursts seen in the low-frequency observations made from space. They are caused by streams of electrons traveling from close to the solar surface out to 1 AU. In most events the type III emissions extend into, or originate at, the time when type II and type IV bursts are reported (some 5 to 10 minutes after the start of the associated soft X-ray flare) and have starting frequencies in the 500 to similar to 100 MHz range that often get lower as a function of time. These later type III emissions are often not reported by ground-based observers, probably because of undue attention to type II bursts. It is suggested to call them type III-l. Type III-l bursts have previously been called shock accelerated (SA) events, but an examination of radio dynamic spectra over an extended frequency range shows that the type III- l bursts usually start at frequencies above any type II burst that may be present. The bursts sometimes continue beyond the time when type II emission is seen and, furthermore, sometimes occur in the absence of any type II emission. Thus the causative electrons are unlikely to be shock accelerated and probably originate in the reconnection regions below fast CMEs. A search did not find any type III- l bursts that were not associated with CMEs. The existence of low-frequency type III bursts proves that open field lines extend from within 0.5 radius of the Sun into the interplanetary medium (the bursts start above 100 MHz, and such emission originates within 0.5 solar radius of the solar surface). Thus it is not valid to assume that only closed field lines exist in the flaring regions associated with CMEs and some interplanetary particles originating in such flare regions might be expected in all solar particle events. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Bruny Isl Radio Spectometer, Bruny Isl, Tas 7150, Australia. Culgoora Solar Observ, IPS Radio Serv, Narrabri, NSW 2390, Australia. Culgoora Solar Observ, Space Serv, Narrabri, NSW 2390, Australia. RP Cane, HV (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. NR 49 TC 94 Z9 96 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT PY 2002 VL 107 IS A10 AR 1315 DI 10.1029/2001JA000320 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634RF UT WOS:000180353900050 ER PT J AU Heber, B Wibberenz, G Potgieter, MS Burger, RA Ferreira, SES Muller-Mellon, R Kunow, H Ferrando, P Raviart, A Paizis, C Lopate, C McDonald, FB Cane, HV AF Heber, B Wibberenz, G Potgieter, MS Burger, RA Ferreira, SES Muller-Mellon, R Kunow, H Ferrando, P Raviart, A Paizis, C Lopate, C McDonald, FB Cane, HV TI Ulysses cosmic ray and solar particle investigation/Kiel Electron Telescope Observations: Charge sign dependence and spatial gradients during the 1990-2000 A > 0 solar magnetic cycle SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE cosmic rays; solar modulation; charge sign dependence; latitudinal gradients; drifts; diffusion ID RAPID LATITUDE SCAN; NORTHERN HELIOSPHERE; INNER HELIOSPHERE; DRIFT MODEL; MODULATION; PROTONS; TRANSPORT; MINIMUM; FLUXES; PERSPECTIVE AB [1] Ulysses, launched in October 1990, began its second out- of- ecliptic orbit in September 1997. From 1991 to mid- 2000, solar polar magnetic field observations indicate a magnetic field pointing outward over the northern polar region (A > 0 epoch). While the first fast latitude scan in 1994/ 1995 was performed around solar minimum, the second Ulysses orbit covering high latitudes is being performed around solar maximum. We present data of similar to 2.5 GV electrons and protons from the Kiel Electron Telescope up to southern heliographic latitudes of 80degrees, reached by Ulysses in November 2000. Spatial gradients are determined by comparison with a near- Earth baseline. The radial gradient for an integral proton channel is found to be 2.2 +/- 0.6%/ AU before early 1998 and 3.5%/ AU thereafter. Until mid- 1999 the latitudinal variation is consistent with a zero gradient at low latitudes and an average gradient of about 0.25%/ degree for latitudes above about +/-25degrees. In contrast, the latitudinal gradient decreases markedly after mid- 1999, leading to a spherically symmetric intensity distribution with the approach to solar maximum conditions. The electron to proton (e/ p) ratio is used to study charge sign dependent modulation. According to drift- dominated modulation models, galactic cosmic ray protons and electrons respond differently to the global heliospheric magnetic field. Comparison of the e/ p ratio over the period 1991 to 2000 with model predictions indicates that drift effects are important over a large part of an 11- year period with A > 0. With the approach to solar maximum the e/ p ratio increases, indicative for the fading out of drift effects and the transition to a diffusion- dominated modulation. C1 Univ Osnabruck, Fachbereich Phys, D-49069 Osnabruck, Germany. Univ Kiel, Inst Expt & Angew Phys, D-24118 Kiel, Germany. Potchefstroom Univ Christian Higher Educ, Unit Space Phys, ZA-2520 Potchefstroom, South Africa. CENS, Serv Astrophys, DAPNIA, CEO Salari, F-91191 Gif Sur Yvette, France. Univ Milan, CNR, Ist Fis Cosm, I-20133 Milan, Italy. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Heber, B (reprint author), Univ Osnabruck, Fachbereich Phys, Barbarians 7, D-49069 Osnabruck, Germany. NR 35 TC 18 Z9 18 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT PY 2002 VL 107 IS A10 AR 1274 DI 10.1029/2001JA000329 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634RF UT WOS:000180353900009 ER PT J AU Hernandez-Pajares, M Juan, JM Sanz, J Colombo, OL AF Hernandez-Pajares, M Juan, JM Sanz, J Colombo, OL TI Improving the real-time ionospheric determination from GPS sites at very long distances over the equator SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE modeling and forecasting; instruments and techniques; equatorial ionosphere; ionospheric propagation; space geodetic surveys ID MODEL AB As the authors have shown in previous work, the tomographic approach reduces significantly the mismodeling in the electron content determination using as data the ionosphere-crossing radio signals of global navigation satellite systems (GNSS) such as the Global Positioning System (GPS). We present in this paper the results of a comprehensive study on the performance of an improved tomographic model of the ionosphere. This model is obtained from the GPS L1 and L2 carrier-phase data, and it is used to estimate undifferenced and double-differenced ionospheric corrections in real time and at very long distances between receivers (500-3000 km). The key point of the strategy is the combination of real-time geodetic and ionospheric techniques to achieve a significant improvement in the reliability of carrier-phase ambiguity resolution. This new approach includes also the use of smoothed pseudo-ranges to help in ambiguity resolution. It has been tested under difficult ionospheric conditions, during four consecutive weeks in March-April 2001, at Solar Maximum, and at latitudes ranging from -40 to +40 degrees, so as to include the equatorial region. Dual-frequency satellite altimetry from TOPEX-Poseidon has been used to verify the accuracy of the ionospheric model over the oceans in that region. C1 UPC, Dept Appl Math & Appl Phys 4, Grp Astron & Geomat, GAGE, E-08034 Barcelona, Spain. NASA, Goddard Space Flight Ctr, Goddard Eareth Sci & Technol Ctr, Greenbelt, MD 20771 USA. RP Hernandez-Pajares, M (reprint author), UPC, Dept Appl Math & Appl Phys 4, Grp Astron & Geomat, GAGE, Mod C-3 Campus Nord, E-08034 Barcelona, Spain. RI Sanz Subirana, Jaume/C-1265-2014; Juan Zornoza, Jose Miguel/S-6224-2016; OI Sanz Subirana, Jaume/0000-0001-8880-7084; Juan Zornoza, Jose Miguel/0000-0003-1126-2367; Hernandez-Pajares, Manuel/0000-0002-9687-5850 NR 18 TC 11 Z9 11 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT PY 2002 VL 107 IS A10 AR 1296 DI 10.1029/2001JA009203 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634RF UT WOS:000180353900031 ER PT J AU Moore, TE Fok, MC Chandler, MO AF Moore, TE Fok, MC Chandler, MO TI The dayside reconnection X line SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE magnetopause; reconnection; X line ID INTERPLANETARY MAGNETIC-FIELD; LATITUDE BOUNDARY-LAYER; MAGNETOPAUSE; PLASMA; MODEL AB [1] The antiparallel reconnection hypothesis states that reconnection occurs at or near the locus along which magnetosheath and magnetospheric fields are antiparallel and the reconnecting component of the magnetic field is maximal. Recent observations have pointed toward significant reconnection rates in locales with much less than antiparallel field shear. We explore the alternative component reconnection hypothesis that reconnection occurs along a locus determined by integrating the local X line (XL) direction away from that region with the largest reconnecting field magnitude. We develop a description of the magnetospheric and magnetosheath magnetic fields at the magnetopause, compute the angle between the sheath and boundary layer fields, and the reconnecting component, everywhere on the magnetopause. We then integrate the XL across the magnetopause from a starting point or points where the reconnecting component is maximal. The resultant XL lies across the equatorial subsolar magnetopause for southerly Bz, as expected. For typical interplanetary magnetic field (IMF) conditions dominated by By, the XL tilts poleward and loops around the cusps into the high-latitude regions, consistent with throat-like cusp region flows. For northerly Bz, the XL bifurcates into high-latitude and low-latitude segments with subsolar reconnection disappearing only for mainly northward Bz. We argue that the component reconnection XL represents the mean location of quasi-steady reconnection on the magnetopause, subject to of course to nonuniformities and variations of the interplanetary magnetic field and plasma. We conclude that reconnection should have appreciable rates across the subsolar magnetopause for most IMF clock angles, with higher rates at high latitudes for northward Bz. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Interplanetary Phys Branch, Greenbelt, MD 20771 USA. NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35812 USA. RP Moore, TE (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Interplanetary Phys Branch, Code 692,Bldg 2, Greenbelt, MD 20771 USA. RI Moore, Thomas/D-4675-2012; Fok, Mei-Ching/D-1626-2012 OI Moore, Thomas/0000-0002-3150-1137; NR 19 TC 74 Z9 75 U1 1 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT PY 2002 VL 107 IS A10 AR 1332 DI 10.1029/2002JA009381 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634RF UT WOS:000180353900067 ER PT J AU Poletto, G Suess, ST Biesecker, DA Esser, R Gloeckler, G Ko, YK Zurbuchen, TH AF Poletto, G Suess, ST Biesecker, DA Esser, R Gloeckler, G Ko, YK Zurbuchen, TH TI Low-latitude solar wind during the Fall 1998 SOHO-Ulysses quadrature SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE SOHO-Ulysses quadrature; low-latitude solar wind; oxygen flow speed; proton flow speed; in situ data ID POLAR CORONAL HOLE; WHOLE SUN MONTH; PHYSICAL-PROPERTIES; STRAY-LIGHT; TEMPERATURE; UVCS/SOHO; MINIMUM; REGIONS; SPECTROMETER; STREAMERS AB The Fall 1998 Solar and Heliospheric Observatory (SOHO)-Ulysses quadrature occurred when Ulysses was at 5.2 AU, 17.4degreesS of the equator, and off the west limb of the Sun. SOHO coronal observations, at heliocentric distances of a few solar radii, showed that the line through the solar center and Ulysses crossed, over the first days of observations, a dark, weakly emitting area and through the northern edge of a streamer complex during the second half of the quadrature campaign. Ulysses in situ observations showed this transition to correspond to a decrease from higher-speed wind typical of coronal hole flow to low-speed wind. Physical parameters of the low-latitude coronal plasma sampled over the campaign are determined using constraints from what is the same plasma measured later in situ and simulating the intensities of the hydrogen Lyman-alpha and OVI 1032 and 1037 Angstrom lines, measured by the Ultraviolet Coronagraph Spectrometer on SOHO. It appears that low-latitude wind from small coronal holes and polar wind have different characteristics in the corona, differences well known at interplanetary distances through in situ experiments. Small, low-latitude coronal holes have a higher expansion factor than typical polar holes, and their plasma moves at a lower speed than plasma from polar holes, reaching, at 3.5 R-sun, only about one-fifth of the terminal speed. Wind emanating from bright regions, above streamer complexes, is, at the altitudes we analyzed (i.e., 3.5 and 4.5 R-sun), about a factor 3 slower than the low-latitude coronal hole wind, implying a shift to even higher altitudes of the region where plasma gets accelerated. We surmise that open field regions, interspersed amidst closed coronal loops/streamers, may be at least partially responsible for the well-known slow wind speed variability. As in polar fast wind, OVI ions move faster than protons, over the range of altitudes we sampled, and are frozen-in at temperatures of approximate to1.3-1.5 10(6) K, depending on the site where the outflow originates. An oxygen abundance variation from a value of 8.55, in low-latitude holes, to 8.73 in bright areas, has also been inferred. C1 Osserv Astrofis Arcetri, I-50125 Florence, Italy. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NASA, Goddard Space Flight Ctr, Commun Analyt Corp L3, Greenbelt, MD 20771 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. RP Poletto, G (reprint author), Osserv Astrofis Arcetri, Largo E Fermi 5, I-50125 Florence, Italy. NR 50 TC 10 Z9 10 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT PY 2002 VL 107 IS A10 AR 1300 DI 10.1029/2001JA000275 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634RF UT WOS:000180353900035 ER PT J AU Richardson, IG Cliver, EW Cane, HV AF Richardson, IG Cliver, EW Cane, HV TI Long-term trends in interplanetary magnetic field strength and solar wind structure during the twentieth century SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE interplanetary magnetic field; geomagnetic activity; cosmic rays; solar wind; long-term trends ID CORONAL MASS EJECTIONS; COSMIC-RAY MODULATION; GEOMAGNETIC-ACTIVITY; SPEED; TRANSPORT; AVERAGES; MINIMUM; STORMS; EARTH; DRIFT AB Lockwood et al. [1999] have recently reported a similar to40% increase in the radial component of the interplanetary magnetic field (IMF) at Earth between 1964 and 1996. We argue that this increase does not constitute a secular trend but is largely the consequence of lower than average fields during solar cycle 20 (1964-1976) in comparison with surrounding cycles. For times after 1976 the average IMF strength has actually decreased slightly. Examination of the cosmic ray intensity, an indirect measure of the IMF strength, over the last five solar cycles (19-23) also indicates that cycle averages of the IMF strength have been relatively constant since similar to1954. We also consider the origin of the well-documented increase in the geomagnetic aa index that occurred primarily during the first half of the twentieth century. We surmise that the coronal mass ejection (CME) rate for recent solar cycles was approximately twice as high as that for solar cycles 100 years ago. However, this change in the CME rate and the accompanying increase in 27-day recurrent storm activity reported by others are unable to account completely for the increase in aa. Rather, the CMEs and recurrent high-speed streams at the beginning of the twentieth century must have been embedded in a background of slow solar wind that was less geoeffective (having, for example, lower IMF strength and/or flow speed) than its modern counterpart. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. USAF, Res Lab, Bedford, MA 01731 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Univ Tasmania, Sch Math & Phys, Hobart, Tas, Australia. RP Richardson, IG (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. OI Richardson, Ian/0000-0002-3855-3634 NR 35 TC 17 Z9 17 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT PY 2002 VL 107 IS A10 AR 1304 DI 10.1029/2001JA000507 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634RF UT WOS:000180353900039 ER PT J AU Sibeck, DG Phan, TD Lin, R Lepping, RP Szabo, A AF Sibeck, DG Phan, TD Lin, R Lepping, RP Szabo, A TI Wind observations of foreshock cavities: A case study SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE foreshock; bow shock; cavities; pulses; energetic ions ID EARTHS BOW SHOCK; UPSTREAM PRESSURE VARIATIONS; HOT DIAMAGNETIC CAVITIES; SOLAR-WIND; 3-DIMENSIONAL PLASMA; ION EVENTS; SIMULATION; ELECTRONS; SHEETS; ORIGIN AB [1] We present a case study of plasma, energetic particle, and magnetic field perturbations seen by Wind in the dawn foreshock on 19 April 1996. A comparison with the results of hybrid simulations confirms model predictions for a diamagnetic cavity flanked by regions of enhanced density and magnetic field strength but filled with a suprathermal ion population. In contrast to previously reported hot flow anomalies, flow velocities within the foreshock cavities are nearly identical to those in the ambient solar wind, ion temperatures do not rise greatly, thermal pressures are only slightly greater than those in the ambient solar wind, and the events do not lie centered upon interplanetary magnetic field (IMF) tangential discontinuities intersecting the bow shock. We attribute the cavities to the diamagnetic effects of ions Fermi accelerated within the foreshock. A review suggests that foreshock cavities are far more common than hot flow anomalies. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sibeck, DG (reprint author), NASA, Goddard Space Flight Ctr, Code 696, Greenbelt, MD 20771 USA. RI Sibeck, David/D-4424-2012 NR 26 TC 49 Z9 50 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT PY 2002 VL 107 IS A10 AR 1271 DI 10.1029/2001JA007539 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634RF UT WOS:000180353900006 ER PT J AU Wu, CC Lepping, RP AF Wu, CC Lepping, RP TI Effects of magnetic clouds on the occurrence of geomagnetic storms: The first 4 years of Wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE magnetic cloud; geomagnetic storm; two-step storm; interplanetary magnetic field; shock; solar wind ID JANUARY 1997; SOLAR-WIND; MAGNETOSPHERE; EARTH; SUBSTORM; EVENT; LOOP; DST AB [1] We investigate geomagnetic activity associated with magnetic clouds as well as some aspects of the clouds' magnetic field structure (e. g., magnetic field distributions of the clouds). Thirty-four magnetic cloud events observed by Wind over the years 1995-1998 are investigated in this study. Magnetic clouds are a principal source of strong, long-lasting, interplanetary, negative B(z) fields (in solar magnetospheric coordinates) and hence are a major source of geomagnetic activity (D(st) < -50 nT). The region just upstream of a cloud may be a significant source of southward fields instead of, or as well as, the cloud itself. We call this upstream region a "sheath'' if it is bounded by a shock (or a pressure pulse) and the cloud. This study helps to identify the major sources (regions of southward Bz following shock passages or within the magnetic clouds) that are most dominant in the generation of geomagnetic storms. It is found that a geomagnetic storm can be induced by (1) a sheath, (2) the leading (i.e., front part) region of a cloud, (3) the trailing part of a cloud, and (4) both sheath and cloud regions. (Because of this complexity a storm with a multistep main phase can occur.) The related occurrence percentages of storms were 17.6% (six events), 44.1% (15 events), 5.9% (two events), and 20.6% (seven events), and the averaged storm intensities (minimum Dst) were -60, -85, -92, and -58 nT, respectively. For the remaining four events (11.8%), there were no storms. The occurrence timing of storm intensity is highly correlated with the occurrence timing of minimum B(z) (maximum VBs or epsilon) for a magnetic cloud with the field rotating from southward to northward. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Wu, CC (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. EM ccwu@LEPVAX.gsfc.nasa.gov NR 33 TC 80 Z9 83 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT PY 2002 VL 107 IS A10 AR 1314 DI 10.1029/2001JA000161 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634RF UT WOS:000180353900049 ER PT J AU Muisener, PAO Clayton, L D'Angelo, J Harmon, JP Sikder, AK Kumar, A Cassell, AM Meyyappan, M AF Muisener, PAO Clayton, L D'Angelo, J Harmon, JP Sikder, AK Kumar, A Cassell, AM Meyyappan, M TI Effects of gamma radiation on poly(methyl methacrylate)/single-wall nanotube composites SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CARBON NANOTUBES; STRESS-RELAXATION; BEHAVIOR; TUBULES; MATRIX; CREEP AB Single-wall carbon nanotube (SWNT)/poly(methyl methacrylate) (PMMA) composites were fabricated and exposed to ionizing radiation for a total dose of 5.9 Mrads. Neat nanotube paper and pure PMMA were also exposed for comparison, and nonirradiated samples served as controls. A concentration of 0.26 wt% SWNT increased the glass transition temperature (T-g), the Vickers hardness number, and modulus of the matrix. Irradiation of the composite did not significantly change the T-g,, the Vickers hardness number, or the modulus; however, the real and imaginary parts of the complex permittivity increased after irradiation. The dielectric properties were found to be more labile to radiation effects than mechanical properties. C1 Univ S Florida, Dept Chem, Tampa, FL 33620 USA. Univ S Florida, Ctr Microelect Res, Tampa, FL 33620 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Harmon, JP (reprint author), Univ S Florida, Dept Chem, 4202 E Fowler Ave, Tampa, FL 33620 USA. NR 36 TC 49 Z9 49 U1 1 U2 15 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD OCT PY 2002 VL 17 IS 10 BP 2507 EP 2513 DI 10.1557/JMR.2002.0365 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 599TN UT WOS:000178351400006 ER PT J AU Brown, LR Sams, RL Kleiner, I Cottaz, C Sagui, L AF Brown, LR Sams, RL Kleiner, I Cottaz, C Sagui, L TI Line intensities of the phosphine dyad at 10 mu m SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE line intensities; PH3; infrared fundamentals; dyad ID LASER STARK SPECTROSCOPY; HARMONIC FORCE-FIELDS; ABINITIO CALCULATION; VIBRATIONAL-SPECTRA; A1-A2 SPLITTINGS; C3V MOLECULES; GROUND-STATE; PH3; NU-2; FUNDAMENTALS AB Over 1000 measured line intensities of phosphine (PH3) are reported for the region 830 to 1310 cm(-1), which contains the two lowest fundamentals in Coriolis interaction. These measurements are fitted to 1.5% for nu(2) at 992.13 cm(-1) and 2.1 % for nu(4) at 1118.31 cm(-1), respectively, using five intensity parameters that include three Herman-Wallis type terms. In addition, some 60 intensities of the 2nu(2) - nu(2) hot band are modeled. The corresponding assignments and line positions of the dyad from previous work [L. Fusina and G. Di Lonardo, J. Mol. Struct. 517-518, 67-78 (2000)] are combined with the present intensity study to provide an improved PH3 database for planetary studies. The total integrated intensity for the dyad is 156.(4) cm(-2) atm(-1) at 296 K. (C) 2002 Elsevier Science (USA). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Paris 11, CNRS, Unite Propre, F-91405 Orsay, France. RP Brown, LR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 33 TC 19 Z9 19 U1 0 U2 4 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD OCT PY 2002 VL 215 IS 2 BP 178 EP 203 DI 10.1006/jmsp.2002.8638 PG 26 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 607LN UT WOS:000178793200002 ER PT J AU Matthews, K Cruden, BA Chen, B Meyyappan, M Delzeit, L AF Matthews, K Cruden, BA Chen, B Meyyappan, M Delzeit, L TI Plasma-enhanced chemical vapor deposition of multiwalled carbon nanofibers SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE carbon nanotubes; multiwall; vertical alignment; plasma deposition; tip growth; nanodevice fabrication ID PATTERNED GROWTH; NANOTUBES; RAMAN; FIBERS; NUCLEATION; ALIGNMENT; GRAPHITE; ARRAYS AB Plasma-enhanced chemical vapor deposition is used to grow vertically aligned multiwalled carbon nanofibers (MWNFs). The graphite basal planes in these nanofibers are not parallel as in nanotubes; instead they exhibit a small angle resembling a stacked cone arrangement. A parametric study with varying process parameters such as growth temperature, feedstock composition, and substrate power has been conducted, and these parameters are found to influence the growth rate, diameter, and morphology. The well-aligned MWNFs are suitable for fabricating electrode systems in sensor and device development. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Meyyappan, M (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 31 TC 33 Z9 33 U1 0 U2 4 PU AMER SCIENTIFIC PUBLISHERS PI STEVENSON RANCH PA 25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA SN 1533-4880 J9 J NANOSCI NANOTECHNO JI J. Nanosci. Nanotechnol. PD OCT PY 2002 VL 2 IS 5 BP 475 EP 480 DI 10.1166/jnn.2002.133 PG 6 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 614VL UT WOS:000179212100007 PM 12908282 ER PT J AU Dateo, CE Gokcen, T Meyyappan, M AF Dateo, CE Gokcen, T Meyyappan, M TI Modeling of the HiPco process for carbon nanotube production. I. Chemical kinetics SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE HiPco process; carbon nanotube growth; Boudouard reaction ID BOND-DISSOCIATION ENERGIES; SINGLE-WALLED NANOTUBES; GAS-PHASE; CATALYTIC GROWTH; MONOXIDE; IRON; DECOMPOSITION; PYROLYSIS; DIAMETER; HYDROGEN AB A chemical kinetic model is developed to help understand and optimize the production of single-walled carbon nanotubes via the high-pressure carbon monoxide (HiPco) process, which employs iron pentacarbonyl as the catalyst precursor and carbon monoxide as the carbon feedstock. The model separates the HiPco process into three steps, precursor decomposition, catalyst growth and evaporation, and carbon nanotube production resulting from the catalyst-enhanced disproportionation of carbon monoxide, known as the Boudouard reaction: 2 CO(g) --> C(S) + CO2(g). The resulting detailed model contains 971 species and 1948 chemical reactions. A second model with a reduced reaction set containing 14 species and 22 chemical reactions is developed on the basis of the detailed model and reproduces the chemistry of the major species. Results showing the parametric dependence of temperature, total pressure, and initial precursor partial pressures are presented, with comparison between the two models. The reduced model is more amenable to coupled reacting flowfield simulations, presented in the following article. C1 NASA, Ames Res Ctr, Eloret Corp, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Dateo, CE (reprint author), NASA, Ames Res Ctr, Eloret Corp, MS 230-3, Moffett Field, CA 94035 USA. NR 39 TC 24 Z9 24 U1 2 U2 10 PU AMER SCIENTIFIC PUBLISHERS PI VALENCIA PA 26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA SN 1533-4880 J9 J NANOSCI NANOTECHNO JI J. Nanosci. Nanotechnol. PD OCT PY 2002 VL 2 IS 5 BP 523 EP 534 DI 10.1166/jnn.2002.125 PG 12 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 614VL UT WOS:000179212100016 PM 12908291 ER PT J AU Gokcen, T Dateo, CE Meyyappan, M AF Gokcen, T Dateo, CE Meyyappan, M TI Modeling of the HiPco process for carbon nanotube production. II. Reactor-scale analysis SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE HiPco process; carbon nanotube growth; reactor modeling; flowfield and chemistry ID SINGLE-WALLED NANOTUBES; HOMOGENEOUS NUCLEATION; PLASMA SYNTHESIS; VAPOR-PHASE; HYDROCARBONS; PYROLYSIS; MONOXIDE; GROWTH AB The high-pressure carbon monoxide (HiPco) process, developed at Rice University, has been reported to produce single-walled carbon nanotubes from gas-phase reactions of iron carbonyl in carbon monoxide at high pressures (10-100 atm). Computational modeling is used here to develop.,an understanding of the HiPco process. A detailed kinetic model of the HiPco process that includes of the precursor, decomposition metal cluster formation and growth, and carbon nanotube growth was developed in the previous article (Part 1). Decomposition of precursor molecules is necessary to initiate metal cluster formation. The metal clusters serve as catalysts for carbon nanotube growth. The diameter of metal clusters and number of atoms in these clusters are some of the essential information for predicting carbon nanotube formation and growth, which is then modeled by the Boudouard reaction with metal catalysts. Based on the detailed model simulations, a reduced kinetic model was also developed in Part I for use in reactor-scale flowfield calculations. Here this reduced kinetic model is integrated with a two-dimensional axisymmetric reactor flow model to predict reactor performance. Carbon nanotube growth is examined with respect to several process variables (peripheral jet temperature, reactor pressure, and Fe(CO)(5) concentration) with the use of the axisymmetric model, and the computed results are compared with existing experimental data. The model, yields most of the qualitative trends observed in the experiments and helps to understanding the fundamental processes in HiPco carbon nanotube production. C1 NASA, Ames Res Ctr, Eloret Corp, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Gokcen, T (reprint author), NASA, Ames Res Ctr, Eloret Corp, MS 230-3, Moffett Field, CA 94035 USA. NR 21 TC 19 Z9 19 U1 3 U2 10 PU AMER SCIENTIFIC PUBLISHERS PI STEVENSON RANCH PA 25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA SN 1533-4880 J9 J NANOSCI NANOTECHNO JI J. Nanosci. Nanotechnol. PD OCT PY 2002 VL 2 IS 5 BP 535 EP 544 DI 10.1166/jnn.2002.126 PG 10 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 614VL UT WOS:000179212100017 PM 12908292 ER PT J AU Seki, MP Lumpkin, R Flament, P AF Seki, MP Lumpkin, R Flament, P TI Hawaii cyclonic eddies and blue marlin catches: The case study of the 1995 Hawaiian International Billfish Tournament SO JOURNAL OF OCEANOGRAPHY LA English DT Article; Proceedings Paper CT 10th Annual Meeting of the North-Pacific-Marine-Sciences-Organization (PICES) CY OCT, 2001 CL VICTORIA, CANADA SP N Pacific Marine Sci Org DE cyclonic eddies, AVHRR SST, hydrography, currents, Pacific blue marlin; tournament catches ID MAKAIRA-NIGRICANS; IMAGERY; WATERS AB The combination of prevailing northeasterly tradewinds and island topography results in the formation of vigorous, westward propagating cyclonic eddies in the lee of the Hawaiian Islands on time scales of 50-70 days. These mesoscale (similar to10(2) km) features are nowhere more conspicuous or spin up more frequently than in the Alenuihaha Channel between the Island of Maui and the Big Island of Hawaii. Cyclonic eddies in subtropical waters such as those around Hawaii vertically displace the underlying nutricline into the overlying, nutrient-depleted euphotic zone creating localized biologically enhanced patches. Insight into how these eddies may directly influence pelagic fish distribution is provided by examination of recreational fish catch data coinciding with the presence of eddies on the fishing grounds. We highlight the 1995 Hawaii International Billfish Tournament in which a cyclonic eddy dominated the ocean conditions during the weeklong event and the fish catch distribution differed significantly from the average historical tournament catch patterns. On the tournament fishing grounds, well-mixed surface layers and strong current flows induced by the eddy's presence characterized the inshore waters where the highest catches of the prized Pacific blue marlin (Makaira mazara) occurred, suggesting possible direct (e.g., physiological limitations) or indirect (e.g., prey availability) biological responses of blue marlin to the prevailing environment. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. Florida State Univ, Dept Oceanog, Tallahassee, FL 32306 USA. Univ Hawaii, SOEST, Dept Oceanog, Honolulu, HI 96822 USA. RP Seki, MP (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, 2570 Dole St, Honolulu, HI 96822 USA. RI Lumpkin, Rick/C-9615-2009 OI Lumpkin, Rick/0000-0002-6690-1704 NR 14 TC 54 Z9 55 U1 0 U2 2 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 2003 SANSEI JIYUGAOKA HAIMU, 5-27-19 OKUSAWA, SETAGAYA-KU, TOKYO, 158, JAPAN SN 0916-8370 J9 J OCEANOGR JI J. Oceanogr. PD OCT PY 2002 VL 58 IS 5 BP 739 EP 745 DI 10.1023/A:1022854609312 PG 7 WC Oceanography SC Oceanography GA 597VG UT WOS:000178241000012 ER PT J AU Brebrick, RF Su, CH AF Brebrick, RF Su, CH TI Partial pressures for several In-Se compositions from optical absorbance of the vapor SO JOURNAL OF PHASE EQUILIBRIA LA English DT Article ID PHASE-EQUILIBRIA; SYSTEM; VAPORIZATION; DIAGRAM AB The optical absorbance of the vapor phase over various In-Se compositions between 33.3-60.99 at.% Se and 673-1418 K was measured and used to obtain the partial pressures Of Se-2(g) and In2Se(g). The results are in agreement with silica Bourdon gauge measurements for compositions between 50-61 at.%, but significantly higher than those from Knudsen cell and simultaneous Knudsen-torsion cell measurements. It is found that 60.99 at.% Se lies outside the sesquiselenide homogeneity range and 59.98 at.% Se lies inside and is the congruently melting composition. The Gibbs energy of formation of the liquid from its pure liquid elements between 1000-1300 K is essentially independent of temperature and falls between -36 to -38 Q per g atomic weight for 50 and 56% Se at 1200 and 1300 K. C1 Marquette Univ, Coll Engn, Mat Sci & Engn Program, Milwaukee, WI 53233 USA. NASA, George C Marshall Space Flight Ctr, Sci Directorate, Micrograv Sci & Applicat Dept SD47, Huntsville, AL 35812 USA. RP Brebrick, RF (reprint author), Marquette Univ, Coll Engn, Mat Sci & Engn Program, Milwaukee, WI 53233 USA. NR 22 TC 3 Z9 3 U1 0 U2 3 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1054-9714 J9 J PHASE EQUILIB JI J. Phase Equilib. PD OCT PY 2002 VL 23 IS 5 BP 397 EP 408 DI 10.1361/105497102770331343 PG 12 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 610UZ UT WOS:000178980900002 ER PT J AU Conner, DA Edwards, BD Decker, WA Marcolini, MA Klein, PD AF Conner, DA Edwards, BD Decker, WA Marcolini, MA Klein, PD TI NASA/Army/Bell XV-15 tiltrotor low noise terminal area operations flight research program SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article AB Three phases of XV-15 acoustic flight tests have been conducted over a five-year period by a NASA/Army/Bell Helicopter team to evaluate the noise reduction potential for tiltrotor aircraft during terminal area operations. Lower hemispherical noise characteristics for a wide range of steady-state terminal area type operating conditions were measured during the phase 1 test and indicated that the takeoff and level flight conditions were not significant contributors to the total noise of tiltrotor operations. Phase 1 results were used to design low noise approach profiles that were tested during the phase 2 and phase 3 tests, which used large area microphone arrays to directly measure the ground noise footprints. Approach profile designs emphasized noise reduction while attempting to maintain handling qualities sufficient for tiltrotor commercial passenger ride comfort and flight safety under Instrument Flight Rules (IFR) conditions. This paper will discuss the weather, aircraft, tracking, guidance, and acoustic instrumentation systems, as well as the approach profile design philosophy, and the overall test program philosophy. Acoustic results are presented documenting the variation in tiltrotor noise due to changes in operating condition, indicating the potential for significant noise reduction using the unique tiltrotor capability of nacelle tilt. C1 USA, Aviat & Missile Command, Langley Res Ctr, Directorate AMRDEC, Hampton, VA 23681 USA. Bell Helicopter Textron Inc, Acoust, Ft Worth, TX 76101 USA. USA, NASA, Ames Res Ctr,Rotorcraft Div, Flight Control & Cockpit Integrat Branch, Moffett Field, CA 94035 USA. NASA, Langley Res Ctr, Adv Measurement & Diag Branch, Hampton, VA 23681 USA. Bell Helicopter Textron Inc, Adv Syst Dev, Ft Worth, TX 76101 USA. RP Conner, DA (reprint author), USA, Aviat & Missile Command, Langley Res Ctr, Directorate AMRDEC, Hampton, VA 23681 USA. NR 21 TC 0 Z9 0 U1 0 U2 0 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD OCT PY 2002 VL 47 IS 4 BP 219 EP 232 PG 14 WC Engineering, Aerospace SC Engineering GA 606AD UT WOS:000178708500001 ER PT J AU Lyle, KH Bark, LW Jackson, KE AF Lyle, KH Bark, LW Jackson, KE TI Evaluation of test/analysis correlation methods for crash applications SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article; Proceedings Paper CT 57th Annual Forum of the American-Helicopter-Society CY MAY 09-11, 2001 CL WASHINGTON, D.C. SP Amer Helicopter Soc AB A research project has been initiated to improve crash test and analysis correlation. The work described in this paper is focused on the test and simulation results for a fuselage section. Two drop tests of the section were conducted. The first test was designed to excite the linear structural response for comparison with finite element modal analysis results. The second test was designed to provide data for correlation with crash simulations. An MSC.Dytran model was developed to generate nonlinear transient dynamic results. Following minor modifications, the same model was executed in MSC.Nastran to generate modal analysis results. The results presented in this paper concentrate on evaluation of correlation methodologies for crash test data and finite element simulation results. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. MSC Software, Santa Ana, CA USA. USA, Vehicle Technol Directorate, Hampton, VA USA. RP Lyle, KH (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 8 TC 3 Z9 3 U1 0 U2 1 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD OCT PY 2002 VL 47 IS 4 BP 233 EP 242 PG 10 WC Engineering, Aerospace SC Engineering GA 606AD UT WOS:000178708500002 ER PT J AU Bradley, AA Peters-Lidard, C Nelson, BR Smith, JA Young, CB AF Bradley, AA Peters-Lidard, C Nelson, BR Smith, JA Young, CB TI Raingage network design using NEXRAD precipitation estimates SO JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION LA English DT Article DE network design; hydrologic sampling; precipitation measurement; NEXRAD; Catskill Mountains ID RADAR-RAINFALL; GAUGE DATA; NUMERICAL-SIMULATION; AREAL RAINFALL; ERROR; ACCURACY; TERRAIN; STORM; TIME AB A general framework is proposed for using precipitation estimates from NEXRAD weather radars in raingage network design. NEXRAD precipitation products are used to represent space time rainfall fields, which can be sampled by hypothetical raingage networks. A stochastic model is used to simulate gage observations based on the areal average precipitation for radar grid cells. The stochastic model accounts for subgrid variability of precipitation within the cell and gage measurement errors. The approach is ideally suited to raingage network design in regions with strong climatic variations in rainfall where conventional methods are sometimes lacking. A case study example involving the estimation of areal average precipitation for catchments in the Catskill Mountains illustrates the approach. The case study shows how the simulation approach can be used to quantify the effects of gage density, basin size, spatial variation of precipitation, and gage measurement error, on network estimates of areal average precipitation. Although the quality of NEXRAD precipitation products imposes limitations on their use in network design, weather radars can provide valuable information for empirical assessment of raingage network estimation errors. Still, the biggest challenge in quantifying estimation errors is understanding subgrid spatial variability. The results from the case study show that the spatial correlation of precipitation at subgrid scales (4 km and less) is difficult to quantify, especially for short sampling durations. Network estimation errors for hourly precipitation are extremely sensitive to the uncertainty in subgrid spatial variability, although for storm total accumulation, they are much less sensitive. C1 Univ Iowa, Iowa Inst Hydraul Res, Iowa City, IA 52242 USA. Univ Iowa, Dept Civil & Environm Engn, Iowa City, IA 52242 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. Princeton Univ, Dept Civil & Environm Engn, Princeton, NJ 08544 USA. Univ Kansas, Dept Civil & Environm Engn, Lawrence, KS 66045 USA. RP Bradley, AA (reprint author), Univ Iowa, Iowa Inst Hydraul Res, Iowa City, IA 52242 USA. RI Nelson, Brian/D-6432-2014; Peters-Lidard, Christa/E-1429-2012 OI Peters-Lidard, Christa/0000-0003-1255-2876 NR 31 TC 21 Z9 21 U1 0 U2 2 PU AMER WATER RESOURCES ASSOC PI MIDDLEBURG PA 4 WEST FEDERAL ST, PO BOX 1626, MIDDLEBURG, VA 20118-1626 USA SN 1093-474X J9 J AM WATER RESOUR AS JI J. Am. Water Resour. Assoc. PD OCT PY 2002 VL 38 IS 5 BP 1393 EP 1407 DI 10.1111/j.1752-1688.2002.tb04354.x PG 15 WC Engineering, Environmental; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 615XV UT WOS:000179273400016 ER PT J AU Rao, MVVS Meyyappan, M Sharma, SP AF Rao, MVVS Meyyappan, M Sharma, SP TI Langmuir probe measurements in inductively coupled CF4-Ar Plasmas SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID GLOBAL-MODEL; DISCHARGES; IMPACT; AR AB Technological advancement in the microelectronics industry requires an understanding of the physical and chemical processes occurring in plasmas of fluorocarbon gases used as etchants to optimize various operating parameters. This paper reports data on electron number density and temperature, electron energy distribution function (EEDF), and plasma potential measured using Langmuir probe in inductively coupled plasmas of CF4-Ar mixtures of various compositions. The probe data were recorded at several radial positions providing radial profiles of these plasma parameters at 10-50 mTorr and 200 and 300 W of radio frequency (rf) power. The measurements indicate that the electron and ion number densities increase with power; the plasma potential and electron temperature decrease with an increase in pressure, and they depend weakly on rf power. The radial profiles show that the electron and ion number densities and the plasma potential peak at the center of the plasma and drop toward the wall. Within the experimental error, the electron temperature is nearly constant in the electrode region and decreases toward the wall. As the CF4 content increases in the mixture, the electron temperature increases but the electron density decreases. At low CF4 concentration, the electron and ion densities increase with pressure, but the densities are nearly independent of pressures at high CF4 concentrations. The EEDFs have a characteristic drop near the low energy end at all pressures and powers and their shapes represent a non-Maxwellian plasma. (C) 2002 The Electrochemical Society. C1 NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA. ELORET Corp, Sunnyvale, CA 94087 USA. RP Rao, MVVS (reprint author), NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA. NR 20 TC 4 Z9 4 U1 0 U2 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD OCT PY 2002 VL 149 IS 10 BP C487 EP C491 DI 10.1149/1.1504454 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 594CA UT WOS:000178030100029 ER PT J AU Lau, KM Li, XF Wu, HT AF Lau, KM Li, XF Wu, HT TI Evolution of the large scale circulation, cloud structure and regional water cycle associated with the South China Sea monsoon during May-June, 1998 SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Article ID ASIAN SUMMER MONSOON; TROPICAL WESTERN PACIFIC; 1997-98 EL-NINO; FIRST TRANSITION; ONSET; OSCILLATION; MECHANISM; VELOCITY; RAINFALL; TRMM AB This paper studies the evolution of the South China Sea (SCS) monsoon during May-4unq,1998, to elucidate relationships among the large scale circulation, organization of convection cloud structures, and fluctuations of the regional water cycle of the SCS. Primary data used include field observations from the South China Sea Monsoon Experiment (SCSMEX), and the satellite rain product's from the Tropical Rainfall Measuring Mission (TRMM). Prior to the onset of the SCS monsoon, enhanced corvective activities associated with. the Madden and Julian Oscillation were detected over the equatorial Indian, Ocean in early May, while the SCS was under the influence of the West Pacific Anticyclone with prevailing low level easterlies and suppressed convection. Subsquently, a bifurcation of the MJO convection near 90degreesE led to the development of strong convection over the Bay of Bengal, which spawned low-level westerlies across Indo-China and contributed to the initial build-up of moisture and convective available potential energy over the northern SCS. The onset of the SCS monsoon occurred around May 18-20, and appeared to be triggered by the equatorward penetration of extratropical. frontal disturbances originating from the continental regions of East Asia. Analysis of TRMM microwave and precipitation radar data revealed that during the onset phase, convection over the northern SCS consisted of squall-type rain cells embedded in meso-scale complexes similar to extratropical systems. The radar Z-factor intensity indicated that SCS clouds possessed a bimodal distribution, with a pronounced signal (>30 dBz) at. a height of 2-3 km, and another one (>25 dBz) at the 8-10 km level, separated by a well-defined melting level signaled by a bright band at around 5-km level. The most convectively active phase of the SCS monsoon, as measured by the abundance of convective and stratiform hydrometeor types, inferred from the radar vertical profile, was found to occur when the large scale vertical wind shear was weakest. C1 NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Atmospheres Lab, Greenbelt, MD 20771 USA. NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD USA. Sci Syst Applicat Inc, Lanham, MD USA. RP Lau, KM (reprint author), NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Atmospheres Lab, Code 913, Greenbelt, MD 20771 USA. RI Li, Xiaofan/F-5605-2010; Li, Xiaofan/G-2094-2014; Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 NR 33 TC 25 Z9 27 U1 0 U2 6 PU METEOROLOGICAL SOC JPN PI TOKYO PA C/O JPN METEOROL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO, JAPAN SN 0026-1165 J9 J METEOROL SOC JPN JI J. Meteorol. Soc. Jpn. PD OCT PY 2002 VL 80 IS 5 BP 1129 EP 1147 DI 10.2151/jmsj.80.1129 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 627XF UT WOS:000179961200003 ER PT J AU Prabhakara, C Iacovazzi, R Yoo, JM AF Prabhakara, C Iacovazzi, R Yoo, JM TI TRMM Precipitation Radar and Microwave Imager Observations of Convective and Stratiform Rain over Land and their Theoretical Implications SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Article ID MIXED-PHASE PRECIPITATION; PROFILING ALGORITHM; SIZE DISTRIBUTIONS; ICE; HYDROMETEORS; CLOUDS; THUNDERSTORM; RADIOMETER AB Observations of brightness temperature, Tb, made over land regions by the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) radiometer are analyzed with the help of nearly simultaneous measurements of the vertical profiles of reflectivity factor, Z, made by the Precipitation Radar (PR) onboard the TRMM satellite.,Furthermore, this analysis is done separately over convective and stratiform rain regions. This examination reveals a clear relationship between TMI and PR data. Possible explanation for this relationship is explored with the help of radiative transfer calculations. With this approach, we demonstrate that the 85 GHz observations of TMI can be simulated crudely from the observations of Z. However, the 37 and 19 GHz observations are not as well simulated, possibly because of horizontal non-uniformity in the hydrometeor distribution in the broad footprints of these channels and contamination introduced by land-surface emissivity. On the other hand, from TMI and PR observations, we find that the brightness temperature difference (T19-T37) minimizes these sources of error. Our simulations of (T19-T37) over convective rain regions are in reasonable agreement with this finding. This investigation indicates that the TMI 85 GHz channel yields the best information about rain over tropical land, because it has minimal surface contamination, strong extinction, and a fine footprint. The brightness temperature difference (T19-T37) can supplement the information given by the 85 GHz channel. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. Ewha Womans Univ, Seoul, South Korea. RP Prabhakara, C (reprint author), NASA, Goddard Space Flight Ctr, Code 913, Greenbelt, MD 20771 USA. EM cuddapah@climate.gsfc.nasa.gov RI Iacovazzi Jr, Robert/G-3867-2010 NR 28 TC 9 Z9 13 U1 0 U2 0 PU METEOROLOGICAL SOC JAPAN PI TOKYO PA C/O JAPAN METEOROLOGICAL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO, 100-0004, JAPAN SN 0026-1165 EI 2186-9057 J9 J METEOROL SOC JPN JI J. Meteorol. Soc. Jpn. PD OCT PY 2002 VL 80 IS 5 BP 1183 EP 1197 DI 10.2151/jmsj.80.1183 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 627XF UT WOS:000179961200006 ER PT J AU Smith, DD Fuller, KA AF Smith, DD Fuller, KA TI Photonic bandgaps in Mie scattering by concentrically stratified spheres SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID ELECTROMAGNETIC SCATTERING; MULTILAYERED SPHERE; ALGORITHMS; CLUSTERS; LIGHT AB The Mie formulation for homogeneous spheres is generalized to handle core-shell systems and multiple concentric layers in a manner that exploits an analogy with stratified planar systems, thereby allowing concentric multilayered structures to be treated as photonic bandgap materials. Representative results from a Mie code employing this analogy demonstrate that photonic bands are present for periodic concentric spheres, though not readily apparent in extinction spectra. Rather, the periodicity simply alters the scattering profile, which enhances the ratio of backscattering to forward scattering inside the bandgap, whereas modification of the interference structure is evident in extinction spectra in accordance with the optical theorem. (C) 2002 Optical Society of America. C1 NASA, George C Marshall Space Flight Ctr, Biol & Phys Sci Grp, Huntsville, AL 35812 USA. Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35895 USA. RP Smith, DD (reprint author), NASA, George C Marshall Space Flight Ctr, Biol & Phys Sci Grp, Huntsville, AL 35812 USA. NR 17 TC 22 Z9 22 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD OCT PY 2002 VL 19 IS 10 BP 2449 EP 2455 DI 10.1364/JOSAB.19.002449 PG 7 WC Optics SC Optics GA 602HM UT WOS:000178499900018 ER PT J AU Davis, AB Love, SP Cahalan, RF McGill, MJ AF Davis, AB Love, SP Cahalan, RF McGill, MJ TI Off-beam lidar senses cloud thickness and density SO LASER FOCUS WORLD LA English DT Article C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Davis, AB (reprint author), Los Alamos Natl Lab, Bikini Atoll Rd,Bldg 30, Los Alamos, NM 87545 USA. RI McGill, Matthew/D-8176-2012; Cahalan, Robert/E-3462-2012 OI Cahalan, Robert/0000-0001-9724-1270 NR 2 TC 1 Z9 1 U1 0 U2 0 PU PENNWELL PUBL CO PI NASHUA PA 98 SPIT BROOK RD, NASHUA, NH 03062-2801 USA SN 0740-2511 J9 LASER FOCUS WORLD JI Laser Focus World PD OCT PY 2002 VL 38 IS 10 BP 101 EP 104 PG 4 WC Optics SC Optics GA 611RB UT WOS:000179030600032 ER PT J AU DellaCorte, C AF DellaCorte, C TI Pleasant wake-up call SO LUBRICATION ENGINEERING LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Washington, DC 20546 USA. RP DellaCorte, C (reprint author), NASA, Glenn Res Ctr, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 0024-7154 J9 LUBR ENG JI Lubric. Eng. PD OCT PY 2002 VL 58 IS 10 BP 3 EP 3 PG 1 WC Engineering, Mechanical SC Engineering GA 609VK UT WOS:000178925300001 ER PT J AU Vitaliano, JJ Reid, RN Frame, AB Packer, DB Arlen, L Sacco, JN AF Vitaliano, JJ Reid, RN Frame, AB Packer, DB Arlen, L Sacco, JN TI Comparison of benthic invertebrate assemblages at Spartina alterniflora marshes reestablished after an oil spill and existing marshes in the Arthur Kill (NY/NJ) SO MARINE POLLUTION BULLETIN LA English DT Article DE benthic invertebrates; community structure; salt marsh; oil spill; Arthur Kill; Spartina alterniflora; sediments ID SALT-MARSH; COMMUNITY STRUCTURE; MACROBENTHOS; IMPACTS; CREEKS; TEXAS AB In January 1990, an oil spill damaged salt marshes along the banks of the Arthur Kill (New York and New Jersey. USA). In the years following the spill. Spartina alterniflora seedlings were planted at a number of the oil damaged sites and successfully reestablished at these sites. In 1996, the National Marine Fisheries Service began a study to compare the benthic invertebrate assemblages at the reestablished S. alterniflora marshes to those at nearby existing marshes in the,Arthur Kill. Oligochaetes, nematodes, and the small tube-building polychaete, Manayunkia aestuarina were the dominant taxi in the study. Significant differences were found in the abundances of all invertebrate individuals, oligochaetes, and nematodes between the September and May sampling times but not between reestablished and existing marshes. Although benthic invertebrate community structure was similar at reestablished and existing marshes three to four years after planting, the functional similarity of these marshes was nut assessed in this study. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. New Jersey Dept Environm Protect, Off Nat Resources Damages, Trenton, NJ 08625 USA. RP Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. EM joseph.vitaliano@noaa.gov NR 25 TC 3 Z9 3 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD OCT PY 2002 VL 44 IS 10 BP 1100 EP 1108 AR PII S0025-326X(02)00164-9 DI 10.1016/S0025-326X(02)00164-9 PG 9 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 616GW UT WOS:000179296900025 PM 12474971 ER PT J AU Benedikt, B Rupnowski, R Kumosa, L Sutter, JK Predecki, PK Kumosa, M AF Benedikt, B Rupnowski, R Kumosa, L Sutter, JK Predecki, PK Kumosa, M TI Determination of interlaminar residual thermal stresses in a woven 8HS graphite/PMR-15 composite using X-ray diffraction measurements SO MECHANICS OF ADVANCED MATERIALS AND STRUCTURES LA English DT Article ID FABRIC COMPOSITES; INCLUSIONS; MATRIX AB This work is a continuation of the research recently presented in [1] and [2] on the determination of residual thermal stresses in graphite/polyimide composites with and without externally applied bending loads. In the previous work [1, 2] a combined experimental and numerical methodology for the determination of the residual stresses in unidirectional graphite/PMR-15 composites based on X-ray diffraction (XRD) measurements of residual strains in embedded aluminum (Al) and silver (Ag) inclusions has been presented. In this research, the previously developed approach has been applied to evaluate the residual thermal interlaminar stresses in an 8 harness satin (8HS) woven graphite/PMR-15 composite. First, residual thermal stresses have been measured by XRD in aluminum inclusions embedded between the first and second plies of a four-ply 8HS woven graphite/PMR-15 composite. The measurements have been conducted with the composite specimens subjected to four-point bending deformations. Second, viscoelastic computations of interlaminar residual stresses in the composite have been performed using classical laminated plate theory (CLPT) following the manufacturing procedure. Third, the residual strains and stresses in the inclusions have been numerically predicted using the viscoelastic Eshelby model for multiple spherical inclusions. Finally, the interlaminar residual stresses in the composite have been extracted from the XRD strains in the Al inclusions, again using the viscoelastic Eshelby model, and subsequently compared with the residual stresses from the CLPT. It has been shown in this study that the residual interlaminar thermal stresses can be accurately determined not only in unidirectional graphite/polyimide systems as presented in [1] and [2], but also in woven graphite polymer matrix composites. C1 Univ Denver, Dept Engn, Ctr Adv Mat & Struct, Denver, CO 80208 USA. NASA, Glenn Res Ctr Lewis Field, Cleveland, OH USA. RP Kumosa, M (reprint author), Univ Denver, Dept Engn, Ctr Adv Mat & Struct, 2390 S York St, Denver, CO 80208 USA. EM mkumosa@du.edu RI Rupnowski, Przemyslaw/B-3520-2008; OI Rupnowski, Przemyslaw/0000-0003-0040-418X NR 22 TC 15 Z9 15 U1 0 U2 4 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1537-6494 J9 MECH ADV MATER STRUC JI Mech. Adv. Mater. Struct. PD OCT-DEC PY 2002 VL 9 IS 4 BP 375 EP 394 DI 10.1080/15376490290097026 PG 20 WC Materials Science, Multidisciplinary; Mechanics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science; Mechanics GA 630CW UT WOS:000180090800004 ER PT J AU Cockell, CS Lee, P Osinski, G Horneck, G Broady, P AF Cockell, CS Lee, P Osinski, G Horneck, G Broady, P TI Impact-induced microbial endolithic habitats SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID ANTARCTIC COLD DESERT; DEVON ISLAND; HAUGHTON FORMATION; POLAR DESERT; DRY VALLEYS; ROSS DESERT; SCYTONEMIN; CANADA; MICROORGANISMS; ENVIRONMENT AB Asteroid and comet impacts on Earth are commonly viewed as agents of ecosystem destruction, be it on local or global scales. However, for some microbial communities, impacts may represent an opportunity for habitat formation as some substrates are rendered more suitable for colonization when processed by impacts. We describe how heavily shocked gneissic crystalline basement rocks exposed at the Haughton impact structure, Devon Island, Nunavut, Arctic Canada, are hosts to endolithic photosynthetic microorganisms in significantly greater abundance than lesser-shocked or unshocked gneisses. Two factors contribute to this enhancement: (a) increased porosity due to impact fracturing and differential mineral vaporization, and (b) increased translucence due to the selective vaporization of opaque mineral phases. Using biological ultraviolet radiation dosimetry, and by measuring the concentrations of photoprotective compounds, we demonstrate that a covering of 0.8 mm of shocked gneiss can provide substantial protection from ultraviolet radiation, reducing the inactivation of Bacillus subtilis spores by 2 orders of magnitude. The colonisation of the shocked habitat represents a potential mechanism for pioneer microorganisms to invade an impact structure in the earliest stages of post-impact primary succession. The communities are analogous to the endolithic communities associated with sedimentary rocks in Antarctica, but because they occur in shocked crystalline rocks, they illustrate a mechanism for the creation of microbial habitats on planetary surfaces that do not have exposed sedimentary units. This might have been the case on early Earth. The data have implications for the microhabitats in which biological signatures might be sought on Mars. C1 British Antarctic Survey, Cambridge CB3 0ET, England. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ New Brunswick, Dept Geol, Planetary & Space Sci Ctr, Fredericton, NB E3B 5A3, Canada. German Aerosp Ctr DLR, Inst Aerosp Med, D-51170 Cologne, Germany. Univ Canterbury, Christchurch 1, New Zealand. RP Cockell, CS (reprint author), British Antarctic Survey, High Cross,Madingley Rd, Cambridge CB3 0ET, England. NR 43 TC 86 Z9 86 U1 0 U2 9 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD OCT PY 2002 VL 37 IS 10 BP 1287 EP 1298 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 608YY UT WOS:000178877100001 ER PT J AU Connors, M Chodas, P Mikkola, S Wiegert, P Veillet, C Innanen, K AF Connors, M Chodas, P Mikkola, S Wiegert, P Veillet, C Innanen, K TI Discovery of an asteroid and quasi-satellite in an Earth-like horseshoe orbit SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID INNER SOLAR-SYSTEM; SUN SYSTEM; DYNAMICS AB The newly discovered asteroid 2002 AA(29) moves in a very Earth-like orbit that relative to Earth has a unique horseshoe shape and allows transitions to a quasi-satellite state. This is the first body known to be in a simple heliocentric horseshoe orbit, moving along its parent planet's orbit. It is similarly also the first true co-orbital object of Earth, since other asteroids in 1:1 resonance with Earth have orbits very dissimilar from that of our planet. When a quasi-satellite, it remains within 0.2 AU of the Earth for several decades. 2002 AA(29) is the first asteroid known to exhibit this behavior. 2002 AA(29) introduces an important new class of objects offering potential targets for space missions and clues to asteroid orbit transfer evolution. C1 Athabasca Univ, Ctr Sci, Athabasca, AB T9S 3A3, Canada. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Turku Univ Observ, FIN-21500 Piikkio, Finland. Queens Univ, Dept Phys, Kingston, ON K7L 3N6, Canada. Canada France Hawaii Telescope Corp, Kamuela, HI 96743 USA. York Univ, Dept Phys & Astron, N York, ON M3J 1P3, Canada. RP Connors, M (reprint author), Athabasca Univ, Ctr Sci, 1 Univ Dr, Athabasca, AB T9S 3A3, Canada. NR 27 TC 43 Z9 43 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD OCT PY 2002 VL 37 IS 10 BP 1435 EP 1441 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 608YY UT WOS:000178877100011 ER PT J AU Pu, ZX Tao, WK Braun, S Simpson, J Jia, YQ Halverson, J Olson, W Hou, A AF Pu, ZX Tao, WK Braun, S Simpson, J Jia, YQ Halverson, J Olson, W Hou, A TI The impact of TRMM data on mesoscale numerical simulation of Supertyphoon Paka SO MONTHLY WEATHER REVIEW LA English DT Article ID DATA ASSIMILATION; PRECIPITATION; PROFILES; SCHEME; INITIALIZATION; RETRIEVALS; RAINFALL; CYCLONE; MODELS; TESTS AB This paper assesses the impact of TRMM Microwave Imager (TMI) derived surface rainfall data on the numerical simulation of Supertyphoon Paka (1997). A series of mesoscale numerical simulations of Supertyphoon Paka is performed during its mature stage by using the Pennsylvania State University-National Center for Atmospheric Research (Penn State-NCAR) Mesoscale Model (MM5). The model initial and boundary conditions were derived from Goddard Earth Observing System (GEOS) global analyses with and without assimilation of the TMI surface rainfall data. Simulation results clearly demonstrate that the GEOS analysis with TMI rainfall data leads to an improved simulation of Supertyphoon Paka in terms of its intensity and kinematical and precipitation structures, because rainfall assimilation modifies the environment of the storm such that the initial conditions are more favorable for development of the storm. Since a bogus vortex is often necessary for initialization of typhoon (hurricane) simulations, additional numerical experiments are also performed by introducing mesoscale bogus vortices into GEOS analysis at the initial time using a four-dimensional variational technique. Simulation results indicate that a well-designed bogus vortex can play a dominant role in the improvements of forecasts of typhoon intensity and track. However, incorporation of the TMI data with a bogus vortex is still beneficial because it improves the simulation of the asymmetric storm structure. C1 NASA, Atmospheres Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. Sci Syst & Applicat Inc, Lanham, MD USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. RP Pu, ZX (reprint author), NASA, Atmospheres Lab, Goddard Space Flight Ctr, Mail Code 912, Greenbelt, MD 20771 USA. RI Hou, Arthur/D-8578-2012 NR 23 TC 34 Z9 40 U1 2 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 2002 VL 130 IS 10 BP 2448 EP 2458 DI 10.1175/1520-0493(2002)130<2448:TIOTDO>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 589WG UT WOS:000177784100006 ER PT J AU Li, XF Sui, CH Lau, KM AF Li, XF Sui, CH Lau, KM TI Dominant cloud microphysical processes in a tropical oceanic convective system: A 2D cloud resolving modeling study SO MONTHLY WEATHER REVIEW LA English DT Article ID ICE-PHASE MICROPHYSICS; LONG-TERM BEHAVIOR; TOGA COARE; RADIATION INTERACTION; MICROSCALE STRUCTURE; EXPLICIT SIMULATION; DIURNAL-VARIATIONS; FRONTAL RAINBANDS; SURFACE PROCESSES; MESOSCALE AB Dominant cloud microphysical processes associated with a tropical oceanic convective system are investigated based on a 2D cloud resolving simulation. The model is forced by the zonal-mean vertical velocity, zonal wind, sea surface temperature, and horizontal temperature and moisture advections measured and derived from the TOGA COARE period. The analysis of cloud microphysics budgets shows that cloud water forms due to vapor condensation, but most of the conversion of cloud water to precipitation occurs primarily through two mechanisms, depending on the temperature when they occur: through riming of cloud water onto precipitation ice (snow or graupel) at colder than 0degreesC and collection of cloud water by rain at warmer temperatures. Processes involving the liquid phase are dominant during the early stages of convection development. The collection process produces rain, and the riming process enhances ice clouds. Ice processes are more dominant during the later stages. The melting of precipitation ice and vapor deposition become important in producing rain and ice clouds, respectively. ased on the analysis of dominant cloud microphysical processes, a simplified set of cloud microphysics parameterization schemes are proposed. Simulations with the simplified and original sets show similar thermodynamic evolution and cloud properties. C1 NOAA, NESDIS, ORA, ARAD, Camp Springs, MD 20746 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Li, XF (reprint author), NOAA, NESDIS, ORA, ARAD, 5200 Auth Rd,Room 601, Camp Springs, MD 20746 USA. RI Li, Xiaofan/F-5605-2010; Li, Xiaofan/G-2094-2014; Lau, William /E-1510-2012; OI Lau, William /0000-0002-3587-3691; SUI, CHUNG-HSIUNG/0000-0003-2842-5660 NR 23 TC 76 Z9 83 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 2002 VL 130 IS 10 BP 2481 EP 2491 DI 10.1175/1520-0493(2002)130<2481:DCMPIA>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 589WG UT WOS:000177784100008 ER PT J AU Nguyen, CV Delzeit, L Cassell, AM Li, J Han, J Meyyappan, M AF Nguyen, CV Delzeit, L Cassell, AM Li, J Han, J Meyyappan, M TI Preparation of nucleic acid functionalized carbon nanotube Arrays SO NANO LETTERS LA English DT Article ID SURFACES AB A vertically aligned carbon nanotube (CNT) array is fabricated as a nanoelectrode platform for biosensor development. Prior to chemical functionalization, metal catalyst particles at the ends of CNT are removed and the closed ends are opened. We find that the oxidative treatment for generating the chemical functional groups at the opened ends of the CNT compromise the mechanical stability of the nanotubes, often leading to total collapse of the aligned CNTs. To solve this problem, we have developed a new approach for filling the gaps between CNTs with a spin-on glass (SOG). Results from the coupling of nucleic acids to the CNT arrays suggest that the SOG enhances the reactivity by providing structural support to the CNTs. The SOG also covers the length of the sidewalls of CNTs, leading to a less hydrophobic interface and thus may aid in improving the chemical reactivity. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Nguyen, CV (reprint author), ELORET Corp, Sunnyvale, CA 94087 USA. RI Li, Jun/H-7771-2013 OI Li, Jun/0000-0002-3689-8946 NR 16 TC 278 Z9 279 U1 4 U2 65 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 J9 NANO LETT JI Nano Lett. PD OCT PY 2002 VL 2 IS 10 BP 1079 EP 1081 DI 10.1021/nl025689f PG 3 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 604VG UT WOS:000178641300010 ER PT J AU Wilson, JW Tweed, J Tai, H Tripathi, RK AF Wilson, JW Tweed, J Tai, H Tripathi, RK TI A simple model for straggling evaluation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article AB Simple straggling models had largely been abandoned in favor of Monte Carlo simulations of straggling which are accurate but time consuming, limiting their application in practice. The difficulty of simple analytic models is the failure to give accurate values past 85% of the particle range. A simple model is derived herein based on a second order approximation upon which rapid analysis tools are developed for improved understanding of material charged particle transmission properties. Published by Elsevier Science B.V. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Old Dominion Univ, Norfolk, VA USA. RP Wilson, JW (reprint author), NASA, Langley Res Ctr, Mail Stop 188B,8 W Taylor St, Hampton, VA 23681 USA. NR 6 TC 12 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD OCT PY 2002 VL 194 IS 4 BP 389 EP 392 AR PII S0168-583X(02)01028-5 DI 10.1016/S0168-583X(02)01028-5 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 599YB UT WOS:000178361800003 PM 12449153 ER PT J AU Williams, DR AF Williams, DR TI Bioastronautics: Optimizing human performance through research and medical innovations SO NUTRITION LA English DT Article; Proceedings Paper CT Meeting of the National-Space-Biomedical-Research-institute CY JAN 14-17, 2002 CL MONTGOMERY, TEXAS SP Nat Space Biomed Res Inst DE nutrition in space; evidence-based space medicine; bioastronautics; physiologic adaptation to space flight; risk mitigation AB A strategic use of resources is essential to achieving long-duration space travel and understanding the human physiological changes in space, including the roles of food and nutrition in space. To effectively address the challenges of space flight, the Bioastronautics Initiative. undertaken in 2001, expands extramural collaboration and leverages unique capabilities of the scientific community and the federal government, all the while applying this integrated knowledge to Earth-bused problems. Integral to the National Aeronautics and Space Administration's missions in space is the reduction of risk of medical complications, particularly during missions of long duration. Cumulative medical experience and research provide the ability to develop evidence-based medicine for prevention, countermeasures. and treatment modalities for space flight. The early approach applied terrestrial clinical judgment to predict medical problems in space. Space medicine has evolved to an evidence-based approach with the use of biomedical data gathered and lessons learned from previous space flight missions to systematically aid in decision making. This approach led, for example, to the determination of preliminary nutritional requirements for space flight, and it aids in the development of nutrition itself as a countermeasure to support nutritional mitigation of adaptation to space. (C) Elsevier Science Inc. 2002. C1 NASA, Lyndon B Johnson Space Ctr, Space & Life Sci Directorate, Houston, TX 77058 USA. RP Williams, DR (reprint author), NASA, Lyndon B Johnson Space Ctr, Space & Life Sci Directorate, Mail Code SA, Houston, TX 77058 USA. NR 2 TC 3 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0899-9007 J9 NUTRITION JI Nutrition PD OCT PY 2002 VL 18 IS 10 BP 794 EP 796 AR PII S0899-9007(02)00896-1 DI 10.1016/S0899-9007(02)00896-1 PG 3 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 599ZU UT WOS:000178366300002 PM 12361769 ER PT J AU Lane, HW Feeback, DL AF Lane, HW Feeback, DL TI History of nutrition in space flight: Overview SO NUTRITION LA English DT Article DE space flight; microgravity; nutrition; Gemini; Skylab; Shuttle; Mir; International Space Station; hematology; immunology; neurosensory; cardiovascular; gastrointestinal; cireadian rhythms; musculoskeletal physiology; radiation; temperature; atmospheric pressure ID BED REST; SPACEFLIGHT; MISSIONS; RAT; MICROGRAVITY; PERSPECTIVE; ASTRONAUTS; RADIATION AB Major accomplishments in nutritional sciences for support of human space travel have occurred over the past 40 y. This article reviews these accomplishments, beginning with the early Gemini program and continuing through the impressive results from the first space station Skylab program that focused on life sciences research, the Russian contributions through the Mir space station, the US Shuttle life sciences research, and the emerging International Space Station missions. Nutrition is affected by environmental conditions such as radiation, temperature, and atmospheric pressures, and these are reviewed. Nutrition with respect to space flight is closely interconnected with other life sciences research disciplines including the study of hematology, immunology, as well as neurosensory, cardiovascular, gastrointestinal, circadian rhythms, and musculoskeletal physiology. These relationships are reviewed in reference to the overall history of nutritional science in human space flight. Cumulative nutritional research over the past four decades has resulted in the current nutritional requirements for astronauts. Space-flight nutritional recommendations are presented along with the critical path road map that outlines the research needed for future development of nutritional requirements. (C)Elsevier Science Inc. 2002. C1 NASA, Lyndon B Johnson Space Ctr, Bioastronaut Off SA, Houston, TX 77058 USA. RP Lane, HW (reprint author), NASA, Lyndon B Johnson Space Ctr, Bioastronaut Off SA, 2101 NASA Rd 1, Houston, TX 77058 USA. NR 58 TC 10 Z9 10 U1 4 U2 10 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0899-9007 J9 NUTRITION JI Nutrition PD OCT PY 2002 VL 18 IS 10 BP 797 EP 804 AR PII S0899-9007(02)00946-2 DI 10.1016/S0899-9007(02)00946-2 PG 8 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 599ZU UT WOS:000178366300003 PM 12361770 ER PT J AU Lane, HW Feeback, DL AF Lane, HW Feeback, DL TI Water and energy dietary requirements and endocrinology of human space flight SO NUTRITION LA English DT Article DE space flight; microgravity; total body water; body weight; nutrition; energy; electrolytes; hormones; endocrinology; dietary requirements; plasma volume; iodine; thyroid hormones ID BED REST; BODY-COMPOSITION; EXERCISE THERMOREGULATION; SIMULATED MICROGRAVITY; NITROGEN-BALANCE; SHUTTLE FLIGHTS; MANNED MISSION; SPACEFLIGHT; EXPENDITURE; METABOLISM AB Fluid and energy metabolism and related endocrine changes have been studied nearly from the beginning of human space flight in association with short- and long-duration flights. Fluid and electrolyte nutrition status is affected by many factors including the microgravity environment, stress, changes in body composition, diet, exercise habits, sleep cycles, and ambient temperature and humidity conditions. Space flight exposes astronauts to all these factors and consequently poses significant challenges to establishing dietary water, sodium, potassium, and energy recommendations. The purpose of this article is to review the results of ground-based and space flight research studies that have led to current water, electrolyte, and energy dietary requirements for humans during space flight and to give an overview of related endocrinologic changes that have been observed in humans during short- and long-duration space flight. (C) Elsevier Science Inc. 2002. C1 NASA, Lyndon B Johnson Space Ctr, Bioastronaut Off SA, Houston, TX 77058 USA. RP Lane, HW (reprint author), NASA, Lyndon B Johnson Space Ctr, Bioastronaut Off SA, 2101 NASA Rd 1, Houston, TX 77058 USA. EM hlane@ems.jsc.nasa.gov NR 70 TC 14 Z9 14 U1 3 U2 11 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0899-9007 J9 NUTRITION JI Nutrition PD OCT PY 2002 VL 18 IS 10 BP 820 EP 828 AR PII S0899-9007(02)00936-X DI 10.1016/S0899-9007(02)00936-X PG 9 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 599ZU UT WOS:000178366300006 PM 12361773 ER PT J AU Wade, CE Miller, MM Baer, LA Moran, MM Steele, MK Stein, TP AF Wade, CE Miller, MM Baer, LA Moran, MM Steele, MK Stein, TP TI Body mass, energy intake, and water consumption of rats and humans during space flight SO NUTRITION LA English DT Article DE energy balance; energy expenditure; microgravity; non-human primate; caloric intake ID SKELETAL-MUSCLE; SPACEFLIGHT; TEMPERATURE; SHUTTLE; DIET; WEIGHTLESSNESS; EXPENDITURE; METABOLISM; SUSPENSION; NUTRITION AB Alteration of metabolism has been suggested as a major limiting factor to long-term space flight. In humans and primates, a negative energy balance has been reported. The metabolic response of rats to space flight has been suggested to result in a negative energy balance. We hypothesized that rats flown in space would maintain energy balance as indicated by maintenance of caloric intake and body mass gain. Further, the metabolism of the rat would be similar to that of laboratory-reared animals. We studied the results from 15 space flights lasting 4 to 19 d. There was no difference in average body weight (206 +/- 13.9 versus 206 +/- 14.8 g), body weight gain (5.8 +/- 0.48 versus 5.9 +/- 0.56 g/d), caloric intake (309 +/- 21.0 versus 309 +/- 20.1 kcal/kg of body mass per day), or water intake (200 +/- 8.6 versus 199 +/- 9.3 mL/kg of body mass per day) between flight and ground control animals. Compared with standard laboratory animals of similar body mass, no differences were noted. The observations suggested that the negative balance observed in humans and non-human primates may be due to other factors in the space-flight environment. (C) Elsevier Science Inc. 2002. C1 NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA 94035 USA. Univ Med & Dent New Jersey, SOM, Stratford, NJ USA. RP Wade, CE (reprint author), NASA, Ames Res Ctr, Div Life Sci, Life Sci M5239-1 1, Moffett Field, CA 94035 USA. NR 50 TC 16 Z9 17 U1 1 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0899-9007 J9 NUTRITION JI Nutrition PD OCT PY 2002 VL 18 IS 10 BP 829 EP 836 AR PII S0899-9007(02)00914-0 DI 10.1016/S0899-9007(02)00914-0 PG 8 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 599ZU UT WOS:000178366300007 PM 12361774 ER PT J AU Smith, SM Heer, M AF Smith, SM Heer, M TI Calcium and bone metabolism during space flight SO NUTRITION LA English DT Article DE weightlessness; calcium kinetics; bone markers ID URINARY CALCIUM; BED REST; WEIGHTLESSNESS; SPACEFLIGHT; EXCRETION; SODIUM; RISK; COUNTERMEASURES; COSMONAUTS; MARKERS AB Weightlessness induces bone loss. Understanding the nature of this loss and developing means to counteract it are significant challenges to potential human exploration missions. This article reviews the existing information from studies of bone and calcium metabolism conducted during space flight. It also highlights areas where nutrition may play a specific role in this bone loss, and where countermeasures may be developed to mitigate that loss. (C) Elsevier Science Inc. 2002. C1 NASA, Lyndon B Johnson Space Ctr, Nutr Biochem Lab, Human Adaptat & Countermeasures Off, Houston, TX 77058 USA. DLR, Inst Aerosp Med, German Aerosp Ctr, Cologne, Germany. RP Smith, SM (reprint author), NASA, Lyndon B Johnson Space Ctr, Nutr Biochem Lab, Human Adaptat & Countermeasures Off, SK3, Houston, TX 77058 USA. NR 49 TC 40 Z9 45 U1 0 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0899-9007 J9 NUTRITION JI Nutrition PD OCT PY 2002 VL 18 IS 10 BP 849 EP 852 AR PII S0899-9007(02)00895-X DI 10.1016/S0899-9007(02)00895-X PG 4 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 599ZU UT WOS:000178366300010 PM 12361777 ER PT J AU Smith, SM AF Smith, SM TI Red blood cell and iron metabolism during space flight SO NUTRITION LA English DT Article DE weightlessness; erythropoiesis; ferritin; erythrocyte volume; iron overload ID SPACEFLIGHT AB Space flight anemia is a widely recognized phenomenon in astronauts. Reduction in circulating red blood cells and plasma volume results in a 10% to 15% decrement in circulatory volume This effect appears to be a normal physiologic adaptation to weightlessness and results from the removal of newly released blood cells from the circulation. Iron availability increases, and (in the few subjects studied) iron stores increase during long-duration space flight. The consequences of these changes are not fully understood. (C)Elsevier Science Inc. 2002. C1 NASA, Lyndon B Johnson Space Ctr, Nutr Biochem Lab, Human Adaptat & Countermeasures Off SK3, Houston, TX 77058 USA. RP Smith, SM (reprint author), NASA, Lyndon B Johnson Space Ctr, Nutr Biochem Lab, Human Adaptat & Countermeasures Off SK3, Houston, TX 77058 USA. NR 27 TC 23 Z9 29 U1 1 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0899-9007 J9 NUTRITION JI Nutrition PD OCT PY 2002 VL 18 IS 10 BP 864 EP 866 AR PII S0899-9007(02)00912-7 DI 10.1016/S0899-9007(02)00912-7 PG 3 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 599ZU UT WOS:000178366300013 PM 12361780 ER PT J AU Smith, SM Uchakin, PN Tobin, BW AF Smith, SM Uchakin, PN Tobin, BW TI Space flight nutrition research: Platforms and analogs SO NUTRITION LA English DT Article DE weightlessness; zero gravity; bedrest; research models AB Conducting research during actual or simulated weightlessness is a challenging endeavor, where even the simplest activities may present significant challenges. This article reviews some of the potential obstacles, associated with performing research during space flight and offers brief descriptions of current and previous space research platforms and ground-based analogs, including those for human, animal, and cell-based research. This review is intended to highlight the main issues of space flight research analogs and leave the specifics for each physiologic system for the other papers in this section. (C) Elsevier Science Inc. 2002. C1 NASA, Lyndon B Johnson Space Ctr, Nutr Biochem Lab, Human Adaptat & Countermeasures Off, Houston, TX 77058 USA. Mercer Univ, Sch Med, Macon, GA 31207 USA. RP Smith, SM (reprint author), NASA, Lyndon B Johnson Space Ctr, Nutr Biochem Lab, Human Adaptat & Countermeasures Off, SK3, Houston, TX 77058 USA. NR 0 TC 8 Z9 9 U1 1 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0899-9007 J9 NUTRITION JI Nutrition PD OCT PY 2002 VL 18 IS 10 BP 926 EP 929 AR PII S0899-9007(02)00904-8 DI 10.1016/S0899-9007(02)00904-8 PG 4 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 599ZU UT WOS:000178366300022 PM 12361789 ER PT J AU Soller, BR Cabrera, M Smith, SM Sutton, JP AF Soller, BR Cabrera, M Smith, SM Sutton, JP TI Smart medical systems with application to nutrition and fitness in space SO NUTRITION LA English DT Article DE sensors; noninvasive measurement; hematocrit; pH ID SKELETAL-MUSCLE; RESONANCE SPECTROSCOPY; RESPIRATORY PROFILE; HEMORRHAGIC-SHOCK; TISSUE PH; EXERCISE; HUMANS; FLIGHT; HEALTH AB Smart medical systems are being developed to allow medical treatments to address alterations in chemical and physiologic status in real time. In a smart medical system, sensor arrays assess subject status, which is interpreted by computer processors that analyze multiple inputs and recommend treatment interventions. The response of the subject to the treatment is again assessed by the sensor arrays, thus closing the loop. An early form of "smart medicine" has been practiced in space to assess nutrition. Nutrient levels are assessed with food frequency questionnaires, which are interpreted by flight surgeons to recommend inflight alterations in diet. In the future, sensor arrays will directly probe body chemistry. Near-infrared spectroscopy can be used to non-invasively measure several blood and tissue parameters that are important in the assessment of nutrition and fitness. In particular, this technology can be used to measure blood hematocrit and interstitial fluid pH. The non-invasive measurement of interstitial pH is discussed as a surrogate for blood lactate measurement for the development and real-time assessment of exercise protocols in space. Earth-based application of these sensors is also described. (C) Elsevier Science Inc. 2002. C1 Univ Massachusetts, Sch Med, Dept Surg, Worcester, MA 01655 USA. Univ Massachusetts, Sch Med, Biomed Engn Program, Worcester, MA 01655 USA. Case Western Reserve Univ, Dept Pediat, Cleveland, OH 44106 USA. Case Western Reserve Univ, Dept Biomed Engn, Cleveland, OH 44106 USA. Case Western Reserve Univ, Dept Physiol, Cleveland, OH 44106 USA. Case Western Reserve Univ, Dept Biophys, Cleveland, OH 44106 USA. NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Off, Houston, TX 77058 USA. Harvard Univ, Sch Med, MIT, Div Hlth Sci & Technol, Boston, MA USA. RP Soller, BR (reprint author), Univ Massachusetts, Sch Med, Dept Surg, 55 Lake Ave N, Worcester, MA 01655 USA. NR 42 TC 8 Z9 8 U1 2 U2 6 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0899-9007 J9 NUTRITION JI Nutrition PD OCT PY 2002 VL 18 IS 10 BP 930 EP 936 AR PII S0899-9007(02)00897-3 DI 10.1016/S0899-9007(02)00897-3 PG 7 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 599ZU UT WOS:000178366300023 PM 12361790 ER PT J AU Allison, SG Fox, RL Froggatt, ME Childers, BA AF Allison, SG Fox, RL Froggatt, ME Childers, BA TI Novel piezoelectric actuators for tuning an optical fiber Bragg grating SO OPTICAL ENGINEERING LA English DT Article DE tuning; optical fiber Bragg grating; piezoelectric actuator ID DISTRIBUTED MEASUREMENT; MODULATION; SENSORS; STRAIN; LASER AB A method of stretching optical fiber holds interest for measuring strain in smart structures where the physical displacement may be used to tune optical fiber lasers. A small, lightweight, tunable fiber laser is ideal for demodulating strain in optical fiber Bragg gratings (FBGs) attached to smart structures such as the reusable launch vehicle that is being developed by NASA. A method is presented for stretching optical fibers using the thin-layer composite unimorph ferroelectric driver and sensor (THUNDER) piezoelectric actuators invented at NASA Langley Research Center. THUNDER actuators use a piezoelectric layer bonded to a metal backing to enable the actuators to produce displacements larger than the unbonded piezoelectric material. The shift in reflected optical wavelength resulting from stretching the FBG is presented. Means of adapting THUNDER actuators for stretching optical fibers are discussed, including ferrules, ferrule clamp blocks, and plastic hinges made with stereo lithography. (C) 2002 society of Photo-Optical Instrumentation Engineers. C1 NASA, Langley Res Ctr, Nondestruct Evaluat Sci Branch, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Technol Dev & Integrat Branch, Hampton, VA 23681 USA. Luna Technol Inc, Blacksburg, VA 24060 USA. RP Allison, SG (reprint author), NASA, Langley Res Ctr, Nondestruct Evaluat Sci Branch, Mail Stop 231, Hampton, VA 23681 USA. NR 23 TC 5 Z9 6 U1 1 U2 5 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD OCT PY 2002 VL 41 IS 10 BP 2448 EP 2455 DI 10.1117/1.1504723 PG 8 WC Optics SC Optics GA 606BU UT WOS:000178713900011 ER PT J AU Dietz, KL Ramsey, BD Alexander, CD Apple, JA Ghosh, KK Swift, WR AF Dietz, KL Ramsey, BD Alexander, CD Apple, JA Ghosh, KK Swift, WR TI Daytime aspect camera for balloon altitudes SO OPTICAL ENGINEERING LA English DT Article DE camera; guidance; balloon; lens; atmospheric model AB We have designed, built, and flight-tested a new star camera for daytime guiding of pointed balloon-borne experiments at altitudes around 40 km. The camera and lens are commercially available, off-the-shelf components, but require a custom-built baffle to reduce stray light, especially near the sunlit limb of the balloon. This new camera, which operates in the 600- to 1000-nm region of the spectrum, successfully provides daytime aspect information of similar to10 arcsec resolution for two distinct star fields near the galactic plane. The detected scattered-light backgrounds show good agreement with the Air Force MODTRAN models used to design the camera, but the daytime stellar magnitude limit was lower than expected due to longitudinal chromatic aberration in the lens. Replacing the commercial lens with a custom-built lens should allow the system to track stars in any arbitrary area of the sky during the daytime. (C) 2002 Society of Photo-Optical Instrumentation Engineers. C1 NASA, George C Marshall Space Flight Ctr, Sci Directorate, Huntsville, AL 35812 USA. Univ Space Res Associates, Huntsville, AL USA. Raytheon Co, ITSS, Huntsville, AL USA. RP Dietz, KL (reprint author), NASA, George C Marshall Space Flight Ctr, Sci Directorate, Huntsville, AL 35812 USA. NR 3 TC 11 Z9 15 U1 1 U2 1 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD OCT PY 2002 VL 41 IS 10 BP 2641 EP 2651 DI 10.1117/1.1501566 PG 11 WC Optics SC Optics GA 606BU UT WOS:000178713900036 ER PT J AU James, GK Dziczek, D Slevin, JA Bray, I AF James, GK Dziczek, D Slevin, JA Bray, I TI Polarization of Lyman-beta radiation from atomic hydrogen excited by electron impact from near-threshold energy to 1000 eV SO PHYSICAL REVIEW A LA English DT Article ID GAS RESONANCE RADIATION; ALPHA; BEAM AB The polarization of Lyman-beta radiation, produced by electron-impact excitation of atomic hydrogen, has been measured over the extended energy range from near threshold to 1000 eV. Measurements were obtained in a crossed-beams experiment using a silica-reflection linear polarization analyzer in tandem with a vacuum ultraviolet monochromator to isolate the emitted line radiation. Our data are in excellent agreement with convergent close-coupling calculations over the entire energy range. The data are broadly similar to the earlier measurements of H Lyman-alpha polarization reported from the Jet Propulsion Laboratory. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Nicholas Copernicus Univ, Inst Phys, PL-87100 Torun, Poland. Murdoch Univ, Sch Math & Phys Sci, Murdoch, WA 6150, Australia. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Dziczek, Dariusz/G-3620-2014; Bray, Igor/B-8586-2009 OI Bray, Igor/0000-0001-7554-8044 NR 22 TC 3 Z9 3 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 2002 VL 66 IS 4 AR 042710 DI 10.1103/PhysRevA.66.042710 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 619XF UT WOS:000179502200075 ER PT J AU Matsko, AB Ilchenko, VS Savchenkov, AA Maleki, L AF Matsko, AB Ilchenko, VS Savchenkov, AA Maleki, L TI Highly nondegenerate all-resonant optical parametric oscillator SO PHYSICAL REVIEW A LA English DT Article ID FREQUENCY COMB GENERATION; WHISPERING-GALLERY MODES; WAVE RECEIVER; MICROSPHERE; MODULATOR AB We show that a nondegenerate multifrequency parametric oscillator has different properties compared with the usual three-wave parametric oscillator. We consider, as an example, a scheme for a resonant cw monolithic microwave-optical parametric oscillator based on high-Q whispering gallery modes excited in a nonlinear dielectric cavity. Such an oscillator may have an extremely low threshold and stable operation, and may be used in spectroscopy and metrology. The oscillator mimics devices based on resonant chi((3)) nonlinearity and can be utilized for efficient four-wave mixing and optical comb generation. Moreover, the oscillator properties are important to better understand the stability conditions of long-baseline interferometers with movable mirrors that are currently used for gravity wave detection. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Matsko, AB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Matsko, Andrey/A-1272-2007 NR 45 TC 16 Z9 16 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 2002 VL 66 IS 4 AR 043814 DI 10.1103/PhysRevA.66.043814 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 619XF UT WOS:000179502200144 ER PT J AU Shortt, BJ van der Burgt, PJM Giammanco, F Slevin, JA Lanigan, W AF Shortt, BJ van der Burgt, PJM Giammanco, F Slevin, JA Lanigan, W TI Wavelength-dependent collective effects in the multiphoton ionization of atomic deuterium SO PHYSICAL REVIEW E LA English DT Article ID ABOVE-THRESHOLD IONIZATION; ENERGY-DISTRIBUTIONS; SPACE-CHARGE; ARGON-LASER; RARE-GASES; ELECTRONS; FIELDS; DISCHARGE; SPECTRA; XENON AB This paper presents the results of an experimental investigation into collective effects in the transient plasma formed by multiphoton ionization of atomic deuterium with a pulsed laser. The laser wavelength is varied in a narrow range around 243 nm, so that the photoionization is resonant with the metastable 2S(1/2) state. The ion yield, the ion time-of-flight spectra, and the yield of Lyman-alpha photons have been measured as a function of laser intensity (from 1 to 340 MW/cm2) and laser detuning around the 1S(1/2)-2S(1/2) two-photon resonance. During and shortly after the laser pulse, collective effects resulting from the mutual interaction of the photoelectrons and the ions affect the spatial and temporal distribution of the ions. Because of the near-degeneracy of the 2S(1/2), 2P(1/2), and 2P(3/2) states, the resonant multiphoton ionization is affected by the Stark mixing of these states in the collective field. As a result, the time-dependent yields of ions and of Lyman-alpha photons are modulated by the interplay of the multiphoton ionization of the atoms and the collective effects in the plasma. From the measurements it is deduced that collective effects are important above a critical charge density of 3x10(8) ions/cm(3). An asymmetry is observed in the line profile of the total ion yield as a function of laser detuning. This asymmetry is interpreted to be due to the effect of the collective field upon the intermediate resonant 2S(1/2) state of the photoionization process. C1 Natl Univ Ireland, Dept Expt Phys, Maynooth, Kildare, Ireland. Univ Pisa, Dipartimento Fis, I-56126 Pisa, Italy. Univ Pisa, Ist Nazl Fis Mat, I-56126 Pisa, Italy. RP Shortt, BJ (reprint author), CALTECH, Jet Prop Lab, Atom & Mol Collis Team, MS 121-104,4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI van der Burgt, Peter/J-6792-2015 NR 27 TC 0 Z9 0 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD OCT PY 2002 VL 66 IS 4 AR 046411 DI 10.1103/PhysRevE.66.046411 PN 2 PG 10 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 614EX UT WOS:000179176300093 ER PT J AU Baird, JK Kim, YW Su, CH Lehoczky, SL AF Baird, JK Kim, YW Su, CH Lehoczky, SL TI Viscosity relaxation in molten HgZnTe SO PHYSICS AND CHEMISTRY OF LIQUIDS LA English DT Article DE pseudo-binary melt; linear Te n-mers; rate equations; transport ID LIQUID TELLURIUM; PSEUDOBINARY AB Rotating cup measurements of the viscosity of the pseudo-binary melt, HgZnTe have shown that the isothermal liquid with ZnTe mole fraction 0.16 requires tens of hours of equilibration time before a steady viscous state can be achieved. Over this relaxation period, the viscosity at 790degreesC increases by a factor of two, while the viscosity at 810degreesC increases by 40%. Noting that the Group VI elements tend to polymerize when molten, we suggest that the viscosity of the melt is enhanced by the slow formation of Te atom chains. To explain the build-up of linear Te n-mers, we propose a scheme, which contains formation reactions with second-order kinetics that increase the molecular weight, and decomposition reactions with first-order kinetics that inactivate the chains. The resulting rate equations can be solved for the time dependence of each molecular weight fraction. Using these molecular weight fractions, we calculate the time dependence of the average molecular weight. Using the standard semi-empirical relation between polymer average molecular weight and viscosity, we then calculate the viscosity relaxation curve. By curve fitting, we find that the data imply that the rate constant for n-mer formation is much smaller than the rate constant for n-mer deactivation, suggesting that Te atoms only weakly polymerize in molten HgZnTe. The steady-state toward which the melt relaxes occurs as the rate of formation of an n-mer becomes exactly balanced by the sum of the rate for its deactivation and the rate for its polymerization to form an (n + 1)-mer. C1 Univ Alabama, Dept Chem, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. RP Baird, JK (reprint author), Univ Alabama, Dept Chem, Huntsville, AL 35899 USA. NR 20 TC 2 Z9 2 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0031-9104 J9 PHYS CHEM LIQ JI Phys. Chem. Liq. PD OCT PY 2002 VL 40 IS 5 BP 607 EP 620 DI 10.1080/0031910029001/0419 PG 14 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 612JE UT WOS:000179070300006 ER PT J AU Edwards, APR Osborne, BP Stoltzfus, JM Howes, T Steinberg, TA AF Edwards, APR Osborne, BP Stoltzfus, JM Howes, T Steinberg, TA TI Instabilities and drop formation in cylindrical liquid jets in reduced gravity SO PHYSICS OF FLUIDS LA English DT Article ID ABSOLUTE INSTABILITY; GAS AB The effects of convective and absolute instabilities on the formation of drops formed from cylindrical liquid jets of glycerol/water issuing into still air were investigated. Medium-duration reduced gravity tests were conducted aboard NASA's KC-135 and compared to similar tests performed under normal gravity conditions to aid in understanding the drop formation process. In reduced gravity, the Rayleigh-Chandrasekhar Equation was found to accurately predict the transition between a region of absolute and convective instability as defined by a critical Weber number. Observations of the physics of the jet, its breakup, and subsequent drop dynamics under both gravity conditions and the effects of the two instabilities on these processes are presented. All the normal gravity liquid jets investigated, in regions of convective or absolute instability, were subject to significant stretching effects, which affected the subsequent drop and associated geometry and dynamics. These effects were not displayed in reduced gravity and, therefore, the liquid jets would form drops which took longer to form (reduction in drop frequency), larger in size, and more spherical (surface tension effects). Most observed changes, in regions of either absolute or convective instabilities, were due to a reduction in the buoyancy force and an increased importance of the surface tension force acting on the liquid contained in the jet or formed drop. Reduced gravity environments allow better investigations to be performed into the physics of liquid jets, subsequently formed drops, and the effects of instabilities on these systems. In reduced gravity, drops form up to three times more slowly and as a consequence are up to three times larger in volume in the theoretical absolute instability region than in the theoretical convective instability region. This difference was not seen in the corresponding normal gravity tests due to the masking effects of gravity. A drop is shown to be able to form and detach in a region of absolute instability, and spanning the critical Weber number (from a region of convective to absolute instability) resulted in a marked change in dynamics and geometry of the liquid jet and detaching drops. (C) 2002 American Institute of Physics. C1 Univ Queensland, Dept Mech Engn, St Lucia, Qld 4072, Australia. NASA White Sands Test Facil, Las Cruces, NM 88004 USA. Univ Queensland, Dept Chem Engn, St Lucia, Qld 4072, Australia. RP Edwards, APR (reprint author), Univ Queensland, Dept Mech Engn, St Lucia, Qld 4072, Australia. OI Osborne, Barnaby/0000-0001-9638-9986; Howes, Tony/0000-0001-5246-6177; Steinberg, Theodore/0000-0002-9270-4130 NR 18 TC 6 Z9 6 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD OCT PY 2002 VL 14 IS 10 BP 3432 EP 3438 DI 10.1063/1.1501825 PG 7 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 591ZK UT WOS:000177911100007 ER PT J AU Abdel-Hameed, H Bellan, J AF Abdel-Hameed, H Bellan, J TI Direct numerical simulations of two-phase laminar jet flows with different cross-section injection geometries SO PHYSICS OF FLUIDS LA English DT Article ID NONCIRCULAR JETS; ELLIPTIC JETS; COHERENT STRUCTURE; SUBGRID ANALYSIS; MIXING LAYER; SQUARE JETS; DYNAMICS; ENTRAINMENT; TURBULENCE; NOZZLES AB Direct numerical simulations are performed of spatial, three-dimensional, laminar jets of different inlet geometric configurations for the purpose of quantifying the characteristics of the flows; both single-phase (SP) and two-phase (TP) free jets are considered. The TP jets consist of gas laden with liquid drops randomly injected at the inlet. Drop evaporation ensues both due to the gaseous flow being initially unvitiated by the vapor species corresponding to the liquid drops, and to drop heating as the initial drop temperature is lower than that of the carrier gas. The conservation equations for the TP flow include complete couplings of mass, momentum, and energy based on thermodynamically self-consistent specification of the vapor enthalpy, internal energy, and latent heat of vaporization. Inlet geometries investigated are circular, elliptic, rectangular, square, and triangular. The results focus both on the different spreading achieved according to the inlet geometry, as well as on the considerable change in the flow field due to the presence of the drops. The most important consequence of the drop interaction with the flow is the production of streamwise vorticity that alters entrainment and species mixing according to the inlet geometry. Similar to their SP equivalent, TP jets are shown to reach steady-state entrainment; examination of the flows at this time station shows that the potential cores of TP jets are shorter by an order of magnitude than their SP counterpart. Moreover, whereas the TP circular jet exhibits a symmetric entrainment pattern well past the streamwise location of the potential core, noncircular jets display at the same location strong departures from symmetry. Furthermore, the SP-jet phenomenon of axis switching is no longer present in TP jets. The distributions of drop-number density, liquid mass, and evaporated species are compared for different inlet cross sections and recommendations are made regarding the optimal choice for different applications. (C) 2002 American Institute of Physics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. Zagazig Univ, Zagazig, Egypt. RP Bellan, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 38 TC 8 Z9 8 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD OCT PY 2002 VL 14 IS 10 BP 3655 EP 3674 DI 10.1063/1.1504712 PG 20 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 591ZK UT WOS:000177911100027 ER PT J AU Rodgers, SD Charnley, SB AF Rodgers, SD Charnley, SB TI Multiply deuterated molecules and constraints on interstellar chemistry SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Deuterium in the Universe CY JUN 25-27, 2001 CL PARIS, FRANCE DE deuterium; astrochemistry; interstellar clouds; molecules; polycyclic aromatic hydrocarbons (PAHs) ID POLYCYCLIC AROMATIC-HYDROCARBONS; DISSOCIATIVE RECOMBINATION; DEUTERIUM ENRICHMENT; SURFACE-CHEMISTRY; CROSS-SECTIONS; EXCITATION; D2CO; PHOTODISSOCIATION; FORMALDEHYDE; ABUNDANCE AB We consider the formation of molecules containing two or more deuterium atoms, and show how the abundances of such molecules may be used as interstellar isotopic labelling experiments to elucidate the principal chemical processes occurring in molecular clouds. Although the overall D/H ratios in deuterated isotopomers will depend on the source of the D, we show that in many cases the relative D/H ratios in singly:doubly deuterated isotopomers depends only on the chemical mechanism forming the molecule. We derive analytic expressions for the steady-state fractionation ratios in a number of molecules, including water, formaldehyde, methanol, ammonia, methane, and acetylene, and show how observations of isotopomers of these species may be used to discriminate between a gas-phase or grain-surface origin. We also briefly consider deuteration of polycyclic aromatic hydrocarbons. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, Div Space Sci, MS 245-3, Moffett Field, CA 94035 USA. EM rodgers@dusty.arc.nasa.gov RI Charnley, Steven/C-9538-2012 NR 33 TC 21 Z9 21 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD OCT-NOV PY 2002 VL 50 IS 12-13 BP 1125 EP 1132 AR PII S0032-0633(02)00073-9 DI 10.1016/S0032-0633(02)00073-9 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 630ZR UT WOS:000180142300002 ER PT J AU Sandford, SA AF Sandford, SA TI Interstellar processes leading to molecular deuterium enrichment and their detection SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Deuterium in the Universe CY JUN 25-27, 2001 CL PARIS, FRANCE DE deuterium enrichment; interstellar medium; interstellar chemistry; polycyclic aromatic hydrocarbons; isotopic anomalies; ultraviolet photolysis; organics ID POLYCYCLIC AROMATIC-HYDROCARBONS; INTERPLANETARY DUST PARTICLES; DARK CLOUD CORES; 3 MICRON SPECTRA; H2O ICE BANDS; MURCHISON METEORITE; INFRARED-EMISSION; SOLAR-SYSTEM; CARBONACEOUS CHONDRITES; ISOTOPIC-SUBSTITUTION AB Large deuterium (D) enrichments in meteoritic materials indicate that interstellar organic materials survived incorporation into parent bodies within the forming Solar System. These enrichments are likely due to one or more of four distinct astrochemical processes. These are (i) low-temperature gas phase ion-molecule reactions, (ii) low-temperature gas-grain reactions, (iii) gas phase photodissociation, and (iv) ultraviolet photolysis in D-enriched ice mantles. Each of these processes should be associated with molecular carriers having distinct structural signatures (D placement on the product molecules, correlation with specific chemical functionalities, etc.). These processes are reviewed and specific spectroscopic signatures for the detection of these processes in space are identified and described. Published by Elsevier Science Ltd. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Sandford, SA (reprint author), NASA, Ames Res Ctr, Mail Stop 245-6, Moffett Field, CA 94035 USA. EM ssandford@mail.arc.nasa.gov NR 75 TC 11 Z9 11 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD OCT-NOV PY 2002 VL 50 IS 12-13 BP 1145 EP 1154 AR PII S0032-0633(02)00075-2 DI 10.1016/S0032-0633(02)00075-2 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 630ZR UT WOS:000180142300004 ER PT J AU Hebrard, G Friedman, SD Kruk, JW Lehner, N Lemoine, M Linsky, JL Moos, HW Oliveira, CM Sembach, KR Sonneborn, G Vidal-Madjar, A Wood, BE AF Hebrard, G Friedman, SD Kruk, JW Lehner, N Lemoine, M Linsky, JL Moos, HW Oliveira, CM Sembach, KR Sonneborn, G Vidal-Madjar, A Wood, BE TI The deuterium-to-oxygen ratio in the local interstellar medium from FUSE observations SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Deuterium in the Universe CY JUN 25-27, 2001 CL PARIS, FRANCE DE ISM : abundances; ISM : clouds; cosmology : observations; ultraviolet : ISM; stars : white dwarfs ID ABUNDANCE AB Since HI, OI, and DI have nearly the same ionization potential, the deuterium-to-oxygen ratio (D/O) is an important tracer of the D/H ratio and its putative spatial variations. D/O is indeed very sensitive to astration, both because of deuterium destruction and oxygen production. Here, we present DI, 01, and NI interstellar column density measurements performed with the Far Ultraviolet Spectroscopic Explorer (FUSE) on eight nearby lines of sight. The first results of this survey show that D/O is a better D/H proxy than D/N, and that D/O is constant in the local interstellar medium. The mean value is D/O = 3.81(+/-0.18) x 10(-2) (1sigma). This result supports both D/H and O/H stability in the LISM. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 CNRS, Inst Astrophys Paris, F-75014 Paris, France. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Hebrard, G (reprint author), CNRS, Inst Astrophys Paris, 98 Bis Blvd Arago, F-75014 Paris, France. RI Sonneborn, George/D-5255-2012; Kruk, Jeffrey/G-4047-2012 NR 21 TC 8 Z9 8 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD OCT-NOV PY 2002 VL 50 IS 12-13 BP 1169 EP 1172 AR PII S0032-0633(02)00078-8 DI 10.1016/S0032-0633(02)00078-8 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 630ZR UT WOS:000180142300007 ER PT J AU Rodgers, SD Charnley, SB AF Rodgers, SD Charnley, SB TI Deuterium in comets - and AGB stars? SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Deuterium in the Universe CY JUN 25-27, 2001 CL PARIS, FRANCE DE comets; deuterium; HDO; evolved stars; IRC+10 degrees 216 ID HALE-BOPP; WATER-VAPOR; C/1995 O1; FORMALDEHYDE; HALLEY; HCN; IRC+10-DEGREES-216; POLYOXYMETHYLENE; FRACTIONATION; CONSTRAINTS AB We discuss the deuterium chemistry of cometary comae, and show how the fractionation observed in coma molecules relates to the D/H ratios in the nuclear ices. For most molecules, we find that the fractionation is unchanged in the coma. In addition, we calculate the potential effects of degradation of D-rich polymers/organic refractory material on selected gas-phase fractionation ratios. We demonstrate that for molecules known to have an extended coma source, the observed D/H ratios may not necessarily reflect those in the nuclear ice. The recent detection of water vapour in the stellar wind of the carbon-rich red giant IRC + 10degrees216 has been attributed to the vaporization of a remnant population of comets surrounding this evolved star. This theory would be confirmed by the detection of deuterated molecules in this object: as deuterium is destroyed in stars, any D-bearing molecules must originate from cometary or planetary objects. We quantitatively assess the possibility of detecting HDO in this source if such comets contain similar D/H ratios to those in our solar system, and show that the 1(11)-0(00) transition at 894 GHz is the most promising candidate for detection. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Rodgers, SD (reprint author), NASA, Ames Res Ctr, Div Space Sci, MS 245-3, Moffett Field, CA 94035 USA. RI Charnley, Steven/C-9538-2012 NR 41 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD OCT-NOV PY 2002 VL 50 IS 12-13 BP 1215 EP 1219 AR PII S0032-0633(02)00085-5 DI 10.1016/S0032-0633(02)00085-5 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 630ZR UT WOS:000180142300014 ER PT J AU Abdalla, MO Dean, D Campbell, S AF Abdalla, MO Dean, D Campbell, S TI Viscoelastic and mechanical properties of thermoset PMR-type polyimide-clay nanocomposites SO POLYMER LA English DT Article DE PMR-15; layered silicates; nanocomposite ID LAYERED SILICATE NANOCOMPOSITES; NYLON 6-CLAY HYBRID; EPSILON-CAPROLACTAM; MONTMORILLONITE; BEHAVIOR; CHEMISTRY AB High temperature thermoset polyimide-clay nanocomposites were prepared by blending 2.5 and 5 wt% of an unmodified Na+-montmorillonite (PGV) and two organically modified PGV (PGVC10COOH, PGVC12) with a methanol solution of PMR-15 precursor. The methanol facilitated the dispersal of the unmodified clay. Dynamic mechanical analysis results showed a significant increase in the thermomechanical properties (E' and E") of 2.5 wt% clay loaded nanocomposites in comparison with the neat polyimide. Higher glass transition temperatures were observed for 2.5 wt% nanocomposites compared to the neat polyimide. Flexural properties measurements for the 2.5 wt% nanocomposites showed a significant improvement in the modulus and strength, with no loss in elongation. This trend was not observed for the 5 wt% nanocomposites. An improvement in the CTE was observed for the PGV/PMR-15 nanocomposites, while a decrease was observed for the organically modified samples. This was attributed to potential variations in the interface caused by modifier degradation. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Tuskegee Univ, Tuskegee Ctr Adv Mat, Chappie James Ctr 101, Tuskegee, AL 36088 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Dean, D (reprint author), Tuskegee Univ, Tuskegee Ctr Adv Mat, Chappie James Ctr 101, Tuskegee, AL 36088 USA. NR 31 TC 54 Z9 57 U1 2 U2 13 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD OCT PY 2002 VL 43 IS 22 BP 5887 EP 5893 AR PII S0032-3861(02)00498-6 DI 10.1016/S0032-3861(02)00498-6 PG 7 WC Polymer Science SC Polymer Science GA 598HB UT WOS:000178269200012 ER PT J AU Thompson, LA Teare, SW Crawford, SL Leach, RW AF Thompson, LA Teare, SW Crawford, SL Leach, RW TI Rayleigh laser guide star systems: UnISIS bow-tie shutter and CCD39 wavefront camera SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID ADAPTIVE OPTICS SYSTEM; TELESCOPE AB Laser guide star systems based on Rayleigh scattering require some means to deal with the flash of low-altitude laser light that follows immediately after each laser pulse. These systems also need a fast shutter to isolate the high-altitude portion of the focused laser beam to make it appear starlike to the wavefront sensor. We describe how these tasks are accomplished with UnISIS, the Rayleigh laser-guided adaptive optics system at the Mount Wilson Observatory 2.5 m telescope. We use several methods: a 10,000 revolution per minute rotating disk, dichroics, a fast sweep and clear mode of the CCD readout electronics on a 10 mus timescale, and a Pockel's cell shutter system. The Pockel's cell shutter would be conventional in design if the laser light were naturally polarized, but the UnISIS 351 nm laser is unpolarized. Therefore, we have designed and put into operation a dual Pockel's cell shutter in a unique bow-tie arrangement. C1 Univ Illinois, Dept Astron, Urbana, IL 61801 USA. New Mexico Inst Min & Technol, Dept Elect Engn, Socorro, NM 87801 USA. New Mexico Inst Min & Technol, Dept Phys, Socorro, NM 87801 USA. San Diego State Univ, Dept Astron, San Diego, CA 92182 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. San Diego State Univ, Astron Res Cameras Inc, San Diego, CA 92182 USA. RP Thompson, LA (reprint author), Univ Illinois, Dept Astron, 1002 W Green St, Urbana, IL 61801 USA. NR 5 TC 5 Z9 5 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD OCT PY 2002 VL 114 IS 800 BP 1143 EP 1149 DI 10.1086/342764 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 596BC UT WOS:000178143000009 ER PT J AU Majumdar, SJ Bishop, CH Buizza, R Gelaro, R AF Majumdar, SJ Bishop, CH Buizza, R Gelaro, R TI A comparison of ensemble-transform Kalman-filter targeting guidance with ECMWF and NRL total-energy singular-vector guidance SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE perturbation growth; signal variance; targeted observations ID ATMOSPHERIC DATA ASSIMILATION; ADAPTIVE OBSERVATIONS; PREDICTION SYSTEM; OPTIMAL PERTURBATIONS; OPTIMAL EXCITATION; BAROCLINIC WAVES; FORECAST ERRORS; FASTEX; SENSITIVITY; MODEL AB Ongoing adaptive observing programmes strive to improve short- and medium-range forecasts of winter weather over populated areas. Aircraft equipped with Global Positioning System (GPS) dropwindsondes are directed over ordinarily data-sparse regions (oceans) to collect observations to enhance the subsequent operational analysis-forecast cycle. Two objective techniques that have been used to identify optimal 'target regions' are the ensemble-transform Kalman filter (ET KF) and the singular-vector technique. The similarities and differences between targeting guidance based on the ET KF and total-energy singular vectors (TESVs) are assessed for ten cases during the North Pacific Experiment (NORPEX). TESVs are computed at the European Centre for Medium-Range Weather Forecasts (ECMWF) and the Naval Research Laboratory (NRL) using their respective global models, and the ET KF uses 25 ECMWF ensemble perturbations. Using measures based on (i) rankings of aircraft flight tracks and (ii) spatial similarities between targeting guidance maps, the main finding is that (a) the ET KF guidance is reasonably correlated with TESV guidance for at least seven of the ten NORPEX cases. Other findings include: (b) the ECMWF and NRL TESV targets sometimes differ significantly, (c) the ET KF and TESV guidance maps often display different optimal locations for targeting on smaller scales, but larger-scale aspects are usually similar, (d) the ET KF generally identifies larger regions over which useful observations can be taken compared with the SV technique, and (e) regions that are deemed effective for targeting by both techniques often correspond to baroclinic zones. The ET KF and SV techniques may identify similar regions for targeting if locations of large ensemble-based analysis-error variance coincide with areas where rapid perturbation growth occurs. On the other hand, they may identify different targeting locations for the following two reasons. First, the ET KF implicitly accounts for error correlation length-scales in its predictions of forecast-error variance reduction produced by any set of targeted observations. Hence, it can identify locations for targeted observations that are distant from the regions of high analysis sensitivity that are selected for targeting by the SV technique. Second, ET KF estimates of analysis-error variance are constrained to a subspace of evolved ensemble perturbations and are, therefore, rank deficient. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, MPO, Miami, FL 33149 USA. Penn State Univ, University Pk, PA 16802 USA. ECMWF, Reading, Berks, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Majumdar, SJ (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, MPO, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. NR 49 TC 39 Z9 42 U1 0 U2 3 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING RG1 7LJ, BERKS, ENGLAND SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD OCT PY 2002 VL 128 IS 585 BP 2527 EP 2549 DI 10.1256/qj.01.214 PN A PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 609VL UT WOS:000178925400017 ER PT J AU Badhwar, GD Atwell, W Reitz, G Beaujean, R Heinrich, W AF Badhwar, GD Atwell, W Reitz, G Beaujean, R Heinrich, W TI Radiation measurements on the Mir Orbital Station SO RADIATION MEASUREMENTS LA English DT Article DE Mir; radiation measurements; radiation exposures; Mir radiation instruments ID NEUTRON ENERGY-SPECTRA; LOW-EARTH-ORBIT; SPACE STATION; ENVIRONMENT; DOSIMETRY; SHUTTLE; EVENTS AB Radiation measurements made onboard the MIR Orbital Station have spanned nearly a decade and covered two solar cycles, including one of the largest solar particle events, one of the largest magnetic storms, and a mean solar radio flux level reaching 250 x 104 Jansky that has been observed in the last 40 years. The cosmonaut absorbed dose rates varied from about 450 muGy day(-1) during solar minimum to approximately half this value during the last solar maximum. There is a factor of about two in dose rate within a given module, and a similar variation from module to module. The average radiation quality factor during solar minimum, using the ICRP-26 definition, was about 2.4. The drift of the South Atlantic Anomaly was measured to be 6.0 +/- 0.5degreesW, and 1.6 +/- 0.5degreesN. These measurements are of direct applicability to the International Space Station. This paper represents a comprehensive review of Mir Space Station radiation data available from a variety of sources. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Boeing Co, Human Space Flight & Explorat, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. DLR, Inst Aerosp Med, Cologne, Germany. Univ Kiel, Kiel, Germany. Univ Siegen, D-5900 Siegen, Germany. RP Atwell, W (reprint author), Boeing Co, Human Space Flight & Explorat, 13100 Space Ctr Blvd,MS-HS 2-10, Houston, TX 77058 USA. NR 50 TC 30 Z9 32 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1350-4487 J9 RADIAT MEAS JI Radiat. Meas. PD OCT PY 2002 VL 35 IS 5 BP 393 EP 422 AR PII S1350-4487(02)00072-0 DI 10.1016/S1350-4487(02)00072-0 PG 30 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 622YK UT WOS:000179675400003 PM 12440430 ER PT J AU Wang, MH Gordon, HR AF Wang, MH Gordon, HR TI Calibration of ocean color scanners: how much error is acceptable in the near infrared? SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID AEROSOL OPTICAL-THICKNESS; WATER-LEAVING RADIANCE; SENSORS; METHODOLOGY; SEAWIFS; SYSTEM AB We simulate vicarious calibration (VC) of a Sea-viewing Wide Field-of-view Sensor (SeaWiFS)-like ocean color sensor relative to its longer near infrared (NIR) spectral band (865 nm) to understand the influence of calibration error at 865 nm, which is difficult to assess in orbit. We show that as long as the calibration error at 865 nm less than similar to 10% in magnitude, the post-vicarious-calibration-corrected radiances are sufficiently accurate to retrieve useful water-leaving reflectances at moderate aerosol optical depths. This is completely independent of the initial calibration error in the shorter-wave bands, but assumes an atmospheric correction approach similar to that currently used with ScaWiFS. Retrievals are only slightly improved by reducing the magnitude of the error at 865 nm below similar to 5%. The simulations immediately suggest that pre-launch calibration is necessary only to the extent required to set the sensitivity of the instrument in the desired range. Rather than trying to achieve a highly accurate pre-launch calibration, e.g., uncertainty <5%, we assert that resources would be better expended on improved radiometric stability (and its monitoring) and complete characterization of the instrument, e.g., polarization sensitivity, out-of-band response, etc. However, these assertions assume the existence of a permanent vicarious calibration facility, e.g., the Marine Optical Buoy (MOBY). (C) 2002 Elsevier Science Inc. All rights reserved. C1 Univ Maryland, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. RP Wang, MH (reprint author), Univ Maryland, NASA, Goddard Space Flight Ctr, Baltimore Cty,Code 970-2, Greenbelt, MD 20771 USA. RI Wang, Menghua/F-5631-2010 OI Wang, Menghua/0000-0001-7019-3125 NR 20 TC 43 Z9 46 U1 0 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD OCT PY 2002 VL 82 IS 2-3 BP 497 EP 504 AR PII S0034-4257(02)00072-X DI 10.1016/S0034-4257(02)00072-X PG 8 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 595TA UT WOS:000178123800026 ER PT J AU Chavers, DG Chang-Diaz, FR AF Chavers, DG Chang-Diaz, FR TI Momentum flux measuring instrument for neutral and charged particle flows SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB An instrument to measure the momentum flux (total pressure) of plasma and neutral particle jets onto a surface has been developed. While this instrument was developed for magnetized plasmas, the concept works for nonmagnetized plasmas as well. We have measured forces as small as 10(-4) N on a surface immersed in the plasma where small forces are due to ionic and neutral particles with kinetic energies on the order of a few eV impacting the surface. This instrument, a force sensor, uses a target plate (surface) that is immersed in the plasma and connected to one end of an alumina rod while the opposite end of the alumina rod is mechanically connected to a titanium beam on which four strain gauges are mounted. The force on the target generates torque, causing strain in the beam. The resulting strain measurements can be correlated to a force on the target plate. The alumina rod electrically and thermally isolates the target plate from the strain gauge beam and allows the strain gauges to be located out of the plasma flow while also serving as a moment arm of several inches to increase the strain in the beam at the strain gauge location. These force measurements correspond directly to momentum flux and may be used with known plasma conditions to place boundaries on the kinetic energies of the plasma and neutral particles. The force measurements may also be used to infer thrust produced by a plasma propulsive device. Stainless steel, titanium, molybdenum, and aluminum flat target plates have been used. Momentum flux measurements of H-2, D-2, He, and Ar plasmas produced in a magnetized plasma device have been performed. C1 NASA, George C Marshall Space Flight Ctr, Prop Res Ctr, Huntsville, AL 35812 USA. NASA, Adv Space Prop Lab, Johnson Space Ctr, Houston, TX 77059 USA. RP Chavers, DG (reprint author), NASA, George C Marshall Space Flight Ctr, Prop Res Ctr, Huntsville, AL 35812 USA. NR 10 TC 16 Z9 16 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD OCT PY 2002 VL 73 IS 10 BP 3500 EP 3507 DI 10.1063/1.1505107 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 598CK UT WOS:000178257400012 ER PT J AU Leong, JR Bhatia, RS Hristov, VV Keating, BG Lange, AE Philhour, BJ AF Leong, JR Bhatia, RS Hristov, VV Keating, BG Lange, AE Philhour, BJ TI Lightweight, space efficient low-pass radio-frequency interference filter modules for bolometric detectors SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB Extremely lightweight and space efficient low-pass radio-frequency interference (RFI) filter modules have been developed and tested for use with bolometric detectors. These filters are based on the compactness of a surface mount electro-magnetic interference chip filter. We have produced densely packed modules containing 21 filtered lines, which weigh 60 g, with dimensions of 38x36x11 mm. These modules provide greater than 20 dB attenuation over the entire frequency range tested (50 MHz-10 GHz) while providing over 60 dB attenuation for frequencies greater than 4.5 GHz. The filters suppress rf voltage noise and prevent radiation from RFI on the lines from entering the detector environment and heating up the bolometers. Modules have been used on bolometric detector systems containing as many as 16 RFI filtered bolometers. (C) 2002 American Institute of Physics. C1 CALTECH, Pasadena, CA 91125 USA. RP Leong, JR (reprint author), Univ Hawaii, Inst Astron, NASA, Infrared Telescope Facil, 2680 Woodlawn Dr, Honolulu, HI 96822 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD OCT PY 2002 VL 73 IS 10 BP 3638 EP 3643 DI 10.1063/1.1502019 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 598CK UT WOS:000178257400032 ER PT J AU Fixsen, DJ Mirel, PGA Kogut, A Seiffert, M AF Fixsen, DJ Mirel, PGA Kogut, A Seiffert, M TI A low noise thermometer readout for ruthenium oxide resistors SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID FIRAS AB The thermometer readout and thermal control system for the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE) experiment is described, including the design, testing, and results from the first flight of ARCADE. The noise is equivalent to about 1 Omega or 0.15 mK in a second for the RuO2 resistive thermometers at 2.7 K. The average power dissipation in each thermometer is 1 nW. The control system can take full advantage of the thermometers to maintain stable temperatures. Systematic effects are still under investigation, but the measured precision and accuracy are sufficient to allow measurement of the cosmic background spectrum. (C) 2002 American Institute of Physics. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Fixsen, DJ (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, SSAI Code 685, Greenbelt, MD 20771 USA. RI Kogut, Alan/D-6293-2012 NR 6 TC 15 Z9 15 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD OCT PY 2002 VL 73 IS 10 BP 3659 EP 3663 DI 10.1063/1.1505108 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 598CK UT WOS:000178257400036 ER PT J AU Conway, EM AF Conway, EM TI America's airports: Airfield development, 1918-1947. SO TECHNOLOGY AND CULTURE LA English DT Book Review RP Conway, EM (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU JOHNS HOPKINS UNIV PRESS PI BALTIMORE PA JOURNALS PUBLISHING DIVISION, 2715 NORTH CHARLES ST, BALTIMORE, MD 21218-4319 USA SN 0040-165X J9 TECHNOL CULT JI Technol. Cult. PD OCT PY 2002 VL 43 IS 4 BP 819 EP 820 DI 10.1353/tech.2002.0155 PG 2 WC History & Philosophy Of Science SC History & Philosophy of Science GA 621AM UT WOS:000179566400029 ER PT J AU Radil, K Howard, S Dykas, B AF Radil, K Howard, S Dykas, B TI The role of radial clearance on the performance of foil air bearings SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT ASME/STLE Tribology Conference CY OCT 27-30, 2002 CL CANCUN, MEXICO SP ASME, STLE DE foil air bearing; gas bearing; turbomachinery ID JOURNAL BEARINGS; LOAD AB Load capacity tests were conducted to determine how radial clearance variations affect the load capacity coefficient of foil air bearings. Two Generation III foil air bearings with the same design but possessing different initial radial clearances were tested at room temperature against an as-ground PS304 coated journal operating at 30000 rpm. Increases in radial clearance were accomplished by reducing the journal's outside diameter via an in-place grinding system. Front each load capacity test the bearing load capacity coefficient was calculated from the rule-of-thumb (ROT) model developed for foil air bearings. The test results indicate that, in terms of the load capacity coefficient, radial clearance has a direct impact on the performance of the foil air bearing. Each test bearing exhibited an optimum radial clearance that resulted in a maximum load capacity coefficient. Relative to this optimum value are two separate operating regimes that are governed by different modes of failure. Bearings operating with radial clearances less than the optimum exhibit load capacity coefficients that are a strong function of radial clearance and are prone to a thermal runaway failure mechanism and bearing seizure. Conversely, a bearing operating with a radial clearance m,ice the optimum suffered only a 20% decline in its maximum load capacity coefficient and did not experience any thermal management problems. However, it is unknown to what degree these changes in radial clearance had on other performance parameters, such (is the stiffness and damping properties of the bearings. C1 USA, Cleveland, OH 44135 USA. NASA, Glenn Res Ctr, Cleveland, OH USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. RP Radil, K (reprint author), USA, Cleveland, OH 44135 USA. NR 19 TC 42 Z9 46 U1 3 U2 10 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PD OCT PY 2002 VL 45 IS 4 BP 485 EP 490 DI 10.1080/10402000208982578 PG 6 WC Engineering, Mechanical SC Engineering GA 613NH UT WOS:000179138000009 ER PT J AU Blanchet, TA Kim, JH Calabrese, SJ Dellacorte, C AF Blanchet, TA Kim, JH Calabrese, SJ Dellacorte, C TI Thrust-washer evaluation of self-lubricating PS304 composite coatings in high temperature sliding contact SO TRIBOLOGY TRANSACTIONS LA English DT Article DE surface films/coatings; composite; solid lubricant adverse environments tribology; high temperature; solid lubricated ID TRIBOLOGICAL PROPERTIES; BEARINGS; TURBOMACHINERY; AIR AB PS304 self-lubricating composite coatings were successfully deposited on steel substrates at various plasma spray facilities using mixtures blended from commercially obtained constituent particles. Coatings were evaluated in thrust-washer tests against Inconel X-750 at low contact pressures to 40kPa, sliding speed of 5.4m/s, and either ambient temperature or 500 degreesC chosen to simulate conditions in air foil bearings during startup and shutdown contact. Wear factors for all PS304 coatings tested, regardless of contact pressure and temperature, ranged from 1-3*10(-4) mm(3)/Nm while coefficients of friction of approximately mu = 0.5 were measured in all cases. While wear and friction behavior of PS304 in air foil bearings appear to have been simulated, surface roughening was observed in these thrust-washer tests which used continuous sliding contact, as opposed to the evolution of smoother surfaces observed in high-temperature foil bearings experiencing cyclic startup/shutdown. Wear-induced surface smoothening of PS304 was additionally simulated in thrust-washer tests with sliding contact instead imposed intermittently. C1 Rensselaer Polytech Inst, Dept Mech Engn, Troy, NY 12180 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Blanchet, TA (reprint author), Rensselaer Polytech Inst, Dept Mech Engn, Troy, NY 12180 USA. NR 12 TC 33 Z9 33 U1 3 U2 10 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PD OCT PY 2002 VL 45 IS 4 BP 491 EP 498 DI 10.1080/10402000208982579 PG 8 WC Engineering, Mechanical SC Engineering GA 613NH UT WOS:000179138000010 ER PT J AU Dellacorte, C Edmonds, BJ Benoy, PA AF Dellacorte, C Edmonds, BJ Benoy, PA TI Thermal processing effects on the adhesive strength of PS304 high temperature solid lubricant coatings SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT ASME/STLE Tribology Conference CY OCT 27-30, 2002 CL CANCUN, MEXICO SP ASME, STLE DE solid lubrication; self-lubricating composites; high temperature AB The effects of post deposition heat treatments on the strength properties of PS304, a plasma sprayed nickel-chrome based, high temperature solid lubricant coating are studied. Coating samples were exposed in air at temperatures from 432 to 650 degreesC for up to 500 hr to promote residual stress relief, enhance particle to particle bonding and increase coating to substrate bond strength. Coating pull off strength was measured using a commercial adhesion tester. The as-deposited (untreated) samples either delaminated at the coating-substrate interface or failed internally (cohesive failure) at about 17 MPa. Samples heat treated at temperatures above 540 degreesC for 100 hr or at 600 degreesC or above for more than 24 hr exhibited strengths above 31 MPa. Coating failure occurred inside the body of the coating (cohesive failure) for nearly all of the heat-treated samples and only occasionally at the coating substrate interface (adhesive failure). A microstructural change is believed to be partially responsible for the coating strength increase. Increasing the heat treatment temperature, exposure time or both accelerate the heat treatment process. C1 Natl Aeronaut & Space Adm, Glenn Res Ctr, Cleveland, OH 44135 USA. St Louis Univ, St Louis, MO 63103 USA. RP Dellacorte, C (reprint author), Natl Aeronaut & Space Adm, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 14 TC 18 Z9 25 U1 1 U2 15 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PD OCT PY 2002 VL 45 IS 4 BP 499 EP 505 DI 10.1080/10402000208982580 PG 7 WC Engineering, Mechanical SC Engineering GA 613NH UT WOS:000179138000011 ER PT J AU Bower, JR Murphy, JM Sato, Y AF Bower, JR Murphy, JM Sato, Y TI Latitudinal gradients in body size and maturation of Berryteuthis anonychus (Cephalopoda : Gonatidae) in the northeast Pacific SO VELIGER LA English DT Article ID SQUID AB Trends in body size and maturation with latitude of the gonatid squid Berryteuthis anonychus in the northeast Pacific are described. Squid were collected during May 1999 at seven stations along 145degrees and 165degreesW between 39degrees and 49degreesN. Mantle lengths ranged from 10.3 to 102.2 mm and increased significantly in both sexes from south to north. Females were both larger and more numerous than males at the northern stations. Both sexes showed a clear pattern of increasing maturity from south to north, and at each station, males were generally in a more advanced stage of maturity than females. Most mature males occurred at the northernmost stations. No mature females were collected. Our data suggest that B. anonychus migrates northward in the northeast Pacific during spring, with males maturing at a smaller size than females. C1 Hokkaido Univ, Fac Fisheries, Hakodate, Hokkaido 0418611, Japan. NOAA, Auke Bay Lab, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Juneau, AK 99801 USA. RP Bower, JR (reprint author), Hokkaido Univ, Fac Fisheries, 3-1-1 Minato Cho, Hakodate, Hokkaido 0418611, Japan. NR 25 TC 12 Z9 12 U1 1 U2 4 PU CALIF MALACOZOOLOGICAL SOC INC PI SANTA BARBARA PA SANTA BARBARA MUSEUM NATURAL HISTORY, 2559 PUESTA DEL SOL RD, SANTA BARBARA, CA 93105 USA SN 0042-3211 J9 VELIGER JI Veliger PD OCT 1 PY 2002 VL 45 IS 4 BP 309 EP 315 PG 7 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 602CD UT WOS:000178487000006 ER PT J AU Turner, MS AF Turner, MS TI The new cosmology SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 20th International Symposium on Lepton and Photon Interactions at High Energy CY JUL 23-28, 2001 CL ROME, ITALY ID COLD DARK-MATTER; OBSERVATIONAL EVIDENCE; ACCELERATING UNIVERSE; CONSTANT; SUPERNOVAE; ANISOTROPY; ABUNDANCE; LAMBDA; MODELS AB Over the past three years we have determined the basic features of our Universe. It is spatially flat; accelerating; comprised of 1/3 a new form of matter, 2/3 a new form of energy, with some ordinary matter and a dash of massive neutrinos; and it apparently began from a great burst of expansion (inflation) during which quantum noise was stretched to astrophysical size seeding cosmic structure. This "New Cosmology" greatly extends the highly successful hot big-bang model. Now we have to make sense of it. What is the dark matter particle? What is the nature of the dark energy? Why this mixture? How did the matter - antimatter asymmetry arise? What is the underlying cause of inflation (if it indeed occurred)? C1 Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Ctr Cosmol Phys, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Dept Phys, Chicago, IL 60637 USA. Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. RP Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Ctr Cosmol Phys, Chicago, IL 60637 USA. EM mturner@oddjob.uchicago.edu NR 63 TC 17 Z9 17 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X EI 1793-656X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD SEP 30 PY 2002 VL 17 IS 24 BP 3446 EP 3457 DI 10.1142/S0217751X02012843 PG 12 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 605ET UT WOS:000178665000009 ER PT J AU Zweck, C Freymueller, JT Cohen, SC AF Zweck, C Freymueller, JT Cohen, SC TI The 1964 great Alaska earthquake: present day and cumulative postseismic deformation in the western Kenai Peninsula SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Article DE subduction zones; plate coupling; postseismic deformation; Alaska; Kenai Peninsula ID WILLIAM-SOUND EARTHQUAKE; CRUSTAL UPLIFT; JAPAN; SLIP; AFTERSLIP; INVERSION; RELEASE; MODELS; FAULT; ZONE AB Global Positioning System (G]PS), triangulation and leveling data are used to derive models for the present day (last similar to5 years) and the 30-year average postseismic deformation on the Kenai Peninsula, Alaska following the 1964 Alaska earthquake. The two datasets are inverted using a three-dimensional elastic dislocation model to estimate the magnitude and spatial distribution of slip on the North America-Pacific plate interface, allowing us to examine the time dependence of the processes controlling postseismic deformation. We determine that the 30-year average postseismic slip rate beneath the western Kenai Peninsula was about twice as large as the present day slip rate. The observations suggest a time-decaying process, but are not consistent with a single exponentially decaying relaxation process initiated immediately after the 1964 earthquake. We conclude that the postseismic deformation observed on the western Kenai Peninsula cannot be explained in terms of any single time-decaying process. Either multiple processes acting on different timescales or significant spatial propagation of the postseismic deformation, or both, must occur. In the latter case, postseismic deformation would not begin everywhere at the same time and the rate of spatial propagation would affect the timescale inferred for the postseismic processes. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. Goddard Space Flight Ctr, Geodynam Branch, Greenbelt, MD USA. RP Freymueller, JT (reprint author), Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. NR 27 TC 20 Z9 20 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD SEP 30 PY 2002 VL 132 IS 1-3 BP 5 EP 20 AR PII S0031-9201(02)00041-9 DI 10.1016/S0031-9201(02)00041-9 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 599NJ UT WOS:000178341200002 ER PT J AU Menon, S Hansen, J Nazarenko, L Luo, YF AF Menon, S Hansen, J Nazarenko, L Luo, YF TI Climate effects of black carbon aerosols in China and India SO SCIENCE LA English DT Article ID CLOUD COVER; TEMPERATURE; OCEAN; MODEL AB In recent decades, there has been a tendency toward increased summer floods in south China, increased drought in north China, and moderate cooling in China and India while most of the world has been warming. We used a global climate model to investigate possible aerosol contributions to these trends. We found precipitation and temperature changes in the model that were comparable to those observed if the aerosols included a large proportion of absorbing black carbon ("soot"), similar to observed amounts. Absorbing aerosols heat the air, alter regional atmospheric stability and vertical motions, and affect the large-scale circulation and hydrologic cycle with significant regional climate effects. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA. Natl Sci Fdn China, Haidian, Peoples R China. RP Menon, S (reprint author), NASA, Goddard Inst Space Studies, New York, NY 10025 USA. NR 27 TC 1069 Z9 1273 U1 36 U2 344 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 27 PY 2002 VL 297 IS 5590 BP 2250 EP 2253 DI 10.1126/science.1075159 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 597LA UT WOS:000178222000044 PM 12351786 ER PT J AU Lissauer, JJ AF Lissauer, JJ TI Extrasolar planets SO NATURE LA English DT Article ID SEARCH; GJ-876; PAIR; STAR C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Lissauer, JJ (reprint author), NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. NR 10 TC 26 Z9 27 U1 0 U2 4 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 26 PY 2002 VL 419 IS 6905 BP 355 EP 358 DI 10.1038/419355a PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 596ZB UT WOS:000178195400033 PM 12353023 ER PT J AU Irigoien, X Harris, RP Verheye, HM Joly, P Runge, J Starr, M Pond, D Campbell, R Shreeve, R Ward, P Smith, AN Dam, HG Peterson, W Tirelli, V Koski, M Smith, T Harbour, D Davidson, R AF Irigoien, X Harris, RP Verheye, HM Joly, P Runge, J Starr, M Pond, D Campbell, R Shreeve, R Ward, P Smith, AN Dam, HG Peterson, W Tirelli, V Koski, M Smith, T Harbour, D Davidson, R TI Copepod hatching success in marine ecosystems with high diatom concentrations SO NATURE LA English DT Article ID ENGLISH-CHANNEL; CALANUS-HELGOLANDICUS; EGG-PRODUCTION; PHYTOPLANKTON; FISHERIES AB Diatoms dominate spring bloom phytoplankton assemblages in temperate waters and coastal upwelling regions of the global ocean. Copepods usually dominate the zooplankton in these regions and are the prey of many larval fish species. Recent laboratory studies suggest that diatoms may have a deleterious effect on the success of copepod egg hatching(1-4). These findings challenge the classical view of marine food-web energy flow from diatoms to fish by means of copepods(5-7). Egg mortality is an important factor in copepod population dynamics(8), thus, if diatoms have a deleterious in situ effect, paradoxically, high diatom abundance could limit secondary production. Therefore, the current understanding of energy transfer from primary production to fisheries in some of the most productive and economically important marine ecosystems(9) may be seriously flawed(1,10). Here we present in situ estimates of copepod egg hatching success from twelve globally distributed areas, where diatoms dominate the phytoplankton assemblage. We did not observe a negative relationship between copepod egg hatching success and either diatom biomass or dominance in the microplankton in any of these regions. The classical model for diatom-dominated system remains valid. C1 AZTI, Pasaia 20110, Spain. Plymouth Marine Lab, Plymouth PL1 3DH, Devon, England. Marine & Coastal Management, ZA-8012 Rogge Bay, Cape Town, South Africa. Inst Maurice Lamontagne, Mont Joli, PQ G5H 3Z4, Canada. British Antarctic Survey, Cambridge CB3 0ET, England. Univ Victoria, Sch Earth & Ocean Sci, Victoria, BC V8W 3P6, Canada. Univ Connecticut, Dept Marine Sci, Groton, CT 06340 USA. Natl Marine Fisheries Serv, Newport, OR 97365 USA. Univ Trieste, Dept Biol, Trieste, Italy. LBM, Trieste, Italy. Netherlands Inst Sea Res, NL-1790 AB Den Burg, Netherlands. Southampton Oceanog Ctr, Southampton SO14 3ZH, Hants, England. RP Irigoien, X (reprint author), AZTI, Herrera Kaia Portualdea S-G, Pasaia 20110, Spain. RI Irigoien, Xabier/B-8171-2009; Dam, Hans/A-9723-2015; OI Irigoien, Xabier/0000-0002-5411-6741; Dam, Hans/0000-0001-6121-5038; Tirelli, Valentina/0000-0002-5152-2891 NR 22 TC 147 Z9 173 U1 4 U2 37 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 26 PY 2002 VL 419 IS 6905 BP 387 EP 389 DI 10.1038/nature01072 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 596ZB UT WOS:000178195400043 PM 12353032 ER PT J AU Saffary, R Nandakumar, R Spencer, D Robb, FT Davila, JM Swartz, M Ofman, L Thomas, RJ DiRuggiero, J AF Saffary, R Nandakumar, R Spencer, D Robb, FT Davila, JM Swartz, M Ofman, L Thomas, RJ DiRuggiero, J TI Microbial survival of space vacuum and extreme ultraviolet irradiation: strain isolation and analysis during a rocket flight SO FEMS MICROBIOLOGY LETTERS LA English DT Article DE extremophile; space vacuum; extreme ultraviolet; space survival; ionizing radiation ID DNA-REPAIR; ARCHAEA; ENVIRONMENTS; FURIOSUS AB We have recovered new isolates from hot springs, in Yellowstone National Park and the Kamchatka Peninsula, after gamma-irradiation and exposure to high vacuum (10(-6) Pa) of the water and sediment samples. The resistance to desiccation and ionizing radiation of one of the isolates, Bacillus sp. strain PS3D, was compared to that of the mesophilic bacterium, Deinococcus radiodurans, a species well known for its extraordinary resistance to desiccation and high doses of ionizing radiation. Survival of these two microorganisms was determined in real and simulated space conditions, including exposure to extreme UV radiation (10-100 nm) during a rocket flight. We found that up to 15 days of desiccation alone had little effect on the viability of either bacterium. In contrast, exposure to space vacuum (similar to 10(-6) Pa) decreased cell survival by two and four orders of magnitude for Bacillus sp. strain PS3D and D. radiodurans, respectively. Simultaneous exposure to space vacuum and extreme UV radiation further decreased the survival of both organisms, compared to unirradiated controls. This is the first report on the isolated effect of extreme UV at 30 nm on cell survival. Extreme UV can only be transmitted through high vacuum, therefore its penetration into the cells may only be superficial, suggesting that in contrast to near UV, membrane proteins rather than DNA were damaged by the radiation. (C) 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved. C1 Univ Maryland, Dept Cell Biol & Mol Genet, College Pk, MD 20742 USA. Univ Maryland, Ctr Marine Biotechnol, Inst Biotechnol, Baltimore, MD 21201 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Catholic Univ Amer, Washington, DC 20064 USA. RP DiRuggiero, J (reprint author), Univ Maryland, Dept Cell Biol & Mol Genet, 3221 HJ Patterson Hall, College Pk, MD 20742 USA. OI Robb, Frank/0000-0001-5833-6496 NR 17 TC 29 Z9 32 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1097 J9 FEMS MICROBIOL LETT JI FEMS Microbiol. Lett. PD SEP 24 PY 2002 VL 215 IS 1 BP 163 EP 168 AR PII S0378-1097(02)00953-9 DI 10.1016/S0378-1097(02)00953-9 PG 6 WC Microbiology SC Microbiology GA 607HG UT WOS:000178785600025 PM 12393217 ER PT J AU Anderhub, H Bates, JR Batzner, D Baumgartner, S Biland, A Camps, C Capell, M Commichau, V Djambazov, L Fanchiang, YJ Flugge, G Fritschi, M Grimm, O Hangarter, K Hofer, H Horisberger, U Kan, R Kastli, W Kenney, GP Kim, GN Kim, KS Koutsenko, V Kraber, M Kuipers, J Lebedev, A Lee, MW Lee, SC Lewis, R Lustermann, W Pauss, F Rauber, T Ren, D Ren, ZL Roser, U Son, D Ting, SCC Tiwari, AN Viertel, GM von Gunten, H Wicki, SW Wang, TS Yang, J Zimmermann, B AF Anderhub, H Bates, JR Batzner, D Baumgartner, S Biland, A Camps, C Capell, M Commichau, V Djambazov, L Fanchiang, YJ Flugge, G Fritschi, M Grimm, O Hangarter, K Hofer, H Horisberger, U Kan, R Kastli, W Kenney, GP Kim, GN Kim, KS Koutsenko, V Kraber, M Kuipers, J Lebedev, A Lee, MW Lee, SC Lewis, R Lustermann, W Pauss, F Rauber, T Ren, D Ren, ZL Roser, U Son, D Ting, SCC Tiwari, AN Viertel, GM von Gunten, H Wicki, SW Wang, TS Yang, J Zimmermann, B TI Design and construction of the prototype synchrotron radiation detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB The Prototype Synchrotron Radiation Detector (PSRD) is a small-scale experiment designed to measure the rate of low-energy charged particles and photons in near the Earth's orbit. It is a precursor to the Synchrotron Radiation Detector (SRD), a proposed addition to the upgraded version of the Alpha Magnetic Spectrometer (AMS-02). The SRD will use the Earth's magnetic field to identify the charge sign of electrons and positrons with energies above 1 TeV by detecting the synchrotron radiation they emit in this field. The differential energy spectrum of these particles is astrophysically interesting and not well covered by the remaining components of AMS-02. Precise measurements of this spectrum offer the possibility to gain information on the acceleration mechanism and characteristics of all cosmic rays in our galactic neighbourhood. The SRD will discriminate against protons as they radiate only weakly. Both the number and energy of the synchrotron photons that the SRD needs to detect are small. The identification is complicated by the presence of a large particle and photon background. Existing measurements of these backgrounds are insufficient for the construction of the large-scale SRD, so a measurement in space was indispensable. The PSRD was designed to fly as a Space Shuttle secondary payload, within the Shuttle Small Payloads Project. The flight on board the Space Shuttle Endeavour took place from 5 to 17 December 2001. The scientific goal, hardware and the flight of the PSRD are described in this report. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Swiss Fed Inst Technol, Lab Hochenergiephys, CH-8093 Zurich, Switzerland. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Swiss Fed Inst Technol, Inst Festkorperphys, Zurich, Switzerland. Rhein Westfal TH Aachen, Inst Phys 3, D-5100 Aachen, Germany. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. CSIST, Tao Yuan 325, Taiwan. Kyungpook Natl Univ, Ctr High Energy Phys, Taegu 702701, South Korea. Ewha Womans Univ, Dept Phys, Seoul, South Korea. Acad Sinica, Inst Phys, Taipei, Taiwan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Viertel, GM (reprint author), Swiss Fed Inst Technol, Lab Hochenergiephys, CH-8093 Zurich, Switzerland. NR 10 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 21 PY 2002 VL 491 IS 1-2 BP 98 EP 112 AR PII S0168-9002(02)01170-1 DI 10.1016/S0168-9002(02)01170-1 PG 15 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 599CP UT WOS:000178316800009 ER PT J AU Eisen, Y Evans, LG Floyd, S Schlemm, C Starr, R Trombka, J AF Eisen, Y Evans, LG Floyd, S Schlemm, C Starr, R Trombka, J TI Radiation damage of Schottky CdTe detectors irradiated by 200 MeV protons SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE Schottky CdTe(Cl) X-ray detector; radiation damage ID GAMMA-RAY DETECTORS; X-RAY; CDZNTE; PERFORMANCE; SPECTROSCOPY AB This study describes the damage of a 2 mm x 2 mm x 1 mm Schottky CdTe detector after being irradiated by 200 MeV protons to a total fluence in the range 10(10)-10(11) p/cm(2). The investigation describes the change of spectroscopic characteristics caused by the irradiation as well as the change of the detector stability with time. A qualitative discussion is presented on the density of deep traps created by the irradiation. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Soreq NRC, IL-81800 Yavne, Israel. NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. Comp Sci Corp, Laurel, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Eisen, Y (reprint author), Soreq NRC, IL-81800 Yavne, Israel. NR 12 TC 18 Z9 18 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 21 PY 2002 VL 491 IS 1-2 BP 176 EP 180 AR PII S0168-9002(02)01229-9 DI 10.1016/S0168-9002(02)01229-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 599CP UT WOS:000178316800016 ER PT J AU Lyapustin, A Knyazikhin, Y AF Lyapustin, A Knyazikhin, Y TI Green's function method in the radiative transfer problem. II. Spatially heterogeneous anisotropic surface SO APPLIED OPTICS LA English DT Article ID SPHERICAL-HARMONICS METHOD; ATMOSPHERIC TRANSFER; AEROSOL AB The most recent theoretical studies have shown that three-dimensional (3-D) radiation effects play an important role in the optical remote sensing of atmospheric aerosol and land surface reflectance. These effects may contribute notably to the error budget of retrievals in a broad range of sensor resolutions, introducing systematic biases in the land surface albedo data sets that emerge from the existing global observation systems. At the same time, 3-D effects are either inadequately addressed or completely ignored in data processing algorithms. Thus there is a need for further development of the radiative transfer theory that can rigorously treat both 3-D and surface anisotropy effects and yet be flexible enough to permit the development of fast forward and inversion algorithms. We describe a new theoretical solution to the 3-D radiative transfer problem with an arbitrary nonhomogeneous non-Lambertian surface. This solution is based on an exact semianalytical solution derived in operator form by the Green's function method. The numerical implementation is based on several parameterizations that accelerate the solution dramatically while keeping its accuracy within several percent under most general conditions. (C) 2002 Optical Society of America. C1 Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Boston Univ, Dept Geog, Boston, MA 02215 USA. RP Lyapustin, A (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. EM alyapustin@pop900.gsfc.nasa.gov RI Lyapustin, Alexei/H-9924-2014 OI Lyapustin, Alexei/0000-0003-1105-5739 NR 16 TC 16 Z9 16 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 20 PY 2002 VL 41 IS 27 BP 5600 EP 5606 DI 10.1364/AO.41.005600 PG 7 WC Optics SC Optics GA 595MJ UT WOS:000178113100002 PM 12269558 ER PT J AU Lyapustin, A AF Lyapustin, A TI Radiative transfer code SHARM-3D for radiance simulations over a non-Lambertian nonhomogeneous surface: intercomparison study SO APPLIED OPTICS LA English DT Article ID SPHERICAL-HARMONICS METHOD; DISCRETE-ORDINATE-METHOD; ATMOSPHERE; MEDIA AB Results of an extensive validation study of the new radiative transfer code SHARM-3D are described. The code is designed for modeling of unpolarized monochromatic radiative transfer in the visible and near-IR spectra in the laterally uniform atmosphere over an arbitrarily inhomogeneous anisotropic surface. The surface boundary condition is periodic. The algorithm is based on an exact solution derived with the Green's function method. Several parameterizations were introduced into the algorithm to achieve superior performance. As a result, SHARM-3D is 2-3 orders of magnitude faster than the rigorous code SHDOM. It can model radiances over large surface scenes for a number of incidence-view geometries simultaneously. Extensive comparisons against SHDOM indicate that SHARM-3D has an average accuracy of better than 1%, which along with the high speed of calculations makes it a unique tool for remote-sensing applications in land surface and related atmospheric radiation studies. (C) 2002 Optical Society of America. C1 Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lyapustin, A (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. EM alyapust@pop900.gsfc.nasa.gov RI Lyapustin, Alexei/H-9924-2014 OI Lyapustin, Alexei/0000-0003-1105-5739 NR 17 TC 18 Z9 18 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 20 PY 2002 VL 41 IS 27 BP 5607 EP 5615 DI 10.1364/AO.41.005607 PG 9 WC Optics SC Optics GA 595MJ UT WOS:000178113100003 PM 12269559 ER PT J AU Vander Wal, RL Berger, GM Ticich, TM Patel, PD AF Vander Wal, RL Berger, GM Ticich, TM Patel, PD TI Application of laser-induced incandescence to the detection of carbon nanotubes and carbon nanofibers SO APPLIED OPTICS LA English DT Article ID SOOT-VOLUME FRACTION; PARTICLE-SIZE MEASUREMENTS; FLICKERING METHANE; DIFFUSION FLAMES; DIAGNOSTICS; VAPORIZATION; PYROLYSIS; HYDROCARBONS; GROWTH; PHASE AB Laser-induced incandescence applied to a heterogeneous, multielement reacting flow is characterized by temporally resolved emission spectra, time-resolved emission at selected detection wavelengths, and fluence dependence. Two-pulse laser measurements are used to further probe the effects of laser-induced changes on the optical signal. Laser fluences above 0.6 J/cm(2) at 1064 nm initiate laser-induced vaporization, yielding a lower incandescence intensity, as found through fluence-dependence measurements. Spectrally derived temperatures show that values of excitation laser fluence greater than this value lead to superheated plasmas with temperatures well above the vaporization point of carbon. The temporal evolution of the emission signal at these fluences is consistent with plasma dissipation processes, not incandescence from solidlike structures. Two-pulse laser experiments reveal that other material changes are produced at fluences below the apparent vaporization threshold, leading to nanostructures with different optical and thermal properties. (C) 2002 Optical Society of America. C1 NASA, Natl Ctr Micrograv Res Fluids & Combust, Glenn Res Ctr, Cleveland, OH 44135 USA. Centenary Coll Louisiana, Dept Chem, Shreveport, LA USA. RP NASA, Natl Ctr Micrograv Res Fluids & Combust, Glenn Res Ctr, Mail Stop 110-3,21000 Brookpk Rd, Cleveland, OH 44135 USA. EM randy@rvander.gre.nasa.gov NR 75 TC 6 Z9 6 U1 0 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 20 PY 2002 VL 41 IS 27 BP 5678 EP 5690 DI 10.1364/AO.41.005678 PG 13 WC Optics SC Optics GA 595MJ UT WOS:000178113100014 PM 12269569 ER PT J AU Griaznov, V Veselovskii, I Kolgotin, A Whiteman, DN AF Griaznov, V Veselovskii, I Kolgotin, A Whiteman, DN TI Angle- and size-dependent characteristics of incoherent Raman and fluorescent scattering by microspheres. 1. General expressions SO APPLIED OPTICS LA English DT Article ID SMALL PARTICLES; AEROSOLS; SPHERES AB A dipole model is used to simulate incoherent Raman and fluorescent scattering by microspheres. The use of the addition theorem for spherical harmonies circumvents the need to evaluate double sums in the final formulas, thereby drastically reducing computational effort. Special attention is paid to consideration of backscattering geometry, which is important for lidar applications. The formulas derived for backscattering geometry decrease the computation time for size parameter x similar to 100 by a factor of 200 compared with the time for calculations performed at other angles. (C) 2002 Optical Society of America. C1 Inst Gen Phys, Phys Instrumentat Ctr, Troitsk 142190, Moscow Region, Russia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Griaznov, V (reprint author), Inst Gen Phys, Phys Instrumentat Ctr, Troitsk 142190, Moscow Region, Russia. EM katyv@ore.ru NR 16 TC 2 Z9 2 U1 2 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 20 PY 2002 VL 41 IS 27 BP 5773 EP 5782 DI 10.1364/AO.41.005773 PG 10 WC Optics SC Optics GA 595MJ UT WOS:000178113100021 PM 12269576 ER PT J AU Veselovskii, I Griaznov, V Kolgotin, A Whiteman, DN AF Veselovskii, I Griaznov, V Kolgotin, A Whiteman, DN TI Angle- and size-dependent characteristics of incoherent Raman and fluorescent scattering by microspheres. 2. Numerical simulation SO APPLIED OPTICS LA English DT Article ID OPTICALLY LEVITATED MICRODROPLETS; SMALL PARTICLES; ANGULAR-DISTRIBUTION; RADIATION-PATTERN; DETECTION LIMITS; LIQUID DROPLETS; WATER-VAPOR; RESONANCES; MOLECULES; SPHERES AB The results of numerical simulation of inelastic scattering by microspheres with the use of a dipole model are presented. The formulas that are derived speed up the computation, thereby permitting larger-sized microspheres to be studied. The angular scattering cross section and depolarization are calculated for a wide range of size parameters as well as for different orientations of incident wave polarization. Calculations performed with small incremental changes in size permit the influence of morphology-dependent resonance (MDR) on the power and angular distribution of scattered radiation to be studied. TM and TE types of MDR produce enhanced scattering of the incident wave with vertical and horizontal polarization; the corresponding shape of the phase function becomes oscillatory. Special attention is paid to the simulation of backward scattering by water droplets, which is important for Raman lidar applications. (C) 2002 Optical Society of America. C1 Inst Gen Phys, Phys Instrumentat Ctr, Troitsk 142190, Moscow Region, Russia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Inst Gen Phys, Phys Instrumentat Ctr, Troitsk 142190, Moscow Region, Russia. EM katyv@orc.ru NR 44 TC 10 Z9 10 U1 2 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 20 PY 2002 VL 41 IS 27 BP 5783 EP 5791 DI 10.1364/AO.41.005783 PG 9 WC Optics SC Optics GA 595MJ UT WOS:000178113100022 PM 12269577 ER PT J AU Marscher, AP Jorstad, SG Mattox, JR Wehrle, AE AF Marscher, AP Jorstad, SG Mattox, JR Wehrle, AE TI High-frequency VLBA total and polarized intensity images of gamma-ray bright blazars SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : jets; quasars : general; radio continuum : galaxies; techniques : high angular resolution ID ACTIVE GALACTIC NUCLEI; RADIO-SOURCES; LINEAR-POLARIZATION; COMPLETE SAMPLE; 43 GHZ; JETS AB We present Very Long Baseline Array images of 42 gamma-ray bright blazars, including 36 with polarization vectors, obtained during the course of a multiepoch monitoring program. Each object was observed at either 43 or 22 GHz, with some objects observed at both frequencies and/or at 15 or 8.4 GHz. The morphologies are varied, with some of the blazars displaying long, thin jets, others short, broad jets, and still others containing cores with only very weak features that are probably knots in faint jets. The polarization of the cores ranges from less than 1% to 8.6%, with electric vector position angles (EVPAs) that are split between nearly parallel and nearly transverse to the jet axis. The polarization of knots in the jets covers a much broader range, from less than 2% to tens of percent. The EVPA of the brightest compact feature in each jet ranges from 0degrees to 80degrees from the jet position angle, with roughly half measuring less than 20degrees. The distribution is consistent with intrinsically oblique magnetic fields whose observed directions are altered by relativistic aberration. C1 Boston Univ, Inst Astrophys Res, Boston, MA 02215 USA. St Petersburg State Univ, Astron Inst, St Petersburg 198904, Russia. Francis Marion Univ, Dept Phys & Astron, Florence, SC 29501 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Marscher, AP (reprint author), Boston Univ, Inst Astrophys Res, 725 Commonwealth Ave, Boston, MA 02215 USA. RI Jorstad, Svetlana/H-6913-2013 OI Jorstad, Svetlana/0000-0001-9522-5453 NR 20 TC 46 Z9 46 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2002 VL 577 IS 1 BP 85 EP 97 DI 10.1086/342138 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 594DJ UT WOS:000178033200009 ER PT J AU Kraemer, SB Crenshaw, DM George, IM Netzer, H Turner, TJ Gabel, JR AF Kraemer, SB Crenshaw, DM George, IM Netzer, H Turner, TJ Gabel, JR TI Variable ultraviolet absorption in the Seyfert 1 galaxy NGC 3516: The case for associated ultraviolet and X-ray absorption SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 3516); galaxies : Seyfert; ultraviolet : galaxies; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; TELESCOPE IMAGING SPECTROGRAPH; PHOTOIONIZATION CROSS-SECTIONS; EMISSION-LINE REGIONS; INTRINSIC ABSORPTION; SPACE-TELESCOPE; ECHELLE OBSERVATIONS; ANALYTIC FITS; NGC-3516; BROAD AB We present observations of the UV absorption lines in the Seyfert 1 galaxy NGC 3516, obtained at a resolution of lambda/Deltalambda approximate to 40; 000 with the Space Telescope Imaging Spectrograph (STIS) on 2000 October 1. The UV continuum was similar to4 times lower than that observed during 1995 with the Goddard High Resolution Spectrograph (GHRS), and the X-ray flux from a contemporaneous Chandra X-Ray Observatory observation was a factor of similar to8 below that observed with ASCA. The STIS spectra show kinematic components of absorption in Lyalpha, C IV and N V at radial velocities of -376, -183, and -36 km s(-1) ( components 1, 2, and 3+4, respectively), which were detected in the earlier GHRS spectra; the last of these is a blend of two GHRS components that have increased greatly in column density. Four additional absorption components have appeared in the STIS spectra at radial velocities of -692, -837, -994, and -1372 km s(-1) ( components 5-8); these may also have been present in earlier low-flux states observed by the International Ultraviolet Explorer. Based on photoionization models, we suggest that the components are arranged in increasing radial distance in the order 3+4, 2, 1, followed by components 5-8. We have achieved an acceptable fit to the X-ray data using the combined X-ray opacity of the UV components 1, 2, and 3+4. By increasing the UV and X-ray fluxes of these models to match the previous high states, we are able to match the GHRS C IV column densities, the absence of detectable C IV absorption in components 5 8, and the 1994 ASCA spectrum. We conclude that variability of the UV and X-ray absorption in NGC 3516 is primarily due to changes in the ionizing flux. C1 Catholic Univ Amer, Greenbelt, MD 20771 USA. NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. RP Kraemer, SB (reprint author), Catholic Univ Amer, Code 681, Greenbelt, MD 20771 USA. NR 67 TC 41 Z9 41 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2002 VL 577 IS 1 BP 98 EP 113 DI 10.1086/342173 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 594DJ UT WOS:000178033200010 ER PT J AU Strohmayer, TE Markwardt, CB AF Strohmayer, TE Markwardt, CB TI Evidence for a millisecond pulsar in 4U 1636-53 during a superburst SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : general; stars : individual ( 4U 1636-53); stars : neutron; stars : rotation; X-rays : bursts; X-rays : stars ID X-RAY-BURSTS; COHERENT OSCILLATIONS; EVOLUTION; BINARIES; PHASE AB We report the discovery with the Proportional Counter Array on board the Rossi X-Ray Timing Explorer of highly coherent 582 Hz pulsations during the 2001 February 22 ( UT) "superburst" from 4U 1636-53. The pulsations are detected during an approximate to800 s interval spanning the flux maximum of the burst. Within this interval the barycentric oscillation frequency increases in a monotonic fashion from 581.89 to 581.93 Hz. The predicted orbital motion of the neutron star during this interval is consistent with such an increase as long as optical maximum corresponds roughly with superior conjunction of V801 Arae, the optical companion to the neutron star in 4U 1636-53. We show that a range of circular orbits with velocity 90 km s(-1) < v(ns) sin i < 175 km s(-1) and fractional phase 0.336 > phi(0) > 0.277 for the neutron star can provide an excellent description of the frequency and phase evolution. The brevity of the observed pulse train with respect to the 3.8 hr orbital period unfortunately does not allow for more precise constraints. The average pulse pro le is sinusoidal, and the time-averaged pulsation amplitude, as inferred from the half amplitude of the sinusoid, is 1%, smaller than typical for burst oscillations observed in normal thermonuclear bursts. We do not detect any higher harmonics nor the putative subharmonic near 290 Hz. The 90% upper limits on signal amplitude at the subharmonic and first harmonic are 0.1% and 0.06%, respectively. The highly coherent pulsation, with a Q = nu(0)/Deltanu > 4.5 x 10(5), provides compelling evidence for a rapidly rotating neutron star in 4U 1636-53 and further supports the connection of burst oscillation frequencies with the spin frequencies of neutron stars. Our results provide further evidence that some millisecond pulsars are spun up via accretion in low-mass X-ray binaries. We also discuss the implications of our orbital velocity constraint for the masses of the components of 4U 1636-53. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. EM stroh@clarence.gsfc.nasa; craigm@milkyway.gsfc.nasa.gov NR 37 TC 111 Z9 111 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2002 VL 577 IS 1 BP 337 EP 345 DI 10.1086/342152 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 594DJ UT WOS:000178033200031 ER PT J AU Gelino, CR Marley, MS Holtzman, JA Ackerman, AS Lodders, K AF Gelino, CR Marley, MS Holtzman, JA Ackerman, AS Lodders, K TI L dwarf variability: I-band observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : atmospheres; stars : low-mass, brown dwarfs ID LOW-MASS STARS; X-RAY FLARE; BROWN DWARF; ATMOSPHERES; DUST; LP-944-20; EMISSION; SPECTRA; JUPITER; CLOUDS AB We report on the results of an I-band photometric variability survey of 18 L dwarfs. We find that seven exhibit statistically significant variations above the 95.4% confidence level with firms scatter (including photometric errors) between 0.010 and 0.083 mag. Another five targets have variability probabilities approximate to80%, suggesting that these are likely variable objects. Two objects display significant peaks in a CLEAN periodogram that are several times higher than the noise. The periods found for 2MASS 0746+20AB and 2MASS 1300+19 are longer than those periods likely from rotation velocity measurements, and they do not represent periodic behavior in the light curve that persists through the entire data set. These observations suggest that we are not observing the rotation modulation of a long-lived albedo feature. Instead, rapid evolution of atmospheric features is likely causing the nonperiodic variability. The remaining variable objects show no prominent features in their light curves, suggesting even more rapid evolution of atmospheric features. We argue against the existence of magnetic spots in these atmospheres and favor the idea that nonuniform condensate coverage is responsible for these variations. The magnetic Reynolds number in the atmospheres of L dwarfs is too small to support the formation of magnetic spots. In contrast, silicate and iron clouds are expected to form in the photospheres of L dwarfs. Inhomogeneities in such cloud decks and the evolution of the inhomogeneities can plausibly produce the observed photometric variations. C1 New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Washington Univ, Dept Earth & Planetary Sci, Planetary Chem Lab, St Louis, MO 63130 USA. RP Gelino, CR (reprint author), New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. RI Ackerman, Andrew/D-4433-2012; Marley, Mark/I-4704-2013 OI Ackerman, Andrew/0000-0003-0254-6253; NR 56 TC 99 Z9 99 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2002 VL 577 IS 1 BP 433 EP 446 DI 10.1086/342150 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 594DJ UT WOS:000178033200039 ER PT J AU Thompson, RR Creech-Eakman, MJ van Belle, GT AF Thompson, RR Creech-Eakman, MJ van Belle, GT TI Multiepoch interferometric study of Mira variables. I. Narrowband diameters of RZ Pegasi and S Lacertae SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : AGB and post-AGB; stars : atmospheres; stars : fundamental parameters; stars : individual (RZ Pegasi, S Lacertae); stars : late-type; techniques : interferometric ID PALOMAR TESTBED INTERFEROMETER; 2.5 MU-M; ANGULAR SIZE MEASUREMENTS; LONG-PERIOD VARIABLES; CARBON-RICH STARS; MASS-LOSS RATES; EFFECTIVE TEMPERATURES; INFRARED-SPECTROSCOPY; ALPHA-ORIONIS; COOL STARS AB As part of the long-term monitoring of Mira variables at the Palomar Testbed Interferometer, we report high-resolution narrowband angular sizes of the oxygen-rich Mira S Lac and the carbon-rich Mira RZ Peg in the near-infrared. The data set spans three pulsation cycles for S Lac and two pulsation cycles for RZ Peg (a total of 1070 25 s observations) and represents the first study to correlate multiepoch narrowband interferometric data of Mira variables. When the calibrated visibility data are fitted using a uniform disk brightness model, differences are seen in their angular diameters as a function of wavelength within the K band (2.0-2.4 mum), the source of which is believed to be molecular absorptions in or above the photospheres of the two chemically different Miras. Using visible photometric data provided by the Association Francaise des Observateurs d'Etoiles Variables (AFOEV), the continuum minimum size of RZ Peg lags this by 0.28 +/- 0.02 in pulsation, similar to the phase lag found in Correlation Radial Velocities (CORAVEL) data. However, for S Lac, the continuum minimum size tracks the visual maximum brightness. Based on the mean of the continuum angular diameter cycloids, basic stellar parameters are computed for both RZ Peg and S Lac, with both showing maximum atmospheric extension with respect to the 2.0 and 2.4 mum diameters near phase 0.9. Using the mean value of the fitted cycloids, RZ Peg has a radius R-mean = 377 +/- 111 R. and a mean T-eff = 2706 +/- 36 K; S Lac has a radius R-mean = 292 +/- 73 R and a mean T-eff = 2605 +/- 47 K. The dominant source of error in the radii is the large uncertainty in the distances to these two stars. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. RP Thompson, RR (reprint author), CALTECH, Jet Prop Lab, MS 171-113,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 79 TC 47 Z9 47 U1 1 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2002 VL 577 IS 1 BP 447 EP 456 DI 10.1086/342147 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 594DJ UT WOS:000178033200040 ER PT J AU Reames, DV Ng, CK AF Reames, DV Ng, CK TI Angular distributions of Fe/O from Wind: New insight into solar energetic particle transport SO ASTROPHYSICAL JOURNAL LA English DT Article DE acceleration of particles; shock waves; Sun : abundances; Sun : coronal mass ejections (CMEs); Sun : particle emission ID CORONAL MASS EJECTIONS; ACCELERATION; EVENTS; EVOLUTION AB We examine the angular distributions of He, O, and Fe in large solar energetic particle (SEP) events measured on the Wind spacecraft. We report, for the first time, that in a fixed velocity interval, Fe/O is often larger for particles flowing sunward along the magnetic field than for particles flowing outward from the Sun in many SEP events. This occurs because the anisotropy for O exceeds that for Fe, even though both species are streaming outward. There are no examples of events for which the outward Fe/O dominates. The behavior of Fe and O conflicts with the expectations of simple diffusion theory, that angular distributions should be independent of species. It also seems to conflict with the idea that energetic Fe scatters less than O of the same velocity. However, preliminary modeling suggests that the presence of a reflecting magnetic boundary beyond 1 AU, together with the increased scattering of O over Fe due to proton-generated Alfven waves, can explain the direction and magnitude of the effect. These observations add a new dimension to the study of SEP transport. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Reames, DV (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 18 TC 15 Z9 15 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2002 VL 577 IS 1 BP L59 EP L62 DI 10.1086/344146 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 594DQ UT WOS:000178033800014 ER PT J AU Leys, D Meyer, TE Tsapin, AS Nealson, KH Cusanovich, MA Van Beeumen, JJ AF Leys, D Meyer, TE Tsapin, AS Nealson, KH Cusanovich, MA Van Beeumen, JJ TI Crystal structures at atomic resolution reveal the novel concept of "electron-harvesting" as a role for the small tetraheme cytochrome c SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID SHEWANELLA-PUTREFACIENS MR-1; NITROSOMONAS-EUROPAEA; FUMARATE REDUCTASE; FLAVOCYTOCHROME-C; IDENTIFICATION; REFINEMENT; C(3); FRIGIDIMARINA; MODEL AB The genus Shewanella produces a unique small tetraheme cytochrome c that is implicated in the iron oxide respiration pathway. It is similar in heme content and redox potential to the well known cytochromes c(3) but related in structure to the cytochrome c domain of soluble fumarate reductases from Shewanella sp. We report the crystal structure of the small tetraheme cytochrome c from Shewanella oneidensis MR-1 in two crystal forms and two redox states. The overall fold and heme core are surprisingly different from the soluble fumarate reductase structures. The high resolution obtained for an oxidized orthorhombic crystal (0.97 Angstrom) revealed several flexible regions. Comparison of the six monomers in the oxidized monoclinic space group (1.55 Angstrom) indicates flexibility in the C-terminal region containing heme IV. The reduced orthorhombic crystal structure (1.02 Angstrom) revealed subtle differences in the position of several residues, resulting in decreased solvent accessibility of hemes and the withdrawal of a positive charge from the molecular surface. The packing between monomers indicates that intermolecular electron transfer between any heme pair is possible. This suggests there is no unique site of electron transfer on the surface of the protein and that electron transfer partners may interact with any of the hemes, a process termed "electron-harvesting." This optimizes the efficiency of intermolecular electron transfer by maximizing chances of productive collision with redox partners. C1 Dept Biochem Physiol & Microbiol, Lab Prot Biochem & Prot Engn, B-9000 Ghent, Belgium. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Arizona, Dept Biochem, Tucson, AZ 85721 USA. RP Leys, D (reprint author), Univ Leicester, Dept Biochem, Leicester LE1 7RH, Leics, England. NR 25 TC 54 Z9 56 U1 3 U2 9 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD SEP 20 PY 2002 VL 277 IS 38 BP 35703 EP 35711 DI 10.1074/jbc.M203866200 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 595PB UT WOS:000178117000132 PM 12080059 ER PT J AU Gregurick, SK Chaban, GM Gerber, RB AF Gregurick, SK Chaban, GM Gerber, RB TI Ab initio and improved empirical potentials for the calculation of the anharmonic vibrational states and intramolecular mode coupling of N-methylacetamide SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID SELF-CONSISTENT-FIELD; RESOLUTION INFRARED-SPECTROSCOPY; DENSITY-FUNCTIONAL THEORY; FORCE-FIELDS; WAVE-FUNCTIONS; PHOTON-ECHOES; NUCLEIC-ACIDS; STRETCHING VIBRATIONS; POLYATOMIC SYSTEMS; AQUEOUS SOLVATION AB The second-order Moller-Plesset ab initio electronic structure method is used to compute points for the anharmonic mode-coupled potential energy surface of N-methylacetamide (NMA) in the trans,, configuration, including all degrees of freedom. The anharmonic vibrational states and the spectroscopy are directly computed from this potential surface using the correlation corrected vibrational self-consistent field (CC-VSCF) method. The results are compared with CC-VSCF calculations using both the standard and improved empirical Amber-like force fields and available low-temperature experimental matrix data. Analysis of our calculated spectroscopic results show that (1) the excellent agreement between the ab initio CC-VSCF calculated frequencies and the experimental data suggest that the computed anharmonic potentials for N-methylacetamide are of a very high quality. (2) For most transitions, the vibrational frequencies obtained from the ab initio CC-VSCF method are superior to those obtained using the empirical CC-VSCF methods, when compared with experimental data. However, the improved empirical force field yields better agreement with the experimental frequencies as compared with a standard AMBER-type force field. (3) The improved empirical force field in particular overestimates anharmonic couplings for the amide 11 mode, the methyl asymmetric bending modes, the out-of-plane methyl bending modes, and the methyl distortions. (4) Disagreement between the ab initio and empirical anharmonic couplings is greater than the disagreement between the frequencies, and thus the anharmonic part of the empirical potential seems to be less accurate than the harmonic contribution. (5) Both the empirical and ab initio CC-VSCF calculations predict a negligible anharmonic coupling between the amide I and other internal modes. The implication of this is that the intramolecular energy flow between the amide I and the other internal modes may be smaller than anticipated. These results may have important implications for the anharmonic force fields of peptides, for which N-methylacetamide is a model. C1 Univ Maryland Baltimore Cty, Dept Chem & Biochem, Baltimore, MD USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Hebrew Univ Jerusalem, Dept Phys Chem, IL-91904 Jerusalem, Israel. Hebrew Univ Jerusalem, Fritz Haber Res Ctr, IL-91904 Jerusalem, Israel. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. RP Gregurick, SK (reprint author), Univ Maryland Baltimore Cty, Dept Chem & Biochem, 1000 Hilltop Circle, Baltimore, MD USA. NR 65 TC 84 Z9 84 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD SEP 19 PY 2002 VL 106 IS 37 BP 8696 EP 8707 DI 10.1021/jp025633+ PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 593TV UT WOS:000178010400026 ER PT J AU Fishman, GJ AF Fishman, GJ TI Gamma-ray bursts - Light from darkness SO NATURE LA English DT Editorial Material C1 NASA, Dept Space Sci, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Fishman, GJ (reprint author), NASA, Dept Space Sci, George C Marshall Space Flight Ctr, SD50, Huntsville, AL 35812 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 19 PY 2002 VL 419 IS 6904 BP 259 EP 261 DI 10.1038/419259a PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 594NH UT WOS:000178056300029 PM 12239550 ER PT J AU Hodis, HN Mack, WJ LaBree, L Mahrer, PR Sevanian, A Liu, CR Liu, CH Hwang, J Selzer, RH Azen, SP AF Hodis, HN Mack, WJ LaBree, L Mahrer, PR Sevanian, A Liu, CR Liu, CH Hwang, J Selzer, RH Azen, SP CA VEAPS Res Grp TI Alpha-tocopherol supplementation in healthy individuals reduces low-density lipoprotein oxidation but not atherosclerosis - The Vitamin E Atherosclerosis Prevention Study (VEAPS) SO CIRCULATION LA English DT Article DE coronary disease; atherosclerosis; antioxidants; trials ID INTIMA-MEDIA THICKNESS; CORONARY HEART-DISEASE; BETA-CAROTENE; MYOCARDIAL-INFARCTION; RANDOMIZED TRIAL; E CONSUMPTION; HUMAN PLASMA; ANTIOXIDANT; ARTERY; SIMVASTATIN AB Background-Epidemiological studies have demonstrated an inverse relationship between vitamin E intake and cardiovascular disease (CVD) risk. In contrast, randomized controlled trials have reported conflicting results as to whether vitamin E supplementation reduces atherosclerosis progression and CVD events. Methods and Results-The study population consisted of men and women greater than or equal to40 years old with an LDL cholesterol level greater than or equal to3.37 mmol/L (130 mg/dL) and no clinical signs or symptoms of CVD. Eligible participants were randomized to DL-alpha-tocopherol 400 IU per day or placebo and followed every 3 months for an average of 3 years. The primary trial end point was the rate of change in the common carotid artery far-wall intima-media thickness (IMT) assessed by computer image-processed B-mode ultrasonograms. A mixed effects model using all determinations of IMT was used to test the hypothesis of treatment differences in IMT change rates. Compared with placebo, alpha-tocopherol supplementation significantly raised plasma vitamin E levels (P<0.0001), reduced circulating oxidized LDL (P=0.03), and reduced LDL oxidative susceptibility (P<0.01). However, vitamin E supplementation did not reduce the progression of IMT over a 3-year period compared with subjects randomized to placebo. Conclusions-The results are consistent with previous randomized controlled trials and extend the null results of vitamin E supplementation to the progression of IMT in healthy men and women at low risk for CVD. C1 Univ So Calif, Keck Sch Med, Atherosclerosis Res Unit, Los Angeles, CA 90033 USA. Univ So Calif, Keck Sch Med, Dept Med, Los Angeles, CA 90033 USA. Univ So Calif, Keck Sch Med, Dept Prevent Med, Los Angeles, CA 90033 USA. Univ So Calif, Sch Pharm, Dept Mol Pharmacol & Toxicol, Los Angeles, CA 90033 USA. Kaiser Permanente Med Ctr, Los Angeles, CA 90034 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Hodis, HN (reprint author), Univ So Calif, Keck Sch Med, Atherosclerosis Res Unit, 2250 Alcazar St,CSC132, Los Angeles, CA 90033 USA. FU NIA NIH HHS [R01-AG-13860] NR 35 TC 187 Z9 194 U1 1 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0009-7322 J9 CIRCULATION JI Circulation PD SEP 17 PY 2002 VL 106 IS 12 BP 1453 EP 1459 DI 10.1161/01.CIR.0000029092.99946.08 PG 7 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA 595RL UT WOS:000178122500008 PM 12234947 ER PT J AU Vander Wal, RL Hall, LJ AF Vander Wal, RL Hall, LJ TI Nanotube coated metals: New reinforcement materials for polymer matrix composites SO ADVANCED MATERIALS LA English DT Article ID WALL CARBON NANOTUBES; LOAD-TRANSFER; PURIFICATION AB Multi-walled carbon nanotubes, synthesized directly upon a stainless steel mesh, remain integrally attached while extending into the surrounding polymer matrix. The bonding between the mesh and polymer matrix is greatly enhanced by a volumetrically distributed interface. The Figure presents evidence of a fractured interface, which demonstrates that the steel mesh wires shear before delamination from the surrounding polymer matrix occurs. C1 NASA Glenn, NCMR, Cleveland, OH 44135 USA. RP Vander Wal, RL (reprint author), NASA Glenn, NCMR, MS 110-3,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 21 TC 6 Z9 6 U1 0 U2 5 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD SEP 16 PY 2002 VL 14 IS 18 BP 1304 EP + DI 10.1002/1521-4095(20020916)14:18<1304::AID-ADMA1304>3.0.CO;2-B PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 598RQ UT WOS:000178290600013 ER PT J AU O'Keefe, S AF O'Keefe, S TI Advanced propulsion eyed SO AVIATION WEEK & SPACE TECHNOLOGY LA English DT Letter C1 NASA, Washington, DC 20546 USA. RP O'Keefe, S (reprint author), NASA, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MCGRAW HILL INC PI NEW YORK PA 1221 AVENUE OF THE AMERICAS, NEW YORK, NY 10020 USA SN 0005-2175 J9 AVIAT WEEK SPACE TEC JI Aviat. Week Space Technol. PD SEP 16 PY 2002 VL 157 IS 12 BP 6 EP 6 PG 1 WC Engineering, Aerospace SC Engineering GA 596DU UT WOS:000178149500001 ER PT J AU Tao, G Tang, XD Joshi, SM AF Tao, G Tang, XD Joshi, SM TI Adaptive output rejection of umnatched input disturbances SO SYSTEMS & CONTROL LETTERS LA English DT Article DE actuator failure; adaptive control; disturbance rejection; output tracking; stability; unmatched disturbances ID FAULT-DIAGNOSIS; SYSTEMS; NOISE AB To adaptively reject the effect of certain unmatched input disturbances on the output of a linear time-invariant system, a transfer function matching condition is needed. A lemma which presents a novel basic property of linear systems is derived to characterize system conditions for such transfer function matching. An adaptive disturbance rejection control scheme is developed for such systems with uncertain dynamics parameters and disturbance parameters. This adaptive control technique is applicable to control of systems with actuator failures whose failure values, failure time instants, and failure patterns are unknown. A solution is presented to this adaptive actuator failure compensation problem, which ensures closed-loop stability and asymptotic output tracking, in the presence of any up to m - 1 uncertain failures of the total m actuators. Desired adaptive system performance is verified by simulation results. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Virginia, Dept Elect & Comp Engn, Charlottesville, VA 22903 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Tao, G (reprint author), Univ Virginia, Dept Elect & Comp Engn, Charlottesville, VA 22903 USA. NR 15 TC 4 Z9 4 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6911 J9 SYST CONTROL LETT JI Syst. Control Lett. PD SEP 16 PY 2002 VL 47 IS 1 BP 25 EP 35 AR PII S0167-6911(02)00166-4 DI 10.1016/S0167-6911(02)00166-4 PG 11 WC Automation & Control Systems; Operations Research & Management Science SC Automation & Control Systems; Operations Research & Management Science GA 584HB UT WOS:000177460200003 ER PT J AU Duesterloh, S Short, JW Barron, MG AF Duesterloh, S Short, JW Barron, MG TI Photoenhanced toxicity of weathered Alaska north slope crude oil to the calanoid copepods Calanus marshallae and Metridia okhotensis SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; PRINCE-WILLIAM-SOUND; EXXON-VALDEZ OIL; GIBBA L G-3; PHOTOINDUCED TOXICITY; PETROLEUM-HYDROCARBONS; SOLAR-RADIATION; DAPHNIA-PULEX; SEDIMENTS; ANTHRACENE AB This study investigated the synergistic toxicity of aqueous polyaromatic compounds (PAC) dissolved from crude oil and ultraviolet radiation (UV) in natural sunlight to the calanoid copepods Calanus marshallae and Metridia okhotensis. These copepods were first exposed to low doses (similar to2 mug of total PAC/Q of the water-soluble fraction of weathered Alaska North Slope crude oil for 24 h and subsequently to low or high levels of natural sunlight. Responses included mortality, impairment of swimming ability, and discoloration of lipid sacs. There was 80-100% mortality and morbidity of C. marshallae exposed to UV and oil as compared to less than 10% effect in oil-only or UV-only treatments. In M. okhotensis, 100% mortality occurred in the UV and oil treatment, 43% mortality and 27% morbidity in the UV-only treatment, and less than 5% effect in the oil-only treatment. Bioaccumulation factors were similar to8000 for C. marshallae and similar to2000 for M. okhotensis. The interaction of the effect of PAC and UV radiation was highly significant (P < 0.005) in both experiments. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. Univ Alaska, Juneau Ctr, Sch Fisheries & Ocean Sci, Juneau, AK 99801 USA. PEAK Res, Longmont, CO 80501 USA. RP NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. EM Jeff.Short@noaa.gov NR 40 TC 29 Z9 30 U1 0 U2 24 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X EI 1520-5851 J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD SEP 15 PY 2002 VL 36 IS 18 BP 3953 EP 3959 AR UNSP ES020685Y DI 10.1021/es02685y PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 593WC UT WOS:000178016600010 PM 12269748 ER PT J AU Gao, BC Kaufman, YJ Tanre, D Li, RR AF Gao, BC Kaufman, YJ Tanre, D Li, RR TI Distinguishing tropospheric aerosols from thin cirrus clouds for improved aerosol retrievals using the ratio of 1.38-mu m and 1.24-mu m channels SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MODIS; OCEANS; SPACE AB [1] The scattering of solar radiation by cirrus clouds often contaminates aerosol products retrieved from satellite-based measurements using channels located in the visible and near-IR spectral region. Previously, it was demonstrated that a narrow satellite channel located near 1.38 mum is very effective in detecting the high level thin cirrus clouds. In this paper, we describe a ratio technique using the 1.38-mum channel and the 1.24-mum channel for identifying pixels contaminated by thin cirrus clouds so that improved aerosol and dust products can be obtained. The multi-channel data acquired with the NASA Moderate Resolution Imaging SpectroRadiometer (MODIS) on the Terra Spacecraft are used to demonstrate this technique. C1 USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CNRS, Opt Atmospher Lab, Villeneuve Dascq, France. Univ Sci & Technol Lille, Villeneuve Dascq, France. Sci Syst & Applicat Inc, Lanham, MD USA. RP Gao, BC (reprint author), USN, Res Lab, Remote Sensing Div, Code 7212, Washington, DC 20375 USA. NR 15 TC 42 Z9 42 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 2002 VL 29 IS 18 AR 1890 DI 10.1029/2002GL015475 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 635KL UT WOS:000180398000037 ER PT J AU Kaufman, YJ Dubovik, O Smirnov, A Holben, BN AF Kaufman, YJ Dubovik, O Smirnov, A Holben, BN TI Remote sensing of non-aerosol absorption in cloud free atmosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SKY RADIANCE MEASUREMENTS; OPTICAL-PROPERTIES; SOLAR-RADIATION; AERONET; IRRADIANCE; NETWORK; SURFACE; SUN AB [1] Knowledge of the absorption of sunlight by atmospheric gases, aerosols and clouds is key to understanding climate and its variation. Several studies suggested that clouds absorb sunlight significantly more than what models predict. Other studies suggested that the anomalous absorption is present in cloud-free conditions. Here we measure absorption in cloud free atmosphere using the Aerosol Robotic Network (AERONET). Measurements of attenuation of direct sunlight are used to derive extinction optical thickness and sky measurements to derive scattering optical thickness, Residual extinction for zero scattering, cannot be caused by aerosols or known gases and would be associated with the cloud free absorption anomaly. The anomalous absorption, if exists, is assumed not to correlate with the presence of aerosol. The measurements, taken for several years in locations around the world, show that in the atmospheric windows 0.44, 0.67, 0.87 and 1.02 mum the only significant absorbers in cloud free atmosphere is aerosol and ozone. Non-aerosol absorption, defined as spectrally independent or smoothly variable, was found to have an optical thickness smaller than 0.002 +/- 0.003, thereby, absorption of sunlight smaller than 1W/m(2). C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. UMBC Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. RP Kaufman, YJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Dubovik, Oleg/A-8235-2009; Smirnov, Alexander/C-2121-2009 OI Dubovik, Oleg/0000-0003-3482-6460; Smirnov, Alexander/0000-0002-8208-1304 NR 16 TC 11 Z9 11 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 2002 VL 29 IS 18 AR 1857 DI 10.1029/2001GL014399 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 635KL UT WOS:000180398000004 ER PT J AU Popp, PJ Ridley, BA Neuman, JA Avallone, LM Toohey, DW Zittel, PF Schmid, O Herman, RL Gao, RS Northway, MJ Holecek, JC Fahey, DW Thompson, TL Kelly, KK Walega, JG Grahek, FE Wilson, JC Ross, MN Danilin, MY AF Popp, PJ Ridley, BA Neuman, JA Avallone, LM Toohey, DW Zittel, PF Schmid, O Herman, RL Gao, RS Northway, MJ Holecek, JC Fahey, DW Thompson, TL Kelly, KK Walega, JG Grahek, FE Wilson, JC Ross, MN Danilin, MY TI The emission and chemistry of reactive nitrogen species in the plume of an Athena II solid-fuel rocket motor SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOSPHERIC OZONE DEPLETION; EXHAUST; SPECTROMETER AB [1] In situ measurements of NO, NOy, HNO3, ClO, CO2, H2O and particles were made in the plume of an Athena II solid-fuel rocket motor (SRM) with instruments onboard the NASA WB-57F high-altitude aircraft. By normalization to CO2, the NOy emission index was calculated to be 2.7 +/- 0.6 g NO2 (kg fuel)(-1). HNO3 is a significant and evolving component plume NOy. The principal source of HNO3 is thought to be the heterogeneous reaction between ClONO2 and HCl on emitted alumina particles. These measurements provide the first experimental evidence for the production of HNO3 and the activation of chlorine on SRM-emitted alumina particles in the lower stratosphere. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. Aerosp Corp, Los Angeles, CA 90009 USA. Univ Denver, Dept Engn, Denver, CO 80208 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. AER Inc, Lexington, MA 02421 USA. RP Popp, PJ (reprint author), NOAA, Aeron Lab, Boulder, CO 80305 USA. RI Neuman, Andy/A-1393-2009; Toohey, Darin/A-4267-2008; Herman, Robert/H-9389-2012; Gao, Ru-Shan/H-7455-2013; Fahey, David/G-4499-2013; Schmid, Otmar/F-1078-2013 OI Neuman, Andy/0000-0002-3986-1727; Toohey, Darin/0000-0003-2853-1068; Herman, Robert/0000-0001-7063-6424; Fahey, David/0000-0003-1720-0634; NR 21 TC 6 Z9 6 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 2002 VL 29 IS 18 AR 1887 DI 10.1029/2002GL015197 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 635KL UT WOS:000180398000034 ER PT J AU Wilkins, SJ Schultz, RA Anderson, RC Dohm, JM Dawers, NH AF Wilkins, SJ Schultz, RA Anderson, RC Dohm, JM Dawers, NH TI Deformation rates from faulting at the Tempe Terra extensional province, Mars SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SEGMENT LINKAGE; DISPLACEMENT; STRAIN; DISTRIBUTIONS; POPULATION; GROWTH; UTAH; SLIP AB [1] Rates of deformation are estimated from exposed normal faults within the Tempe Terra extensional province, Mars, through an analysis that incorporates fault segment linkage and utilizes regional observations of displacement-length relationships measured from Mars Orbiter Laser Altimeter topographic data. Moment rates (from 10(14)-10(16) N-m/yr), strain rates (10(-12) -10(-11) yr(-1)) and rifting velocities (similar to0.003 mm/yr) are comparable to rates of deformation on stable plate interiors of Earth. The calculated low rates of rifting may result from the poorly constrained timing of deformation on Mars. Cumulative moment release estimates decrease linearly with time from Noachian (similar to1 x 10(25) N-m) to Early Hesperian (similar to6 x 10(24) N-m) and Late Hesperian-Early Amazonian (similar to1 x 10(24)). These results indicate that a portion of Tharsis-related deformation remained localized within the Tempe Rift throughout much of Martian history, and provide important constraints for models of Martian mantle convection. C1 Univ Nevada, Dept Geol Sci, Geomech Rock Fracture Grp, Reno, NV 89557 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. Tulane Univ, Dept Geol, New Orleans, LA 70118 USA. RI Dawers, Nancye/F-5692-2012; Dohm, James/A-3831-2014; OI Schultz, Richard/0000-0003-3198-5263 NR 24 TC 28 Z9 28 U1 2 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 2002 VL 29 IS 18 AR 1884 DI 10.1029/2002GL015391 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 635KL UT WOS:000180398000031 ER PT J AU Bihary, Z Chaban, GM Gerber, RB AF Bihary, Z Chaban, GM Gerber, RB TI Stability of a chemically bound helium compound in high-pressure solid helium SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RARE-GAS; XENON; SPECTROSCOPY AB HHeF, a chemically-bound helium compound, has been predicted to be metastable in the gas phase. It decays by tunneling through energy barriers in picosecond timescales into He+HF and H+He+F. This paper studies the stability of HHeF in pressurized solid helium. Using realistic potentials for the HHeF/He interaction, the potential energy along the minimum energy paths for decomposition is evaluated, and tunneling decay times are computed by the WKB approximation. It is found that for pressures above 500 MPa, decomposition into H+He+F is completely suppressed. At 23 GPa, the highest pressure studied, the timescale for HHeF-->He+HF is in the millisecond range. At pressures well above 23 GPa, HHeF is thus expected to remain stable indefinitely. (C) 2002 American Institute of Physics. C1 Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Hebrew Univ Jerusalem, Dept Chem Phys, IL-91904 Jerusalem, Israel. Hebrew Univ Jerusalem, Fritz Haber Res Ctr, IL-91904 Jerusalem, Israel. RP Bihary, Z (reprint author), Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. NR 24 TC 22 Z9 22 U1 3 U2 12 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 2002 VL 117 IS 11 BP 5105 EP 5108 DI 10.1063/1.1506150 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 588CZ UT WOS:000177684400002 ER PT J AU Bhatt, RT Chen, YL Morscher, GN AF Bhatt, RT Chen, YL Morscher, GN TI Microstructure and tensile properties of BN/SiC coated Hi-Nicalon, and Sylramic SiC fiber preforms SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID DAMAGE ACCUMULATION; MATRIX COMPOSITES; ACOUSTIC-EMISSION; CRACK INITIATION; WOVEN AB Batch to batch and within batch variations, and the influence of fiber architecture on room temperature physical and tensile properties of BN/SiC coated Hi-Nicalon and Sylramic SiC fiber preform specimens were determined. The three fiber architectures studied were plain weave (PW), 5-harness satin (5HS), and 8-harness satin (8HS). Results indicate that the physical properties vary up to 10 percent within a batch, and up to 20 percent between batches of preforms. Load-reload (Hysteresis) and acoustic emission methods were used to analyze damage accumulation occurring during tensile loading. Early acoustic emission activity, before observable hysteretic behavior, indicates that the damage starts with the formation of nonbridged tunnel cracks. These cracks then propagate and intersect the load bearing "0degrees" fibers giving rise to hysteretic behavior. For the Hi-Nicalon preform specimens, the onset of "0degrees" bundle cracking stress and strain appeared to be independent of the fiber architecture. Also, the "0degrees" fiber bundle cracking strain remained nearly the same for the preform specimens of both fiber types. TEM analysis indicates that the CVI BN interface coating is mostly amorphous and contains carbon and oxygen impurities, and the CVI SiC coating is crystalline. No reaction exists between the CVI BN and SiC coating. (C) 2002 Kluwer Academic Publishers. C1 NASA, USA, Res Lab, Glenn Res Ctr, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Brookpark, OH 44142 USA. Dynacs Engn Co Inc, Brookpark, OH 44142 USA. RP Bhatt, RT (reprint author), NASA, USA, Res Lab, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 21 TC 7 Z9 8 U1 0 U2 12 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD SEP 15 PY 2002 VL 37 IS 18 BP 3991 EP 3998 DI 10.1023/A:1019692514089 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 581TJ UT WOS:000177309000024 ER PT J AU Ustinov, EA AF Ustinov, EA TI Analytic evaluation of the weighting functions for remote sensing of blackbody planetary atmospheres: a general linearization approach SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE radiative transfer; remote sensing; weighting functions ID EMISSION SPECTROMETER; SOUNDER AB An analytic approach is proposed far the evaluation of weighting functions for remote sensing of a black-body planetary atmosphere based on straightforward, general linearization. In the present paper, this approach is applied to the case of remote sensing with the nadir (down-looking) geometry. Expressions for weighting functions for various atmospheric parameters are derived. It is demonstrated that in a realistic case of temperature-dependent atmospheric absorption, an additional term appears in the expression for the temperature weighting function which contains the temperature derivative of the atmospheric absorption coefficient. The approach is applied to the case of a semi-infinite atmosphere and then, to the atmosphere of a finite optical depth with the underlying surface. In this, latter case, the expressions are also obtained for partial derivatives of observed radiances with respect to surface parameters: surface pressure, temperature and emissivity. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. RP Ustinov, EA (reprint author), CALTECH, Jet Prop Lab, Div Earth & Space Sci, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Ustinov, Eugene/D-1350-2015 OI Ustinov, Eugene/0000-0003-0227-4286 NR 14 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD SEP 15 PY 2002 VL 74 IS 6 BP 683 EP 696 AR PII S0022-4073(01)00279-5 DI 10.1016/S0022-4073(01)00279-5 PG 14 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 569TL UT WOS:000176618300002 ER PT J AU Cropper, M Ramsay, G Hellier, C Mukai, K Mauche, C Pandel, D AF Cropper, M Ramsay, G Hellier, C Mukai, K Mauche, C Pandel, D TI X-ray observations of accreting white-dwarf systems SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article; Proceedings Paper CT Royal-Society Discussion Meeting on X-Ray Astronomy in the New Millennium CY FEB, 2002 CL LONDON, ENGLAND SP Royal Soc DE XMM-Newton; Chandra; binaries; cataclysmic variables; X-rays; stars ID MAGNETIC CATACLYSMIC VARIABLES; XMM-NEWTON OBSERVATIONS; RX J0806.3+1527; PERIOD BINARY; OY-CAR; DP-LEO; WW-HOR; EMISSION; FLOWS AB Accretion in white-dwarf binary systems can occur through discs, accretion columns or a combination of these, depending on the magnetic field of the white dwarf. Recent high-quality X-ray observations with the XMM-Newton and Chandra observatories have significantly advanced our understanding of the physics of the accretion process, and place severe tests on our existing models. There have been some surprises, such as the strong dependence of atmospheric heating on accretion rate. However, we believe that we are now confident that we understand in general the physical processes in the accretion region, although some complicating factors, such as absorption, remain. We also discuss new developments in ultra-short-period white-dwarf binary systems. C1 UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Univ Keele, Dept Phys & Astron, Keele ST5 5BG, Staffs, England. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Lawrence Livermore Natl Lab, Astrophys Grp, Livermore, CA 94550 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. RP Cropper, M (reprint author), UCL, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England. RI Cropper, Mark/C-1574-2008; OI Pandel, Dirk/0000-0003-2085-5586 NR 28 TC 11 Z9 11 U1 0 U2 0 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD SEP 15 PY 2002 VL 360 IS 1798 BP 1951 EP 1966 DI 10.1098/rsta.2002.1046 PG 16 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 593QL UT WOS:000178003600005 PM 12804239 ER PT J AU Mushotzky, R AF Mushotzky, R TI Clusters of galaxies: a cosmological probe SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article; Proceedings Paper CT Royal-Society Discussion Meeting on X-Ray Astronomy in the New Millennium CY FEB, 2002 CL LONDON, ENGLAND SP Royal Soc DE cosmological parameters; Fe abundance; cluster evolution; group abundance; elliptical galaxies ID X-RAY-CLUSTERS; INTRACLUSTER MEDIUM; ELLIPTIC GALAXIES; ABUNDANCES; ENRICHMENT; ASCA; TEMPERATURE; METALLICITY; PARAMETERS; REGIONS AB The constraints on cosmological parameters presently obtained and those that can be obtained from X-ray cluster surveys are presented. Extremely strong bounds on the values of Omega, Lambda, sigma(8) and the power spectrum of fluctuations, as well as constraints on the equation of state of dark energy, can be determined. Recent Advanced Satellite for Cosmology and Astrophysics and XMM results on the chemical composition of clusters show that the Fe abundance is not universal, but is correlated with cluster mass and central gas density. The Si, S and Fe abundances do not resemble those seen in Milky Way Halo stars or those in the Lyman-limit galaxies. The XMM RGS abundances for gas in elliptical galaxies are subsolar and the abundance pattern is not alpha-element rich, in contradiction with all models of elliptical-galaxy gas abundances. C1 NASA, Goddard Space Flight Ctr, Off Publ Affairs, Greenbelt, MD 20771 USA. RP Mushotzky, R (reprint author), NASA, Goddard Space Flight Ctr, Off Publ Affairs, Code 130, Greenbelt, MD 20771 USA. NR 62 TC 3 Z9 3 U1 0 U2 1 PU ROYAL SOC LONDON PI LONDON PA 6 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X J9 PHILOS T ROY SOC A JI Philos. Trans. R. Soc. Lond. Ser. A-Math. Phys. Eng. Sci. PD SEP 15 PY 2002 VL 360 IS 1798 BP 2019 EP 2033 DI 10.1098/rsta.2002.1050 PG 15 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 593QL UT WOS:000178003600010 PM 12804244 ER PT J AU Boykin, TB Klimeck, G Bowen, RC Oyafuso, F AF Boykin, TB Klimeck, G Bowen, RC Oyafuso, F TI Diagonal parameter shifts due to nearest-neighbor displacements in empirical tight-binding theory SO PHYSICAL REVIEW B LA English DT Article ID DEFORMATION POTENTIALS; ELECTRONIC-STRUCTURE; SEMICONDUCTORS AB Nanoscale heterostructures are generally characterized by local strain variations. Because the atoms in such systems can be irregularly positioned, theroretical models and parameterizations that are restricted to hydrostatic and uniaxial strain are generally not applicable. To address this shortcoming, a method that enables the incorporation of general distortions into the empirical tight binding model is presented. The method shifts the diagonal Hamiltonian matrix elements due to displacements of neighboring atoms from their ideal bulk positions. The new, efficient, and flexible method is developed for zincblende semiconductors and employed to calculate gaps for GaAs and InAs under hydrostatic and uniaxial strain. Where experimental and theoretical data are available our new method compares favorably with other methods, yet it is not restricted to the cases of uniaxial or hydrostatic strain. Because our method handles arbitrary nearest-neighbor displacements it permits the incorporation of diagonal parameter shifts in general, three-dimensional nanoscale electronic structure simulations, such as the nanoelectronic modeling tool (NEMO 3D). C1 Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Boykin, TB (reprint author), Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. RI Klimeck, Gerhard/A-1414-2012 OI Klimeck, Gerhard/0000-0001-7128-773X NR 17 TC 150 Z9 152 U1 1 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2002 VL 66 IS 12 AR 125207 DI 10.1103/PhysRevB.66.125207 PG 6 WC Physics, Condensed Matter SC Physics GA 601RH UT WOS:000178461100029 ER PT J AU Li, J Cassell, A Delzeit, L Han, J Meyyappan, M AF Li, J Cassell, A Delzeit, L Han, J Meyyappan, M TI Novel three-dimensional electrodes: Electrochemical properties of carbon nanotube ensembles SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID OXIDATION AB We report on the electrochemical study of three carbon nanotube ensemble electrodes: single-walled nanotube paper, as-produced multiwalled nanotube towers, and heat-treated multiwalled nanotube towers. Cyclic voltammetry was used in 0.10 M KCl containing 5.0 mM K4Fe(CN)(6) to obtain information on both the capacitive background and electron transfer rate from the faradaic reaction of the redox species. The capacitance gives insight into the effective surface area (including both the exterior surface and the interior surface within the filth) as well as the "pseudocapacitance" due to faradaic reactions of surface bonded oxides. We found that a large portion of the carbon nanotube surface of the as-produced multiwalled nanotube tower electrode was blocked by amorphous carbon. It can be largely removed by prolonged heat treatment. Among the three types of samples, the single-walled nanotube paper electrode presented the largest volume specific capacitance, consistent with its highest carbon nanotube packing density (i.e., largest effective carbon nanotube surface area). The redox reaction of Fe(CN)(6)(3-)/Fe(CN)(6)(4-) was found to occur not only at the outer surface of the carbon nanotube film but also at the interior surface of the nanotube ensemble electrodes. This indicates that the carbon nanotube ensemble behaves as a three-dimensional electrode. The apparent electron transfer rate (as indicated by the redox peak separation) was found to correlate to both the area of the exposed side-walls (with graphite basal-plane-like properties) and the density of graphite edge-plane-like defects. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Li, J (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RI Li, Jun/H-7771-2013 OI Li, Jun/0000-0002-3689-8946 NR 21 TC 235 Z9 238 U1 3 U2 79 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 12 PY 2002 VL 106 IS 36 BP 9299 EP 9305 DI 10.1021/jp021201n PG 7 WC Chemistry, Physical SC Chemistry GA 591JR UT WOS:000177876900019 ER PT J AU Kump, LR AF Kump, LR TI Reducing uncertainty about carbon dioxide as a climate driver SO NATURE LA English DT Editorial Material ID CO2 AB The lack of an adequate ancient analogue for future climates means that we ultimately must use and trust climate models, evaluated against modern observation and our best geologic records of warm and cold climates of the past. Armed with an elevated confidence in the models, we will then be able to make reliable predictions of the Earth's response to our risky experiment with the climate system. C1 Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. Penn State Univ, NASA, Astrobiol Inst, University Pk, PA 16802 USA. RP Kump, LR (reprint author), Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. RI Kump, Lee/H-8287-2012 NR 14 TC 49 Z9 54 U1 1 U2 13 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 12 PY 2002 VL 419 IS 6903 BP 188 EP 190 DI 10.1038/nature01087 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 592HK UT WOS:000177931200047 PM 12226672 ER PT J AU Kaufman, YJ Tanre, D Boucher, O AF Kaufman, YJ Tanre, D Boucher, O TI A satellite view of aerosols in the climate system SO NATURE LA English DT Review ID INDIAN-OCEAN EXPERIMENT; OPTICAL DEPTH; MINERAL DUST; ANTHROPOGENIC AEROSOLS; TROPOSPHERIC AEROSOLS; RADIATIVE PROPERTIES; ABSORBING PARTICLES; CLOUD MICROPHYSICS; SULFATE AEROSOLS; UNITED-STATES AB Anthropogenic aerosols are intricately linked to the climate system and to the hydrologic cycle. The net effect of aerosols is to cool the climate system by reflecting sunlight. Depending on their composition, aerosols can also absorb sunlight in the atmosphere, further cooling the surface but warming the atmosphere in the process. These effects of aerosols on the temperature profile, along with the role of aerosols as cloud condensation nuclei, impact the hydrologic cycle, through changes in cloud cover, cloud properties and precipitation. Unravelling these feedbacks is particularly difficult because aerosols take a multitude of shapes and forms, ranging from desert dust to urban pollution, and because aerosol concentrations vary strongly over time and space. To accurately study aerosol distribution and composition therefore requires continuous observations from satellites, networks of ground-based instruments and dedicated field experiments. Increases in aerosol concentration and changes in their composition, driven by industrialization and an expanding population, may adversely affect the Earth's climate and water supply. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Lille, CNRS, Opt Atmospher Lab, Villeneuve Dascq, France. RP Kaufman, YJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Boucher, Olivier/J-5810-2012; Boucher, Olivier/K-7483-2012 OI Boucher, Olivier/0000-0003-2328-5769; Boucher, Olivier/0000-0003-2328-5769 NR 100 TC 1013 Z9 1070 U1 30 U2 249 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 12 PY 2002 VL 419 IS 6903 BP 215 EP 223 DI 10.1038/nature01091 PG 9 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 592HK UT WOS:000177931200051 PM 12226676 ER PT J AU Jun, I Ratliff, JM Garrett, HB McEntire, RW AF Jun, I Ratliff, JM Garrett, HB McEntire, RW TI Monte Carlo simulations of the Galileo energetic particle detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE energetic particle detector (EPD); response function; geometric factor; MCNP; MCNPX; Galileo spacecraft AB Monte Carlo radiation transport studies have been performed for the Galileo spacecraft energetic particle detector (EPD) in order to study its response to energetic electrons and protons. Three-dimensional Monte Carlo radiation transport codes, MCNP version 413 (for electrons) and MCNPX version 2.2.3 (for protons), were used throughout the study. The results are presented in the form of "geometric factors" for the high-energy channels studied in this paper: B1, DC2, and DC3 for electrons and B0, DC0, and DC1 for protons. The geometric factor is the energy-dependent detector response function that relates the incident particle fluxes to instrument count rates. The trend of actual data measured by the EPD was successfully reproduced using the geometric factors obtained in this study. (C) 2002 Elsevier Science B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. RP Jun, I (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 122-107, Pasadena, CA 91109 USA. NR 10 TC 17 Z9 17 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 11 PY 2002 VL 490 IS 3 BP 465 EP 475 AR PII S0168-9002(02)01072-0 DI 10.1016/S0168-9002(02)01072-0 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 599CM UT WOS:000178316600005 ER PT J AU Eisen, Y Evans, LG Starr, R Trombka, JI AF Eisen, Y Evans, LG Starr, R Trombka, JI TI CdWO4 scintillator as a compact gamma ray spectrometer for planetary lander missions SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE CdWO4 scintillator; gamma-ray compact spectrometer ID CADMIUM TUNGSTATE; LIGHT AB The objective of this work is to develop a gamma ray spectrometer (GRS) suitable for use on planetary rover missions. The main characteristics of this detector are low weight, small volume low power and resistance to cosmic ray radiation over a long period of time. We describe a 3 cm diameter by 3 cm thick CdWO4 cylindrical scintillator coupled to a PMT as a GRS for the energy region 0.662-7.64 MeV. Its spectral performance and efficiency are compared to that of a CsI(Tl) scintillator 2.5 cm diameter by 6 cm thick coupled to a 28 mm x 28 mm PIN photodiode, The comparison is made experimentally using Cs-137, Co-60, 6.13 MeV gamma rays from a C-13(alpha, gamman)O-16* source, 7.64 MeV thermal neutron capture gamma rays emitted from iron bars using a Cf-252 neutron source, and natural radioactivity 1.46 MeV K-40 and 2.61 MeV Th-232 gamma rays. We use a Monte Carlo method to calculate the total peak efficiency of these detectors and the full energy, first and second escape peak efficiencies. The experimental and calculated results agree well. We investigated the usefulness of these detectors for a GRS on a Mars lander mission. Although both detectors meet desired specifications, it was found that CdWO4 has advantages over CsI(TI) being a more compact detector of higher efficiency, Using a shaping amplifier of 24 ms, CdWO4 spectrometer exhibited a 6.8% FWHM at 662 keV. At 6.13 MeV, CdWO4 detector possesses an intrinsic total and full energy peak efficiencies of 16.7% and 6.3%. respectively. These efficiencies are nearly a factor of 1.6 and 4 greater than the corresponding efficiencies of the CsI(Tl) detector. A proposed gamma ray spectroscopy system to be placed on a rover, consists of a central detector surrounded by a Compton suppressor shield, The central detector is a cylindrical CdWO4 detector and the Compton suppressor shield is made of segmented CdWO4, Coupled to PIN photodiodes. The shield also prevents thermal neutron activation of the central detector, (C) 2002 Elsevier Science B,V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Comp Sci Corp, Lanham, MD 20706 USA. RP Eisen, Y (reprint author), Soreq NRC, IL-81800 Yavne, Israel. NR 11 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 11 PY 2002 VL 490 IS 3 BP 505 EP 517 AR PII S0168-9002(02)01089-6 DI 10.1016/S0168-9002(02)01089-6 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 599CM UT WOS:000178316600008 ER PT J AU Nandra, K Mushotzky, RF Arnaud, K Steidel, CC Adelberger, KL Gardner, JP Teplitz, HI Windhorst, RA AF Nandra, K Mushotzky, RF Arnaud, K Steidel, CC Adelberger, KL Gardner, JP Teplitz, HI Windhorst, RA TI X-ray properties of Lyman break galaxies in the Hubble Deep Field North Region SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : evolution; galaxies : high-redshift; galaxies : nuclei; X-rays : galaxies ID STAR-FORMATION HISTORY; ULTRAVIOLET LUMINOSITY DENSITY; SPECTRAL ENERGY-DISTRIBUTIONS; HIGH-REDSHIFT GALAXIES; BLACK-HOLE MASS; INFRARED GALAXIES; FORMING GALAXIES; VELOCITY DISPERSION; SOURCE COUNTS; CHANDRA AB We describe the X-ray properties of a large sample of z similar to 3 Lyman break galaxies (LBGs) in the region of the Hubble Deep Field North, derived from the 1 Ms public Chandra observation. Of our sample of 148 LBGs, four are detected individually. This immediately gives a measure of the bright AGN fraction in these galaxies of similar to3%, which is in agreement with that derived from the UV spectra. The X-ray color of the detected sources indicates that they are probably moderately obscured. Stacking of the remainder shows a significant detection (6sigma) with an average luminosity of 3.4 x 10(41) ergs s(-1) per galaxy in the rest-frame 2-10 keV band. We have also studied a comparison sample of 95 z similar to 1 "Balmer break" galaxies. Eight of these are detected directly, with at least two clear AGNs based on their high X-ray luminosity and very hard X-ray spectra. The remainder are of relatively low luminosity (<10(42) ergs s(-1)), and the X-rays could arise from either AGNs or rapid star formation. The X-ray colors and evidence from other wave bands favor the latter interpretation. Excluding the clear AGNs, we deduce a mean X-ray luminosity of 6.6 x 10(40) ergs s(-1), a factor of &SIM;5 lower than the LBGs. The average ratio of the UV and X-ray luminosities of these star-forming galaxies L-UV/L-X, however, is approximately the same at z = 1 as it is at z = 3. This scaling implies that the X-ray emission follows the current star formation rate, as measured by the UV luminosity. We use our results to constrain the star formation rate at z &SIM; 3 from an X-ray perspective. Assuming the locally established correlation between X-ray and far-IR luminosity, the average inferred star formation rate in each LBG is found to be approximately 60 M. yr(-1), in excellent agreement with the extinction-corrected UV estimates. This provides an external check on the UV estimates of the star formation rates and on the use of X-ray luminosities to infer these rates in rapidly star-forming galaxies at high redshift. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. CALTECH, Palomar Observ, Pasadena, CA 91125 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. RP Nandra, K (reprint author), Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, Prince Consort Rd, London SW7 2BW, England. NR 98 TC 111 Z9 111 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2002 VL 576 IS 2 BP 625 EP 639 DI 10.1086/341888 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 590EF UT WOS:000177804800002 ER PT J AU Bonamente, M Lieu, R Joy, MK Nevalainen, JH AF Bonamente, M Lieu, R Joy, MK Nevalainen, JH TI The soft X-ray emission in a large sample of galaxy clusters with the ROSAT Position Sensitive Proportional Counter SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : general; X-rays : galaxies : clusters ID EXTREME-ULTRAVIOLET EMISSION; COOLING FLOWS; COMA-CLUSTER; OXYGEN ABSORPTION; TEMPERATURE STRUCTURE; INTRACLUSTER MEDIUM; INTERSTELLAR-MEDIUM; CROSS-SECTIONS; VIRGO CLUSTER; THIN PLASMAS AB The study of soft X-ray emission of 38 X-ray selected galaxy clusters observed by the ROSAT Position Sensitive Proportional Counter indicates that the soft excess phenomenon may be a common occurrence in galaxy clusters. Excess soft X-ray radiation, above the contribution from the hot intracluster medium, is evident in a large fraction of sources and is clearly detected with large statistical significance in the deepest observations. The investigation relies on new, high-resolution 21 cm H I observations. The sample selection also features analysis of infrared images to further ensure reliability of results with respect to the characteristics of Galactic absorption. The possibility of background or calibration effects as cause of the excess emission is likewise investigated; a detailed analysis of the distribution of the excess emission with respect to detector position and Galactic H I column density shows that the excess emission is a genuine celestial phenomenon. We find evidence for a preferential distribution of the soft excess emission at distances larger than similar to150-200 kpc from the centers of clusters; this behavior may be naturally explained in the context of a non-thermal inverse Compton scenario. Alternatively, we propose that the phenomenon may be caused by thermal emission of very large scale "warm" laments seen in recent hydrodynamic simulations. This new interpretation relieves the very demanding requirements of either the traditional intracluster "warm" gas and the nonthermal scenarios. We also investigate the possibility of the soft excess originating from unresolved, X-ray-faint cluster galaxies. C1 Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Bonamente, M (reprint author), Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. NR 88 TC 38 Z9 38 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2002 VL 576 IS 2 BP 688 EP 707 DI 10.1086/341806 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 590EF UT WOS:000177804800008 ER PT J AU Padoan, P Nordlund, A AF Padoan, P Nordlund, A TI The stellar initial mass function from turbulent fragmentation SO ASTROPHYSICAL JOURNAL LA English DT Review DE ISM : kinematics and dynamics; stars : formation; stars : luminosity function, mass function turbulence ID MOLECULAR CLOUD COMPLEXES; COSMIC GAS CLOUDS; STAR-FORMATION; BROWN DWARFS; DENSE CORES; DARK CLOUDS; INTERSTELLAR TURBULENCE; SUPERSONIC TURBULENCE; FRACTAL STRUCTURE; GRAVITATIONAL COLLAPSE AB The morphology and kinematics of molecular clouds (MCs) are best explained as the consequence of supersonic turbulence. Supersonic turbulence fragments MCs into dense sheets, laments, and cores and large low-density "voids", via the action of highly radiative shocks. We refer to this process as turbulent fragmentation. In this work we derive the mass distribution of gravitationally unstable cores generated by the process of turbulent fragmentation. The mass distribution above 1 M.. depends primarily on the power spectrum of the turbulent flow and on the jump conditions for isothermal shocks in a magnetized gas. For a power spectrum index beta = 1.74, consistent with Larson's velocity dispersion size relation as well as with new numerical and analytic results on supersonic turbulence, we obtain a power-law mass distribution of dense cores with a slope equal to 3/(4 - beta) = 1.33, consistent with the slope of the stellar initial mass function (IMF). Below 1 M., the mass distribution flattens and turns around at a fraction of 1 M., as observed for the stellar IMF in a number of stellar clusters, because only the densest cores are gravitationally unstable. The mass distribution at low masses is determined by the probability distribution of the gas density, which is known to be approximately lognormal for an isothermal turbulent gas. The intermittent nature of the turbulent density distribution is thus responsible for the existence of a significant number of small collapsing cores, even of substellar mass. Since turbulent fragmentation is unavoidable in supersonically turbulent molecular clouds, and given the success of the present model in predicting the observed shape of the stellar IMF, we conclude that turbulent fragmentation is essential to the origin of the stellar IMF. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Astron Observ, DK-2100 Copenhagen, Denmark. Theoret Astrophys Ctr, DK-2100 Copenhagen, Denmark. RP Padoan, P (reprint author), CALTECH, Jet Prop Lab, MS 169-506,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM padoan@ted.jpl.nasa.gov; aake@astro.ku.dk RI Nordlund, Aake/M-4528-2014; OI Nordlund, Aake/0000-0002-2219-0541; Padoan, Paolo/0000-0002-5055-5800 NR 127 TC 561 Z9 562 U1 0 U2 10 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2002 VL 576 IS 2 BP 870 EP 879 DI 10.1086/341790 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 590EF UT WOS:000177804800023 ER PT J AU Quintana, EV Lissauer, JJ Chambers, JE Duncan, MJ AF Quintana, EV Lissauer, JJ Chambers, JE Duncan, MJ TI Terrestrial planet formation in the alpha Centauri system SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : general; planetary systems : formation; planetary systems : protoplanetary disks ID BINARY STAR SYSTEMS; MASSIVE BODIES; PLANETESIMALS; STABILITY; EVOLUTION; GROWTH AB We examine the late stages of terrestrial planet formation around each star in the Centauri A and alphaCentauri B binary system. Each integration begins with a bimodal mass distribution of 14 large embryos embedded in a disk of smaller planetesimals orbiting one of the stars. These initial conditions were chosen because when they are used in simulations about a single star with giant planets, they lead to systems most closely resembling our solar system. However, it is far from certain that such a planetesimal distribution actually occurs either in single or binary star systems. We follow the evolution of the accreting bodies at various values of the inclination of the midplane of the disk relative to the binary orbit for 200 Myr to 1 Gyr. In simulations in which the midplane of the disk was inclined less than or equal to30degrees relative to the binary orbital plane, three to five terrestrial planets were formed around alpha Cen A. When the embryos in the disk were moving retrograde relative to the binary plane, four or five terrestrial planets formed. From two to five planets formed in a disk centered around alpha Cen B, with alpha Cen A perturbing the system in the same plane. The aforementioned resulting terrestrial planetary systems are quite similar to those produced by calculations of terrestrial planet growth in the Sun-Jupiter or Sun-Jupiter-Saturn systems. In contrast, terrestrial planet growth around a star lacking both stellar and giant planet companions is slower and extends to larger semimajor axis for the same initial disk of planetary embryos. In systems with the accreting disk initially inclined at degrees45 relative to the binary star orbit, two to five planets formed despite the fact that more than half of the disk mass was perturbed into the central star. When the disk was inclined at 60degrees to the binary plane, the stability of the planetary embryos decreased dramatically because of larger variations in eccentricity caused by the Kozai resonance, and almost all of the planetary embryos and planetesimals were lost from these systems. C1 NASA, Space Sci Div 245 3, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Queens Univ, Dept Phys, Kingston, ON K7L 3N6, Canada. RP Quintana, EV (reprint author), NASA, Space Sci Div 245 3, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 29 TC 65 Z9 65 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2002 VL 576 IS 2 BP 982 EP 996 DI 10.1086/341808 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 590EF UT WOS:000177804800034 ER PT J AU Sekanina, Z AF Sekanina, Z TI Runaway fragmentation of sungrazing comets observed with the Solar and Heliospheric Observatory SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets : general; methods : data analysis AB The observed clustering of the Solar and Heliospheric Observatory ( SOHO) sungrazing comets is a product of runaway fragmentation that occurs throughout their orbits about the Sun. Since the sungrazers in tight pairs occasionally appear simultaneously in the field of view of the SOHO coronagraphs, their offsets can be used to determine their separation parameters, including the time of their parent's breakup, by applying the author's standard model for split comets. The fragmentation mode of seven sungrazer pairs is shown to differ fundamentally from that of a SOHO non-Kreutz double comet. Further support for runaway fragmentation is provided by a statistically significant argument that employs an orbit-based search for pairs among the sungrazers. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sekanina, Z (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 6 TC 16 Z9 16 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2002 VL 576 IS 2 BP 1085 EP 1089 DI 10.1086/341801 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 590EF UT WOS:000177804800042 ER PT J AU Bernstein, MP Elsila, JE Dworkin, JP Sandford, SA Allamandola, LJ Zare, RN AF Bernstein, MP Elsila, JE Dworkin, JP Sandford, SA Allamandola, LJ Zare, RN TI Side group addition to the polycyclic aromatic hydrocarbon coronene by ultraviolet photolysis in cosmic ice analogs SO ASTROPHYSICAL JOURNAL LA English DT Article DE astrobiology; astrochemistry; ISM : molecules; meteors, meteoroids; molecular processes; ultraviolet : ISM ID INTERPLANETARY DUST PARTICLES; INSOLUBLE ORGANIC-MATTER; YOUNG STELLAR OBJECTS; MURCHISON METEORITE; INTERSTELLAR ICES; ASTROPHYSICAL IMPLICATIONS; MACROMOLECULAR MATERIAL; INFRARED-SPECTROSCOPY; DEUTERIUM ENRICHMENT; DENSE CLOUDS AB Ultraviolet photolysis of various coronene-ice mixtures at low temperature and pressure caused the addition of amino (-NH(2)), methyl (-CH(3)), methoxy (-OCH(3)), cyano/isocyano (-CN, -NC), and acid (-COOH) functional groups to the polycyclic aromatic hydrocarbon (PAH) coronene (C(24)H(12)), in addition to previously reported alcohol (-OH) and ketone ( >C=O) formation. This work represents the first experimental evidence that ice photochemistry may have contributed to the aromatics bearing carbon and nitrogen containing side groups that are detected in primitive meteorites and interplanetary dust particles. Furthermore, these results suggest that a wide range of modified PAHs should be expected in interstellar ices and materials that predated solar system formation. The implications of these results for interstellar and meteoritic chemistry are discussed. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. SETI Inst, Ctr Study Life Universe, Mountain View, CA 94043 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RP Bernstein, MP (reprint author), NASA, Ames Res Ctr, Mail Stop 245-6, Moffett Field, CA 94035 USA. EM mbernstein@mail.arc.nasa.gov RI Zare, Richard/A-8410-2009; Elsila, Jamie/C-9952-2012; Dworkin, Jason/C-9417-2012 OI Dworkin, Jason/0000-0002-3961-8997 NR 56 TC 66 Z9 66 U1 0 U2 16 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2002 VL 576 IS 2 BP 1115 EP 1120 DI 10.1086/341863 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 590EF UT WOS:000177804800046 ER PT J AU Beiersdorfer, P Behar, E Boyce, KR Brown, GV Chen, H Gendreau, KC Gu, MF Gygax, J Kahn, SM Kelley, RL Porter, FS Stahle, CK Szymkowiak, AE AF Beiersdorfer, P Behar, E Boyce, KR Brown, GV Chen, H Gendreau, KC Gu, MF Gygax, J Kahn, SM Kelley, RL Porter, FS Stahle, CK Szymkowiak, AE TI Laboratory measurements of the relative intensity of the 3s -> 2p and 3d -> 2p transitions in Fe XVII SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; stars : coronae; stars : individual (Capella, Procyon); Sun : X-rays, gamma rays; X-rays : general ID X-RAY-SPECTRA; ELECTRON-IMPACT EXCITATION; BEAM ION-TRAP; CROSS-SECTIONS; LINE EMISSION; SPECTROMETER; RESONANCE; REGION; MICROCALORIMETER; TRANSMISSION AB The intensity ratios of the 3s-->2p and 3d-->2p lines in Fe XVII were measured on the Livermore electron beam ion trap employing a complementary set of spectrometers, including a high-resolution crystal spectrometer and the Goddard 32 pixel calorimeter. The resulting laboratory data are in agreement with satellite measurements of the Sun and astrophysical sources in collisional equilibrium such as Capella, Procyon, and NGC 4636. The results disagree with earlier laboratory measurements and assertions that processes not accounted for in laboratory measurements must play a role in the formation of the Fe XVII spectra in solar and astrophysical plasmas. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. RP Beiersdorfer, P (reprint author), Lawrence Livermore Natl Lab, 7000 E Ave, Livermore, CA 94551 USA. RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012 OI Porter, Frederick/0000-0002-6374-1119; NR 36 TC 51 Z9 52 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2002 VL 576 IS 2 BP L169 EP L172 DI 10.1086/343785 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 590EG UT WOS:000177804900017 ER PT J AU Ehrenfreund, P Cami, J Jimenez-Vicente, J Foing, BH Kaper, L Van der Meer, A Cox, N AF Ehrenfreund, P Cami, J Jimenez-Vicente, J Foing, BH Kaper, L Van der Meer, A Cox, N TI Detection of diffuse interstellar bands in the Magellanic Clouds SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : ISM; ISM : lines and bands; ISM : molecules; Magellanic Clouds ID EXTINCTION; DUST; CARRIERS; GALAXIES; PROFILES; C-60(+); PAHS AB With the Ultraviolet Visual Echelle Spectrograph mounted at the Very Large Telescope, we have observed at unprecedented spectral resolution the absorption spectrum toward reddened stars in the Magellanic Clouds over the wavelength range of 3500-10500 Angstrom. This range covers the strong transitions associated with neutral and charged large carbon molecules of varying sizes and structures. We report the first detection of diffuse interstellar bands (DIBs) at 5780 and 5797 Angstrom in the Small Magellanic Cloud and the variation of the 6284 Angstrom DIB toward several targets in the Large Magellanic Cloud. The variation of DIBs in the Magellanic Clouds compared with Galactic targets may be governed by a combination of the different chemical processes prevailing in low-metallicity regions and the local environmental conditions. C1 Leiden Observ, NL-2300 RA Leiden, Netherlands. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. ESA, ESTEC SCISR, Res Support Div, NL-2200 AG Noordwijk, Netherlands. Inst Astrophys Spatiale, F-91405 Orsay, France. Univ Basel, Inst Phys Chem, CH-4053 Basel, Switzerland. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Univ Nottingham, Sch Chem, Nottingham NG7 2RD, England. Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RP Ehrenfreund, P (reprint author), Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands. RI Jimenez-Vicente, Jorge/K-1209-2014; OI Jimenez-Vicente, Jorge/0000-0001-7798-3453; Salama, Farid/0000-0002-6064-4401 NR 31 TC 46 Z9 47 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2002 VL 576 IS 2 BP L117 EP L120 DI 10.1086/343731 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 590EG UT WOS:000177804900005 ER PT J AU Ofman, L Aschwanden, MJ AF Ofman, L Aschwanden, MJ TI Damping time scaling of coronal loop oscillations deduced from Transition Region and Coronal Explorer observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun : corona; Sun : magnetic fields; waves ID ALFVEN WAVES; RESONANT ABSORPTION; MAGNETIC-FIELD AB The damping mechanism of recently discovered coronal loop transverse oscillations provides clues to the mechanism of coronal heating. We determine the scaling of the damping time with the parameters of the loops observed in extreme ultraviolet by the Transition Region and Coronal Explorer. We find excellent agreement of the scaling power to the power predicted by phase mixing and poor agreement with the power predicted by the wave leakage or ideal decay of the cylindrical kink mode mechanisms. Phase mixing leads to rapid dissipation of the Alfven waves due to the variation of the Alfven speed across the wave front and formation of small scales. Our results suggest that the loop oscillations are dissipated by phase mixing with anomalously high viscosity. C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Lockheed Martin Adv Technol Ctr, Solar & Astrophys Lab, Palo Alto, CA 94304 USA. RP Ofman, L (reprint author), Tel Aviv Univ, Dept Geophys, IL-69978 Tel Aviv, Israel. NR 19 TC 127 Z9 129 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2002 VL 576 IS 2 BP L153 EP L156 DI 10.1086/343886 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 590EG UT WOS:000177804900013 ER PT J AU Trombka, JI Schweitzer, J Selavka, C Dale, M Gahn, N Floyd, S Marie, J Hobson, M Zeosky, J Martin, K McClannahan, T Solomon, P Gottschang, E AF Trombka, JI Schweitzer, J Selavka, C Dale, M Gahn, N Floyd, S Marie, J Hobson, M Zeosky, J Martin, K McClannahan, T Solomon, P Gottschang, E TI Crime scene investigations using portable, non-destructive space exploration technology SO FORENSIC SCIENCE INTERNATIONAL LA English DT Article DE gunshot residue (GSR); X-ray fluorescence; blood; semen; remote sensing; teleforensics; database; portable instrument; barium (Ba); antimony (Sb); lead (Pb) ID RAY SPECTROMETER; X-RAY AB The National Institute of Justice (NIJ) and the National Aeronautics and Space Administration's (NASAs) Goddard Space Flight Center (GSFC) have teamed up to explore the use of NASA developed technologies to help criminal justice agencies and professionals solve crimes. The objective of the program is to produce instruments and communication networks that have application within both NASAs space program and NIJ programs with state and local forensic laboratories. A working group of NASA scientists and law enforcement professionals has been established to develop and implement a feasibility demonstration program. Specifically, the group has focused its efforts on identifying gunpowder and primer residue, blood, and semen at crime scenes. Non-destructive elemental composition identification methods are carried out using portable X-ray fluorescence (XRF) systems. These systems are similar to those being developed for planetary exploration programs. A breadboard model of a portable XRF system has been constructed for these tests using room temperature silicon and cadmium-zinc telluride (CZT) detectors. Preliminary tests have been completed with gunshot residue (GSR), blood-spatter and semen samples. Many of the element composition lines have been identified. Studies to determine the minimum detectable limits needed for the analyses of GSR, blood and semen in the crime scene environment have been initiated and preliminary results obtained. Furthermore, a database made up of the inorganic composition of GSR is being developed. Using data obtained from the open literature of the elemental composition of barium (Ba) and antimony (Sb) in handswipes of GSR, we believe that there may be a unique GSR signature based on the Sb to Ba ratio. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Lab Extraterr Phys, Greenbelt, MD 20771 USA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Massachuetts State Police Crime Lab, Sudbury, MA 01776 USA. New York State Police Forens Invest Ctr, Albany, NY 12226 USA. Milwaukee Cty Dist Attorneys Off, Milwaukee, WI 53233 USA. Wake Forest Univ, Dept Phys, Winston Salem, NC 27109 USA. George Washington Univ, Dept Forens Sci, Washington, DC 20052 USA. RP Trombka, JI (reprint author), NASA, Goddard Space Flight Ctr, Lab Extraterr Phys, Bldg 2,Rm S105,Code 691, Greenbelt, MD 20771 USA. NR 7 TC 26 Z9 27 U1 5 U2 22 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0379-0738 J9 FORENSIC SCI INT JI Forensic Sci.Int. PD SEP 10 PY 2002 VL 129 IS 1 BP 1 EP 9 AR PII S0379-0738(02)00079-8 DI 10.1016/S0379-0738(02)00079-8 PG 9 WC Medicine, Legal SC Legal Medicine GA 602QB UT WOS:000178515000001 PM 12230992 ER PT J AU Curtis, S AF Curtis, S TI Interannual variability of the bimodal distribution of summertime rainfall over Central America and tropical storm activity in the far-eastern Pacific SO CLIMATE RESEARCH LA English DT Article DE rainfall; tropical storms; summer; Central America; ENSO ID NORTH PACIFIC; PRECIPITATION; OSCILLATION; CLIMATOLOGY; PATTERNS; CYCLONES; MONSOON; MEXICO; ENSO AB The summer climate of southern Mexico and Central America is characterized by a midsummer drought (MSD), where rainfall is reduced by 40 % in July as compared to June and September. A mid-summer reduction in the climatological number of eastern Pacific tropical cyclones has also been noted. Little is understood about the climatology and interannual variability of these minima. The present study uses a novel approach to quantify the bimodal distribution of summertime rainfall for the globe and finds that this feature of the annual cycle is most extreme over Pan America and adjacent oceans, One dominant interannual. signal in this region occurs the summer before a strong winter El Nino/Southern Oscillation (ENSO). Before El Nino events the region is dry, the MSD is strong and centered over the ocean, and the mid-summer minimum in tropical cyclone frequency is most pronounced. This is significantly different from Neutral cases (non-El Nino and non-La Nina), when the MSD is weak and positioned over the land bridge. The MSD is highly variable for La Nina years, and there is not an obvious mid-summer minimum in the number of tropical cyclones. C1 Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, NASA, Dept Geog,Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Curtis, S (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, NASA, Dept Geog,Goddard Space Flight Ctr, Code 912, Greenbelt, MD 20771 USA. RI Curtis, Scott/C-1115-2013; OI Curtis, Scott/0000-0001-9065-8639 NR 17 TC 22 Z9 23 U1 0 U2 4 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0936-577X J9 CLIMATE RES JI Clim. Res. PD SEP 6 PY 2002 VL 22 IS 2 BP 141 EP 146 DI 10.3354/cr022141 PG 6 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 608EW UT WOS:000178833200004 ER PT J AU Huyse, L Padula, SL Lewis, RM Li, W AF Huyse, L Padula, SL Lewis, RM Li, W TI Probabilistic approach to free-form airfoil shape optimization under uncertainty SO AIAA JOURNAL LA English DT Article ID UNSTRUCTURED GRIDS; TURBULENT FLOWS; DESIGN AB Free-form shape optimization of airfoils to minimize drag directly poses unexpected difficulties. Practical experience has indicated that a deterministic optimization for discrete operating conditions can result in dramatically inferior performance when the actual operating conditions are different from the (somewhat arbitrarily selected) design conditions used during the optimization. Extensions from single-point to multipoint optimization have proven unable to remedy this problem of localized optimization adequately near the sampled operating conditions. An intrinsically statistical approach is presented, and how the shortcomings of traditional optimization methods can be overcome is demonstrated. We discuss two algorithms. The first one is based on a numerical evaluation of the expectation integral during each optimization step. The second one is based on a closed-form second-order analytic approximation of the integration. The airfoil geometry optimization example (inviscid Euler flow) also reveals how the relative likelihood of each of the operating conditions is automatically taken into consideration during the optimization process. This is a key advantage over the use of multipoint methods. C1 SW Res Inst, San Antonio, TX 78228 USA. NASA, Langley Res Ctr, Multidisciplinary Optimizat Branch, Hampton, VA 23681 USA. Coll William & Mary, Dept Math, Williamsburg, VA 23187 USA. Old Dominion Univ, Dept Math & Stat, Norfolk, VA 23529 USA. RP Huyse, L (reprint author), SW Res Inst, 6220 Culebra Rd, San Antonio, TX 78228 USA. NR 26 TC 43 Z9 45 U1 0 U2 5 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD SEP PY 2002 VL 40 IS 9 BP 1764 EP 1772 DI 10.2514/2.1881 PG 9 WC Engineering, Aerospace SC Engineering GA 590JW UT WOS:000177820600008 ER PT J AU Schairer, ET Mehta, RD Olsen, ME AF Schairer, ET Mehta, RD Olsen, ME TI Effects of pressure-sensitive paint on experimentally measured wing forces and pressures SO AIAA JOURNAL LA English DT Article ID ROUGHNESS AB Recent experiences with pressure-sensitive paint have shown that very thin paint layers on wind-tunnel models tested at high Reynolds numbers can significantly alter the pressure distributions, and thus the forces and moments, on the models. This was observed during two tests of transport-like wings: a "clean" supercritical wing at transonic cruise conditions in the NASA Ames High Reynolds Number Channel 2 and a high-lift wing, complete with slats and flaps, at landing conditions in the NASA Ames 12-Foot Pressure Wind Tunnel. The effect of paint on the cruise wing was to displace the shock wave slightly upstream from its no-paint position. Smoothing the paint, and even removing it entirely from the leading edge, decreased this displacement slightly. Applying paint to only the slats of the high-lift wing caused the wing to stall prematurely at the highest Reynolds number. This effect could be eliminated by smoothing the paint. Adding paint to other parts of the model had little effect. Paint intrusiveness was much smaller and more ambiguous at lower Reynolds numbers. In both tests, paint intrusiveness occurred because the model surfaces were rougher when they were painted than when they were not, and this additional roughness altered the development of the turbulent boundary layers. C1 NASA, Ames Res Ctr, Aeronaut Projects & Programs Off, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Numer Aerosp Simulat Syst Div, Moffett Field, CA 94035 USA. RP Schairer, ET (reprint author), NASA, Ames Res Ctr, Aeronaut Projects & Programs Off, MS 260-1, Moffett Field, CA 94035 USA. NR 39 TC 3 Z9 3 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD SEP PY 2002 VL 40 IS 9 BP 1830 EP 1838 DI 10.2514/2.1860 PG 9 WC Engineering, Aerospace SC Engineering GA 590JW UT WOS:000177820600016 ER PT J AU Canals, A Breen, AR Ofman, L Moran, PJ Fallows, RA AF Canals, A Breen, AR Ofman, L Moran, PJ Fallows, RA TI Estimating random transverse velocities in the fast solar wind from EISCAT Interplanetary Scintillation measurements SO ANNALES GEOPHYSICAE LA English DT Article; Proceedings Paper CT 10th International EISCAT Workshop CY JUL 23-27, 2001 CL TOKYO, JAPAN DE interplanetary physics; MHD waves and turbulence; solar wind plasma; instruments and techniques ID CORONAL HOLES; WAVE DISSIPATION; ACCELERATION; ULYSSES; CYCLE; MODEL; SUN; LATITUDE; DENSITY; REGIONS AB Interplanetary scintillation measurements can yield estimates of a large number of solar wind parameters, including bulk flow speed, variation in bulk velocity along the observing path through the solar wind and random variation in transverse velocity. This last parameter is of particular interest, as it can indicate the flux of low-frequency Alfven waves, and the dissipation of these waves has been proposed as an acceleration mechanism for the fast solar wind. Analysis of IPS data is, however, a significantly unresolved problem and a variety of a priori assumptions must be made in interpreting the data. Furthermore, the results may be affected by the physical structure of the radio source and by variations in the solar wind along the scintillation ray path. We have used observations of simple point-like radio sources made with EISCAT between 1994 and 1998 to obtain estimates of random transverse velocity in the fast solar wind. The results obtained with various a priori assumptions made in the analysis are compared, and we hope thereby to be able to provide some indication of the reliability of our estimates of random transverse velocity and the variation of this parameter with distance from the Sun. C1 Univ Wales, Dept Phys, Aberystwyth, Dyfed, Wales. Catholic Univ Amer, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Breen, AR (reprint author), Univ Wales, Dept Phys, Aberystwyth, Dyfed, Wales. NR 53 TC 24 Z9 25 U1 0 U2 0 PU EUROPEAN GEOPHYSICAL SOC PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 0992-7689 J9 ANN GEOPHYS-GERMANY JI Ann. Geophys. PD SEP PY 2002 VL 20 IS 9 BP 1265 EP 1277 PG 13 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 608TN UT WOS:000178862900003 ER PT J AU Sugino, M Fujii, R Nozawa, S Nagatsuma, T Buchert, SC Gjerloev, JW Kosch, MJ AF Sugino, M Fujii, R Nozawa, S Nagatsuma, T Buchert, SC Gjerloev, JW Kosch, MJ TI Field-aligned currents and ionospheric parameters deduced from EISCAT radar measurements in the post-midnight sector SO ANNALES GEOPHYSICAE LA English DT Article; Proceedings Paper CT 10th International EISCAT Workshop CY JUL 23-27, 2001 CL TOKYO, JAPAN DE ionosphere; auroral ionosphere; electric fields and currents; particle precipitation ID ELECTRIC-FIELDS; AURORAL ARC; HARANG-DISCONTINUITY; POLAR IONOSPHERE; NEUTRAL WIND; ENERGY FLUX; PLASMA; CONDUCTANCES; CONDUCTIVITY; REGIONS AB Attempting to derive the field-aligned current (FAC) density using the EISCAT radar and to understand the role of the ionosphere on closing FACs, we conducted special radar experiments with the EISCAT radar on 9 October 1999. In order to derive the gradient of the ionospheric conductivity (grad Sigma) and the divergence of the electric field (div E) nearly simultaneously, a special experiment employed an EISCAT radar mode which let the transmitting antenna sequentially point to four directions within 10 min; two pairs of the four directions formed two orthogonal diagonals of a square. Our analysis of the EISCAT radar data disclosed that Sigma(P) div E and E (.) grad Sigma(P) produced FACs with the same direction inside a stable broad arc around 05:00MLT, when the EISCAT radar presumably crossed the boundary between the large-scale upward and downward current regions. In the most successfully observed case, in which the conductances and the electric field were spatially varying with little temporal variations, the contribution of Sigma(P) div E was nearly twice as large as that of E (.) grad Sigma(P). On the other hand, the contribution of (b x E) - grad EH was small and not effective in closing FACs. The present EISCAT radar mode along with auroral images also enables us to focus on the temporal or spatial variation of high electric fields associated with auroral arcs. In the present experiment, the electric field associated with a stable arc was confined in a spatially restricted region, within similar to100km from the arc, with no distinct depletion of electron density. We also detected a region of the high are associated electric field, accompanied by the depletion of electron density above 110 km. Using auroral images, this region was identified as a dark spot with a spatial scale of over 150 x 150 km. The dark spot and the electron depletion were likely in existence for a limited time of a few minutes. C1 Nagoya Univ, Solar Terr Environm Lab, Chikusa Ku, Nagoya, Aichi 4648601, Japan. Commun Res Labs, Tokyo 1848795, Japan. Swedish Inst Space Phys, Uppsala Div, S-75121 Uppsala, Sweden. NASA, Goddard Space Flight Ctr, Natl Res Council, Greenbelt, MD 20771 USA. Univ Lancaster, Dept Commun Syst, Lancaster LA1 4YR, England. RP Sugino, M (reprint author), Nagoya Univ, Solar Terr Environm Lab, Chikusa Ku, Nagoya, Aichi 4648601, Japan. OI Nagatsuma, Tsutomu/0000-0002-9334-0738 NR 50 TC 0 Z9 0 U1 1 U2 1 PU EUROPEAN GEOPHYSICAL SOC PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 0992-7689 J9 ANN GEOPHYS-GERMANY JI Ann. Geophys. PD SEP PY 2002 VL 20 IS 9 BP 1335 EP 1348 PG 14 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 608TN UT WOS:000178862900008 ER PT J AU Gibson, JAE Andersen, DT AF Gibson, JAE Andersen, DT TI Physical structure of epishelf lakes of the southern Bunger Hills, East Antarctica SO ANTARCTIC SCIENCE LA English DT Article DE Bunger Hills; climate change; epishelf; stratification; salinity; temperature ID OASIS; ICE; WATER; THICKNESS; CLIMATE AB Epishelf lakes, positioned between ice-free areas and floating ice shelves or glaciers, are unusual tidal, but largely freshwater, environments found in both the Arctic and the Antarctic. The greatest concentration of these lakes is in the Bunger Hills, East Antarctica (66degreesS, 100degreesE). We present and discuss temperature and salinity profiles for five epishelf lakes from this region, most of which show unusual properties. White Smoke Lake is fresh and cold (<0.1degreesC) throughout; Lake Pol'anskogo has two basins, one fresh and cold, the other saline and warm; 'Southern' Lake is cold and saline at depth; Transkriptsii Gulf has a deep, warm saline layer; and 'Northern' Lake is relatively warm throughout. The structures of these lakes can be explained in terms of a simple model in which the isolated saline water evident in three of the lakes entered the basins through the connection to the marine waters during periods of reduced freshwater input. By dating these marine incursions, periods of reduced melt, presumably due to colder temperatures, can be determined. C1 Australian Antarctic Div, Kingston, Tas 7050, Australia. NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. RP Gibson, JAE (reprint author), CSIRO, GPO Box 1538, Hobart, Tas 7001, Australia. NR 39 TC 20 Z9 21 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4221 USA SN 0954-1020 J9 ANTARCT SCI JI Antarct. Sci. PD SEP PY 2002 VL 14 IS 3 BP 253 EP 261 DI 10.1017/S09541020020000100 PG 9 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA 647KW UT WOS:000181092800008 ER PT J AU Larruquert, JI Keski-Kuha, RAM AF Larruquert, JI Keski-Kuha, RAM TI Sub-quarter-wave multilayer coatings with high reflectance in the extreme ultraviolet SO APPLIED OPTICS LA English DT Article ID VACUUM-ULTRAVIOLET; ABSORBING MATERIALS; OPTICAL-PROPERTIES; CARBIDE COATINGS; THIN-FILMS; ENHANCEMENT; CONSTANTS; NM AB Multilayer coatings with a small number of layers were designed and prepared to provide an increase in normal-incidence reflectance in the extreme ultraviolet compared with the reflectance of available single-layer coatings, namely, SiC, B4C, and Ir. Multilayers were designed to produce coatings with the highest possible reflectance at 91.2 and at 58.4 nm. At these wavelengths all the materials absorb radiation strongly, but still a reflectance enhancement can be obtained by means of sub-quarter-wave multilayer coatings with two or more different materials. Sub-quarter-wave multilayer coatings based on Al, MgF2, diamondUe carbon, B4C, SiC, and Ir showed higher reflectance than single-layer coatings of SiC and B4C not only at the target wavelength but in a wide band ranging from 50 nm to the 121.6-nm H Lyrnan-alpha line. Multilayer coatings suffered some reflectance degradation over time. However, after approximately 80-100 days of aging in a desiccator, the reflectance for the multilayer coatings was greater than for the single-layer coatings. (C) 2002 Optical Society of America. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Larruquert, JI (reprint author), Inst Fis Aplicada, Consejo Super Invest Cient, Madrid 28006, Spain. EM larruquert@io.csic.es OI Larruquert, Juan/0000-0001-6356-9702 NR 24 TC 19 Z9 20 U1 0 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 1 PY 2002 VL 41 IS 25 BP 5398 EP 5404 DI 10.1364/AO.41.005398 PG 7 WC Optics SC Optics GA 588JR UT WOS:000177698800027 PM 12211570 ER PT J AU Okajima, T Tamura, K Ogasaka, Y Haga, K Takahashi, S Ichimaru, S Kito, H Fukuda, S Goto, A Nomoto, K Satake, H Kato, S Kamata, Y Furuzawa, A Akimoto, F Yoshioka, T Kondo, K Haba, Y Tanaka, T Wada, K Hamada, N Hudaverdi, M Tawara, Y Yamashita, K Serlemitsos, PJ Soong, Y Chan, KW Owens, SM Berendse, FB Tueller, J Misaki, K Shibata, R Mori, H Itoh, K Kunieda, H Namba, Y AF Okajima, T Tamura, K Ogasaka, Y Haga, K Takahashi, S Ichimaru, S Kito, H Fukuda, S Goto, A Nomoto, K Satake, H Kato, S Kamata, Y Furuzawa, A Akimoto, F Yoshioka, T Kondo, K Haba, Y Tanaka, T Wada, K Hamada, N Hudaverdi, M Tawara, Y Yamashita, K Serlemitsos, PJ Soong, Y Chan, KW Owens, SM Berendse, FB Tueller, J Misaki, K Shibata, R Mori, H Itoh, K Kunieda, H Namba, Y TI Characterization of the supermirror hard-x-ray telescope for the InFOC mu S balloon experiment SO APPLIED OPTICS LA English DT Article ID MULTILAYER SUPERMIRROR; FABRICATION; MIRRORS AB A hard-x-ray telescope is successfully produced for balloon observations by making use of depth-graded multilayers, or so-called supermirrors, with platinum-carbon (Pt/C) layer pairs. It consists of four quadrant units assembled in an optical configuration with a diameter of 40 cm and a focal length of 8 m. Each quadrant is made of 510 pieces of coaxially and confocally aligned supermirrors that significantly enhance the sensitivity in an energy range of 20-40 keV. The configuration of the telescope is similar to the x-ray telescope onboard Astro-E, but with a longer focal length. The reflectivity of supermirrors is of the order of 40% in the energy range concerned at a grazing angle of 0.2 deg. The effective area of a fully assembled telescope is 50 cm(2) at 30 keV. The angular resolution is 2.37 are min at half-power diameter 8.0 keV. The field of view is 12.6 arc min in the hard-x-ray region, depending somewhat on x-ray energies. We discuss these characteristics, taking into account the figure errors of reflectors and their optical alignment in the telescope assembly. This hard-x-ray telescope is unanimously afforded in the International Focusing Optics Collaboration for muCrab Sensitivity balloon experiment. 0 2002 Optical Society of America. C1 Nagoya Univ, Dept Phys, Nagoya, Aichi 4648602, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. Chubu Univ, Dept Mech Engn, Kasugai, Aichi 487, Japan. RP Nagoya Univ, Dept Phys, Nagoya, Aichi 4648602, Japan. EM okajima@u.phys.nagoya-u.ac.jp RI Tueller, Jack/D-5334-2012 NR 21 TC 29 Z9 29 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 1 PY 2002 VL 41 IS 25 BP 5417 EP 5426 DI 10.1364/AO.41.005417 PG 10 WC Optics SC Optics GA 588JR UT WOS:000177698800030 PM 12211573 ER PT J AU Adams, JD Stauffer, JR Skrutskie, MF Monet, DG Portegies Zwart, S Janes, KA Beichman, CA AF Adams, JD Stauffer, JR Skrutskie, MF Monet, DG Portegies Zwart, S Janes, KA Beichman, CA TI Structure of the Praesepe star cluster SO ASTRONOMICAL JOURNAL LA English DT Article DE astrometry; open clusters and associations : individual (Praesepe); stars : activity; stars : low-mass, brown dwarfs ID LOW-MASS STARS; PROPER MOTION MEMBERSHIP; MAIN-SEQUENCE; FAINT MEMBERS; BROWN DWARFS; PLEIADES; HYADES; EVOLUTION; SEARCH; 2MASS AB We have used the Two Micron All Sky Survey and Palomar Observatory Sky Survey photographic plates, digitized by the US Naval Observatory's Precision Measuring Machine program, to derive proper motions over a 100 square degree, spatially complete region centered on the Praesepe open cluster. Proper-motion measurements spanned the magnitude range R similar to 12-19, which covers most of the lower main sequence in Praesepe. The incidence of H emission from moderate-resolution (similar to2600), red spectroscopy of 434 faint candidate members and 126 field control stars demonstrates that similar to60%-80% of candidates within 2degrees of the cluster center are genuine Praesepe members. Spectral index ratios from TiO and CaH absorption features show a well-defined sequence with J magnitude for high-probability candidates, relative to that of field stars. The inferred membership data have allowed us to estimate Praesepe's mass function and general projected structure for stars with mass 0.1-1.0 M-circle dot. The mass function, when fitted with a power law of the form dN/dm alpha m(-alpha), rises ( alpha approximate to 1.6) from 1.0 to 0. 4 M-circle dot, where it distinctly becomes at (alpha approximate to 0) down to 0.1 M-circle dot. The mass function also exhibits a marginal ( 1) radial dependence, which, when compared with recent N-body simulations, suggests that the core is depleted of low-mass stars. The outer halo of Praesepe is diffuse and shows a slightly elliptical shape among the highest probability members. We place an upper limit on the surface density of escaped members at 2.2 stars deg(-2) outside the limiting radius. C1 Boston Univ, Inst Astrophys Res, Boston, MA 02215 USA. CALTECH, SIRTF Sci Ctr, Pasadena, CA 91125 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Sect Computat Sci, NL-1098 SJ Amsterdam, Netherlands. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Adams, JD (reprint author), Boston Univ, Inst Astrophys Res, 725 Commonwealth Ave, Boston, MA 02215 USA. EM jdadams@bu.edu; stauffer@ipac.caltech.edu; mfs4n@virginia.edu; dgm@nofs.navy.mil; spz@science.uva.nl; janes@hyades.bu.edu; chas@pop.jpl.nasa.gov NR 59 TC 41 Z9 43 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD SEP PY 2002 VL 124 IS 3 BP 1570 EP 1584 DI 10.1086/342016 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 586ND UT WOS:000177589300021 ER PT J AU van Belle, GT Thompson, RR Creech-Eakman, MJ AF van Belle, GT Thompson, RR Creech-Eakman, MJ TI Angular size measurements of Mira variable stars at 2.2 microns. II. SO ASTRONOMICAL JOURNAL LA English DT Article DE infrared radiation; Miras; stars : fundamental parameters; stars : late-type; techniques : interferometric ID ECLIPSING BINARY HV-2274; CIRCUMSTELLAR DUST SHELLS; LARGE-MAGELLANIC-CLOUD; EFFECTIVE TEMPERATURES; R-LEONIS; IOTA INTERFEROMETER; PULSATION MODES; TIME-SERIES; MASS-LOSS; DIAMETER AB We present angular size measurements of 22 oxygen-rich Mira variable stars. These data are part of a long-term observational program using the Infrared Optical Telescope Array to characterize the observable behavior of these stars. Complementing the infrared angular size measurements, values for variable star phase, spectral type, bolometric flux, and distance were established for stars in the sample; flux and distance led to values for effective temperature (Te-ff) and linear radius, respectively. Additionally, values for the K-[12] color excess were established for these stars, which is indicative of dusty mass loss. Stars with higher color excess are shown to be systematically 120 R. larger than their low color excess counterparts, regardless of period. This analysis appears to present a solution to a long-standing question presented by the evidence that some Mira angular diameters are indicative of first-overtone pulsation, while other diameters are more consistent with fundamental pulsation. A simple examination of the resultant sizes of these stars in the context of pulsation mode is consistent with at least some of these objects pulsating in the fundamental mode. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP van Belle, GT (reprint author), CALTECH, Jet Prop Lab, MS 171-113,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 78 TC 36 Z9 36 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2002 VL 124 IS 3 BP 1706 EP 1715 DI 10.1086/342282 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 586ND UT WOS:000177589300030 ER PT J AU Grimani, C Stephens, SA Cafagna, FS Basini, G Bellotti, R Brunetti, MT Circella, M Codino, A De Marzo, C De Pascale, MP Finetti, N Golden, RL Hof, M Menn, W Mitchell, JW Morselli, A Ormes, JF Papini, P Pfeifer, C Piccardi, S Picozza, P Ricci, M Simon, M Spillantini, P Stochaj, SJ Streitmatter, RE AF Grimani, C Stephens, SA Cafagna, FS Basini, G Bellotti, R Brunetti, MT Circella, M Codino, A De Marzo, C De Pascale, MP Finetti, N Golden, RL Hof, M Menn, W Mitchell, JW Morselli, A Ormes, JF Papini, P Pfeifer, C Piccardi, S Picozza, P Ricci, M Simon, M Spillantini, P Stochaj, SJ Streitmatter, RE TI Measurements of the absolute energy spectra of cosmic-ray positrons and electrons above 7 GeV SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ISM : cosmic rays ID SPECTROMETER; CALORIMETER; PERFORMANCE; RADIATION AB A measurement of the energy spectra of cosmic-ray positrons and electrons was made with a balloon-borne magnet-spectrometer, which was flown at a mean geomagnetic cut-off of 4.5 GV/c. The observed positron flux in the energy range 7-16 GeV is approximately an order of magnitude lower than that of electrons, as measured in other experiments at various energies. The power law spectral index of the observed differential energy spectrum of electrons is -2.89 +/- 0.10 in the energy interval 7.5-47 GeV. For positrons the overall fit of the available data above 7 GeV has been considered. The spectral index is found to be 3.37 +/- 0.26 and the fraction of positrons, e(+) /(e(+) +e(-)) has a mean value of 0.064 +/- 0.003. The world data on e(+) /(e(+) +e(-)) from 0.1 to 30 GeV indicate that a plerion type electron spectrum is preferred over the other types. The trend of the presently existing high energy data also suggests a possible contribution of positrons produced at the pulsar polar cap. High resolution experiments capable of identifying positrons at least up to 100 GeV with high statistics are required to pinpoint the origin of both electrons and positrons in the cosmic radiation. C1 Ist Nazl Fis Nucl, I-06100 Perugia, Italy. Univ Perugia, Dipartimento Fis, I-06100 Perugia, Italy. Ist Nazl Fis Nucl, I-70126 Bari, Italy. Univ Bari, Dipartimento Fis, I-70126 Bari, Italy. Ist Nazl Fis Nucl, I-00133 Rome, Italy. Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy. New Mexico State Univ, Particle Astrophys Lab, Las Cruces, NM 88003 USA. Univ Gesamthsch Siegen, D-57068 Siegen, Germany. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Ist Nazl Fis Nucl, I-50125 Florence, Italy. Univ Florence, Dipartimento Fis, I-50125 Florence, Italy. RP Grimani, C (reprint author), Univ Urbino, Via S Chiara, I-61029 Urbino, Italy. RI Morselli, Aldo/G-6769-2011; Cafagna, Francesco/A-9299-2010; OI Morselli, Aldo/0000-0002-7704-9553; Cafagna, Francesco/0000-0002-7450-4784; Bellotti, Roberto/0000-0003-3198-2708; Picozza, Piergiorgio/0000-0002-7986-3321; Papini, Paolo/0000-0003-4718-2895 NR 34 TC 86 Z9 87 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2002 VL 392 IS 1 BP 287 EP 294 DI 10.1051/0004-6361:20020845 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 591FH UT WOS:000177868700028 ER PT J AU Pian, E Falomo, R Hartman, RC Maraschi, L Tavecchio, F Tornikoski, M Treves, A Urry, CM Ballo, L Mukherjee, R Scarpa, R Thompson, DJ Pesce, JE AF Pian, E Falomo, R Hartman, RC Maraschi, L Tavecchio, F Tornikoski, M Treves, A Urry, CM Ballo, L Mukherjee, R Scarpa, R Thompson, DJ Pesce, JE TI Broad-band continuum and line emission of the gamma-ray blazar PKS 0537-441 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : active; BL Lacertae objects : individual : PKS 0537-441; ultraviolet : galaxies; X-ray : galaxies; gamma rays : observations ID BL LAC OBJECTS; SPECTRAL ENERGY-DISTRIBUTIONS; ACTIVE GALACTIC NUCLEI; EGRET OBSERVATIONS; RADIO-SOURCES; MULTIFREQUENCY OBSERVATIONS; INTRADAY VARIABILITY; INFRARED-EMISSION; LACERTAE OBJECTS; ULTRAVIOLET AB PKS 0537-441, a bright gamma-ray emitting blazar, was observed at radio, optical, UV and X-ray frequencies during various EGRET pointings, often quasi-simultaneously. In 1995 the object was found in an intense emission state at all wavelengths. BeppoSAX observations made in 1998, non-simultaneously with exposures at other frequencies, allow us to characterize precisely the spectral shape of the high energy blazar component, which we attribute to inverse Compton scattering. The optical-to-gamma-ray spectral energy distributions at the different epochs show that the gamma-ray luminosity dominates the bolometric output. This, together with the presence of optical and UV line emission, suggests that, besides the synchrotron self-Compton mechanism, the Compton upscattering of photons external to the jet (e.g., in the broad line region) may have a significant role in the production of high energy radiation. The multiwavelength variability can be reproduced by changes of the plasma bulk Lorentz factor. The spectrum secured by IUE in 1995 appears to be partially absorbed shortward of similar to1700 Angstrom. However, this signature is not detected in the HST spectrum taken during a lower state of the source. The presence of intervening absorbers is not supported by optical imaging and spectroscopy of the field. C1 Osserv Astron Trieste, I-34131 Trieste, Italy. Osserv Astron Padova, I-35122 Padua, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Osserv Astron Brera, I-20121 Milan, Italy. Metsahovi Radio Observ, Kylmala 02540, Finland. Univ Insubria, Dipartimento Sci, I-22100 Como, Italy. Yale Univ, Dept Phys, New Haven, CT 06520 USA. Columbia Univ Barnard Coll, Dept Phys & Astron, New York, NY 10027 USA. European So Observ, Santiago 19, Chile. George Mason Univ, Fairfax, VA 22030 USA. Eureka Sci, Fairfax, VA 22030 USA. RP Pian, E (reprint author), Osserv Astron Trieste, Via GB Tiepolo 11, I-34131 Trieste, Italy. RI Thompson, David/D-2939-2012; Urry, Claudia/G-7381-2011; OI Thompson, David/0000-0001-5217-9135; Urry, Claudia/0000-0002-0745-9792; Ballo, Lucia/0000-0002-5036-3497; Falomo, Renato/0000-0003-4137-6541; Pian, Elena/0000-0001-8646-4858 NR 82 TC 29 Z9 29 U1 0 U2 2 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2002 VL 392 IS 2 BP 407 EP 415 DI 10.1051/0004-6361:20020881 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 593PJ UT WOS:000178001100004 ER PT J AU Veronig, A Vrsnak, B Dennis, BR Temmer, M Hanslmeier, A Magdalenic, J AF Veronig, A Vrsnak, B Dennis, BR Temmer, M Hanslmeier, A Magdalenic, J TI Investigation of the Neupert effect in solar flares - I. Statistical properties and the evaporation model SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE Sun : flares; Sun : X-rays, gamma rays; Sun : corona; Sun : chromosphere; methods : statistical ID X-RAY-BURSTS; MAGNETIC RECONNECTION MODEL; CHROMOSPHERIC EVAPORATION; EMISSION MEASURE; MAGNETOHYDRODYNAMIC SIMULATION; TEMPERATURE; ENERGETICS; PARAMETERS; ELECTRONS; DYNAMICS AB Based on a sample of 1114 flares observed simultaneously in hard X-rays (HXR) by the BATSE instrument and in soft X-rays (SXR) by GOES, we studied several aspects of the Neupert effect and its interpretation in the frame of the electron-beam-driven evaporation model. In particular, we investigated the time differences (Deltat) between the maximum of the SXR emission and the end of the HXR emission, which are expected to occur at almost the same time. Furthermore, we performed a detailed analysis of the SXR peak flux - HXR fluence relationship for the complete set of events, as well as separately for subsets of events which are likely compatible/incompatible with the timing expectations of the Neupert effect. The distribution of the time differences reveals a pronounced peak at Deltat = 0. About half of the events show a timing behavior which can be considered to be consistent with the expectations from the Neupert effect. For these events, a high correlation between the SXR peak flux and the HXR fluence is obtained, indicative of electron-beam-driven evaporation. However, there is also a significant fraction of flares (about one fourth), which show strong deviations from Deltat = 0, with a prolonged increase of the SXR emission distinctly beyond the end of the HXR emission. These results suggest that electron-beam-driven evaporation plays an important role in solar flares. Yet, in a significant fraction of events, there is also clear evidence for the presence of an additional energy transport mechanism other than nonthermal electron beams, where the relative contribution is found to vary with the flare importance. C1 Graz Univ, Inst Geophys Astrophys & Meteorol, A-8010 Graz, Austria. Univ Zagreb, Fac Geodesy, Hvar Observ, HR-10000 Zagreb, Croatia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Veronig, A (reprint author), Graz Univ, Inst Geophys Astrophys & Meteorol, Univ Pl 5, A-8010 Graz, Austria. RI Dennis, Brian/C-9511-2012; Veronig, Astrid/B-8422-2009; OI Temmer, Manuela/0000-0003-4867-7558 NR 47 TC 78 Z9 80 U1 1 U2 3 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2002 VL 392 IS 2 BP 699 EP 712 DI 10.1051/0004-6361:20020947 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 593PJ UT WOS:000178001100029 ER PT J AU Horvath, I AF Horvath, I TI A further study of the BATSE gamma-ray burst duration distribution SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma rays : bursts, theory, observations; methods : data analysis, observational, statistical ID ANGULAR-DISTRIBUTION; ANISOTROPY AB Two classes of gamma-ray bursts have been identified so far, characterized by durations shorter and longer than about 2 s. In 1998 two independent papers indicated the existence of the third class of the bursts with duration between approximately 2 and 10 s. In this paper, using the full BATSE Catalog, the maximum likelihood estimation is presented, which gives a 0.5% probability for having only two subclasses. A Monte-Carlo simulation also confirms this probability. C1 Bolyai Mil Univ, Dept Phys, H-1456 Budapest, Hungary. RP Horvath, I (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 17 TC 72 Z9 74 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2002 VL 392 IS 3 BP 791 EP 793 DI 10.1051/0004-6361:20020808 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 594MM UT WOS:000178054400003 ER PT J AU Tzioumis, A King, E Morganti, R Dallacasa, D Tadhunter, C Fanti, C Reynolds, J Jauncey, D Preston, R McCulloch, P Tingay, S Edwards, P Costa, M Jones, D Lovell, J Clay, R Meier, D Murphy, D Gough, R Ferris, R White, G Jones, P AF Tzioumis, A King, E Morganti, R Dallacasa, D Tadhunter, C Fanti, C Reynolds, J Jauncey, D Preston, R McCulloch, P Tingay, S Edwards, P Costa, M Jones, D Lovell, J Clay, R Meier, D Murphy, D Gough, R Ferris, R White, G Jones, P TI A sample of southern Compact Steep Spectrum radio sources: The VLBI observations SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : active; radio continuum : general ID GIGAHERTZ PEAKED-SPECTRUM; GALAXIES; IMAGES; YOUNG; GHZ AB A small sample of 7 southern Compact Steep Spectrum (CSS) radio sources has been selected as part of the study of a larger flux-limited complete sample of radio sources. High resolution images, using the VLBI network in the southern hemisphere and the high resolution MERLIN array, are presented for all sources in the CSS sample. The overall morphology of each source consists of well-defined double lobes but with substantial diffuse and extended components present. In the majority of cases only a fraction of the total flux density is detected on the VLBI baselines, indicating the presence of larger extended radio structures. However, all sources are unresolved at arcsecond scales and are of sub-galactic size, with linear size in the range 0.1-2 kpc. The radio properties of the sources agree well with CSS sources in other samples. C1 CSIRO, Australia Telescope Natl Facil, Epping, NSW 2121, Australia. CNR, Ist Radioastron, I-40129 Bologna, Italy. Netherlands Fdn Res Astron, NL-7990 AA Dwingeloo, Netherlands. Univ Sheffield, Dept Phys, Sheffield S10 2TN, S Yorkshire, England. CALTECH, Jet Prop Lab, Pasadena, CA USA. Univ Tasmania, Hobart, Tas, Australia. Univ Adelaide, Adelaide, SA, Australia. Univ Western Sydney, Kingswood, NSW, Australia. Univ Bologna, Dept Astron, I-40127 Bologna, Italy. Univ Bologna, Dept Phys, I-40126 Bologna, Italy. CSIRO, EOC, COSSA, Canberra, ACT, Australia. ISAS, Kanagawa, Japan. RP Tzioumis, A (reprint author), CSIRO, Australia Telescope Natl Facil, Epping, NSW 2121, Australia. RI King, Edward/A-1473-2012; Tingay, Steven/B-5271-2013 OI King, Edward/0000-0002-6898-2130; NR 43 TC 30 Z9 30 U1 0 U2 2 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2002 VL 392 IS 3 BP 841 EP 850 DI 10.1051/0004-6361:20020964 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 594MM UT WOS:000178054400008 ER PT J AU Sakelliou, I Peterson, JR Tamura, T Paerels, FBS Kaastra, JS Belsole, E Bohringer, H Branduardi-Raymont, G Ferrigno, C den Herder, JW Kennea, J Mushotzky, RF Vestrand, WT Worrall, DM AF Sakelliou, I Peterson, JR Tamura, T Paerels, FBS Kaastra, JS Belsole, E Bohringer, H Branduardi-Raymont, G Ferrigno, C den Herder, JW Kennea, J Mushotzky, RF Vestrand, WT Worrall, DM TI High resolution soft X-ray spectroscopy of M 87 with the reflection grating spectrometers on XMM-Newton SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : clusters : general; galaxies : clusters : individual : virgo; galaxies : individual : M 87; galaxies : cooling flows; galaxies : abundances; X-rays : galaxies ID EARLY-TYPE GALAXIES; COOLING FLOWS; ELLIPTIC GALAXIES; VIRGO CLUSTER; HOT GAS; M87; HALO; ABUNDANCES; METALLICITY; MULTIPHASE AB We present high-resolution X-ray spectroscopic observations of M 87 with the Reflection Grating Spectrometers on XMM-Newton. We detect strong K-shell line emission from N, O, Ne, Mg, some emission from He-like Si, a fully resolved set of Fe L-shell emission spectra, and some emission from C. The angular intensity distributions of the strong emission lines are detectably resolved on scales (15-160)". The gas in the inner arcmin of M 87 has a multi-phase structure, as indicated by the similarity of the emission line profiles of Fe L shell ions with widely separated ionization potentials. The global Fe L spectrum is approximately consistent with an isothermal plasma at kT(e) similar to 1.8 keV, in addition to a component with a temperature distribution appropriate to an isobaric cooling flow, but with a minimum temperature cutoff of kT(min) approximate to 600 eV. The behaviour of this cooling-flow component is qualitatively similar to what is seen in other cooling flow clusters. Finally, we do not find any strong evidence for a spatial variation in abundances due to resonance scattering redistribution in the inner arcminute of the core. C1 Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. SRON, Natl Inst Space Res, NL-3584 CA Utrecht, Netherlands. CEA Saclay, Serv Astrophys, F-91191 Gif Sur Yvette, France. Max Planck Inst Extraterr Phys, D-37075 Garching, Germany. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Bristol, Dept Phys, Bristol BS8 1TL, Avon, England. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. RP Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England. EM irini@star.sr.bham.ac.uk RI Ferrigno, Carlo/H-4139-2012; Tamura, Takayuki/K-8236-2012 NR 41 TC 54 Z9 54 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2002 VL 391 IS 3 BP 903 EP 909 DI 10.1051/0004-6361:20020900 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 586NR UT WOS:000177590500010 ER PT J AU Sutaria, FK Kolb, U Charles, P Osborne, JP Kuulkers, E Casares, J Harlaftis, ET Shahbaz, T Still, M Wheatley, P AF Sutaria, FK Kolb, U Charles, P Osborne, JP Kuulkers, E Casares, J Harlaftis, ET Shahbaz, T Still, M Wheatley, P TI XMM-Newton detection of Nova Muscae 1991 in quiescence SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE X-rays : binaries; X-rays : individuals : GU Mus; black hole physics; accretion, accretion disks ID X-RAY TRANSIENT; BLACK-HOLE; SPECTRAL EVOLUTION; NOVA-MUSCAE-1991; PARAMETERS; RATIO; GINGA AB The soft X-ray transient GU Mus has been detected by XMM-Newton in the quiescent state. The source is very faint, with a 0.5-10.0 keV unabsorbed flux of similar or equal to 1.1 x 10(14) ergs cm(-2) s(-1). The spectra is well fit by an absorbed powerlaw with a photon index of alpha = 1.6 +/- 0.4, close to the value seen when the source was in the low/hard state in Aug. 1991. From our observed luminosity, it seems unlikely that the quiescent state emission is dominated by coronal X-rays from the secondary. The flux also appears to be in agreement with the ADAF model of BH-transients in quiescence. C1 Open Univ, Milton Keynes MK7 6AA, Bucks, England. Univ Leicester, Dept Phys & Astron, Xray Astron Grp, Leicester LE1 7RH, Leics, England. IAC, Tenerife, Spain. Natl Observ Athens, Inst Astron & Astrophys, Athens 11810, Greece. Univ Oxford, Dept Astrophys, Oxford OX1 2JD, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sutaria, FK (reprint author), Open Univ, Milton Keynes MK7 6AA, Bucks, England. OI Wheatley, Peter/0000-0003-1452-2240 NR 27 TC 16 Z9 16 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2002 VL 391 IS 3 BP 993 EP 997 DI 10.1051/0004-6361:20020842 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 586NR UT WOS:000177590500017 ER PT J AU Seiffert, M Mennella, A Burigana, C Mandolesi, N Bersanelli, M Meinhold, P Lubin, P AF Seiffert, M Mennella, A Burigana, C Mandolesi, N Bersanelli, M Meinhold, P Lubin, P TI 1/f noise and other systematic effects in the Planck-LFI radiometers SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE cosmology : cosmic microwave background, observations; instrumentation : detectors; methods : analytical ID MAP-MAKING ALGORITHM; ANISOTROPIES; SURVEYOR; FREQUENCY AB We use an analytic approach to study the susceptibility of the PLANCK Low Frequency Instrument radiometers to various systematic effects. We examine the effects of fluctuations in amplifier gain, in amplifier noise temperature and in the reference load temperature. We also study the effect of imperfect gain modulation, non-ideal matching of radiometer parameters, imperfect isolation in the two legs of the radiometer and back-end 1/f noise. We find that with proper gain modulation 1/f gain fluctuations are suppressed, leaving fluctuations in amplifier noise temperature as the main source of 1/f noise. We estimate that with a gain modulation factor within +/- 1% of its ideal value the overall 1/f knee frequency will be relatively small (<0.1 Hz). C1 CNR, IASF, Sez Milano, I-20133 Milan, Italy. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CNR, IASF, Sez Bologna, I-40126 Bologna, Italy. Univ Milan, I-20133 Milan, Italy. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. RP Mennella, A (reprint author), CNR, IASF, Sez Milano, Via Bassini 15, I-20133 Milan, Italy. OI Burigana, Carlo/0000-0002-3005-5796 NR 24 TC 50 Z9 50 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2002 VL 391 IS 3 BP 1185 EP 1197 DI 10.1051/0004-6361:20020880 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 586NR UT WOS:000177590500037 ER PT J AU Hamilton, TS Casertano, S Turnshek, DA AF Hamilton, TS Casertano, S Turnshek, DA TI The luminosity function of QSO host galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : elliptical and lenticular, cD; galaxies : spiral; quasars : general ID OPTICALLY SELECTED QUASARS; BAND ENERGY-DISTRIBUTION; SPACE-TELESCOPE IMAGES; ROSAT DETECTED QUASARS; RADIO-LOUD; STELLAR OBJECTS; REDSHIFT SURVEY; SPECTRUM; EMISSION; NUCLEI AB We present some results from our HST archival image study of 71 QSO host galaxies. The objects are selected to have z less than or equal to 0.46 and total absolute magnitude M-V less than or equal to -23 in our adopted cosmology ( H-0 = 50 km s(-1) Mpc(-1), q(0) = 0.5, and Lambda = 0). The aim of this initial study is to investigate the composition of the sample with respect to host morphology and radio loudness, as well as to derive the QSO host galaxy luminosity function. We have analyzed available WFPC2 images in R or I band (U band, in one case), using a uniform set of procedures. The host galaxies span a narrow range of luminosities and are exceptionally bright, much more so than normal galaxies, usually L > L-V*. The QSOs are almost equally divided among three subclasses: radio-loud QSOs with elliptical hosts, radio-quiet QSOs with elliptical hosts, and radio-quiet QSOs with spiral hosts. Radio-loud QSOs with spiral hosts are extremely rare. Using a weighting procedure, we derive the combined luminosity function of QSO host galaxies. We find that the luminosity function of QSO hosts differs in shape from that of normal galaxies but that they coincide at the highest luminosities. The ratio of the number of quasar hosts to the number of normal galaxies at a luminosity L-V is R = (L-V/11.48L(V)*)(2.46), where L-V* corresponds to M-V* = -22.35, and a QSO is defined to be an object with total nuclear plus host light M-V less than or equal to -23. This ratio can be interpreted as the probability that a galaxy with luminosity L-V will host a QSO at redshift z approximate to 0.26. C1 Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Hamilton, TS (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. OI Hamilton, Timothy/0000-0002-9753-1769 NR 46 TC 67 Z9 67 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2002 VL 576 IS 1 BP 61 EP 74 DI 10.1086/341724 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 586NB UT WOS:000177589100005 ER PT J AU McCammon, D Almy, R Apodaca, E Tiest, WB Cui, W Deiker, S Galeazzi, M Juda, M Lesser, A Mihara, T Morgenthaler, JP Sanders, WT Zhang, J Figueroa-Feliciano, E Kelley, RL Moseley, SH Mushotzky, RF Porter, FS Stahle, CK Szymkowiak, AE AF McCammon, D Almy, R Apodaca, E Tiest, WB Cui, W Deiker, S Galeazzi, M Juda, M Lesser, A Mihara, T Morgenthaler, JP Sanders, WT Zhang, J Figueroa-Feliciano, E Kelley, RL Moseley, SH Mushotzky, RF Porter, FS Stahle, CK Szymkowiak, AE TI A high spectral resolution observation of the soft X-ray diffuse background with thermal detectors SO ASTROPHYSICAL JOURNAL LA English DT Article DE instrumentation : detectors; instrumentation : spectrographs; intergalactic medium; space vehicles : instruments; X-rays : diffuse background; X-rays : ISM ID DOPED SILICON; ASTRO-E; MICROCALORIMETER SPECTROMETER; HOPPING CONDUCTION; ENERGY RESOLUTION; SPECTROSCOPY; CALORIMETERS; ABUNDANCES; PHYSICS; CLOUD AB A high spectral resolution observation of the diffuse X-ray background in the 60 1000 eV energy range has been made using an array of 36 1 mm(2) microcalorimeters own on a sounding rocket. Detector energy resolution ranged from 5 to 12 eV FWHM, and a composite spectrum of similar to1 sr of the background centered at l = 90degrees, b = +60degrees was obtained with a net resolution of similar to9 eV. The target area includes bright 1/4 keV regions but avoids Loop I and the North Polar Spur. Lines of C VI O VII and O VIII are clearly detected with intensities of 5.4 +/- 2.3, 4.8 +/- 0.8, and 1.6 +/- 0.4 photons cm(-2) s(-1) sr(-1), respectively. The oxygen lines alone account for a majority of the diffuse background observed in the ROSAT R4 band that is not due to resolved extragalactic discrete sources. We also have a positive detection of the Fe-M line complex near 70 eV at an intensity consistent with previous upper limits that indicate substantial gas-phase depletion of iron. We include a detailed description of the instrument and its detectors. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP McCammon, D (reprint author), Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA. RI Porter, Frederick/D-3501-2012; Moseley, Harvey/D-5069-2012; Kelley, Richard/K-4474-2012; Bergmann Tiest, Wouter/N-8535-2013; Mihara, Tatehiro/C-5536-2017; OI Porter, Frederick/0000-0002-6374-1119; Mihara, Tatehiro/0000-0002-6337-7943; Juda, Michael/0000-0002-4375-9688; Cui, Wei/0000-0002-6324-5772 NR 59 TC 240 Z9 240 U1 2 U2 7 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2002 VL 576 IS 1 BP 188 EP 203 DI 10.1086/341727 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 586NB UT WOS:000177589100018 ER PT J AU Turolla, R Zane, S Titarchuk, L AF Turolla, R Zane, S Titarchuk, L TI Power-law tails from dynamical comptonization in converging flows SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; radiation mechanisms : nonthermal; radiative transfer ID NEAR-CRITICAL ACCRETION; MONTE-CARLO SIMULATIONS; HIGH-ENERGY SPECTRA; X-RAY-EMISSION; BLACK-HOLES; NEUTRON-STARS; BULK-MOTION; FLUID-FLOW; INTRINSIC SIGNATURE; SPHERICAL FLOWS AB The effects of bulk motion Comptonization on the spectral formation in a converging flow onto a black hole are investigated. The problem is tackled by means of both a fully relativistic, angle-dependent transfer code and a semianalytical, diffusion approximation method. We find that a power-law high-energy tail is a ubiquitous feature in converging flows and that the two approaches produce consistent results at large enough accretion rates when photon diffusion holds. Our semianalytical approach is based on an expansion in eigenfunctions of the diffusion equation. Contrary to previous investigations based on the same method, we find that although the power-law tail at extremely large energies is always dominated by the flatter spectral mode, the slope of the hard X-ray portion of the spectrum is dictated by the second mode and it approaches Gamma = 3 at large accretion rates, irrespective of the model parameters. The photon index in the tail is found to be largely independent on the spatial distribution of soft seed photons when the accretion rate is either quite low (less than or similar to5 in Eddington units) or sufficiently high (greater than or similar to10). On the other hand, the spatial distribution of source photons controls the photon index at intermediate accretion rates, when Gamma switches from the first to the second mode. Our analysis confirms that a hard tail with photon index Gamma < 3 is produced by the upscattering of primary photons onto infalling electrons if the central object is a black hole. C1 Univ Padua, Dept Phys, I-35131 Padua, Italy. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. George Mason Univ, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. USN, Res Lab, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Turolla, R (reprint author), Univ Padua, Dept Phys, Via Marzolo 8, I-35131 Padua, Italy. EM turolla@pd.infn.it; sz@mssl.ucl.ac.uk; lev@xip.nrl.navy.mil NR 27 TC 16 Z9 16 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2002 VL 576 IS 1 BP 349 EP 356 DI 10.1086/341631 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 586NB UT WOS:000177589100030 ER PT J AU Harding, AK Muslimov, AG Zhang, B AF Harding, AK Muslimov, AG Zhang, B TI Regimes of pulsar pair formation and particle energetics SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : theory; pulsars : general; radiation mechanisms : nonthermal; relativity; stars : neutron ID GAMMA-RAY PULSARS; RAPIDLY SPINNING PULSARS; POLAR CAPS; MILLISECOND PULSARS; OUTER MAGNETOSPHERE; NEUTRON-STAR; RADIATION; EMISSION; GAPS; CASCADES AB We investigate the conditions required for the production of electron-positron pairs above a pulsar polar cap ( PC) and the influence of pair production on the energetics of the primary particle acceleration. Assuming space charge limited flow acceleration including the inertial frame-dragging effect, we allow both one-photon and two-photon pair production by either curvature radiation (CR) photons or photons resulting from inverse Compton scattering of thermal photons from the PC by primary electrons. We find that while only the younger pulsars can produce pairs through CR, nearly all known radio pulsars are capable of producing pairs through nonresonant inverse Compton scatterings. The effect of the neutron star equations of state on the pair death lines is explored. We show that pair production is facilitated in more compact stars and more massive stars. Therefore, accretion of mass by pulsars in binary systems may allow pair production in most of the millisecond pulsar population. We also find that two-photon pair production may be important in millisecond pulsars if their surface temperatures are above similar or equal tothree million kelvins. Pulsars that produce pairs through CR will have their primary acceleration limited by the effect of screening of the electric field. In this regime, the high-energy luminosity should follow an L-HE proportional to (E)over dot(rot)(1/2) dependence. The acceleration voltage drop in pulsars that produce pairs only through inverse Compton emission will not be limited by electric field screening. In this regime, the high-energy luminosity should follow an L-HE proportional to (E)over dot(rot) dependence. Thus, older pulsars will have significantly lower gamma-ray luminosity. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. ManTech Int Corp, Lexington Pk, MD 20653 USA. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. RP Harding, AK (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. RI Harding, Alice/D-3160-2012 NR 32 TC 80 Z9 82 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2002 VL 576 IS 1 BP 366 EP 375 DI 10.1086/341633 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 586NB UT WOS:000177589100032 ER PT J AU Harding, AK Strickman, MS Gwinn, C Dodson, R Moffet, D McCulloch, P AF Harding, AK Strickman, MS Gwinn, C Dodson, R Moffet, D McCulloch, P TI The multicomponent nature of the Vela pulsar nonthermal X-ray spectrum SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : individual (PSR B0833-45); X-rays : stars ID POLAR-CAP CASCADES; GAMMA-RAY; OUTER MAGNETOSPHERE; PHOTOMETRY; RADIATION; EMISSION AB We report on our analysis of a 274 ks observation of the Vela pulsar with the Rossi X-Ray Timing Explorer (RXTE). The double-peaked, pulsed emission at 2-30 keV, which we had previously detected during a 93 ks observation, is confirmed with much-improved statistics. There is now clear evidence, in both the spectrum and the light curve, that the emission in the RXTE band is a blend of two separate nonthermal components. The spectrum of the harder component connects smoothly with the OSSE, COMPTEL, and EGRET spectra, and the peaks in the light curve are in phase coincidence with those of the high-energy light curve. The spectrum of the softer component is consistent with an extrapolation to the pulsed optical flux, and the second RXTE pulse is in phase coincidence with the second optical peak. In addition, we see a peak in the 2-8 keV RXTE pulse pro le at the radio phase. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Res Lab, Washington, DC USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Univ Tasmania, Hobart, Tas 7001, Australia. RP Harding, AK (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM harding@twinkie.gsfc.nasa.gov RI Harding, Alice/D-3160-2012 NR 20 TC 46 Z9 46 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2002 VL 576 IS 1 BP 376 EP 380 DI 10.1086/341732 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 586NB UT WOS:000177589100033 ER PT J AU Woods, PM Kouveliotou, C Gogus, E Finger, MH Swank, J Markwardt, CB Hurley, K van der Klis, M AF Woods, PM Kouveliotou, C Gogus, E Finger, MH Swank, J Markwardt, CB Hurley, K van der Klis, M TI Large torque variations in two soft gamma repeaters SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : general; stars : individual (SGR 1900+14, SGR 1806-20); X-rays : bursts ID X-RAY PULSAR; MAGNETIZED NEUTRON-STARS; VARIABLE SPIN-DOWN; SGR 1900+14; TIMING NOISE; GIANT FLARES; AUGUST 27; SGR-1900+14; BURST; MAGNETARS AB We have monitored the pulse frequencies of the two soft gamma repeaters SGR 1806-20 and SGR 1900+14 through the beginning of year 2001 using primarily Rossi X-Ray Timing Explorer Proportional Counter Array observations. In both sources, we observe large changes in the spin-down torque up to a factor of similar to4, which persist for several months. Using long-baseline phase-connected timing solutions as well as the overall frequency histories, we construct torque noise power spectra for each SGR. The power spectrum of each source is very red (power-law slope similar to-3.5). The torque noise power levels are consistent with some accreting systems on timescales of similar to1 yr, yet the full power spectrum is much steeper in frequency than any known accreting source. To the best of our knowledge, torque noise power spectra with a comparably steep frequency dependence have been seen only in young, glitching radio pulsars (e.g., Vela). The observed changes in spin-down rate do not correlate with burst activity; therefore, the physical mechanisms behind each phenomenon are also likely unrelated. Within the context of the magnetar model, seismic activity cannot account for both the bursts and the long-term torque changes unless the seismically active regions are decoupled from one another. C1 Univ Space Res Assoc, Columbia, MD USA. Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Univ Amsterdam, CHEAF, NL-1098 SJ Amsterdam, Netherlands. RP Woods, PM (reprint author), Univ Space Res Assoc, Columbia, MD USA. RI Swank, Jean/F-2693-2012 NR 58 TC 71 Z9 72 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2002 VL 576 IS 1 BP 381 EP 390 DI 10.1086/341536 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 586NB UT WOS:000177589100034 ER PT J AU Davis, SS AF Davis, SS TI Vorticity-induced wave motion in a compressible protoplanetary disk SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; hydrodynamics; planetary systems : formation ID THIN ACCRETION DISKS; GASEOUS DISKS; SOLAR NEBULA; CIRCUMSTELLAR DISKS; INSTABILITY; EVOLUTION; DYNAMICS AB The impact of an isolated vortex in a compressible Keplerian disk is examined using higher order numerical solutions of the Euler and entropy-conserving energy equations. The vortex is stretched by the background shear flow with longer lasting anticyclonic vortices persisting for about 10 vortex revolutions. Simultaneously, the vortex emits transient radial waves consisting of almost axisymmetrical density/shock waves and a slower, nonaxisymmetric Rossby wave. Nonlinear processes are found to transmit a small amount of mass and angular momentum outward. These wave systems may contribute to certain transient events in proto-planetary disks as well as moving matter to the outer part of the disk. The vortex stretching and waves are found to have little long-term feedback on the baseline standard solar nebula structure except for a small second-order redistribution of mass and angular momentum, and generally confirm the globally stable structure of non self-gravitating, entropy-conserving disks. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Davis, SS (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. NR 26 TC 13 Z9 13 U1 1 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2002 VL 576 IS 1 BP 450 EP 461 DI 10.1086/341537 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 586NB UT WOS:000177589100040 ER PT J AU Weaver, KA Heckman, TM Strickland, DK Dahlem, M AF Weaver, KA Heckman, TM Strickland, DK Dahlem, M TI Chandra observations of the evolving core of the starburst galaxy NGC 253 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (NGC 253); galaxies : nuclei; galaxies : starburst; X-rays : galaxies ID X-RAYS; NGC-253; EMISSION; SPECTRA; EVOLUTION; BINARIES; NUCLEUS; LINES AB Chandra observations of the core of the nearby starburst galaxy NGC 253 reveal a heavily absorbed source of hard X-rays embedded within the nuclear starburst region. The source has an unabsorbed, 2-10 keV luminosity of greater than or equal to10(39) ergs s(-1) and photoionizes the surrounding gas. We observe this source through a dusty torus with a neutral absorbing column density of N-H similar to 2 x 10(23) cm(-2). The torus is hundreds of parsecs across and collimates the starburst-driven nuclear outflow. We suggest that the ionizing source is an intermediate-mass black hole or a weakly accreting supermassive black hole, which may signal the beginnings or endings of active galactic nucleus activity. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. European So Observ, Santiago 19, Chile. RP Weaver, KA (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. NR 28 TC 62 Z9 62 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2002 VL 576 IS 1 BP L19 EP L23 DI 10.1086/342977 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 586NC UT WOS:000177589200005 ER PT J AU Sebo, KM Rawson, D Mould, J Madore, BF Putman, ME Graham, JA Freedman, WL Gibson, BK Germany, LM AF Sebo, KM Rawson, D Mould, J Madore, BF Putman, ME Graham, JA Freedman, WL Gibson, BK Germany, LM TI The Cepheid period-luminosity relation in the Large Magellanic Cloud SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE Cepheids; distance scale; Magellanic Clouds; techniques : photometric ID GRAVITATIONAL LENSING EXPERIMENT; HUBBLE-SPACE-TELESCOPE; DISTANCE SCALE; CONSTRAINTS; INDICATORS; VARIABLES; CONSTANT; STARS AB A homogeneous set of ground-based BVRI observations of similar to600 Cepheids is presented to check the Cepheid period-luminosity zero point for the Large Magellanic Cloud (LMC). The sample of Cepheids is completely self-contained and has been reduced consistently to eliminate photometric differences caused by combining multiple sources of photometry. The Cepheid distances to nearby galaxies obtained by the Hubble Space Telescope (HST) Key Project on the Extragalactic Distance Scale were computed assuming a "standard" PL relation based on a compilation of photoelectric observations of 34 Cepheids and a standard distance modulus to the LMC of 18.50. The final Key Project results substituted a statistically stronger PL relation obtained by the OGLE collaboration. In this paper we compare our data with the OGLE PL relation; the subsample of LMC Cepheids with similar periods to those discovered in the nearby galaxies is fainter at the relevant periods by 0.04 +/- 0.02 mag than the OGLE sample. Substituting in turn this PL relation for that of the OGLE collaboration would raise the Hubble constant by 2% +/- 1%, a correction which is not significant. The multicolor data set will also be useful in considering the effects of reddening and chemical composition and deriving an improved Cepheid period-luminosity relation for the LMC. C1 Australian Natl Univ, Res Sch Astron & Astrophys, Mt Stromlo Observ, Weston, ACT 2611, Australia. Natl Opt Astron Observ, Tucson, AZ 85726 USA. CALTECH, IPAC Extragalact Database, NASA, Pasadena, CA 91125 USA. Carnegie Inst Washington, Washington, DC 20005 USA. Univ Colorado, CASA, Boulder, CO 80309 USA. Carnegie Inst Washington, DTM, Washington, DC 20015 USA. Swinburne Univ, Ctr Astrophys & Supercomp, Hawthorn, Vic 3122, Australia. European So Observ, Santiago 19, Chile. RP Sebo, KM (reprint author), Australian Natl Univ, Res Sch Astron & Astrophys, Mt Stromlo Observ, Weston, ACT 2611, Australia. RI Gibson, Brad/M-3592-2015 OI Gibson, Brad/0000-0003-4446-3130 NR 19 TC 31 Z9 31 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2002 VL 142 IS 1 BP 71 EP 78 DI 10.1086/341177 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 585KU UT WOS:000177524600004 ER PT J AU Malkan, MA Hicks, EK Teplitz, HI McLean, IM Sugai, H Guichard, J AF Malkan, MA Hicks, EK Teplitz, HI McLean, IM Sugai, H Guichard, J TI 1-1.4 micron spectral atlas of stars SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE infrared : stars; line : identification; stars : fundamental parameters ID TELESCOPE; BAND AB We present a catalog of J-band (1.08 to 1.35 mum) stellar spectra at low resolution (R similar to 400). The targets consist of 105 stars ranging in spectral type from O9.5 to M7 and luminosity classes I through V. The relatively featureless spectra of hot stars, earlier than A4, can be used to remove the atmospheric features which dominate ground-based J-band spectroscopy. We measure equivalent widths for three absorption lines and nine blended features which we identify in the spectra. Using detailed comparison with higher resolution spectra, we demonstrate that low-resolution data can be used for stellar classification, since several features depend on the effective temperature and gravity. For example, the CN index (1.096-1.104 mum) decreases with temperature, but the strength of a blended feature at 1.28 mum (consisting of primarily Pbeta) increases. The slope of a star's spectrum can also be used to estimate its effective temperature. The luminosity class of a star correlates with the ratio of the Mg I(1.1831 mum) line to a blend of several species at 1.16 mum. Using these indicators, a star can be classified to within several subclasses. Fifteen stars with particularly high and low metal abundances are included in the catalog, and some spectral dependence on metal abundance is also found. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Natl Opt Astron Observ, Tucson, AZ 85719 USA. Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Kyoto Univ, Dept Astron, Sakyo Ku, Kyoto 6068502, Japan. Inst Nacl Astrofis Opt & Elect, Puebla 72840, Mexico. RP Malkan, MA (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RI Sugai, Hajime/C-6197-2011 NR 13 TC 5 Z9 5 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2002 VL 142 IS 1 BP 79 EP 94 DI 10.1086/341176 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 585KU UT WOS:000177524600005 ER PT J AU Groner, P Albert, S Herbst, E De Lucia, FC Lovas, FJ Drouin, BJ Pearson, JC AF Groner, P Albert, S Herbst, E De Lucia, FC Lovas, FJ Drouin, BJ Pearson, JC TI Acetone: Laboratory assignments and predictions through 620 GHz for the vibrational-torsional ground state SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE ISM : molecules; molecular data; molecular processes; radio lines : ISM ID HOT MOLECULAR CORES; ORION COMPACT RIDGE; FOURIER-TRANSFORM; ROTATIONAL SPECTRUM; FORMING REGIONS; DIMETHYL ETHER; INTERSTELLAR; CHEMISTRY; METHANOL; MOMENT AB The acetone molecule has a complex rotational spectrum arising from the internal rotation of two methyl tops and their interaction with each other and the rigid-body rotation of the molecule. Here we report the measurement and assignment of a large number of new rotational-torsional transitions of acetone in the vibrational-torsional ground state at frequencies of up to 620 GHz. The newly measured lines have been combined with previously measured transition frequencies and fitted by a procedure used successfully for dimethyl ether. From the fit to the global data set, we have extracted parameters that have enabled us to predict accurately the frequencies and intensities of over 10,000 lines of possible astronomical importance at frequencies of up to 620 GHz. The detection of interstellar acetone was first reported by Combes et al. based on two transitions with partially resolved internal rotation structure. The present work will aid further interstellar studies to verify acetone as an interstellar constituent. C1 Univ Missouri, Dept Chem, Kansas City, MO 64110 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Natl Inst Stand & Technol, Opt Techol Div, Gaithersburg, MD 20899 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. RP Groner, P (reprint author), Univ Missouri, Dept Chem, Kansas City, MO 64110 USA. NR 40 TC 44 Z9 44 U1 0 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2002 VL 142 IS 1 BP 145 EP 151 DI 10.1086/341221 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 585KU UT WOS:000177524600009 ER PT J AU Wade, CE Moran, MM Oyama, J AF Wade, CE Moran, MM Oyama, J TI Resting energy expenditure of rats acclimated to hypergravity SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE centrifugation; metabolism; age; body mass; carbon dioxide production ID SOLEUS MUSCLE ATROPHY; TEMPERATURE; METABOLISM; SIZE AB Background: The use of centrifugation at 1 G has been advocated as a control condition during spaceflight and as a countermeasure to compensate for the adverse effects of spaceflight. Rodents are the primary animal model for the study of the effects of spaceflight and will be used in the evaluation of centrifugation as a countermeasure and means of control at 1 G during flight. Hypothesis. The present study was designed to assess whether resting energy expenditure (EER) Of Male rats was increased in relation to the magnitude of the level of gravity to which the animals were exposed. The influence of body mass and age on resting energy expenditure (EER) of male rats (n = 42, age 40-400 d) was determined following 2 wk of acclimation to 1, 2.3, or 4.1 G. Hypergravity environments were created by centrifugation. Measurements were made at the gravity level to which the animal was acclimated and during the lights-on period. Results: In rats matched for body mass (similar to400 g), mean O-2 consumption and CO2 production were higher (18% and 27%, respectively) in the 2.3- and 4.1 -G groups than controls. Mean respiratory exchange ratio (RER) increased from 0.80 to 0.87. EER was increased from 47 +/- 0.1 kcal . d(-1) at 1 G, to 57 +/- 1.5 and 58 +/- 2.2 kcal . d(-1) at 2.3 and 4.1 G, respectively. There was no difference in EER between the hypergravity groups. When age differences were considered, EER (kcal . kg(-1) . d(-1)) with increased gravity was 40% higher than at 1 G. The increase in EER was not proportional over gravity levels. Conclusion: Acclimation of rats to hypergravity increases their EER, dependent on body mass and age, and may alter substrate metabolism. The increase in EER was not related to the level of gravity increase. C1 NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA 94035 USA. RP Wade, CE (reprint author), NASA, Ames Res Ctr, Div Life Sci, MS 239-11, Moffett Field, CA 94035 USA. NR 38 TC 11 Z9 12 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD SEP PY 2002 VL 73 IS 9 BP 859 EP 864 PG 6 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 590DL UT WOS:000177802600002 PM 12234035 ER PT J AU Kirkpatrick, AW Nicolaou, S Campbell, MR Sargsyan, AE Dulchavsky, SA Melton, S Beck, G Dawson, DL Billica, RD Johnston, SL Hamilton, DR AF Kirkpatrick, AW Nicolaou, S Campbell, MR Sargsyan, AE Dulchavsky, SA Melton, S Beck, G Dawson, DL Billica, RD Johnston, SL Hamilton, DR TI Percutaneous aspiration of fluid for management of peritonitis in space SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE weightlessness; space flight; peritonitis; surgery; percutaneous drainage ID INTRAABDOMINAL ABSCESSES; SURGICAL INVESTIGATIONS; ENDOSCOPIC SURGERY; IN-SPACE; MICROGRAVITY; DRAINAGE; APPENDECTOMY; WEIGHTLESSNESS; ENVIRONMENT; PRINCIPLES AB Background: As a medical emergency that can affect even well-screened, healthy individuals, peritonitis developing during a long-duration space exploration mission may dictate deviation from traditional clinical practice due to the absence of otherwise indicated surgical capabilities. Medical management can treat many intra-abdominal processes, but treatment failures are inevitable. In these circumstances, percutaneous aspiration under sonographic guidance could provide a "rescue" strategy. Hypothesis: Sonographically guided percutaneous aspiration of intra-peritoneal fluid can be performed in microgravity. Methods: Investigations were conducted in the microgravity environment of NASA's KC-135 research aircraft (0 G). The subjects were anesthetized female Yorkshire pigs weighing 50 kg. The procedures were rehearsed in a terrestrial animal lab (1 G). Colored saline (500 mL) was introduced through an intra-peritoneal catheter during flight. A high-definition ultrasound system (HDI-5000, ATL, Bothell, WA) was used to guide a 16-gauge needle into the peritoneal cavity to aspirate fluid. Results. Intra-peritoneal fluid collections were easily identified, distinct from surrounding viscera, and on occasion became more obvious during weightless conditions. Subjectively, with adequate restraint of the subject and operators, the procedure was no more demanding than during the 1-G rehearsals. Conclusions: Sonographically guided percutaneous aspiration of intra-peritoneal fluid collections is feasible in weightlessness. Treatment of intra-abdominal inflammatory conditions in spaceflight might rely on pharmacological options, backed by sonographically guided percutaneous aspiration for the "rescue" of treatment failures. While this risk mitigation strategy cannot guarantee success, it may be the most practical option given severe resource limitations. C1 Vancouver Gen Hosp, Vancouver, BC, Canada. Wyle Life Sci, Houston, TX USA. Wayne State Univ, Detroit, MI USA. NASA, Space & Life Sci Directorate, Houston, TX USA. RP Kirkpatrick, AW (reprint author), Foothills Med Ctr, Reg Trauma Serv, Rm EG23,1403 29 St NW, Calgary, AB T2N 2T9, Canada. NR 44 TC 21 Z9 21 U1 0 U2 1 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD SEP PY 2002 VL 73 IS 9 BP 925 EP 930 PG 6 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 590DL UT WOS:000177802600013 PM 12234046 ER PT J AU Atlas, D AF Atlas, D TI Radar calibration - Some simple approaches SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID RAINFALL AB In considering new and promising methods to calibrate radar, it is worth remembering some of the old and perhaps forgotten methods that were used over the last half century. RP Atlas, D (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 17 TC 32 Z9 32 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 2002 VL 83 IS 9 BP 1313 EP 1316 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 602DL UT WOS:000178490400019 ER PT J AU Lindzen, RS Chou, MD Hou, AY AF Lindzen, RS Chou, MD Hou, AY TI Comment on ''No evidence for iris" SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material C1 MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Lindzen, RS (reprint author), MIT, Dept Earth Atmospher & Planetary Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA. RI Hou, Arthur/D-8578-2012 NR 5 TC 13 Z9 13 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 2002 VL 83 IS 9 BP 1345 EP 1349 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 602DL UT WOS:000178490400022 ER PT J AU Zak, M AF Zak, M TI Entanglement-based self-organization SO CHAOS SOLITONS & FRACTALS LA English DT Article AB Based upon quantum entanglement, several paradigms of self-organization (such as inverse diffusion, transmissions of conditional information, decentralized coordination, cooperative computing, competitive games, topological evolution in active systems) are introduced and discussed. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Ultracomp Grp, Pasadena, CA 91109 USA. Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Oak Ridge, TN USA. RP Zak, M (reprint author), CALTECH, Jet Prop Lab, Ultracomp Grp, 4800 Oak Grove Dr,M-S 126-347, Pasadena, CA 91109 USA. NR 5 TC 4 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0960-0779 J9 CHAOS SOLITON FRACT JI Chaos Solitons Fractals PD SEP PY 2002 VL 14 IS 5 BP 745 EP 758 AR PII S0960-0779(02)00021-8 DI 10.1016/S0960-0779(02)00021-8 PG 14 WC Mathematics, Interdisciplinary Applications; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 561WR UT WOS:000176166500009 ER PT J AU Vidal, N Hedges, SB AF Vidal, N Hedges, SB TI Higher-level relationships of snakes inferred from four nuclear and mitochondrial genes SO COMPTES RENDUS BIOLOGIES LA English DT Article DE serpentes; snakes; phylogeny; macrostomatan; C-mos; 12S rRNA; 16S rRNA; cytochrome b ID 12S RIBOSOMAL-RNA; PHYLOGENETIC-RELATIONSHIPS; EVOLUTION; DNA; TREES; SUBSTITUTION; SERPENTES; SEQUENCES; MODEL AB Higher-level snake relationships are inferred from sequence analyses of one nuclear gene (C-mos) and three mitochondrial genes (12S rRNA, 165 rRNA and cytochrome b). Extant snakes belong to two lineages: the fossorial Scolecophidia, which feed on small prey on a frequent basis, and the ecologically diverse Alethinophidia (`typical' snakes), which feed on large prey on an infrequent basis. The vast majority of Alethinophidia, if not all of them, belong to two clades, corresponding to two distinct prey neutralization modes: unimodal constriction for the Henophidia (locomotor and feeding systems coupled) and injection of toxic saliva, in addition (or not) to diverse alternate modes of constriction, for the Caenophidia (locomotor and feeding systems uncoupled). Within Alethinophidia, non-macrostomatan (small gape) Aniliidae (genus Anilius) and macrostomatan (large gape) Tropidophiidae (genera Trachyboa and Tropidophis), both from the Neotropics, are closest relatives. Although our data are insufficient to robustly infer the ancestral mode of life of snakes, we find evidence of plasticity in the basic ecological and trophic modes of snakes. Consequently, the macrostomatan condition should not be treated a priori as a derived character state devoid of homoplasy. To cite this article: N. Vidal, S.B. Hedges, C. R. Biologies 325 (2002) 977-985. (C) 2002 Academie des Sciences / Editions scientifiques et medicales Elsevier SAS. C1 Museum Natl Hist Nat, CNRS, FR 1541, Inst Systemat,Serv Systemat Mol, F-75231 Paris 05, France. Penn State Univ, NASA, Astrobiol Inst, University Pk, PA 16802 USA. Penn State Univ, NASA, Dept Biol, University Pk, PA 16802 USA. RP Vidal, N (reprint author), Museum Natl Hist Nat, CNRS, FR 1541, Inst Systemat,Serv Systemat Mol, 43,Rue Cuvier, F-75231 Paris 05, France. NR 48 TC 63 Z9 70 U1 1 U2 6 PU EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS CEDEX 15 PA 23 RUE LINOIS, 75724 PARIS CEDEX 15, FRANCE SN 1631-0691 J9 CR BIOL JI C. R. Biol. PD SEP PY 2002 VL 325 IS 9 BP 977 EP 985 AR PII S163106910201510X/FLA DI 10.1016/S1631-0691(02)01510-X PG 9 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 620PG UT WOS:000179541300007 PM 12487103 ER PT J AU Vidal, N Hedges, SB AF Vidal, N Hedges, SB TI Higher-level relationships of caenophidian snakes inferred from four nuclear and mitochondrial genes SO COMPTES RENDUS BIOLOGIES LA English DT Article DE caenophidia; advanced snakes; colubroidea; phylogeny; venom apparatus; C-mos; 12S rRNA; 16S rRNA; ND4 ID PHYLOGENETIC-RELATIONSHIPS; DNA SEQUENCES; RIBOSOMAL-RNA; ELAPID SNAKES; SERPENTES; EVOLUTION; COLUBRIDAE; 12S C1 Museum Natl Hist Nat, CNRS, FR 1541, Inst Systemat,Serv Systemat Mol, F-75231 Paris 05, France. Penn State Univ, NASA, Astrobiol Inst, University Pk, PA 16802 USA. Penn State Univ, NASA, Dept Biol, University Pk, PA 16802 USA. RP Vidal, N (reprint author), Museum Natl Hist Nat, CNRS, FR 1541, Inst Systemat,Serv Systemat Mol, 43,Rue Cuvier, F-75231 Paris 05, France. NR 27 TC 68 Z9 71 U1 0 U2 7 PU EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS CEDEX 15 PA 23 RUE LINOIS, 75724 PARIS CEDEX 15, FRANCE SN 1631-0691 J9 CR BIOL JI C. R. Biol. PD SEP PY 2002 VL 325 IS 9 BP 987 EP 995 AR PII S1631069102015093/FLA DI 10.1016/S1631-0691(02)01509-3 PG 9 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 620PG UT WOS:000179541300008 PM 12481691 ER PT J AU Yeh, KS Lin, SJ Rood, RB AF Yeh, KS Lin, SJ Rood, RB TI Applying local discretization methods in the NASA finite-volume general circulation model SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Article C1 NASA, Goddard Space Flight Ctr, Data Assimilat Off, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Earth & Space Data Comp Div, Greenbelt, MD 20771 USA. Univ Maryland, Goddard Earth Sci & Technol Ctr, College Pk, MD 20742 USA. RP Yeh, KS (reprint author), NASA, Goddard Space Flight Ctr, Data Assimilat Off, Code 910-3, Greenbelt, MD 20771 USA. RI Rood, Richard/C-5611-2008 OI Rood, Richard/0000-0002-2310-4262 NR 8 TC 4 Z9 4 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD SEP-OCT PY 2002 VL 4 IS 5 BP 49 EP 54 DI 10.1109/MCISE.2002.1032429 PG 6 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 586VZ UT WOS:000177608000011 ER PT J AU Jhabvala, M Babu, RS Monroy, C Freund, MM Dowell, CD AF Jhabvala, M Babu, RS Monroy, C Freund, MM Dowell, CD TI Development of low-noise high value chromium silicide resistors for cryogenic detector applications SO CRYOGENICS LA English DT Article ID CAMERA AB Extremely high sensitivity detectors, such as silicon bolometers are required in, many NASA missions for detection of photons from the X-ray to the far infrared regions. Typically, these detectors are cooled to well below the liquid helium (LHe) temperature of 4.2 K to achieve the maximum detection performance. As photodetectors, they are generally operated with a load resistor and a pre-set bias voltage, which is coupled to the input gate of a source-follower field effect transistor (FET) circuit. It is imperative that the detector system signal-to-noise performance be limited by the noise of the detector and not by the noise of the external components. The load resistor value is selected to optimize the detector performance. These two criteria tend to be contradictory in that these detectors require load resistors in the hundreds of megaohms, which leads, to a higher Johnson noise. Additionally, the physical size of the resistor must be small for device integration as required by such missions as the NASA High Resolution Airborne Wide-Band Camera instrument and the Submillimeter High-Angular Resolution Camera for the Caltech Submillimeter Observatory, both of which employ 384 detectors and resistors. We have designed, fabricated and characterized thin film resistors using a CrSi/TiW/AI metal system on optical quality quartz substrates. The resistor values range from 75 MOmega to over 650 MOmega and are Johnson noise limited to below LHe temperatures. The resistor film is sputtered with a sheet resistance ranging from 300 to 1600 Omega/square and the processing sequence developed for these devices allows for chemically fine-tuning the sheet resistance in situ. The wafer fabrication process was of sufficiently high yield (>80%) providing clusters of good resistors for integrated multiple detector channels, a very important feature in the assembly of these two instruments. Published by Elsevier Science Ltd. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Raytheon ITSS, Lanham, MD 20706 USA. CALTECH, Pasadena, CA 91125 USA. RP Jhabvala, M (reprint author), NASA, Goddard Space Flight Ctr, Bldg 11,Rm E30, Greenbelt, MD 20771 USA. NR 5 TC 7 Z9 9 U1 0 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD SEP PY 2002 VL 42 IS 9 BP 517 EP 526 AR PII S0011-2275(02)00078-4 DI 10.1016/S0011-2275(02)00078-4 PG 10 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA 611HE UT WOS:000179009900001 ER PT J AU Rashkovich, LN Gvozdev, NV Sil'nikova, MI Chernov, AA AF Rashkovich, LN Gvozdev, NV Sil'nikova, MI Chernov, AA TI Fluctuations in the step velocity and the generation of a dislocation spiral on the (101) face of monoclinic lysozyme crystals SO CRYSTALLOGRAPHY REPORTS LA English DT Article ID 010 FACE; GROWTH AB The generation of a dislocation spiral and fluctuations in the step velocity on the (101) face of monoclinic lysozyme crystals have been studied by in situ atomic force microscopy (AFM). It is shown that the (101) face grows by the dislocation mechanism and that the steps move via the formation of one-dimensional nuclei. The velocity of a part of the step fluctuates, with the fluctuations increasing proportionally to the fourth-order root of time. In the process of spiral generation, a segment of the step attains a certain critical length and then moves with a constant velocity. Even under constant supersaturation, the fluctuations can give rise to changes in the segment length. The interstep distance in the step echelon also varies. (C) 2002 MAIK "Nauka/Interperiodica". C1 Moscow MV Lomonosov State Univ, Dept Phys, Moscow 119899, Russia. NASA, Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Rashkovich, LN (reprint author), Moscow MV Lomonosov State Univ, Dept Phys, Leninskie Gory, Moscow 119899, Russia. NR 9 TC 9 Z9 9 U1 0 U2 5 PU MAIK NAUKA/INTERPERIODICA PUBL PI MELVILLE PA C/O AMERICAN INST PHYSICS, 2 HUNTINGTON QUANDRANGLE, STE 1NO1, MELVILLE, NY 11747-4502 USA SN 1063-7745 J9 CRYSTALLOGR REP+ JI Crystallogr. Rep. PD SEP-OCT PY 2002 VL 47 IS 5 BP 859 EP 866 DI 10.1134/1.1509406 PG 8 WC Crystallography SC Crystallography GA 605TX UT WOS:000178694100026 ER PT J AU Pindera, MJ Aboudi, J Arnold, SM AF Pindera, MJ Aboudi, J Arnold, SM TI Analysis of spallation mechanism in thermal barrier coatings with graded bond coats using the higher-order theory for FGMs SO ENGINEERING FRACTURE MECHANICS LA English DT Article ID BEHAVIOR; FAILURE AB A major failure mechanism in plasma-sprayed thermal barrier coatings (TBCs) is spallation of the top coat due to the top/bond coat thermal expansion mismatch concomitant with deposition-induced interfacial roughness, oxide film growth and creep-induced normal stress reversal at the rough interface's crest. Experiments indicate that reduction of the thermal expansion mismatch by embedding alumina particles in the bond coat may increase coating durability. This approach is examined using the higher-order theory for functionally graded materials (FGMs). Specifically, combined effects of a graded bond coat microstructure and oxide film thickness on the crack-tip stress field in the vicinity of a rough top/bond coat interface are investigated during thermal cycling in the presence of a local horizontal delamination situated within the homogeneous top coat at the rough interface's crest. The analysis, which accounts for the high-temperature creep/relaxation effects within the individual constituents, is conducted in two distinct ways which reflect the present dichotomy in the modeling of FGMs. The coupled approach explicitly accounts for the micro-macrostructural interaction due to the particles' presence and is an intrinsic feature of the higher-order theory. The uncoupled approach, which is the prevailing paradigm in the mechanics/materials communities, replaces the actual graded microstructure with a fictitious material having continuously or discretely varying homogenized properties. These homogenized properties are then used in the structural analysis of a TBC without regard for particle-particle or particle-interface interactions. The feasibility of using graded bond coat microstructures to reduce horizontal delamination driving forces is critically examined and the limitations of the homogenization-based approach are highlighted. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ Virginia, Dept Civil Engn & Appl Mech, Charlottesville, VA 22901 USA. Tel Aviv Univ, IL-69978 Ramat Aviv, Israel. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Pindera, MJ (reprint author), Univ Virginia, Dept Civil Engn & Appl Mech, Thornton Hall, Charlottesville, VA 22901 USA. NR 17 TC 22 Z9 26 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-7944 J9 ENG FRACT MECH JI Eng. Fract. Mech. PD SEP PY 2002 VL 69 IS 14-16 BP 1587 EP 1606 AR PII S0013-7944(02)00048-6 DI 10.1016/S0013-7944(02)00048-6 PG 20 WC Mechanics SC Mechanics GA 588PT UT WOS:000177710400004 ER PT J AU Van Kooten, GK Short, JW Kolak, JJ AF Van Kooten, GK Short, JW Kolak, JJ TI Low-maturity Kulthieth Formation coal: A possible source of polycyclic aromatic hydrocarbons in benthic sediment of the northern Gulf of Alaska SO ENVIRONMENTAL FORENSICS LA English DT Article; Proceedings Paper CT 25th Artic and Marine Oil Spill Technical Seminar CY JUN, 2002 CL CALGARY, CANADA DE PAH; Kulthieth; coal; hydrocarbons; geochemistry; thermal maturity; benthic sediment; Gulf of Alaska ID PRINCE-WILLIAM-SOUND; OIL AB The successful application of forensic geology to contamination studies involving natural systems requires identification of appropriate endmembers and an understanding of the geologic setting and processes affecting the systems. Studies attempting to delineate the background, or natural, source for hydrocarbon contamination in Gulf of Alaska (GOA) benthic sediments have invoked a number of potential sources, including seep oils, source rocks, and coal. Oil seeps have subsequently been questioned as significant sources of hydrocarbons present in benthic sediments of the GOA in part because the pattern of relative polycyclic aromatic hydrocarbon (PAH) abundance characteristic of benthic GOA sediments is inconsistent with patterns typical of weathered seep oils. Likewise, native coal has been dismissed in part because ratios of labile hydrocarbons to total organic carbon (e.g. PAH:TOC) for Bering River coal field (BRCF) sources are too low-i.e. the coals are over mature-to be consistent with GOA sediments. We present evidence here that native coal may have been prematurely dismissed, because BRCF coals do not adequately represent the geochemical signatures of coals elsewhere in the Kulthieth Formation. Contrary to previous thought, Kulthieth Formation coals east of the BRCF have much higher PAH: TOC ratios, and the patterns of labile hydrocarbons in these low thermal maturity coals suggest a possible genetic relationship between Kulthieth Formation coals and nearby oil seeps on the Sullivan anticline. Analyses of low-maturity Kulthieth Formation coal indicate the low maturity coal is a significant source of PAH. Source apportionment models that neglect this source will underestimate the contribution of native coals to the regional background hydrocarbon signature. (C) Published by Elsevier Science Ltd. on behalf of AEHS. C1 Petrotech Resources Alaska, Anchorage, AK USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK USA. US Geol Survey, Reston, VA 22092 USA. RP Van Kooten, GK (reprint author), Calvin Coll, Dept Geol Geog & Environm Studies, 3201 Burton St,SE, Grand Rapids, MI 49546 USA. OI Kolak, Jonathan/0000-0003-2981-9522 NR 28 TC 16 Z9 16 U1 1 U2 8 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1527-5922 J9 ENVIRON FORENSICS JI Environ. Forensics PD SEP-DEC PY 2002 VL 3 IS 3-4 BP 227 EP 241 DI 10.1006/enfo.2002.0096 PG 15 WC Environmental Sciences SC Environmental Sciences & Ecology GA 615ZF UT WOS:000179276700006 ER PT J AU Short, JW AF Short, JW TI Oil identification based on a goodness-of-fit metric applied to hydrocarbon analysis results SO ENVIRONMENTAL FORENSICS LA English DT Article; Proceedings Paper CT 25th Artic and Marine Oil Spill Technical Seminar CY JUN, 2002 CL CALGARY, CANADA DE oil spill; fingerprinting; polycyclic aromatic hydrocarbons (PAH) ID PRINCE-WILLIAM-SOUND; SEDIMENTS; ALASKA AB Assessment of environmental damage following accidental oil spills requires reliable oil identification methods. Results from hydrocarbon analyses of environmental samples are often difficult to interpret, because of the changes in oil composition (or weathering) that follows release into the environment, and because of confounding by hydrocarbons from other sources. To a first-order approximation, weathering proceeds according to simple first-order loss-rate (FOLR) kinetics for polycyclic aromatic hydrocarbons (PAH) based on molecular size. This relationship between relative weathering rate and molecular size can be exploited to infer the initial PAH composition of spilled oils, and this information can be combined with results for weathering-invariant analytes to substantially increase the precision and accuracy of hydrocarbon source recognition methods. The approach presented here evaluates a goodness-of-fit metric between the measured hydrocarbon composition of an environmental sample and a suspected source, after correcting for PAH weathering losses based on FOLR kinetics. Variability from analytical and sampling error may thus be accounted for, and source identifications can be expressed as objective probability statements. This approach is illustrated by application to four independent case studies. (C) Published by Elsevier Science Ltd on behalf of AEHS. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. RP Short, JW (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. NR 10 TC 10 Z9 10 U1 0 U2 5 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1527-5922 J9 ENVIRON FORENSICS JI Environ. Forensics PD SEP-DEC PY 2002 VL 3 IS 3-4 BP 349 EP 355 DI 10.1006/enfo.2002.0105 PG 7 WC Environmental Sciences SC Environmental Sciences & Ecology GA 615ZF UT WOS:000179276700016 ER PT J AU Tou, JCL Wade, CE AF Tou, JCL Wade, CE TI Determinants affecting physical activity levels in animal models SO EXPERIMENTAL BIOLOGY AND MEDICINE LA English DT Review DE activity; body weight; obesity; energy expenditure; rodents ID 24-HOUR ENERGY-EXPENDITURE; WHEEL-RUNNING ACTIVITY; DIET-INDUCED OBESITY; MONOSODIUM GLUTAMATE; GENETICALLY-OBESE; BODY-WEIGHT; ZUCKER RATS; HYPOTHALAMIC-LESIONS; EXPLORATORY-BEHAVIOR; LOCOMOTOR-ACTIVITY AB Weight control is dependent on energy balance. Reduced energy expenditure (EE) associated with decreased physical activity is suggested to be a major underlying cause in the increasing prevalence of weight gain and obesity. Therefore, a better understanding of the biological determinants involved in the regulation of physical activity is essential. To facilitate interpretation in humans, it is helpful to consider the evidence from animal studies. This review focuses on animal studies examining the biological determinants influencing activity and potential implications to human. It appears that physical activity is influenced by a number of parameters. However, regardless of the parameter involved, body weight appears to play an underlying role in the regulation of activity. Furthermore, the regulation of activity associated with body weight appears to occur only after the animal achieves a critical weight. This suggests that activity levels are a consequence rather than a contributor to weight control. However, the existence of an inverse weight-activity relationship remains inconclusive. Confounding the results are the multifactorial nature of physical activity and the lack of appropriate measuring devices. Furthermore, many determinants of body weight are closely interlocked, making it difficult to determine whether a single, combination, or interaction of factors is important for the regulation of activity. For example, diet-induced obesity, aging, lesions to the ventral medial hypothalamus, and genetics all produce hypoactivity. Providing a better understanding of the biological determinants involved in the regulation of activity has important implications for the development of strategies for the prevention of weight gain leading to obesity and subsequent morbidity and mortality in the human population. C1 NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA 94035 USA. Lockheed Martin Engn & Sci, Moffett Field, CA 94035 USA. RP Wade, CE (reprint author), NASA, Ames Res Ctr, Div Life Sci, MS 239-11, Moffett Field, CA 94035 USA. EM cwade@mail.arc.nasa.gov NR 119 TC 74 Z9 74 U1 2 U2 8 PU ROYAL SOC MEDICINE PRESS LTD PI LONDON PA 1 WIMPOLE STREET, LONDON W1G 0AE, ENGLAND SN 1535-3702 EI 1535-3699 J9 EXP BIOL MED JI Exp. Biol. Med. PD SEP PY 2002 VL 227 IS 8 BP 587 EP 600 PG 14 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA 587KT UT WOS:000177640100006 PM 12192100 ER PT J AU Tunstel, E Howard, A Seraji, H AF Tunstel, E Howard, A Seraji, H TI Rule-based reasoning and neural network perception for safe off-road robot mobility SO EXPERT SYSTEMS LA English DT Article DE safe navigation; planetary rovers; neural networks; fuzzy logic; off-road mobility ID TRACTION CONTROL; TERRAIN; NAVIGATION; VEHICLES; BRAKING AB Operational safety and health monitoring are critical matters for autonomous field mobile robots such as planetary rovers operating on challenging terrain. This paper describes relevant rover safety and health issues and presents an approach to maintaining vehicle safety in a mobility and navigation context. The proposed rover safety module is composed of two distinct components: safe attitude (pitch and roll) management and safe traction management. Fuzzy logic approaches to reasoning about safe attitude and traction management are presented, wherein inertial sensing of safety status and vision-based neural network perception of terrain quality are used to infer safe speeds of traversal. Results of initial field tests and laboratory experiments are also described. The approach provides an intrinsic safety cognizance and a capacity for reactive mitigation of robot mobility and navigation risks. C1 CALTECH, Jet Prop Lab, Robot Vehicles Grp, Pasadena, CA 91109 USA. CALTECH, Jet Prop Lab, Telerobot Res & Applicat Grp, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, Robot Vehicles Grp, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM tunstel@robotics.jpl.nasa.gov NR 23 TC 10 Z9 10 U1 0 U2 1 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0266-4720 EI 1468-0394 J9 EXPERT SYST JI Expert Syst. PD SEP PY 2002 VL 19 IS 4 BP 191 EP 200 DI 10.1111/1468-0394.00204 PG 10 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods SC Computer Science GA 598UH UT WOS:000178294500002 ER PT J AU Seki, MP Polovina, JJ Kobayashi, DR Bidigare, RR Mitchum, GT AF Seki, MP Polovina, JJ Kobayashi, DR Bidigare, RR Mitchum, GT TI An oceanographic characterization of swordfish (Xiphias gladius) longline fishing grounds in the springtime subtropical North Pacific SO FISHERIES OCEANOGRAPHY LA English DT Article DE chloropigments; mesoscale variability; physical-biological coupling; satellite altimetry; Sub-tropical Front; Xiphias gladius ID DEEP CHLOROPHYLL MAXIMUM; COMMUNITY STRUCTURE; PIGMENT SIGNATURES; CATCH RATES; OCEAN; VARIABILITY; FRONTS; ATLANTIC; DISTRIBUTIONS; ASSOCIATION AB During January-May, surface manifestation of multiple, individual basin-scale fronts accentuate the central North Pacific Subtropical Frontal Zone (STFZ) system. The most prominent of these fronts are climatologically located at 32degrees-34degreesN and at 28degrees-30degreesN latitudes [herein nominally referred to as the 'Subtropical Front' (STF) and the 'South Subtropical Front' (SSTF), respectively], although considerable interannual variability in both position and intensity is observed. This seasonally dynamic system is also the region typically targeted by the Hawaii-based swordfish (Xiphias gladius ) longline fishing fleet, where the presence, position, and strength of the convergent fronts are believed to play a key role with regard to the catch and catch rates of swordfish. Information furnished by a recent series of meridional hydrographic surveys and concurrent satellite remote sensing data elucidate structural patterns and coupling of the physics and biology associated with these fronts. This enables a re-characterization of the spring North Pacific STFZ and offers new insight into the seasonal variability of the phytoplankton dynamics in the subtropical North Pacific. On synoptic time scales, geographical positioning of the fronts may be systematically identified through surface outcropping of diagnostic thermohaline isopleths and therefore readily discerned from both shipboard surveys and by spaceborne sensors. The STF during spring can be characterized by the surface expression of the 34.8 isohaline and the 17degreesC isotherm within the frontal gradient. Biologically, the STF marks the transition from low chloropigment (chlorophyll + phaeopigments), nutrient-depleted surface waters to the south to a more productive regime to the north. To the south, the 20degreesC and 35.0 surface isotherm and isohaline, respectively, are characteristically embedded in the thermohaline gradients associated with the SSTF. A sharp increase in depth-integrated chloropigment is also observed at the SSTF and is ascribed to an increase in the concentration and thickness of the subsurface chloropigment maximum (SCM) prompted by the shoaling of the nutricline with the thermocline structure into the euphotic zone. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Dept Oceanog, Honolulu, HI 96822 USA. Univ S Florida, St Petersburg, FL 33701 USA. RP Seki, MP (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, 2570 Dole St, Honolulu, HI 96822 USA. NR 58 TC 51 Z9 53 U1 0 U2 6 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD SEP PY 2002 VL 11 IS 5 BP 251 EP 266 DI 10.1046/j.1365-2419.2002.00207.x PG 16 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 599QW UT WOS:000178347500001 ER PT J AU de Viron, O Dickey, JO Marcus, SL AF de Viron, O Dickey, JO Marcus, SL TI Effect of changes in total atmospheric mass on length-of-day modeling SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANGULAR-MOMENTUM; SYSTEM AB [1] The Earth's rotation rate, and the associated length-of-day (LOD), show fluctuations at different timescales. At the decadal timescale, this is due mainly to the interaction between the mantle and the liquid core, while the variations at shorter time scales are attributed to interaction with the external fluid layers, in particular the atmosphere, with the oceans and hydrology contributing at about the 1% level. In this paper, we investigate the effect of changes of atmospheric mass on the length-of-day modeling, which are associated with evaporation/precipitation and mass closure problems in the atmospheric analyses. We show that an important part of the residuals between observed LOD and the ocean and atmosphere induced LOD variations can be explained by this mass exchange. C1 Royal Observ Belgium, Brussels, Belgium. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP de Viron, O (reprint author), Royal Observ Belgium, Brussels, Belgium. RI de Viron, Olivier/N-6647-2014 OI de Viron, Olivier/0000-0003-3112-9686 NR 12 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 2002 VL 29 IS 17 AR 1849 DI 10.1029/2002GL015572 PG 3 WC Geosciences, Multidisciplinary SC Geology GA 635KF UT WOS:000180397500030 ER PT J AU Hu, H Liu, WT AF Hu, H Liu, WT TI QuikSCAT reveals the surface circulation of the Catalina Eddy SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID KELVIN WAVES; CALIFORNIA; SIMULATION; PREDICTION AB [1] The Catalina Eddy, a small, recurring cyclonic vortex in the ocean off Los Angeles, is of keen interest to local weather forecasters because of the moderating oceanic effect it brings to the city. Its small size and shallow vertical extent have made it difficult to monitor and predict using conventional data. The microwave scatterometer on the QuikSCAT spacecraft has generated high-resolution surface wind vectors that provide the first visualization of the complete cyclonic flow of the eddy. Moreover, the superior performance of the QuikSCAT scatterometer demonstrates the relative inaccuracy and inconsistency of predictions of the eddy based upon numerical weather prediction models. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hu, H (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-323, Pasadena, CA 91109 USA. NR 19 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 2002 VL 29 IS 17 AR 1821 DI 10.1029/2001GL014203 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 635KF UT WOS:000180397500002 ER PT J AU Pan, JY Yan, XH Zheng, QN Liu, WT AF Pan, JY Yan, XH Zheng, QN Liu, WT TI Observation of western boundary current atmospheric convergence zones using scatterometer winds SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB [1] A merged scatterometer wind data set from ERS-1/2, NSCAT, and QuikSCAT missions was used to observe the atmospheric convergence zones (ACZs) caused by the western boundary currents, the Gulf Stream and Kuroshio. The long-term means of the atmospheric convergence show the ACZs' spatial features, which are related to the precipitation patterns in these regions. Seasonal images of the ACZs were produced to show annual cycles of the ACZs, indicating that the intensities of the ACZs over these two regions strengthen in winter and weaken in summer. Furthermore, we calculated the total convergence over the Gulf Stream and Kuroshio ACZs, which is defined as the integral of the convergence over the ACZs. The interannual variability of the total convergence was extracted by using a multi-stage filter, revealing that in response to strong El Nino events in 1991-92 and 1997-98, the total convergence reached maxima. C1 Univ Delaware, Grad Coll Marine Studies, Newark, DE 19716 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Ocean Univ Qingdao, Ocean Remote Sensing Inst, Qingdao, Peoples R China. RP Pan, JY (reprint author), Univ Delaware, Grad Coll Marine Studies, Newark, DE 19716 USA. RI Zheng, Quanan/F-9025-2010 NR 7 TC 7 Z9 7 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 2002 VL 29 IS 17 AR 1832 DI 10.1029/2002GL015015 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 635KF UT WOS:000180397500013 ER PT J AU Sato, OT Polito, PS Liu, WT AF Sato, OT Polito, PS Liu, WT TI Intra-decadal variability in the Ekman heat flux from scatterometer winds SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATLANTIC-OCEAN; NORTH-ATLANTIC; WORLD OCEAN; TRANSPORT; MECHANISMS; INTERFACE; LATITUDE AB [1] We examine evidences of low frequency variability in the Ekman heat flux due to changes in the global temperature and wind patterns. The 10-year long time series of high resolution surface wind vectors was provided by the European Remote Sensing Satellites 1 and 2. A linear regression of the zonally averaged Ekman heat flux shows a latitudinal trend for the period between 1992 and 1997. This trend indicates a decrease in the poleward Ekman heat flux of warmer waters from the tropics and a slight decrease in the equatorward flux in the high latitudes. This intra-decadal trend ended after the 1998 El Nino event. These variations are mostly due to changes in the wind stress field. The decrease in the poleward Ekman heat flux may have far reaching consequences involving the global heat balance. C1 Inst Nacl Pesquisas Espaciais, Div Sensoriamento Remoto, SERE 2, BR-12227010 Sao Jose Dos Campos, Brazil. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Sato, OT (reprint author), Inst Nacl Pesquisas Espaciais, Div Sensoriamento Remoto, SERE 2, Ave Astronautas 1758, BR-12227010 Sao Jose Dos Campos, Brazil. RI Polito, Paulo/F-3040-2013; Sato, Olga/G-3656-2013 OI Polito, Paulo/0000-0003-2217-3853; Sato, Olga/0000-0003-0751-4373 NR 21 TC 2 Z9 2 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 2002 VL 29 IS 17 AR 1831 DI 10.1029/2002GL014775 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 635KF UT WOS:000180397500012 ER PT J AU Schafer, JS Eck, TF Holben, BN Artaxo, P Yamasoe, MA Procopio, AS AF Schafer, JS Eck, TF Holben, BN Artaxo, P Yamasoe, MA Procopio, AS TI Observed reductions of total solar irradiance by biomass-burning aerosols in the Brazilian Amazon and Zambian Savanna SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SINGLE SCATTERING ALBEDO; OPTICAL-PROPERTIES; ABSORPTION; AERONET AB [1] Several aerosol and solar flux monitoring sites were established in Brazil for the Large Scale Biosphere-Atmosphere Experiment in Amazonia project. CIMEL sunphotometers and collocated pyranometers were employed at two southern Amazonian sites in order to quantify instantaneous reductions of total irradiance due to high aerosol optical thickness (AOT) smoke events (relative to values modeled for background aerosol conditions). Results from the Brazilian sites are presented for 1999 and for comparison, a similar analysis is discussed for data from three south-central African sites during the burning season of 2000. The relative reductions in total irradiance at the surface resulting from biomass burning aerosol are observed to be substantial at all sites, ranging from 16% for an aerosol optical thickness (500 nm) of 1.0 for the Brazilian sites to an average rate of 22% for the African sites. For a solar zenith interval (25-35degrees), these rates equate to reductions of roughly 145 W/m(2) and 210 W/m(2) respectively, for an AOT = 1.0. Instantaneous reductions of 337 W/m(2) were observed for the heaviest smoke conditions (AOT: similar to3.0) in Brazil. C1 SSAI, Lanham, MD 20706 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. Univ Sao Paulo, Inst Fis, Dept Fis Aplicada, BR-05508900 Sao Paulo, Brazil. RP Schafer, JS (reprint author), SSAI, Lanham, MD 20706 USA. RI Procopio, Aline/B-3367-2008; Schafer, Joel/A-3978-2010; ECK, THOMAS/D-7407-2012; Yamasoe, Marcia/L-3667-2013; Artaxo, Paulo/E-8874-2010; S. Procopio, Aline/L-7483-2013 OI Yamasoe, Marcia/0000-0003-3066-9146; Artaxo, Paulo/0000-0001-7754-3036; S. Procopio, Aline/0000-0002-2326-2500 NR 18 TC 30 Z9 31 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 2002 VL 29 IS 17 AR 1823 DI 10.1029/2001GL014309 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 635KF UT WOS:000180397500004 ER PT J AU Vasilkov, AP Joiner, J Gleason, J Bhartia, PK AF Vasilkov, AP Joiner, J Gleason, J Bhartia, PK TI Ocean Raman scattering in satellite backscatter UV measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article DE ultraviolet radiation; Ring effect; Raman scattering. ID ULTRAVIOLET MEASUREMENTS; OPTICAL-PROPERTIES; WATER; ATMOSPHERE; SPECTRUM; MODEL; NM AB [1] Vibrational Raman scattering by liquid water (ocean Raman scattering) significantly contributes to the filling-in of solar Fraunhofer lines observed by satellite backscatter ultraviolet (buv) instruments in the cloudless atmosphere over clear ocean waters. A radiative transfer model accounting for this effect in buv measurements has been developed and the results compared with observations from the European Space Agency's Global Ozone Monitoring Experiment (GOME). The model extends existing models for ocean Raman scattering to the UV spectral range. Ocean Raman scattering radiance is propagated through the atmosphere using a concept of the Lambert equivalent reflectivity and an accurate radiative transfer model for Rayleigh scattering. The good agreement between model and observations suggests that buv instruments may be useful for estimating chlorophyll and dissolved organic matter contents. C1 Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Vasilkov, AP (reprint author), Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RI Joiner, Joanna/D-6264-2012; Gleason, James/E-1421-2012; Bhartia, Pawan/A-4209-2016 OI Bhartia, Pawan/0000-0001-8307-9137 NR 16 TC 20 Z9 20 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 2002 VL 29 IS 17 AR 1837 DI 10.1029/2002GL014955 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 635KF UT WOS:000180397500018 ER PT J AU Lefsky, MA Cohen, WB Harding, DJ Parker, GG Acker, SA Gower, ST AF Lefsky, MA Cohen, WB Harding, DJ Parker, GG Acker, SA Gower, ST TI Lidar remote sensing of above-ground biomass in three biomes SO GLOBAL ECOLOGY AND BIOGEOGRAPHY LA English DT Article DE above-ground biomass; biomass measurement; carbon storage; global carbon cycle; forest biomass; interbiome comparison; lidar remote sensing; SLICER sensor ID LEAF-AREA INDEX; DECIDUOUS FORESTS; LASER ALTIMETER; VEGETATION; CANOPY; ECOSYSTEM AB Estimation of the amount of carbon stored in forests is a key challenge for understanding the global carbon cycle, one which remote sensing is expected to help address. However, estimation of carbon storage in moderate to high biomass forests is difficult for conventional optical and radar sensors. Lidar (light detection and ranging) instruments measure the vertical structure of forests and thus hold great promise for remotely sensing the quantity and spatial organization of forest biomass. In this study, we compare the relationships between lidar-measured canopy structure and coincident field measurements of above-ground biomass at sites in the temperate deciduous, temperate coniferous, and boreal coniferous biomes. A single regression for all three sites is compared with equations derived for each site individually. The single equation explains 84% of variance in above-ground biomass (P < 0.0001) and shows no statistically significant bias in its predictions for any individual site. C1 Oregon State Univ, Forest Sci Lab, Corvallis, OR 97331 USA. US Forest Serv, USDA, Forest Sci Lab, Corvallis, OR 97331 USA. NASA, Goddard Space Flight Ctr, Geodynam Branch, Greenbelt, MD 20771 USA. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. Natl Pk Serv, Seattle, WA 98104 USA. Univ Wisconsin, Dept Forest Ecol & Management, Madison, WI 53706 USA. RP Lefsky, MA (reprint author), Colorado State Univ, Dept Forestry Sci, Forestry Bldg 131, Ft Collins, CO 80523 USA. RI Lefsky, Michael/A-7224-2009; Harding, David/F-5913-2012; OI Parker, Geoffrey/0000-0001-7055-6491 NR 24 TC 233 Z9 253 U1 8 U2 96 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0960-7447 J9 GLOBAL ECOL BIOGEOGR JI Glob. Ecol. Biogeogr. PD SEP PY 2002 VL 11 IS 5 BP 393 EP 399 DI 10.1046/j.1466-822x.2002.00303.x PG 7 WC Ecology; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA 596WQ UT WOS:000178189800004 ER PT J AU Suleiman-Rosado, D Hinkley, JA AF Suleiman-Rosado, D Hinkley, JA TI The solubility of polyimides in polar aprotic solvents SO HIGH PERFORMANCE POLYMERS LA English DT Article DE solubility; polyimides; phase equilibria; isomers AB Activity coefficients and Gibbs free energies of mixing were calculated for aromatic polyimides in various polar aprotic solvents. Group additivity approaches were used to derive approximate solubility parameters for the polymers. Free energies of mixing were found to be negative, and limiting activity coefficients were indicative of very strong solvating forces. Contrary to experiment, these results would predict complete miscibility. Two explanations are proposed for these findings: (i) a single cohesive energy density parameter may not properly characterize specific interactions; and (ii) even nominally amorphous samples may contain various degrees of crystalline-like order which provide additional free energy differences. C1 Univ Puerto Rico, Dept Chem Engn, Mayaguez, PR 00681 USA. NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. RP Suleiman-Rosado, D (reprint author), Univ Puerto Rico, Dept Chem Engn, Mayaguez, PR 00681 USA. NR 19 TC 1 Z9 1 U1 1 U2 4 PU SAGE PUBLICATIONS LTD PI LONDON PA 6 BONHILL STREET, LONDON EC2A 4PU, ENGLAND SN 0954-0083 J9 HIGH PERFORM POLYM JI High Perform. Polym. PD SEP PY 2002 VL 14 IS 3 BP 317 EP 323 PG 7 WC Polymer Science SC Polymer Science GA 617WE UT WOS:000179383200008 ER PT J AU Tango-Lowy, T Robertson, RA AF Tango-Lowy, T Robertson, RA TI Predisposition toward adoption of open ocean aquaculture by Northern New England's inshore, commercial fishermen SO HUMAN ORGANIZATION LA English DT Article DE aquaculture; commercial fishermen; technology transfer; New England ID INNOVATION AB Aquaculture has been promoted as an enterprise that will provide regional economic development, new employment opportunities for displaced fishers. and the replenishment of commercially important fish stock. Conversely, how will open ocean aquaculture fit into the occupational life of the traditional Northern New England inshore, commercial fisher? Our objective was to identify those fishers with a predisposition to adopt the innovation, as determined by the relationship between the probability of potential adoption and particular explanatory variables. We drew upon adoption of innovations research and fishing-specific studies to establish the explanatory variables: fishers' attitudes toward specific innovation attributes and their personal and situational characteristics. Results suggest that nearly one-third of those surveyed were willing to consider adoption of open ocean aquaculture. We found adoption research to be effective in formulating a model that yielded statistically significant explanatory variables relative to the dependent variable. Respondents' fishing characteristics, communication behavior, and attitudes toward specific innovation attributes were the best predictors in the model. Open ocean aquaculture programs specifically designed to address the needs and interests of these fishers could serve to encourage adoption of the innovation and increase adoption success. C1 Univ New Hampshire, Dept Resource Econ & Dev, Durham, NH 03824 USA. Univ New Hampshire, Open Ocean Aquaculture Demonstrat Project, Durham, NH 03824 USA. Natl Marine Fisheries Serv, Gloucester, MA USA. NR 33 TC 12 Z9 12 U1 0 U2 3 PU SOC APPLIED ANTHROPOLOGY PI OKLAHOMA CITY PA 3000 UNITED FOUNDERS BLVD, STE 148, OKLAHOMA CITY, OK 73112 USA SN 0018-7259 J9 HUM ORGAN JI Hum. Organ. PD FAL PY 2002 VL 61 IS 3 BP 240 EP 251 PG 12 WC Anthropology; Social Sciences, Interdisciplinary SC Anthropology; Social Sciences - Other Topics GA 596MV UT WOS:000178169400005 ER PT J AU Baines, KH Carlson, RW Kamp, LW AF Baines, KH Carlson, RW Kamp, LW TI Fresh ammonia ice clouds in Jupiter - I. Spectroscopic identification, spatial distribution, and dynamical implications SO ICARUS LA English DT Article DE atmospheres; composition; atmospheres, dynamics; ices; Jupiter, atmosphere; spectrophotometry ID FOURIER-TRANSFORM SPECTRA; NORTH EQUATORIAL BELT; GALILEO PROBE; HOT-SPOTS; ATMOSPHERIC COMPOSITION; JOVIAN ATMOSPHERE; PLANETARY-WAVES; SPECTROMETER; (NH3)-N-14; OPACITY AB We report the first spectroscopic detection of discrete ammonia ice clouds in the atmosphere of Jupiter, as discovered utilizing the Galileo Near-Infrared Mapping Spectrometer (NIMS). Spectrally identifiable ammonia clouds (SIACs) cover less than 1% of the globe, as measured in complete global imagery obtained in September 1996 during Galileo's second orbit. More than half of the most spectrally prominent SIACs reside within a small latitudinal band, extending from 2degrees to 7degrees N latitude, just south of the 5-mum hot spots. The most prominent of these are spatially correlated with nearby 5-mum-bright hot spots lying 1.5degrees-3.0degrees of latitude to the north: they reside over a small range of relative longitudes on the eastward side of hot spots, about 37% of the longitudinal distance to the next hot spot to the east. This strong correlation between the positions of hot spots and the most prominent equatorial SIACs suggests that they are linked by a common planetary wave. Good agreement is demonstrated between regions of condensation predicted by the Rossby wave model of A. J. Friedson and G. S. Orton (1999, Bull. Am. Astron. Assoc 31, 1155-1156) and the observed longitudinal positions of fresh ammonia clouds relative to 5-mum hot spots. Consistency is also demonstrated between (1) the lifetime of particles as determined by the wave phase speed and cloud width and (2) the sedimentation time for 10-mum radius particles consistent with previously reported ammonia particle size by T. Y. Brooke et al. (1998, Icarus 136, 1-13). A young age ( direction. Complete spanning of the interiors of V's and other mesa shapes with concave corners by webbed cantilevers was accomplished. Optical microscopy, synchrotron white beam x-ray topography and atomic force microscopy analysis of webbed regions formed over a micropipe and closed-core screw dislocations show that c-axis propagation of these defects is terminated by the webbing. Despite the nonoptimized process employed in this initial study, webbed surfaces as large as 1.4x10(-3) cm(2), more than four times the pregrowth mesa area, were grown. However, the largest webbed surfaces were not completely free of bilayer steps, due to unintentional growth of 3C-SiC that occurred in the nonoptimized process. Further process optimization should enable larger step-free webs to be realized. (C) 2002 American Institute of Physics. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. OAI, Cleveland, OH 44135 USA. SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. RP NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 77-1, Cleveland, OH 44135 USA. EM neudeck@grc.nasa.gov NR 28 TC 29 Z9 29 U1 2 U2 15 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 2002 VL 92 IS 5 BP 2391 EP 2400 DI 10.1063/1.1497456 PG 10 WC Physics, Applied SC Physics GA 585WX UT WOS:000177548500028 ER PT J AU Minnis, P Nguyen, L Doelling, DR Young, DF Miller, WF Kratz, DP AF Minnis, P Nguyen, L Doelling, DR Young, DF Miller, WF Kratz, DP TI Rapid calibration of operational and research meteorological satellite imagers. Part I: Evaluation of research satellite visible channels as references SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID RAINFALL MEASURING MISSION; ENERGY SYSTEM CERES; NEAR-INFRARED CHANNELS; CLOUD; SPACECRAFT; REFLECTANCE; ALGORITHM; EOS-AM1; SCANNER; SENSORS AB Operational meteorological satellites generally lack reliable onboard calibration systems for solar-imaging channels. Current methods for calibrating these channels and for normalizing similar channels on contemporaneous satellite imagers typically rely on a poorly calibrated reference source. To establish a more reliable reference instrument for calibration normalization, this paper examines the use of research satellite imagers that maintain their solar-channel calibrations by using onboard diffuser systems that rely on the sun as an absolute reference. The Visible Infrared Scanner (VIRS) on the Tropical Rainfall Measuring Mission (TRMM) satellite and the second Along-Track Scanning Radiometer (ATSR-2) on the second European Remote Sensing Satellite (ERS-2) are correlated with matched data from the eighth Geostationary Operational Environmental Satellite (GOES-8), the fifth Geostationary Meteorological satellite (GMS-5), and with each other to examine trends in the solar channels. VIRS data are also correlated with the Terra satellite's Moderate Resolution Imaging Spectroradiometer (MODIS) provisional data as a preliminary assessment of their relative calibrations. As an additional check on their long-term stability, the VIRS data are compared to the relevant corresponding broadband shortwave radiances of the Clouds and the Earth's Radiant Energy System (CERES) scanners on TRMM. No statistically significant trend in the calibration of the VIRS 0.65- and 1.64-mum channels could be detected from the comparisons with CERES data taken during 1998 and 2000. The VIRS-to-GOES-8 correlations revealed an annual degradation rate for the GOES-8 visible (0.67 mm) channel of similar to7.5% and an initial drop of 16% in the gain from the prelaunch value. The slopes in the GOES-8 visible-channel gain trend lines derived from VIRS data taken after January 1998 and ATSR-2 data taken between October 1995 and December 1999 differed by only 1%-2% indicating that both reference instruments are highly stable. The mean difference of 3%-4.8% between the VIRS-GOES-8 and ATSR-2-GOES-8 gains is attributed to spectral differences between ATSR-2 and VIRS and to possible biases in the ATSR-2 channel-2 calibration. A degradation rate of 1.3% per year found for the GMS-5 visible channel was confirmed by comparisons with earlier calibrations. The MODIS and VIRS calibrations agreed to within 21% to 3%. Some of the differences between VIRS and the provisional MODIS radiances can be explained by spectral differences between the two instruments. The MODIS measures greater reflectance than VIRS for bright scenes. Although both VIRS and ATSR-2 provide temporally stable calibrations, it is recommended that, at least until MODIS calibrations are finalized, VIRS should be used as a reference source for normalizing operational meteorological satellite imagers because of its broader visible filter. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Analyt Serv & Mat Inc, Hampton, VA 23666 USA. Sci Applicat Int Corp, Hampton, VA USA. RP Minnis, P (reprint author), NASA, Langley Res Ctr, MS 420, Hampton, VA 23681 USA. RI Minnis, Patrick/G-1902-2010 OI Minnis, Patrick/0000-0002-4733-6148 NR 40 TC 71 Z9 71 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD SEP PY 2002 VL 19 IS 9 BP 1233 EP 1249 DI 10.1175/1520-0426(2002)019<1233:RCOOAR>2.0.CO;2 PG 17 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 588RT UT WOS:000177715000001 ER PT J AU Minnis, P Nguyen, L Doelling, DR Young, DF Miller, WF Kratz, DP AF Minnis, P Nguyen, L Doelling, DR Young, DF Miller, WF Kratz, DP TI Rapid calibration of operational and research meteorological satellite imagers. Part II: Comparison of infrared channels SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID RAINFALL MEASURING MISSION; ENERGY SYSTEM CERES; CLOUD; SCANNER; SPACECRAFT; ALGORITHM; EOS-AM1 AB To establish a more reliable reference instrument for calibration normalization, this paper examines the differences between the various thermal infrared imager channels on a set of research and operational satellites. Mean brightness temperatures from the Visible Infrared Scanner (VIRS) on the Tropical Rainfall Measuring Mission (TRMM) satellite and the second Along-Track Scanning Radiometer (ATSR-2) on the second European Remote Sensing Satellite (ERS-2) are correlated with matched data from the eighth Geostationary Operational Environmental Satellite (GOES-8), the fifth Geostationary Meteorological Satellite (GMS-5), and with each other. VIRS data are also correlated with the Terra satellite's Moderate Resolution Imaging Spectroradiometer (MODIS) provisional data as a preliminary assessment of their relative calibrations. As an additional check on their long-term stability, the VIRS data are compared to the broadband longwave radiances of the Clouds and the Earth's Radiant Energy System (CERES) scanners on TRMM. No statistically significant trend in the calibration of any of the three (3.7, 10.8, and 12.0 mum) VIRS thermal channels could be detected from the comparisons with CERES data taken during 1998 and 2000 indicating that the VIRS channels can serve as a reliable reference for intercalibrating satellite imagers. However, a small day-night difference in the VIRS thermal channels detected at very low temperatures should be taken into account. In general, most of the channels agreed to within less than +/-0.7 K over a temperature range between 200 and 300 K. Some of the smaller differences can be explained by spectral differences in the channel response functions. A few larger differences were found at 200 K for some of the channels suggesting some basic calibration differences for lower temperatures. A nearly 3-K bias in the ATSR-2 11-mum channel relative to VIRS and GOES-8 was found at the cold end of the temperature range. The intercalibrations described here are being continued on a routine basis. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Analyt Serv & Mat Inc, Hampton, VA USA. Sci Applicat Int Corp, Hampton, VA USA. RP Minnis, P (reprint author), NASA, Langley Res Ctr, MS 420, Hampton, VA 23681 USA. RI Minnis, Patrick/G-1902-2010 OI Minnis, Patrick/0000-0002-4733-6148 NR 25 TC 36 Z9 36 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD SEP PY 2002 VL 19 IS 9 BP 1250 EP 1266 DI 10.1175/1520-0426(2002)019<1250:RCOOAR>2.0.CO;2 PG 17 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 588RT UT WOS:000177715000002 ER PT J AU Boccippio, DJ Koshak, WJ Blakeslee, RJ AF Boccippio, DJ Koshak, WJ Blakeslee, RJ TI Performance assessment of the optical transient detector and lightning Imaging sensor. Part I: Predicted diurnal variability SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID CLOUDS AB Laboratory calibration and observed background radiance data are used to determine the effective sensitivities of the Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS), as functions of local hour and pixel location within the instrument arrays. The effective LIS thresholds, expressed as radiances emitted normal to cloud top, are 4.0 +/- 0.7 and 7.6 +/- 3.3 muJ sr(-1) m(-2) for night and local noon; the OTD thresholds are 11.7 +/- 2.2 and 16.8 +/- 4.6 muJ sr(-1) m(-2). LIS and OTD minimum signal-to-noise ratios occur from 0800 to 1600 local time, and attain values of 10 6 2 and 20 6 3, respectively. False alarm rate due to instrument noise yields similar to5 false triggers per month for LIS, and is negligible for OTD. Flash detection efficiency, based on prior optical pulse sensor measurements, is predicted to be 93 +/- 4% and 73 +/- 11% for LIS night and noon; 56 +/- 7% and 44 +/- 9% for OTD night and noon, corresponding to a 12%-20% diurnal variability and LIS: OTD ratio of 1.7. Use of the weighted daily mean detection efficiency (i.e., not controlling for local hour) corresponds to sigma = 8%-9% uncertainty. These are likely overestimates of actual flash detection efficiency due to differences in pixel ground field of view across the instrument arrays that are not accounted for in the validation optical pulse sensor data. C1 NASA, Marshall Space Flight Ctr SD60, Natl Space Sci & Technol Ctr, Huntsville, AL 35812 USA. RP Boccippio, DJ (reprint author), NASA, Marshall Space Flight Ctr SD60, Natl Space Sci & Technol Ctr, Huntsville, AL 35812 USA. NR 14 TC 122 Z9 142 U1 1 U2 16 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD SEP PY 2002 VL 19 IS 9 BP 1318 EP 1332 DI 10.1175/1520-0426(2002)019<1318:PAOTOT>2.0.CO;2 PG 15 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 588RT UT WOS:000177715000007 ER PT J AU Negri, AJ Bell, TL Xu, LM AF Negri, AJ Bell, TL Xu, LM TI Sampling of the diurnal cycle of precipitation using TRMM SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SATELLITE INFRARED TECHNIQUE; MEASURING MISSION TRMM; RAINFALL; VARIABILITY; ERROR AB The temporal sampling of tropical regions is examined using observations from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and precipitation radar (PR). It is concluded that PR estimates at any one hour, even using three years of data, are inadequate to describe the diurnal cycle of precipitation over regions smaller than 12degrees, due to high spatial variability in sampling. It is shown that the optimum period of accumulation is 4 h. Diurnal signatures display half as much sampling error when averaged over 4 h of local time. A similar pattern of sampling variability is found in the TMI data, despite the TMI's wider swath and increased sampling. These results are verified using an orbital model. The sensitivity of the sampling to satellite altitude is presented, as well as sampling patterns at the new TRMM altitude of 402.5 km. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. RP Negri, AJ (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Bldg 33,Room C408,Code 912, Greenbelt, MD 20771 USA. RI Bell, Thomas/G-5425-2012 NR 13 TC 91 Z9 96 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD SEP PY 2002 VL 19 IS 9 BP 1333 EP 1344 DI 10.1175/1520-0426(2002)019<1333:SOTDCO>2.0.CO;2 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 588RT UT WOS:000177715000008 ER PT J AU Shiiba, M Arnaud, SB Tanzawa, H Kitamura, E Yamauchi, M AF Shiiba, M Arnaud, SB Tanzawa, H Kitamura, E Yamauchi, M TI Regional alterations of type I collagen in rat tibia induced by skeletal unloading SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Article DE type I collagen; cross-link; lysyl hydroxylation; bone region; tail suspension ID WEIGHT-BEARING BONES; MESSENGER-RNA LEVEL; CROSS-LINKING; POSTTRANSLATIONAL MODIFICATIONS; SIMULATED WEIGHTLESSNESS; MOLECULAR PACKING; CELLS; DIFFERENTIATION; SPACEFLIGHT; LIGAMENT AB Skeletal unloading induces loss of mineral density in weight-bearing bones that leads to inferior bone mechanical strength. This appears to be caused by a failure of bone formation; however, its mechanisms still are not well understood. The objective of this study was to characterize collagen, the predominant matrix protein in bone, in various regions of tibia of rats that were subjected to skeletal unloading by 4 weeks tail suspension. Sixteen male Sprague-Dawley rats (4 months old) were divided into tail suspension and ambulatory controls (eight rats each). After the tail suspension, tibias from each animal were collected and divided into five regions and collagen was analyzed. The collagen cross-linking and the extent of lysine (Lys) hydroxylation in unloaded bones were significantly altered in proximal epiphysis, diaphysis, and, in particular, proximal metaphysis but not in distal regions. The pool of immature/nonmineralized collagen measured by its extractability with a chaotropic solvent was significantly increased in proximal metaphysis. These results suggest that skeletal unloading induced an accumulation of post-translationally altered norunineralized collagen and that these changes are bone region specific. These alterations might be caused by impaired osteoblastic function/differentiation resulting in a mineralization defect. C1 Univ N Carolina, Dent Res Ctr, Chapel Hill, NC 27599 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Chiba Univ, Sch Med, Dept Oral Surg, Chiba 280, Japan. RP Yamauchi, M (reprint author), Univ N Carolina, Dent Res Ctr, CB 7455, Chapel Hill, NC 27599 USA. FU NIDCR NIH HHS [DE10489] NR 35 TC 20 Z9 20 U1 0 U2 2 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2002 VL 17 IS 9 BP 1639 EP 1645 DI 10.1359/jbmr.2002.17.9.1639 PG 7 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 586ZN UT WOS:000177616200010 PM 12211434 ER PT J AU Arnaud, SB Cephas, S De Paoli, A Sayavongsa, P Locklear, S Thierry-Palmer, M AF Arnaud, SB Cephas, S De Paoli, A Sayavongsa, P Locklear, S Thierry-Palmer, M TI The kidney and the calcium endocrine system of one-year-old Dahl salt-sensitive and salt-resistant male rats. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract CT 24th Annual Meeting of the American-Society-for-Bone-and-Mineral-Research CY SEP 20-24, 2002 CL SAN ANTONIO, TEXAS SP American-Soc-Bone-Mineral-Res C1 IDEXX Vet Serv, Sacramento, CA USA. Morehouse Sch Med, Dept Biochem, Atlanta, GA 30310 USA. NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA 94035 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2002 VL 17 SU 1 MA M404 BP S486 EP S486 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 592TK UT WOS:000177952801578 ER PT J AU Globus, RK van der Meulen, MCH Damsky, C Kim, JB Amblard, D Nishimura, Y Almeida, E Iwaniec, UT Wronski, TJ AF Globus, RK van der Meulen, MCH Damsky, C Kim, JB Amblard, D Nishimura, Y Almeida, E Iwaniec, UT Wronski, TJ TI Skeletal phenotype of transgenic mice expressing the beta-1 integrin cytoplasmic tail in osteoblasts. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract CT 24th Annual Meeting of the American-Society-for-Bone-and-Mineral-Research CY SEP 20-24, 2002 CL SAN ANTONIO, TEXAS SP American-Soc-Bone-Mineral-Res C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Cornell Univ, Ithaca, NY USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. Univ Florida, Gainesville, FL USA. RI van der Meulen, Marjolein/D-1549-2010 OI van der Meulen, Marjolein/0000-0001-6637-9808 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2002 VL 17 SU 1 MA SU60 BP S307 EP S307 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 592TK UT WOS:000177952800773 ER PT J AU Shapiro, JR Beck, TJ LeBlanc, A Schneider, V Mustapha, B Shakelford, L Oreskovic, T Ballard, P Ruff, C Toerge, J Caminis, J AF Shapiro, JR Beck, TJ LeBlanc, A Schneider, V Mustapha, B Shakelford, L Oreskovic, T Ballard, P Ruff, C Toerge, J Caminis, J TI Patterns of femoral neck bone loss in spinal cord injury and spaceflight. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract CT 24th Annual Meeting of the American-Society-for-Bone-and-Mineral-Research CY SEP 20-24, 2002 CL SAN ANTONIO, TEXAS SP American-Soc-Bone-Mineral-Res C1 Uniformed Serv Univ Hlth Sci, Bethesda, MD 20814 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Baylor Coll Med, Houston, TX 77030 USA. NASA, Washington, DC 20546 USA. Natl Rehabil Hosp, Washington, DC USA. Lyndon B Johnson Space Ctr, Clearlake, TX USA. Novartis Pharmaceut, E Hanover, NJ USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2002 VL 17 SU 1 MA M170 BP S434 EP S434 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 592TK UT WOS:000177952801344 ER PT J AU Yao, MS Del Genio, AD AF Yao, MS Del Genio, AD TI Effects of cloud parameterization on the simulation of climate changes in the GISS GCM. Part II: Sea surface temperature and cloud feedbacks SO JOURNAL OF CLIMATE LA English DT Article ID GENERAL-CIRCULATION MODELS; TROPICAL PACIFIC; OCEAN MODEL; IMPACT; SENSITIVITY; CO2 AB The influence of the sea surface temperature distribution on cloud feedbacks is studied by making two sets of doubled CO2 experiments with the Goddard Institute for Space Studies (GISS) GCM at 4degrees latitude x 5degrees longitude resolution. One set uses Q fluxes obtained by prescribing observed sea surface temperatures (MODELII'), and the other set uses Q fluxes obtained by prescribing the simulated sea surface temperature of a coupled ocean-atmosphere model (MODELIIO). The global and annual mean surface air temperature change (DeltaT(s)) obtained in MODELII' is reduced from 4.11degrees to 3.02degreesC in MODELIIO. This reduced sensitivity, aside from reduced sea ice/snow-albedo feedback, is mainly due to cloud feedback that becomes nearly neutral in MODELIIO. Furthermore, the negative effect on climate sensitivity of anvil clouds of large optical thickness identified by Yao and Del Genio changes its sign in MODELIIO primarily due to sharply reduced increases of cloud water in the tropical upper troposphere. Colder tropical sea surface temperature in MODELIIO results in weaker deep convective activity and a more humid lower atmosphere in the warmer climate relative to MODELII', which then removes the negative feedback of anvil clouds and sharply reduces the positive feedback of low clouds. However, an overall positive cloud optical thickness feedback is still maintained in MODELIIO. It is suggested that the atmospheric climate sensitivity, partially due to changes in cloud feedbacks, may be significantly different for climate changes associated with different patterns of sea surface temperature change, as for example in warm versus cold paleoclimate epochs. Likewise, the climate sensitivity in coupled atmosphere-ocean models is also likely to be significantly different from the results obtained in Q-flux models due to the different simulations of sea surface temperature patterns in each type of model. C1 NASA, Goddard Space Flight Ctr, Inst Space Studies, GISS, New York, NY 10025 USA. NASA, SGT Inc, Goddard Space Flight Ctr, Inst Space Studies, New York, NY USA. RP Del Genio, AD (reprint author), NASA, Goddard Space Flight Ctr, Inst Space Studies, GISS, 2880 Broadway, New York, NY 10025 USA. RI Del Genio, Anthony/D-4663-2012 OI Del Genio, Anthony/0000-0001-7450-1359 NR 30 TC 9 Z9 10 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 2002 VL 15 IS 17 BP 2491 EP 2503 DI 10.1175/1520-0442(2002)015<2491:EOCPOT>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 586FC UT WOS:000177573100014 ER PT J AU Chou, MD Lindzen, RS AF Chou, MD Lindzen, RS TI Comments on "Tropical convection and the energy balance at the top of the atmosphere'' SO JOURNAL OF CLIMATE LA English DT Editorial Material ID SEA-SURFACE TEMPERATURE; PACIFIC; EARTH; BUDGETS; CLOUDS C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA USA. RP Chou, MD (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 913, Greenbelt, MD 20771 USA. NR 14 TC 6 Z9 6 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 2002 VL 15 IS 17 BP 2566 EP 2570 DI 10.1175/1520-0442(2002)015<2566:COTCAT>2.0.CO;2 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 586FC UT WOS:000177573100022 ER PT J AU Del Genio, AD Kovari, W AF Del Genio, AD Kovari, W TI Climatic properties of tropical precipitating convection under varying environmental conditions SO JOURNAL OF CLIMATE LA English DT Article ID SUPERCOOLED LIQUID WATER; ICE-SCATTERING SIGNATURE; TOGA COARE; CLOUD PARAMETERIZATION; LIGHTNING OBSERVATIONS; MARSHALL ISLANDS; RAINFALL; SYSTEM; MODEL; CIRRUS AB A clustering algorithm is used to define the radiative, hydrological, and microphysical properties of precipitating convective events in the equatorial region observed by the Tropical Rainfall Measuring Mission (TRMM) satellite. Storms are separated by surface type, size, and updraft strength, the latter defined by the presence or absence of lightning. SST data and global reanalysis products are used to explore sensitivity to changes in environmental conditions. Small storms are much more numerous than mesoscale convective systems, and account for fairly little of the total rainfall but contribute significantly to reflection of sunlight. Lightning storms rain more heavily, have greater cloud area, extend to higher altitude, and have higher albedos than storms without lightning. Lightning is favored by a steep lower-troposphere lapse rate and moist midlevel humidity. Storms occur more often at SST greater than or equal to 28degreesC and with strong upward 500-mb mean vertical velocity. In general, storms over warmer ocean waters rain more heavily, are larger, and have higher cloud tops, but they do not have noticeably higher albedos than storms over cooler ocean waters. Mesoscale convective system properties are more sensitive to SST. Rain rates and cloud-top heights increase statistically significantly with mean upward motion. Rain rates increase with albedo and cloud-top height over ocean, but over land there are also storms with cloud-top temperatures > -35degreesC whose rain rates decrease with increasing albedo. Both the fraction of available moisture that rains out and the fraction that detrains as ice increase with SST, the former faster than the latter. TRMM ice water paths derived from cloud-resolving models but constrained by observed microwave radiances are only weakly correlated with observed albedo. The results are inconsistent with the "adaptive iris'' hypothesis and suggest feedbacks due primarily to increasing convective cloud cover with warming, but more weakly than predicted by the "thermostat'' hypothesis. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Del Genio, AD (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. RI Del Genio, Anthony/D-4663-2012 OI Del Genio, Anthony/0000-0001-7450-1359 NR 43 TC 72 Z9 72 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 2002 VL 15 IS 18 BP 2597 EP 2615 DI 10.1175/1520-0442(2002)015<2597:CPOTPC>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 586FD UT WOS:000177573200002 ER PT J AU Chou, MD Lindzen, RS Hou, AY AF Chou, MD Lindzen, RS Hou, AY TI Comments on "The iris hypothesis: A negative or positive cloud feedback?'' SO JOURNAL OF CLIMATE LA English DT Editorial Material ID TROPICAL CIRRUS; EARTH C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA USA. RP Chou, MD (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 913, Greenbelt, MD 20771 USA. RI Hou, Arthur/D-8578-2012 NR 7 TC 11 Z9 15 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 2002 VL 15 IS 18 BP 2713 EP 2715 DI 10.1175/1520-0442(2002)015<2713:COTIHA>2.0.CO;2 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 586FD UT WOS:000177573200012 ER PT J AU Chambers, L Lin, B Wielicki, B Hu, YX Xu, KM AF Chambers, L Lin, B Wielicki, B Hu, YX Xu, KM TI Comments on "The iris hypothesis: A negative or positive cloud feedback?" - Reply SO JOURNAL OF CLIMATE LA English DT Editorial Material ID EARTH C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Chambers, L (reprint author), NASA, Langley Res Ctr, MS 420, Hampton, VA 23681 USA. RI Xu, Kuan-Man/B-7557-2013; Hu, Yongxiang/K-4426-2012 OI Xu, Kuan-Man/0000-0001-7851-2629; NR 5 TC 6 Z9 6 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 2002 VL 15 IS 18 BP 2716 EP 2717 DI 10.1175/1520-0442(2002)015<2716:R>2.0.CO;2 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 586FD UT WOS:000177573200013 ER PT J AU Yamaleev, NK Carpenter, MH AF Yamaleev, NK Carpenter, MH TI On accuracy of adaptive grid methods for captured shocks SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE high-order accuracy; grid adaptation; local grid refinement; grid redistribution; shock capturing; finite difference scheme ID EQUATIONS; ERROR AB The accuracy of two grid adaptation strategies, grid redistribution and local grid refinement, is examined by solving the 2-D Euler equations for the supersonic steady flow around a cylinder. Second- and fourth-order linear finite difference shock-capturing schemes, based on the Lax-Friedrichs flux splitting, are used to discretize the governing equations. The grid refinement study shows that for the second-order scheme, neither grid adaptation strategy improves the numerical solution accuracy compared to that calculated on a uniform grid with the same number of grid points. For the fourth-order scheme, the dominant first-order error component is reduced by the grid adaptation, while the design-order error component drastically increases because of the grid nonuniformity. As a result, both grid adaptation techniques improve the numerical solution accuracy only on the coarsest mesh or on very fine grids that are seldom found in practical applications because of the computational cost involved. Similar error behavior has been obtained for the pressure integral across the shock. A simple analysis shows that both grid adaptation strategies are not without penalties in the numerical solution accuracy. Based on these results, a new grid adaptation criterion for captured shocks is proposed. (C) 2002 Elsevier Science (USA). C1 CNR, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Yamaleev, NK (reprint author), CNR, Hampton, VA 23681 USA. NR 18 TC 7 Z9 7 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 1 PY 2002 VL 181 IS 1 BP 280 EP 316 DI 10.1006/jcph.2002.7125 PG 37 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 593GN UT WOS:000177982800011 ER PT J AU Schupp, JD Duraj, SA Richman, RM Hepp, AF Fanwick, PE AF Schupp, JD Duraj, SA Richman, RM Hepp, AF Fanwick, PE TI The crystal and molecular structure of acetatochlorobis(4-methylpyridine) oxovanadium (IV) SO JOURNAL OF COORDINATION CHEMISTRY LA English DT Article DE vanadyl; carboxylate; crystal structure; oxo; monomeric; vanadium ID VANADIUM; CHEMISTRY; REDOX AB The crystal and molecular structure of the title compound, VOCl(O2CCH3)(4-CH3C5H4N)(2), has been determined by single-crystal X-ray diffraction. The material crystallizes in the space group PI (#2) with a = 7.822(2), b = 8.023(l), c = 14.841(2) Angstrom, alpha = 99.73(1)degrees, beta = 91.41 (1)degrees, and gamma = 117.13(1)degrees. The coordination geometry around the vanadium is a highly distorted octahedron. The molecule is remarkable for being a monomeric oxovanadium(IV) carboxylate. A generalized synthetic strategy is proposed for the preparation of oxovanadium(IV) monomers. C1 NASA, John H Glenn Res Ctr, Thin Film Grp, Cleveland, OH 44135 USA. Cleveland State Univ, Dept Chem, Cleveland, OH 44115 USA. Mt St Marys Coll, Dept Sci, Emmitsburg, MD 21727 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. RP Hepp, AF (reprint author), NASA, John H Glenn Res Ctr, Thin Film Grp, Cleveland, OH 44135 USA. NR 19 TC 1 Z9 1 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0095-8972 J9 J COORD CHEM JI J. Coord. Chem. PD SEP PY 2002 VL 55 IS 9 BP 1045 EP 1051 DI 10.1080/0095897021000010008 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 587MQ UT WOS:000177645300007 ER PT J AU Carter, GA Spiering, BA AF Carter, GA Spiering, BA TI Optical properties of intact leaves for estimating chlorophyll concentration SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article; Proceedings Paper CT Bouyoucos 2000 Conference CY OCT, 2000 CL CORPUS CHRISTI, TEXAS ID REFLECTANCE MEASUREMENTS; SPECTRAL REFLECTANCE; PIGMENT CONCENTRATIONS; EUCALYPTUS LEAVES; REMOTE ESTIMATION; CANOPY SCALES; LEAF; NITROGEN; SPECTROSCOPY; ALGORITHM AB Changes in leaf chlorophyll content can serve as relative indicators of plant vigor and environmental quality. This study identified reflectance, transmittance, and absorptance wavebands and band ratios within the 400- to 850-nm range for intact leaves that could be used to estimate extracted leaf chlorophyll per unit leaf area (areal concentration) with minimal error. Leaf optical properties along with chlorophyll a, b, and a + b concentrations were measured for the planar-leaved sweetgum (Liquidambar styraciflua L.), red maple (Acer rubrum L.), wild grape (Vitis rotundifolia Michx), and switchcane [Arandinaria gigantea (Walter) Muhl.], and for needles of longleaf pine (Pinus palustris Miller). Generally, reflectance, transmittance, and absorptance corresponded most precisely with chlorophyll concentrations at wavelengths near 700 run, although regressions were also strong in the 550- to 625-nm range. A power function was superior to a simple linear function in yielding low standard deviations of the estimate (s). When data were combined among the planar-leaved species, s values were low at approximately 50 mumol/m(2) out of a 940 mumol/m(2) range in chlorophyll a + b at best-fit wavelengths of 707 to 709 nm. Minimal s values for chlorophyll a + b ranged from 32 to 62 mumol/m(2) across species when band ratios having numerator wavelengths of 693 to 720 nm were used with the application of a power function. Optimal denominator wavelengths for the band ratios were 850 nm for reflectance and transmittance and 400 nm for absorptance. This information can be applied in designing field portable chlorophyll meters and in the landscape-scale remote sensing of plant responses to the environment. C1 NASA, Earth Sci Applicat Directorate, Stennis Space Ctr, MS 39529 USA. RP Carter, GA (reprint author), NASA, Earth Sci Applicat Directorate, Stennis Space Ctr, MS 39529 USA. NR 29 TC 66 Z9 74 U1 5 U2 25 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 USA SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD SEP-OCT PY 2002 VL 31 IS 5 BP 1424 EP 1432 PG 9 WC Environmental Sciences SC Environmental Sciences & Ecology GA 596GR UT WOS:000178156800001 PM 12371158 ER PT J AU Hirsch, D Hshieh, FY Beeson, H Pedley, M AF Hirsch, D Hshieh, FY Beeson, H Pedley, M TI Carbon dioxide fire suppressant concentration needs for International Space Station environments SO JOURNAL OF FIRE SCIENCES LA English DT Article DE carbon dioxide; fire suppressant; international space station; microgravity combustion AB Fire suppression onboard spacecraft is a critical issue. Currently, requirements for the International Space Station (ISS) include achieving a 50% concentration of carbon dioxide (CO2) fire suppressant when extinguishing fires. This requirement is in accordance with NFPA 12, the governing standard for CO2 extinguishing systems, which requires concentrations of 50% for smoldering fires and 34% for flaming combustion. NFPA 12 was developed for fire suppression at ground conditions. This paper discusses combustion of materials in microgravity and evaluates CO2 fire suppressant concentration needed in microgravity and specifically for ISS environments. In a normal 20.9% oxygen environment on the ISS, the NFPA requirement should be more than adequate to extinguish flaming combustion in on-orbit microgravity conditions. For environments with initial oxygen concentrations higher than 25%, if a CO2 concentration less than 34% is desired, materials control should be exercised. C1 Honeywell Technol Solut Inc, NASA, Lyndon B Johnson Space Ctr, White Sands Test Facil, Las Cruces, NM 88004 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77258 USA. RP Hirsch, D (reprint author), Honeywell Technol Solut Inc, NASA, Lyndon B Johnson Space Ctr, White Sands Test Facil, POB 20, Las Cruces, NM 88004 USA. NR 15 TC 2 Z9 2 U1 4 U2 7 PU SAGE PUBLICATIONS LTD PI LONDON PA 6 BONHILL STREET, LONDON EC2A 4PU, ENGLAND SN 0734-9041 J9 J FIRE SCI JI J. Fire Sci. PD SEP PY 2002 VL 20 IS 5 BP 391 EP 399 DI 10.1106/073490402031483 PG 9 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 667AR UT WOS:000182209100003 ER PT J AU Stoner, AW Abookire, AA AF Stoner, AW Abookire, AA TI Sediment preferences and size-specific distribution of young-of-the-year Pacific halibut in an Alaska nursery SO JOURNAL OF FISH BIOLOGY LA English DT Article DE habitat selection; sediment; behaviour; distribution; Pacific halibut ID FLOUNDER PSEUDOPLEURONECTES-AMERICANUS; PLAICE PLEURONECTES-PLATESSA; GENERALIZED ADDITIVE-MODELS; JUVENILE PLAICE; WINTER FLOUNDER; LABORATORY EXPERIMENTS; KODIAK-ISLAND; WADDEN SEA; FIELD OBSERVATIONS; BURYING ABILITY AB A combination of laboratory experiments and field Surveys was used to test the hypotheses that responses to sediments change with fish size and that sediment grain-size is the predominant environmental factor affecting small-scale distribution in young-of-the-year (yoy). Pacific halibut Hippoglossus stenolepis. Laboratory tests showed that the smallest fish (31 40 mm L-T) chose fine sediments (muddy and fine sands), fish 51.70mm had high selectivity (primarily medium sand), and the largest fish (80-150 mm) were not selective although they avoided the largest grain-sizes (pebbles and granules). Sediment preferences were correlated with size-dependent burial capabilities. Beam trawl collections were made over a 6 year period in Kachemak Bay, Alaska, to examine the distribution of yoy Pacific halibut (14 120mm L-T) using small size classes (e.g. 10mm intervals), Canonical correlation analysis showed that the per cent of sand in the sediment was a highly significant variable for all but one size and date combination. Catch per unit of effort (CPUE) for newly settled fish (<30 mm L-T) was highest on very fine sand, fish 41 80 min were most abundant oil title smid, and the largest yoy fish (81-120 mm) were abundant over a range of sediments from title sand to mud Except for the smallest fish. Pacific halibut in the field were associated with sediments somewhat finer than predicted from the laboratory experiments however, virtually all were captured where they could bury easily. The ability of flatfish to bury and shelter in sediment is related to fish sized consequently, habitat associations shift rapidly during the first bear of life. Habitat models for yoy flatfishes should consider size-dependent shifts in capabilities and preferences. (C) 2002 The Fisheries Society of the British Isles. Published by Elsevier Science Ltd. All rights reserved. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Kodiak, AK 99615 USA. RP Stoner, AW (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, 2030 S Marine Sci Dr, Newport, OR 97365 USA. NR 52 TC 28 Z9 28 U1 0 U2 10 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD SEP PY 2002 VL 61 IS 3 BP 540 EP 559 DI 10.1006/jfbi.2002.2056 PG 20 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 614BQ UT WOS:000179168400003 ER PT J AU Condie, KC Abbott, D Des Marais, DJ AF Condie, KC Abbott, D Des Marais, DJ TI Superplume Events in Earth History: Causes and Effects - Preface SO JOURNAL OF GEODYNAMICS LA English DT Editorial Material C1 New Mexico Inst Min & Technol, Dept Earth & Evironm Sci, Socorro, NM 87801 USA. Lamont Doherty Earth Observ, Palisades, NY 10964 USA. Ames Res Ctr, Moffett Field, CA 94035 USA. RP Condie, KC (reprint author), New Mexico Inst Min & Technol, Dept Earth & Evironm Sci, Socorro, NM 87801 USA. NR 10 TC 4 Z9 4 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0264-3707 J9 J GEODYN JI J. Geodyn. PD SEP PY 2002 VL 34 IS 2 BP 159 EP 162 AR PII S0264-3707(02)00018-2 DI 10.1016/S0264-3707(02)00018-2 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 577PA UT WOS:000177069300001 ER PT J AU Artaxo, P Martins, JV Yamasoe, MA Procopio, AS Pauliquevis, TM Andreae, MO Guyon, P Gatti, LV Leal, AMC AF Artaxo, P Martins, JV Yamasoe, MA Procopio, AS Pauliquevis, TM Andreae, MO Guyon, P Gatti, LV Leal, AMC TI Physical and chemical properties of aerosols in the wet and dry seasons in Rondonia, Amazonia SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE Amazonia; global change; aerosol; biomass burning; trace gases ID TRACE-ELEMENTS; ATMOSPHERIC AEROSOLS; SOURCE APPORTIONMENT; TROPICAL FOREST; SMOKE PARTICLES; BLACK CARBON; SCAR-B; BASIN; BRAZIL; EMISSIONS AB As part of the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA), a large study of aerosol and trace gas properties was conducted in Amazonia during the dry and wet seasons and for pasture and primary forest sites. Aerosol mass and elemental composition were measured on filters for both fine (d(p) <2.0 mu m) and coarse (2.0 < d(p) <10 m m) modes using polycarbonate filters mounted in stacked filter units (SFU). Measurements with real-time aerosol and trace gas monitors were made, parallel to the collection of filter samples to obtain high time resolution (1-30 min). Black carbon equivalent (BCE) was determined with a multiwavelength Aethalometer as well as by reflectance in the fine-mode SFU samples. Elemental carbon as well as total and organic carbon was measured using an R&P 5400 real-time carbon monitor. PM10 aerosol mass concentrations were determined with a Tapered Element Oscillating Monitor (TEOM) monitor every 5 min. CO, O-3, NO, and NO2 were analyzed with Thermo Environment monitors with trace level capabilities for NOx. A TSI 3010 particle counter measured the total particle number concentration (d(p) > 10 nm) every minute. A 55-m tower in a primary forest in Rondonia and a facility built on a pasture site were used to operate the instrumentation for 4 months in the wet season and 3 months in the dry season of 1999. Particle-Induced X-Ray Emission (PIXE) was used to measure the concentration of 22 trace elements for fine- and coarse-mode aerosol. During the wet season, very clean atmospheric conditions were observed at both sites. Particle concentration averaged 900 cm 3, black carbon averaged 250 ng m(-3), and mean fine- mode mass concentration was 2.9 mug m(-3). In sharp contrast, very high concentrations were observed in the dry season for all the parameters at both sampling sites. Aerosol mass concentrations up to 250 mug m 3 and particle number concentrations of more than 40,000 cm(-3) were observed, while the CO peaked at 8 ppm and NO2 reached 16 ppb. High correlation was observed between BCE, NO2, CO, aerosol particle number, mass, aerosol optical thickness, and other properties linked to biomass-burning emissions. Relatively large concentrations of phosphorus in the coarse-mode particles were observed, especially at nighttime. The emission of biogenic particulate P could have an effect in the nutrient cycling of this essential and key nutrient, which is present almost exclusively in the form of aerosol particles. Phosphorus is exchanged in the aerosol phase and mostly for coarse-mode particles and during nighttime. C1 Univ Sao Paulo, Inst Fis, BR-05508900 Sao Paulo, Brazil. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. UMBC, JCET, Greenbelt, MD 20771 USA. Max Planck Inst Chem, Abt Biogeochem, D-55020 Mainz, Germany. IPEN CNEN SP, Ctr Quim & Meio Ambiente, BR-0550890 Sao Paulo, Brazil. RP Univ Sao Paulo, Inst Fis, Rua Matao,Travessa R 187, BR-05508900 Sao Paulo, Brazil. EM artaxo@if.usp.br; vanderlei@if.usp.br; moa@mpch-mainz.mpg.de; lvgatti@net.ipen.br RI Artaxo, Paulo/E-8874-2010; Gatti, Luciana/J-8569-2012; Procopio, Aline/B-3367-2008; Pauliquevis, Theotonio/B-9408-2012; Yamasoe, Marcia/L-3667-2013; Procopio, Aline/L-7483-2013; Andreae, Meinrat/B-1068-2008 OI Artaxo, Paulo/0000-0001-7754-3036; Yamasoe, Marcia/0000-0003-3066-9146; Procopio, Aline/0000-0002-2326-2500; Andreae, Meinrat/0000-0003-1968-7925 NR 48 TC 130 Z9 134 U1 1 U2 25 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8081 DI 10.1029/2001JD000666 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200053 ER PT J AU Bell, N Hsu, L Jacob, DJ Schultz, MG Blake, DR Butler, JH King, DB Lobert, JM Maier-Reimer, E AF Bell, N Hsu, L Jacob, DJ Schultz, MG Blake, DR Butler, JH King, DB Lobert, JM Maier-Reimer, E TI Methyl iodide: Atmospheric budget and use as a tracer of marine convection in global models SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE methyl iodide; marine convection; atmospheric tracer; global budget of methyl iodide ID ACE-1 LAGRANGIAN-B; ATLANTIC-OCEAN; PHOTOCHEMICAL PRODUCTION; TROPOSPHERIC CHEMISTRY; PACIFIC-OCEAN; HALIDES; OZONE; SEA; TRANSPORT; EMISSIONS AB We simulate the oceanic and atmospheric distribution of methyl iodide (CH3I) with a global 3-D model driven by assimilated meteorological observations from the Goddard Earth Observing System of the NASA Data Assimilation Office and coupled to an oceanic mixed layer model. A global compilation of atmospheric and oceanic observations is used to constrain and evaluate the simulation. Seawater CH3I( aq) in the model is produced photochemically from dissolved organic carbon, and is removed by reaction with Cl- and emission to the atmosphere. The net oceanic emission to the atmosphere is 214 Gg yr(-1). Small terrestrial emissions from rice paddies, wetlands, and biomass burning are also included in the model. The model captures 40% of the variance in the observed seawater CH3I( aq) concentrations. Simulated concentrations at midlatitudes in summer are too high, perhaps because of a missing biological sink of CH3I( aq). We define a marine convection index (MCI) as the ratio of upper tropospheric (8-12 km) to lower tropospheric (0-2.5 km) CH3I concentrations averaged over coherent oceanic regions. The MCI in the observations ranges from 0.11 over strongly subsiding regions (southeastern subtropical Pacific) to 0.40 over strongly upwelling regions (western equatorial Pacific). The model reproduces the observed MCI with no significant global bias (offset of only +11%) but accounts for only 15% of its spatial and seasonal variance. The MCI can be used to test marine convection in global models, complementing the use of radon-222 as a test of continental convection. C1 Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Adv Pollut Instrumentat, San Diego, CA 92121 USA. Max Planck Inst Meteorol, D-20146 Hamburg, Germany. RP Bell, N (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM nbell@giss.nasa.gov; Lhsu@eps.berkeley.edu; djj@io.harvard.edu; martin.schultz@dkrz.de; drblake@uci.edu; J.H.Butler@noaa.gov; Daniel.B.King@noaa.gov; jlobert@advpol.com; maier-reimer@kdrz.de RI Hsu, Leslie/D-5881-2012; Unger, Nadine/M-9360-2015; Schultz, Martin/I-9512-2012 OI Hsu, Leslie/0000-0002-5353-807X; Schultz, Martin/0000-0003-3455-774X NR 72 TC 77 Z9 77 U1 2 U2 27 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP PY 2002 VL 107 IS D17 AR 4340 DI 10.1029/2001JD001151 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 635YF UT WOS:000180427200020 ER PT J AU Bevilacqua, RM Fromm, MD Alfred, JM Hornstein, JS Nedoluha, GE Hoppel, KW Lumpe, JD Randall, CE Shettle, EP Browell, EV Butler, C Dornbrack, A Strawa, AW AF Bevilacqua, RM Fromm, MD Alfred, JM Hornstein, JS Nedoluha, GE Hoppel, KW Lumpe, JD Randall, CE Shettle, EP Browell, EV Butler, C Dornbrack, A Strawa, AW TI Observations and analysis of polar stratospheric clouds detected by POAM III during the 1999/2000 Northern Hemisphere winter SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE polar stratospheric clouds (PSCs); polar stratospheric temperatures; vortex phenomena; denitrification ID NITRIC-ACID TRIHYDRATE; AEROSOL; OZONE; INSTRUMENT; VORTEX; DENITRIFICATION; VALIDATION AB We present an overview of polar stratospheric cloud (PSC) measurements obtained by POAM III in the 1999/2000 Northern Hemisphere winter. PSCs were observed at POAM latitudes from mid-November to 15 March. PSCs in the early season generally occurred between 17 and 25 km. The central altitude of the PSC observations, roughly 21 km, is unchanged between November and late January. PSCs were not observed between 7 and 27 February. When they reappeared, they formed at distinctly lower altitudes, centered roughly at 16 km. We also present both qualitative and quantitative comparisons with airborne lidar and in situ balloon measurements of PSCs obtained over the Norwegian Sea and Scandinavia over the 25-27 January time period. We find that the large-scale PSC altitude features and morphology are well reproduced in the POAM measurements. Finally, we use PSC occurrence probabilities, analyzed as a function of ambient temperature relative to the NAT saturation point, to infer irreversible denitrification. This denitrification is observed to maximize in late February at levels of at least 75% in the 19-21 km region, with similar values in the 16-18 km region. No denitrification was inferred above 21 km or below 16 km. C1 USN, Res Lab, Washington, DC 20375 USA. Computat Phys Inc, Springfield, VA 22151 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NASA, Langley Res Ctr, SAIC, Lidar Applicat Grp, Hampton, VA 23681 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Inst Phys Atmospharr, DLR Oberpfaffenhofen, D-82230 Wessling, Germany. RP Bevilacqua, RM (reprint author), USN, Res Lab, Code 7220, Washington, DC 20375 USA. RI Fromm, Michael/F-4639-2010; Randall, Cora/L-8760-2014 OI Randall, Cora/0000-0002-4313-4397 NR 37 TC 19 Z9 19 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8281 DI 10.1029/2001JD000477 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200052 ER PT J AU Birkett, CM Mertes, LAK Dunne, T Costa, MH Jasinski, MJ AF Birkett, CM Mertes, LAK Dunne, T Costa, MH Jasinski, MJ TI Surface water dynamics in the Amazon Basin: Application of satellite radar altimetry SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE Amazon river; gradient; radar; altimeter ID SOUTH-AMERICA; FLOOD-PLAIN; RIVER; BRAZIL; VARIABILITY; INUNDATION; SEDIMENT; STORAGE; CHANNEL AB Satellite radar altimetry has the ability to monitor variations in surface water height (stage) for large wetlands, rivers, and associated floodplains. A clear advantage is the provision of data where traditional gauges are absent. As part of an international program, a complete altimetric analysis of the Amazon Basin is being undertaken. Here, an updated and more rigorous evaluation of the TOPEX/POSEIDON (T/P) data set is presented for the first similar to7.5 years of the mission. With an initial study group of 230 targets, height variability at many ungauged locations can be observed for 30-50%, the range reflecting the clarity of the variations in lieu of instrument limitations. An assessment of the instrument performance confirms that the minimum river width attainable is 1 km in the presence of some inundated floodplain. This constraint does allow observation of the main stem (Solimoes/Amazon) and the larger tributaries, but rugged terrain in the vicinity of the target additionally places severe limitations on data retrieval. First-order validation exercises with the deduced 1992-1999 time series of stage fluctuations reveal accuracies ranging from tens of centimeters to several meters (mean similar to1.1 m rms). Altimetric water levels in the Solimoes and Amazon are particularly well defined with amplitudes <13 m and variations in peak-level timing from May to July. The water-surface gradient of the main stem is found to vary both spatially and temporally, with values ranging from 1.5 cm/km downstream to 4.0 cm/km for more upstream reaches. In agreement with ground-based estimates, the seasonal variability of the gradients reveals that the hysteresis characteristic of the flood wave varies along the main stem and the derived altimetric velocity of this flood wave is estimated to be &SIM;0.35 m/s. Overall, the altimetric results demonstrate that the T/P mission is successfully monitoring the transient flood waves of this continental-scale river basin. C1 NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. Univ Calif Santa Barbara, Dept Geog, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, ICESS, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Bren Sch Environm Sci & Management, Santa Barbara, CA 93106 USA. Univ Fed Vicosa, Dept Agr Engn, Vicosa, MG, Brazil. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Birkett, CM (reprint author), NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Code 971, Greenbelt, MD 20771 USA. RI Costa, Marcos/A-5695-2009; Dunne, Thomas/B-6374-2014 OI Costa, Marcos/0000-0001-6874-9315; Dunne, Thomas/0000-0002-5281-6517 NR 37 TC 131 Z9 132 U1 2 U2 24 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8059 DI 10.1029/2001JD000609 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200016 ER PT J AU Burris, J McGee, T Hoegy, W Newman, P Lait, L Twigg, L Sumnicht, G Heaps, W Hostetler, C Neuber, R Kunzi, KF AF Burris, J McGee, T Hoegy, W Newman, P Lait, L Twigg, L Sumnicht, G Heaps, W Hostetler, C Neuber, R Kunzi, KF TI Lidar temperature measurements during the SOLVE campaign and the absence of polar stratospheric clouds from regions of very cold air SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE polar stratospheric clouds; temperature; NAT condensation temperature ID NITRIC-ACID TRIHYDRATE; RAMAN LIDAR; OZONE AB NASA Goddard Space Flight Center's Airborne Raman Ozone, Temperature, and Aerosol Lidar (AROTEL) measured extremely cold temperatures during all three deployments (1-16 December 1999, 14-29 January 2000, and 27 February to 15 March 2000) of the SAGE III Ozone Loss and Validation Experiment (SOLVE). Temperatures were significantly below values observed in previous years with large regions regularly below 191 K and frequent temperature retrievals yielding values at or below 187 K. Temperatures well below the saturation point of type I polar stratospheric clouds (PSCs) were regularly encountered, but their presence was not well correlated with PSC observations made by NASA Langley Research Center's aerosol lidar colocated with AROTEL. Temperature measurements by meteorological sondes launched within areas traversed by the DC-8 showed minimum temperatures consistent in time and vertical extent with those derived from AROTEL data. Calculations to establish whether PSCs could exist at measured AROTEL temperatures and observed mixing ratios of nitric acid and water vapor showed large areas favorable to PSC formation but that were lacking PSCs. The flight on 12 December 1999 encountered large regions having temperatures up to 10 K below the NAT saturation temperature but only small, localized regions that might be identified as PSCs. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Instrument Technol Ctr, Greenbelt, MD 20771 USA. Alfred Wegner Inst Polar Res, D-14473 Potsdam, Germany. Univ Bremen, Inst Environm Phys, D-28334 Bremen, Germany. Langley Res Ctr, Radiat & Aerosols Branch, Hampton, VA 23681 USA. RP Burris, J (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 916, Greenbelt, MD 20771 USA. RI Newman, Paul/D-6208-2012; McGee, Thomas/G-4951-2013; Neuber, Roland/B-4923-2014 OI Newman, Paul/0000-0003-1139-2508; Neuber, Roland/0000-0001-7382-7832 NR 20 TC 4 Z9 4 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8297 DI 10.1029/2001JD001036 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200094 ER PT J AU Burris, J McGee, T Hoegy, W Lait, L Twigg, L Sumnicht, G Heaps, W Hostetler, C Bui, TP Neuber, R McDermid, IS AF Burris, J McGee, T Hoegy, W Lait, L Twigg, L Sumnicht, G Heaps, W Hostetler, C Bui, TP Neuber, R McDermid, IS TI Validation of temperature measurements from the airborne Raman ozone temperature and aerosol lidar during SOLVE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE lidar temperature retrievals; stratospheric temperatures; polar stratospheric clouds ID STRATOSPHERIC OZONE; ATMOSPHERE; SYSTEMS; MIDDLE AB The Airborne Raman Ozone, Temperature, and Aerosol Lidar (AROTEL) participated in the recent SAGE III Ozone Loss and Validation Experiment (SOLVE) by providing profiles of aerosols, polar stratospheric clouds (PSCs), ozone, and temperature with high vertical and horizontal resolution. Temperatures were derived from just above the aircraft to 60 km geometric altitude with a reported vertical resolution of similar to0.6 km. The horizontal footprint varied from 4 to 70 km. This paper explores the measurement uncertainties associated with the temperature retrievals and makes comparisons with independent, coincident measurements of temperature. Measurement uncertainties range from 0.1 to similar to4 K depending on altitude and integration time. Comparisons between AROTEL and balloon sonde temperatures retrieved under clear sky conditions using both Rayleigh and Raman scattered data showed AROTEL similar to1 K colder than sonde values. Comparisons between AROTEL and the Meteorological Measurement System (MMS) on NASA's ER-2 show AROTEL being from 2 to 3 K colder for altitudes ranging from 14 to 18 km. Temperature comparisons between AROTEL and the UK Met Office's model showed differences of similar to1 K below similar to25 km and a very strong cold bias of similar to12 K at altitudes between 30 and 35 km. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Instrument Technol Ctr, Greenbelt, MD 20771 USA. Langley Res Ctr, Radiat & Aerosols Branch, Hampton, VA 23681 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Alfred Wegener Inst Polar Res, D-14473 Potsdam, Germany. Jet Propuls Lab, Table Mt Facil, Wrightwood, CA 92397 USA. RP Burris, J (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RI McGee, Thomas/G-4951-2013; Neuber, Roland/B-4923-2014 OI Neuber, Roland/0000-0001-7382-7832 NR 21 TC 7 Z9 7 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8286 DI 10.1029/2001JD001028 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200060 ER PT J AU Choi, WK Kim, S Grant, WB Shiotani, M Sasano, Y Schoeberl, MR AF Choi, WK Kim, S Grant, WB Shiotani, M Sasano, Y Schoeberl, MR TI Transport of methane in the stratosphere associated with the breakdown of the Antarctic polar vortex SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LIMB-ATMOSPHERIC-SPECTROMETER; POTENTIAL VORTICITY; OZONE HOLE; SOUTHERN-HEMISPHERE; TRACER TRANSPORT; LATE WINTER; ILAS; EVOLUTION; HALOE; EDGE AB [1] Transport of methane associated with the polar vortex and its breakdown was observed by the data from the Improved Limb Atmospheric Spectrometer (ILAS) during November and December of 1996. The zonal mean mixing ratio in the middle stratosphere at high latitudes in the Southern Hemisphere increased rapidly during the period, and the vertical gradient of methane sometimes showed an unusual reversal. The reversal of the vertical gradient confirms that the erosion of the vortex and the subsequent breakdown occurs in the upper stratosphere first and descends with time. The variation of the tracer mixing ratio was investigated with respect to the boundary of the polar vortex. The mixing ratios inside and outside of the polar vortex evolved with distinctive patterns with time. The small difference in methane between inside and outside of the vortex in the upper stratosphere is presumably a result of the vortex erosion prior to November. Also, the small difference between inside and outside of the vortex in the lower stratosphere confirms the weak barrier effect of the polar vortex on that altitude. High concentrations of methane observed inside the vortex show mixing of lower-latitude air into the vortex. An RDF calculation confirms the behavior of methane transport into the vortex. C1 Seoul Natl Univ, Sch Earth & Environm Sci, Seoul, South Korea. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Kyoto Univ, Radio Sci Ctr Space & Atmosphere, Kyoto, Japan. Natl Inst Environm Studies, Div Atmospher Environm, Tsukuba, Ibaraki, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Choi, WK (reprint author), Seoul Natl Univ, Sch Earth & Environm Sci, Seoul, South Korea. RI Sasano, Yasuhiro/C-2927-2009; Grant, William/B-8311-2009 OI Sasano, Yasuhiro/0000-0001-7470-5642; Grant, William/0000-0002-1439-3285 NR 60 TC 7 Z9 7 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D24 AR 8209 DI 10.1029/2001JD000644 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 637BN UT WOS:000180491900005 ER PT J AU Danilin, MY Ko, MKW Froidevaux, L Santee, ML Lyjak, LV Bevilacqua, RM Zawodny, JM Sasano, Y Irie, H Kondo, Y Russell, JM Scott, CJ Read, WG AF Danilin, MY Ko, MKW Froidevaux, L Santee, ML Lyjak, LV Bevilacqua, RM Zawodny, JM Sasano, Y Irie, H Kondo, Y Russell, JM Scott, CJ Read, WG TI Trajectory hunting as an effective technique to validate multiplatform measurements: Analysis of the MLS, HALOE, SAGE-II, ILAS, and POAM-II data in October-November 1996 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE trajectory hunting; satellite measurements; validation technique ID LIMB-ATMOSPHERIC-SPECTROMETER; TRACE GAS OBSERVATIONS; POLAR OZONE; OCCULTATION EXPERIMENT; STRATOSPHERIC AEROSOL; CHLORINE ACTIVATION; LAGRANGIAN APPROACH; MIDDLE ATMOSPHERE; ARCTIC WINTER; AIR MASSES AB The goal of this study is to show that trajectory hunting is an effective technique for comparison of multiplatform measurements. In order to achieve this goal, we (1) describe in detail the trajectory hunting technique (THT), (2) perform several consistency tests for THT (self-hunting and reversibility), (3) estimate uncertainties of this technique, and (4) validate THT results against those obtained by the traditional correlative analysis (TCA). THT launches backward and forward trajectories from the locations of measurements and finds air parcels sampled at least twice within a prescribed match criterion during the course of several days. TCA finds matched profiles for a chosen match criterion, averages them for each instrument separately, and compares the averaged profiles. As an example, we consider the 22 October to 30 November 1996 period in the Southern Hemisphere and compare the latest versions of relevant measurements made by the following five instruments: Microwave Limb Sounder (MLS, version 5 (v. 5)), Halogen Occultation Experiment (HALOE, v. 19), Polar Ozone and Aerosol Measurement II (POAM-II, v. 6), Stratospheric Aerosol and Gas Experiment II (SAGE-II, v. 6.1), and Improved Limb Atmospheric Spectrometer (ILAS, v. 5.20). We present results for O-3, H2O, CH4, HNO3, and NO2, which show that (1) ozone measurements from all five instruments agree to better than 0.4 (0.2) ppmv below (above) 30 km; (2) water vapor measurements agree within +/-5-10% above 22 km; (3) methane measurements by HALOE and ILAS agree to better than 10% above 30 km with a possible positive offset of up to 10-15% by ILAS in the lower stratosphere; (4) MLS HNO3 data corrected to account for some excited vibrational lines omitted in the v. 5 HNO3 retrieval agree with ILAS HNO3 measurements to within similar to0.5 ppbv (similar to10-20%) over the range similar to450-750 K; (5) ILAS sunset NO2 measurements are larger than both POAM-II and SAGE-II values by up to 10-15% below 30 km. The self-hunting tests show that the THT RMS noise is of the order of 1-2% for O-3, CH4, and H2O and 4% for NO2 and HNO3 measurements in the stratosphere. Total THT-related uncertainties may be 3-5% for O-3 measurements when photochemical effects and sensitivities of the results to duration of trajectories and match criteria are taken into account. Good agreement is found between the THT and TCA results for each of these products and for each possible pair of instruments, with considerably better statistics (typically by at least an order of magnitude) in the THT case. This agreement validates the THT results. C1 Boeing Co, Seattle, WA 98124 USA. AER Inc, Lexington, MA 02421 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Natl Ctr Atmospher Res, Boulder, CO 80303 USA. USN, Res Lab, Washington, DC 20375 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Natl Inst Environm Studies, Tsukuba, Ibaraki 3050053, Japan. Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, Tokyo 1538904, Japan. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. RP Danilin, MY (reprint author), Boeing Co, POB 3707 MC OR-RC, Seattle, WA 98124 USA. RI Sasano, Yasuhiro/C-2927-2009; Kondo, Yutaka/D-1459-2012; Ko, Malcolm/D-5898-2015 OI Sasano, Yasuhiro/0000-0001-7470-5642; NR 58 TC 26 Z9 26 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 4420 DI 10.1029/2001JD002012 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200074 ER PT J AU Dornbrack, A Birner, T Fix, A Flentje, H Meister, A Schmid, H Browell, EV Mahoney, MJ AF Dornbrack, A Birner, T Fix, A Flentje, H Meister, A Schmid, H Browell, EV Mahoney, MJ TI Evidence for inertia gravity waves forming polar stratospheric clouds over Scandinavia SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE polar stratospheric clouds; inertia gravity waves; mountain waves; mesoscale numerical modelling; lidar observations ID AIRBORNE LIDAR MEASUREMENTS; NITRIC-ACID TRIHYDRATE; OZONE DEPLETION; VORTEX; PARTICLES; VALIDATION AB At three successive days at the end of January 2000 the Deutsches Zentrum fur Luft- und Raumfahrt (DLR) airborne lidar Ozone Lidar Experiment explored mountain-wave-induced polar stratospheric clouds above the Scandinavian mountain ridge. Global analyses and mesoscale modeling are applied to explain their complex internal structure and their day-to-day variability. Depending on the synoptical-scale meteorological conditions, stratospheric temperature anomalies of different amplitude and horizontal extent are generated by the upward propagating mountain waves. Short-term excitation of about 6 hours resulted in localized stratospheric temperature anomalies directly above the mountain ridge as for 25 January 2000. In this case, the elevation of the observed clouds differed not much from the synoptic-scale clouds upstream above the Norwegian Sea. On the other hand, long-lasting flow past the Scandinavian mountain ridge formed huge 400-km horizontally extending stratospheric ice clouds in altitudes as much as 5 km above the elevation of the upstream clouds just 1 day later. Inertia gravity waves with horizontal wavelengths of about 350 km are responsible for their formation. For the first time a predicted temperature minimum far downstream of the mountains could be proofed by the observation of an isolated stratospheric ice cloud above Finland. The observed particles are classified in terms of their measured optical properties such as backscatter ratio and depolarization. In all cases, mountain waves generated ice clouds. In contrast to the nitric acid trihydrate tail of the ice cloud on 25 January the same classification results in a tail of liquid supercooled ternary solutions droplets 1 day later. The particle structure downstream of the mountains is very complex and needs detailed microphyical modeling and interpretation. C1 Inst Phys Atmosphare, DLR Oberpfaffenhofen, D-82230 Wessling, Germany. DLR Oberpfaffenhofen, Lidar Grp, D-82230 Wessling, Germany. NASA, Langley Res Ctr, Lidar Applicat Grp, Hampton, VA 23681 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Dornbrack, A (reprint author), Inst Phys Atmosphare, DLR Oberpfaffenhofen, D-82230 Wessling, Germany. RI Birner, Thomas/A-2108-2008 OI Birner, Thomas/0000-0002-2966-3428 NR 43 TC 55 Z9 55 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8287 DI 10.1029/2001JD000452 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200061 ER PT J AU Eidmann, G Offermann, D Schaeler, B Jarisch, M Schmidlin, FJ AF Eidmann, G Offermann, D Schaeler, B Jarisch, M Schmidlin, FJ TI Stratospheric variability of temperature and ozone as inferred from the second CRISTA mission: Zonal means and local structures SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GRAVITY-WAVE VARIANCE; CRYOGENIC INFRARED SPECTROMETERS; SUMMER STRATOSPHERE; EFFECTIVE DIFFUSIVITY; MIDDLE ATMOSPHERE; UARS MLS; CLIMATOLOGY; TRANSPORT; N2O; FLUCTUATIONS AB [1] During the second Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) orbital mission from 8 to 16 August 1997, temperature, potential temperature, and ozone data have been derived with unprecedented spatial and temporal resolution on a global scale. The variability of these quantities is analyzed by statistical means. This "fluctuation analysis'' determines the variability of the quantity under investigation within well-defined "regions'' with horizontal dimensions of about 20 by 20 degrees. Spatial variability is expressed in terms of standard deviations of differences of observed quantities with about 250, 500, 750, or 1000 km horizontal separation. The variances of temperature and therefore potential temperature for pressure levels between about 100 and 0.45 hPa and ozone between about 50 and 0.45 hPa depend greatly on geographical location and altitude. Practically all latitudes and altitudes exhibit strong zonal asymmetries. In contrast to the temperature variability distribution, that of potential temperature appears to focus more strongly on adiabatic processes, i.e., mainly on gravity and planetary wave activity depending upon geographical location and altitude. From the variances in a given "region'' an autocorrelation function depending on horizontal scale can be derived. This correlation function suggests frequent wavelike structures with horizontal scales around 1000 km. C1 Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany. NASA, Goddard Space Flight Ctr, Wallops Isl, VA 23337 USA. RP Vacuumschmelze GmbH & Co KG, Hanau, Germany. EM offerm@wpos2.physik.uni-wuppertal.de NR 38 TC 7 Z9 7 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D23 AR 8180 DI 10.1029/2001JD000721 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 637AT UT WOS:000180490000007 ER PT J AU Greenblatt, JB Jost, HJ Loewenstein, M Podolske, JR Hurst, DF Elkins, JW Schauffler, SM Atlas, EL Herman, RL Webster, CR Bui, TP Moore, FL Ray, EA Oltmans, S Vomel, H Blavier, JF Sen, B Stachnik, RA Toon, GC Engel, A Muller, M Schmidt, U Bremer, H Pierce, RB Sinnhuber, BM Chipperfield, M Lefevre, F AF Greenblatt, JB Jost, HJ Loewenstein, M Podolske, JR Hurst, DF Elkins, JW Schauffler, SM Atlas, EL Herman, RL Webster, CR Bui, TP Moore, FL Ray, EA Oltmans, S Vomel, H Blavier, JF Sen, B Stachnik, RA Toon, GC Engel, A Muller, M Schmidt, U Bremer, H Pierce, RB Sinnhuber, BM Chipperfield, M Lefevre, F TI Tracer-based determination of vortex descent in the 1999/2000 Arctic winter SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE N2O; CH4; polar vortex; subsidence; descent; stratosphere ID STRATOSPHERIC POLAR VORTEX; HALOGEN OCCULTATION EXPERIMENT; 3-DIMENSIONAL MODEL SIMULATIONS; GENERAL-CIRCULATION MODEL; IN-SITU MEASUREMENTS; OZONE DEPLETION; ER-2 AIRCRAFT; PROFILE OBSERVATIONS; POTENTIAL VORTICITY; VERTICAL STRUCTURE AB A detailed analysis of available in situ and remotely sensed N2O and CH4 data measured in the 1999/2000 winter Arctic vortex has been performed in order to quantify the temporal evolution of vortex descent. Differences in potential temperature (theta) among balloon and aircraft vertical profiles (an average of 19-23 K on a given N2O or CH4 isopleth) indicated significant vortex inhomogeneity in late fall as compared with late winter profiles. A composite fall vortex profile was constructed for 26 November 1999, whose error bars encompassed the observed variability. High-latitude extravortex profiles measured in different years and seasons revealed substantial variability in N2O and CH4 on theta surfaces, but all were clearly distinguishable from the first vortex profiles measured in late fall 1999. From these extravortex-vortex differences we inferred descent prior to 26 November: as much as 397 +/- 15 K (1sigma) at 30 ppbv N2O and 640 ppbv CH4, and falling to 28 +/- 13 K above 200 ppbv N2O and 1280 ppbv CH4. Changes in theta were determined on five N2O and CH4 isopleths from 26 November through 12 March, and descent rates were calculated on each N2O isopleth for several time intervals. The maximum descent rates were seen between 26 November and 27 January: 0.82 +/- 0.20 K/day averaged over 50-250 ppbv N2O. By late winter (26 February to 12 March), the average rate had decreased to 0.10 +/- 0.25 K/day. Descent rates also decreased with increasing N2O; the winter average (26 November to 5 March) descent rate varied from 0.75 +/- 0.10 K/day at 50 ppbv to 0.40 +/- 0.11 K/day at 250 ppbv. Comparison of these results with observations and models of descent in prior years showed very good overall agreement. Two models of the 1999/2000 vortex descent, SLIMCAT and REPROBUS, despite theta offsets with respect to observed profiles of up to 20 K on most tracer isopleths, produced descent rates that agreed very favorably with the inferred rates from observation. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Bay Area Environm Res Inst, Sonoma, CA USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Leeds, Sch Environm, Leeds LS2 9JT, W Yorkshire, England. Goethe Univ Frankfurt, Inst Meteorol & Geophys, D-60054 Frankfurt, Germany. NASA, Langley Res Ctr, Hampton, VA 23681 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Princeton Univ, Program Atmospher & Ocean Sci, POB CN710,Sayre Hall, Princeton, NJ 08544 USA. EM buygreen@splash.princeton.edu; hjost@mail.arc.nasa.gov; mloewenstein@mail.arc.nasa.gov; jpodolske@mail.arc.nasa.gov; Dale.Hurst@noaa.gov; James.W.Elkins@noaa.gov; sues@ucar.edu; atlas@acd.ucar.edu; Robert.L.Herman@jpl.nasa.gov; Chris.R.Webster@jpl.nasa.gov; pbui@mail.arc.nasa.gov; Fred.Moore@noaa.gov; eray@al.noaa.gov; samuel.j.oltmans@noaa.gov; Holger.Voemel@noaa.gov; Jeanfrancois.L.Blavier@jpl.nasa.gov; bhaswar.sen@jpl.nasa.gov; Robert.A.Stachnik@jpl.nasa.gov; Geoffrey.C.Toon@jpl.nasa.gov; an.engel@meteor.uni-frankfurt.de; m.mueller@meteor.uni-frankfurt.de; u.schmidt@meteor.uni-frankfurt.de; bremer@iup.physik.uni-bremen.de; r.b.pierce@larc.nasa.gov; bms@iup.physik.uni-bremen.de; martyn@env.leeds.ac.uk; franck.lefevre@aero.jussieu.fr RI Pierce, Robert Bradley/F-5609-2010; Herman, Robert/H-9389-2012; Sinnhuber, Bjorn-Martin/A-7007-2013; Chipperfield, Martyn/H-6359-2013; Ray, Eric/D-5941-2013; Atlas, Elliot/J-8171-2015; Hurst, Dale/D-1554-2016; Engel, Andreas/E-3100-2014 OI Pierce, Robert Bradley/0000-0002-2767-1643; Herman, Robert/0000-0001-7063-6424; Sinnhuber, Bjorn-Martin/0000-0001-9608-7320; Chipperfield, Martyn/0000-0002-6803-4149; Ray, Eric/0000-0001-8727-9849; Hurst, Dale/0000-0002-6315-2322; Engel, Andreas/0000-0003-0557-3935 NR 77 TC 22 Z9 22 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8279 DI 10.1029/2001JD000937 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200050 ER PT J AU Greenblatt, JB Jost, HJ Loewenstein, M Podolske, JR Bui, TP Hurst, DF Elkins, JW Herman, RL Webster, CR Schauffler, SM Atlas, EL Newman, PA Lait, LR Muller, M Engel, A Schmidt, U AF Greenblatt, JB Jost, HJ Loewenstein, M Podolske, JR Bui, TP Hurst, DF Elkins, JW Herman, RL Webster, CR Schauffler, SM Atlas, EL Newman, PA Lait, LR Muller, M Engel, A Schmidt, U TI Defining the polar vortex edge from an N2O : potential temperature correlation SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE N2O; polar vortex; potential temperature; vortex edge; stratosphere; Arctic ID METEOROLOGICAL MEASUREMENT SYSTEM; IN-SITU MEASUREMENTS; POTENTIAL VORTICITY; LOWER STRATOSPHERE; ARCTIC VORTEX; TRACE GASES; N2O; TROPOSPHERE; DYNAMICS; AIRCRAFT AB A prerequisite to studying phenomena in the winter stratospheric polar vortex is the separation of measurements inside and outside the dynamical barrier of the vortex edge. We describe a technique to accurately determine the inner edge of the vortex boundary region from measurements of potential temperature and a trace gas, such as N2O, and apply it to in situ aircraft and balloon measurements from the SOLVE/THESEO 2000 Arctic campaign. The method may be used to refine the Nash algorithm, which, due to the inherently coarser resolution of potential vorticity on which it is dependent, may misidentify the inner edge by more than 400 km and omit the identification of small, extravortex filaments within the vortex. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Bay Area Environm Res Inst, San Francisco, CA USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Frankfurt, Inst Meteorol & Geophys, D-60054 Frankfurt, Germany. RP Greenblatt, JB (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, POB CN710,Sayre Hall, Princeton, NJ 08544 USA. RI Newman, Paul/D-6208-2012; Herman, Robert/H-9389-2012; Atlas, Elliot/J-8171-2015; Hurst, Dale/D-1554-2016; Engel, Andreas/E-3100-2014 OI Newman, Paul/0000-0003-1139-2508; Herman, Robert/0000-0001-7063-6424; Hurst, Dale/0000-0002-6315-2322; Engel, Andreas/0000-0003-0557-3935 NR 30 TC 17 Z9 17 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8268 DI 10.1029/2001JD000575 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200029 ER PT J AU Grooss, JU Gunther, G Konopka, P Muller, R McKenna, DS Stroh, F Vogel, B Engel, A Muller, M Hoppel, K Bevilacqua, R Richard, E Webster, CR Elkins, JW Hurst, DF Romashkin, PA Baumgardner, DG AF Grooss, JU Gunther, G Konopka, P Muller, R McKenna, DS Stroh, F Vogel, B Engel, A Muller, M Hoppel, K Bevilacqua, R Richard, E Webster, CR Elkins, JW Hurst, DF Romashkin, PA Baumgardner, DG TI Simulation of ozone depletion in spring 2000 with the Chemical Lagrangian Model of the Stratosphere (CLaMS) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE stratosphere; ozone; ozone depletion; CLaMS; Lagrangian; denitrification ID IN-SITU MEASUREMENTS; ARCTIC WINTER STRATOSPHERE; POLAR VORTEX; ER-2 AIRCRAFT; LOSS RATES; CLO; PHOTOCHEMISTRY; FORMULATION; TROPOSPHERE; CHEMISTRY AB Simulations of the development of the chemical composition of the Arctic stratosphere for spring 2000 are made with the Chemical Lagrangian Model of the Stratosphere (CLaMS). The simulations are performed for the entire Northern Hemisphere on four isentropic levels (400-475 K). The initialization in early February is based on observations made from satellite, balloon and ER-2 aircraft platforms. Tracer-tracer correlations from balloon-borne cryosampler (Triple) and ER-2 measurements, as well as tracer-PV correlations, are used to derive a comprehensive hemispherical initialization of all relevant chemical trace species. Since significant denitrification has been observed on the ER-2 flights, a parameterization of the denitrification is derived from NOy and N2O observations on board the ER-2 aircraft and the temperature history of the air masses under consideration. Over the simulation period from 10 February to 20 March, a chemical ozone depletion of up to 60% was derived for 425-450 K potential temperature. Maximum vortex-averaged chemical ozone loss rates of 50 ppb d(-1) or 4 ppb per sunlight hour were simulated in early March 2000 at the 425 and 450 K potential temperature levels. We show comparisons between the measurements and the simulations for the location of the ER-2 flight paths in late February and March and the location of the Triple balloon flight. The simulated tracer mixing ratios are in good agreement with the measurements. It was not possible to reproduce the exact details of the inorganic chlorine compounds. The simulation agrees with ClOx observations on the Triple balloon flight but overestimates for the ER-2 flights. The simulated ozone depletion agrees with estimates from other observations in the 425 and 450 K levels, but is underestimated on the 475 K level. C1 Forschungszentrum Julich, Inst Stratospher Chem ICG1, D-52425 Julich, Germany. Goethe Univ Frankfurt, Inst Meteorol, D-60325 Frankfurt, Germany. USN, Res Lab, Washington, DC 20375 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Nacl Autonoma Mexico, Ctr Ciencias Atmosfera, Mexico City 04510, DF, Mexico. RP Forschungszentrum Julich, Inst Stratospher Chem ICG1, Postfach 1913, D-52425 Julich, Germany. EM j.-u.grooB@fz-juelich.de; an.engel@meteor.uni-frankfurt.de; m.mueller@meteor.uni-frankfurt.de; bevilacqua@nrl.navy.mil; richard@al.noaa.gov; Chris.R.Webster@jpl.nasa.gov; James.W.Elkins@noaa.gov; dhurst@cmdl.noaa.gov; Pavel.Romashkin@noaa.gov; darrel@servidor.unam.mx RI Stroh, Fred/A-6505-2009; Guenther, Gebhard/K-7583-2012; Muller, Rolf/A-6669-2013; Konopka, Paul/A-7329-2013; GrooSS, Jens-Uwe/A-7315-2013; Vogel, Barbel/A-9988-2013; McKenna, Daniel/E-7806-2014; Hurst, Dale/D-1554-2016; Engel, Andreas/E-3100-2014 OI Stroh, Fred/0000-0002-4492-2977; Guenther, Gebhard/0000-0003-4111-6221; Muller, Rolf/0000-0002-5024-9977; GrooSS, Jens-Uwe/0000-0002-9485-866X; McKenna, Daniel/0000-0002-4360-4782; Hurst, Dale/0000-0002-6315-2322; Engel, Andreas/0000-0003-0557-3935 NR 40 TC 27 Z9 27 U1 2 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8295 DI 10.1029/2001JD000456 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200092 ER PT J AU Hanisco, TF Smith, JB Stimpfle, RM Wilmouth, DM Anderson, JG Richard, EC Bui, TP AF Hanisco, TF Smith, JB Stimpfle, RM Wilmouth, DM Anderson, JG Richard, EC Bui, TP TI In situ observations of HO2 and OH obtained on the NASA ER-2 in the high-ClO conditions of the 1999/2000 Arctic polar vortex SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE hydroperoxyl; stratosphere; photochemistry; hypochlorous acid; ozone loss ID TEMPERATURE-DEPENDENCE; 72-DEGREES-S LATITUDE; INSITU OBSERVATIONS; UPPER TROPOSPHERE; AIRCRAFT; STRATOSPHERE; ABSORPTION; KINETICS; O-3; 54-DEGREES-S AB Extensive observations of OH and HO2 obtained aboard the NASA ER-2 inside the Arctic polar vortex during the SAGE III Ozone loss and Validation Experiment (SOLVE) provide the opportunity to identify and test interferences during the measurement of HO2 in the presence of high concentrations of ClO. In-flight calibrations are consistent with small interferences from CH3O2 (8%) and from ClO (3%) to the total signal on average inside the vortex. Measurements of HO2, OH, ClO, and O-3 are used with rate constants derived from laboratory measurements to test the consistency of the reactions that control HO2/OH. Inside the vortex the calculated HO2/OH under predicts the observed HO2/OH by 7% with the JPL-00 rate constants and over-predicts the observations by 23% when recent laboratory rates are used. Measurements of HO2 and ClO are used to calculate ozone loss rates and concentrations of HOCl with uncertainties determined from the analysis of HO2/OH. The calculated concentration of HOCl is 52(-28)(+50) pptv, or 0.07 x ClO on average in the vortex. The ozone loss rate from the two cycles controlled by HO2 + ClO is 1.5(-0.5)(+1.2) ppbv d(-1) in early March. C1 Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. NOAA, Aeron Lab, Boulder, CO USA. NASA, Ames Res Ctr, Mt View, CA 94035 USA. RP Hanisco, TF (reprint author), Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. NR 26 TC 11 Z9 11 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8283 DI 10.1029/2001JD001024 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200055 ER PT J AU Hanisco, TF Smith, JB Stimpfle, RM Wilmouth, DM Perkins, KK Spackman, JR Anderson, JG Baumgardner, D Gandrud, B Webster, CR Dhaniyala, S McKinney, KA Bui, TP AF Hanisco, TF Smith, JB Stimpfle, RM Wilmouth, DM Perkins, KK Spackman, JR Anderson, JG Baumgardner, D Gandrud, B Webster, CR Dhaniyala, S McKinney, KA Bui, TP TI Quantifying the rate of heterogeneous processing in the Arctic polar vortex with in situ observations of OH SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NITRIC-ACID TRIHYDRATE; SOLID STRATOSPHERIC PARTICLES; REACTIVE UPTAKE COEFFICIENTS; SULFURIC-ACID; CLONO2; HCL; OZONE; ICE; UNCERTAINTIES; DEPENDENCE AB We present simultaneous in situ observations of OH, HO2, ClONO2, HCl, and particle surface area inside a polar stratospheric cloud undergoing rapid heterogeneous processing. A steady-state analysis constrained by in situ observations is used to show that concentrations of OH calculated during a processing event are extremely sensitive to the assumptions regarding aerosol composition and reactivity. This analysis shows that large perturbations in the abundance of OH are consistent with the heterogeneous production of HOCl via ClONO2 + H2O --> HOCl + HNO3 and removal via HOCl + HCl --> Cl-2 + H2O in a polar stratospheric cloud. If the cloud is composed of supercooled ternary solution (STS) aerosols and solid nitric acid trihydrate (NAT) particles, comparison with observations of OH show that modifications to surface reactivity to account for high HNO3 content in STS aerosols and low HCl coverage on NAT particles are appropriate. These results indicate that with the low HCl levels in this encounter and in a processed polar vortex in general, reactions on STS aerosols dominate the total heterogeneous processing rate. As a consequence, the formation of NAT does not lead to significantly faster reprocessing rates when HCl concentrations are low and STS aerosols are present. Model calculations that include these modifications to uptake coefficients for STS and NAT will lead to significantly slower reprocessing and faster recovery rates of chlorine in the springtime Arctic polar vortex. C1 Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. Univ Nacl Autonoma Mexico, Mexico City 04510, DF, Mexico. Natl Ctr Atmospher Res, Boulder, CO 80305 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Dept Geol & Planetary Sci, Pasadena, CA 91107 USA. NASA, Ames Res Ctr, Mt View, CA USA. RP Hanisco, TF (reprint author), Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. NR 33 TC 7 Z9 7 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8278 DI 10.1029/2000JD000425 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200049 ER PT J AU Hansen, J Sato, M Nazarenko, L Ruedy, R Lacis, A Koch, D Tegen, I Hall, T Shindell, D Santer, B Stone, P Novakov, T Thomason, L Wang, R Wang, Y Jacob, D Hollandsworth, S Bishop, L Logan, J Thompson, A Stolarski, R Lean, J Willson, R Levitus, S Antonov, J Rayner, N Parker, D Christy, J AF Hansen, J Sato, M Nazarenko, L Ruedy, R Lacis, A Koch, D Tegen, I Hall, T Shindell, D Santer, B Stone, P Novakov, T Thomason, L Wang, R Wang, Y Jacob, D Hollandsworth, S Bishop, L Logan, J Thompson, A Stolarski, R Lean, J Willson, R Levitus, S Antonov, J Rayner, N Parker, D Christy, J TI Climate forcings in Goddard Institute for Space Studies SI2000 simulations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review DE climate forcings; climate models; greenhouse gases; aerosols; solar irradiance; ozone ID STRATOSPHERIC WATER-VAPOR; GENERAL-CIRCULATION MODEL; EXTINCTION OPTICAL-THICKNESS; TEMPERATURE TIME-SERIES; TROPOSPHERIC OZONE; PINATUBO ERUPTION; SULFATE AEROSOLS; RADIATIVE IMPACT; MAUNDER MINIMUM; EARTHS CLIMATE AB [1] We define the radiative forcings used in climate simulations with the SI2000 version of the Goddard Institute for Space Studies (GISS) global climate model. These include temporal variations of well-mixed greenhouse gases, stratospheric aerosols, solar irradiance, ozone, stratospheric water vapor, and tropospheric aerosols. Our illustrations focus on the period 1951-2050, but we make the full data sets available for those forcings for which we have earlier data. We illustrate the global response to these forcings for the SI2000 model with specified sea surface temperature and with a simple Q-flux ocean, thus helping to characterize the efficacy of each forcing. The model yields good agreement with observed global temperature change and heat storage in the ocean. This agreement does not yield an improved assessment of climate sensitivity or a confirmation of the net climate forcing because of possible compensations with opposite changes of these quantities. Nevertheless, the results imply that observed global temperature change during the past 50 years is primarily a response to radiative forcings. It is also inferred that the planet is now out of radiation balance by 0.5 to 1 W/m(2) and that additional global warming of about 0.5 C is already "in the pipeline.'' C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA. SGT Inc, New York, NY USA. Yale Univ, Dept Geol, New Haven, CT USA. Max Planck Inst Biogeochem, D-07701 Jena, Germany. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. MIT, Ctr Meteorol, Cambridge, MA 02139 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Rutgers State Univ, Dept Environm Sci, New Brunswick, NJ 08901 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Honeywell Int, Buffalo, NY 14210 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. NOAA, Natl Oceanog Data Ctr, Silver Spring, MD 20910 USA. Meteorol Off, Hadley Ctr Climate Predict & Res, Bracknell RG12 2SY, Berks, England. Univ Alabama, Ctr Earth Syst Sci, Huntsville, AL 35899 USA. RP NASA, Goddard Inst Space Studies, New York, NY 10025 USA. EM jhansen@giss.nasa.gov; lnazarenko@giss.nasa.gov; alacis@giss.nasa.gov; itegen@bgc-jena.mpg.de; thall@scrapple.giss.nasa.gov; dshindell@giss.nasa.gov; santer1@llnl.gov; phstone@mit.edu; tnovakov@lbl.gov; l.w.thomason@larc.nasa.gov; raywang@eas.gatech.edu; yhw@envsci.rutgers.edu; djj@io.harvard.edu; lane.bishop@alliedsignal.co; lean@demeter.nrl.navy.mil; slevitus@nodc.noaa.gov; John.Antonov@noaa.gov; nrayner@meto.gov.uk; deparker@meto.gov.uk; christy@atmos.uah.edu RI Santer, Benjamin/F-9781-2011; Shindell, Drew/D-4636-2012; Lacis, Andrew/D-4658-2012; Stolarski, Richard/B-8499-2013; Wang, Yuhang/B-5578-2014 OI Stolarski, Richard/0000-0001-8722-4012; NR 145 TC 229 Z9 235 U1 4 U2 36 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP PY 2002 VL 107 IS D18 AR 4347 DI 10.1029/2001JD001143 PG 37 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 635YH UT WOS:000180427400014 ER PT J AU Harvey, VL Pierce, RB Fairlie, TD Hitchman, MH AF Harvey, VL Pierce, RB Fairlie, TD Hitchman, MH TI A climatology of stratospheric polar vortices and anticyclones SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE polar vortex; stratospheric anticyclones ID ROSSBY-WAVE BREAKING; LOW-OZONE POCKETS; SOUTHERN-HEMISPHERE; 3-DIMENSIONAL TRANSPORT; ELLIPTIC DIAGNOSTICS; NORTHERN HEMISPHERE; POTENTIAL VORTICITY; PLANETARY-WAVES; JANUARY 1992; LIFE-CYCLE AB United Kingdom Meteorological Office global analyses from 1991 to 2001 are used to create a global climatology of stratospheric polar vortices and anticyclones. New methodologies are developed that identify vortices in terms of evolving three-dimensional (3-D) air masses. A case study illustrates the performance of the identification schemes during February and March of 1999 when a merger of anticyclones led to a stratospheric warming that split the Arctic polar vortex. The 3-D structure and temporal evolution of the Arctic vortex and identified anticyclones demonstrates the algorithm's ability to capture complicated phenomena. The mean geographical distribution of polar vortex and anticyclone frequency is shown for each season. The frequency distributions illustrate the climatological location and persistence of polar vortices and anticyclones. A counterpart to the Aleutian High is documented in the Southern Hemisphere: the "Australian High." The temporal evolution of the area occupied by polar vortices and anticyclones in each hemisphere is shown as a function of potential temperature. Large polar vortex area leads to an increase in anticyclone area, which in turn results in a decrease in the size of the polar vortex. During Northern winter and Southern spring, 9 years of daily anticyclone movement are shown on the 1200 K (36 km, 4 hPa) isentropic surface. Preferred locations of anticyclogenesis are related to cross-equatorial flow and weak inertial stability. Regimes of traveling and stationary anticyclones are discussed. C1 Sci Applicat Int Corp, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Univ Wisconsin, Dept Atmospher & Ocean Sci, Madison, WI USA. RP Harvey, VL (reprint author), Sci Applicat Int Corp, MS 401B, Hampton, VA 23681 USA. RI Pierce, Robert Bradley/F-5609-2010 OI Pierce, Robert Bradley/0000-0002-2767-1643 NR 90 TC 75 Z9 76 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 4442 DI 10.1029/2001JD001471 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200111 ER PT J AU Herdies, DL da Silva, A Dias, MAFS Ferreira, RN AF Herdies, DL da Silva, A Dias, MAFS Ferreira, RN TI Moisture budget of the bimodal pattern of the summer circulation over South America SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATLANTIC CONVERGENCE ZONE; SCALE COMMON FEATURES; BAIU FRONTAL ZONE; VARIABILITY; MODEL; REANALYSIS; TRANSPORT; DATASET; CLIMATE; SPCZ AB Submonthly variations in warm-season (January-February) precipitation over South America, in particular over the Amazon basin, central southwest Brazil, north Argentina, and Paraguay are studied. Two distinct regimes of lower tropospheric winds (westerlies and easterlies) were observed in Rondonia during the Wet Season Atmospheric Mesoscale Campaign (WETAMC) component of the Large-Scale Atmosphere-Biosphere Experiment in Amazonia (LBA) and the Tropical Rainfall Measuring Mission (TRMM) field campaign. The westerly (easterly) winds were associated with strong (weak) convective activity over the South Atlantic Convergence Zone (SACZ). The period of this study (January and February of 1999) was divided into SACZ and no SACZ (NSACZ) regimes. The vertically integrated moisture fluxes over South America obtained from the National Aeronautics and Space Administration/Goddard Data Assimilation Office (NASA/DAO) assimilation system show that during the SACZ (NSACZ) period, strong (weak) convergence occurred over the Amazon basin with divergence (convergence) over southwestern Brazil, northern Argentina, and Paraguay. These moisture budgets also indicated that moisture transport from the tropics to the extratropics in the South American sector occurs more efficiently during the SACZ regime than during the NSACZ regime. C1 Univ Maryland Baltimore Cty, GEST, Greenbelt, MD USA. NASA, Goddard Space Flight Ctr, DAO, Greenbelt, MD 20771 USA. Univ Sao Paulo, Inst Astron & Geophys, Sao Paulo, Brazil. NASA, Goddard Space Flight Ctr, Seasonal Interannual Predict Project, Greenbelt, MD 20771 USA. Inst Nacl Pesquisas Espaciais, Ctr Previsao Tempo & Estudos Climat, Cachoeira Paulista, SP, Brazil. RP Herdies, DL (reprint author), Univ Maryland Baltimore Cty, GEST, Greenbelt, MD USA. RI da Silva, Arlindo/D-6301-2012; Herdies, Dirceu/C-6675-2013 OI da Silva, Arlindo/0000-0002-3381-4030; Herdies, Dirceu/0000-0002-2872-8453 NR 31 TC 40 Z9 42 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8075 DI 10.1029/2001JD000997 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200036 ER PT J AU Hu, RM Carslaw, KS Hostetler, C Poole, LR Luo, BP Peter, T Fueglistaler, S McGee, TJ Burris, JF AF Hu, RM Carslaw, KS Hostetler, C Poole, LR Luo, BP Peter, T Fueglistaler, S McGee, TJ Burris, JF TI Microphysical properties of wave polar stratospheric clouds retrieved from lidar measurements during SOLVE/THESEO 2000 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE microphysical properties; optical properties; lidar retrieval; polar stratospheric clouds ID AEROSOL-SIZE DISTRIBUTION; AIRBORNE LIDAR; ARCTIC STRATOSPHERE; MOUNTAIN WAVES; TEMPERATURE; PARTICLES; CLIMATOLOGY; SCANDINAVIA; RELEVANCE; WINTER AB Mountain wave induced ice clouds in the stratosphere are known to cause the formation of nitric acid hydrate particles downwind. Understanding the microphysical properties of these solid particles is important because they may contribute to a general background of solid polar stratospheric clouds (PSCs) that is observed but whose origin is not understood. Based on the limited set of observations of PSCs directly attributable to mountain waves, it has not been possible to determine their general microphysical properties. Here we analyze lidar observations from the SOLVE/THESEO 2000 campaign. Between December 1999 and March 2000, seven of the twelve flights of the DC-8 aircraft showed clear signs of mountain wave induced clouds, with nitric acid hydrate clouds often extending many hundreds of kilometers downwind of mountains. On the basis of T-matrix calculations, we have developed a technique to estimate the microphysical properties of spherical and nonspherical particles from multiwavelength backscatter and depolarization data from the Goddard Space Flight Center/Langley Research Center (GSFC/LaRC) aerosol lidar. The technique allows particle radius, condensed mass, and number densities of ice, nitric acid trihydrate, and liquid PSCs to be estimated. Ice clouds were found to contain approximately 1-3 ppmv of condensed water with a number density from 1 to 10 cm 3 and a narrow size distribution width with mode radii from 1 to 1.5 mum. Nitric acid hydrate particles downwind of the ice clouds were consistent with 1-5 ppbv condensed HNO3, a number density from 0.5 to 2 cm(-3), and mode radius around 0.5 m m. These hydrate clouds are characterized by high aerosol backscatter and depolarization and are distinct from type 1a clouds that are observed away from mountains, which have low aerosol backscatter. C1 Univ Leeds, Sch Environm, Leeds LS2 9JT, W Yorkshire, England. NASA, Langley Res Ctr, Hampton, VA USA. Swiss Fed Inst Technol, Lab Atmospher Phys, CH-8093 Zurich, Switzerland. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Hu, RM (reprint author), Univ Leeds, Sch Environm, Leeds LS2 9JT, W Yorkshire, England. RI Carslaw, Ken/C-8514-2009; McGee, Thomas/G-4951-2013; Fueglistaler, Stephan/I-5803-2013 OI Carslaw, Ken/0000-0002-6800-154X; NR 35 TC 17 Z9 17 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8294 DI 10.1029/2001JD001125 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200089 ER PT J AU Hurst, DF Schauffler, SM Greenblatt, JB Jost, H Herman, RL Elkins, JW Romashkin, PA Atlas, EL Donnelly, SG Podolske, JR Loewenstein, M Webster, CR Flesch, GJ Scott, DC AF Hurst, DF Schauffler, SM Greenblatt, JB Jost, H Herman, RL Elkins, JW Romashkin, PA Atlas, EL Donnelly, SG Podolske, JR Loewenstein, M Webster, CR Flesch, GJ Scott, DC TI Construction of a unified, high-resolution nitrous oxide data set for ER-2 flights during SOLVE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE nitrous oxide; stratosphere; SOLVE; ER-2; data combination method ID ARCTIC POLAR VORTEX; IN-SITU MEASUREMENTS; LOWER STRATOSPHERE; UPPER TROPOSPHERE; TRACE GASES; OZONE LOSS; WINTER; N2O; DENITRIFICATION; SPECTROMETER AB Four nitrous oxide (N2O) instruments were part of the NASA ER-2 aircraft payload during the 2000 SAGE-III Ozone Loss and Validation Experiment (SOLVE). Coincident data from the three in situ instruments and a whole air sampler are compared. Agreement between these instruments was typically good; however, there are several types of important differences between the data sets. These differences prompted a collaborative effort to combine data from the three in situ instruments, using an objective method, to produce a self-consistent, high-resolution, unified N2O data set for each SOLVE flight. The construction method developed by the four N2O instrument teams is described in detail. An important step in this method is the evaluation and reduction of bias in each of the in situ data sets before they are combined. The quality of unified N2O data is examined through its agreement with high-accuracy and high-precision N2O data from whole air samples collected from the ER-2 during SOLVE flights. Typical agreement between these two data sets is 2.9 ppb (1.5%), better than the typical agreement between any pair of N2O instruments. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Bay Area Environm Res Inst, San Francisco, CA USA. RP Hurst, DF (reprint author), NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. RI Herman, Robert/H-9389-2012; Atlas, Elliot/J-8171-2015; Hurst, Dale/D-1554-2016 OI Herman, Robert/0000-0001-7063-6424; Hurst, Dale/0000-0002-6315-2322 NR 17 TC 14 Z9 14 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8271 DI 10.1029/2001JD000417 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200033 ER PT J AU Irie, H Kondo, Y Koike, M Danilin, MY Camy-Peyret, C Payan, S Pommereau, JP Goutail, F Oelhaf, H Wetzel, G Toon, GC Sen, B Bevilacqua, RM Russell, JM Renard, JB Kanzawa, H Nakajima, H Yokota, T Sugita, T Sasano, Y AF Irie, H Kondo, Y Koike, M Danilin, MY Camy-Peyret, C Payan, S Pommereau, JP Goutail, F Oelhaf, H Wetzel, G Toon, GC Sen, B Bevilacqua, RM Russell, JM Renard, JB Kanzawa, H Nakajima, H Yokota, T Sugita, T Sasano, Y TI Validation of NO2 and HNO3 measurements from the Improved Limb Atmospheric Spectrometer (ILAS) with the version 5.20 retrieval algorithm SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ARCTIC STRATOSPHERE; NITRIC-ACID; OZONE; RADICALS; NITROGEN; VORTEX AB [1] The Improved Limb Atmospheric Spectrometer (ILAS) on board the Advanced Earth Observing Satellite (ADEOS) measured nitrogen dioxide (NO2) and nitric acid (HNO3) profiles from November 1996 to June 1997 at high latitudes in both hemispheres. The ILAS NO2 profiles (version 5.20) are compared with those obtained by balloon-borne and satellite measurements to validate ILAS NO2 data. Comparisons with balloon-borne measurements indicate that ILAS NO2 at 25-30 km has a positive bias of 0.3-0.4 ppbv (6-11%). The random difference in NO2 at 25-30 km is 0.2-0.3 ppbv (3-9%). The random error in the ILAS NO2 measurements is larger than 100% below 20 km and above 45 km, where the NO2 mixing ratios were less than 1.0 ppbv. It is possible that ILAS NO2 values were lowered by optically thick aerosols with aerosol extinction coefficients at 780 nm of greater than 0.001 km(-1). The lack of diurnal correction along the line of sight contributes to the positive bias in the ILAS NO2 values below 25 km. Agreement of the ILAS NO2 values with those by the Polar Ozone and Aerosol Measurement (POAM) II instrument is within 10-30% at 25-35 km. The agreement with the Halogen Occultation Experiment (HALOE) is as good as +/-10% at 25-40 km. ILAS HNO3 (version 5.20) agrees with balloon-borne HNO3 to within 0.1 ppbv (0-1%), and the random difference is within 10% at 25-30 km. C1 Nagoya Univ, Solar Terr Environm Lab, Aichi 4428507, Japan. Univ Tokyo, Adv Sci & Technol Res Ctr, Tokyo 1538904, Japan. Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Tokyo 1130033, Japan. Atmospher & Environm Res Inc, Lexington, MA USA. Univ Paris 06, Lab Phys Mol & Applicat, CNRS, F-75252 Paris 05, France. CNRS, Serv Aeron, F-91371 Verrieres Les Buissons, France. Forschungszentrum Karlsruhe, Inst Meteorol & Klimaforsch, D-76021 Karlsruhe, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. USN, Res Lab, Washington, DC 20375 USA. CNRS, Lab Phys & Chim Environm, F-45071 Orleans 2, France. Natl Inst Environm Studies, Tsukuba, Ibaraki, Japan. NASA, LaRC, Div Atmospher Sci, Hampton, VA USA. RP Irie, H (reprint author), Nagoya Univ, Solar Terr Environm Lab, 3-13 Honohara, Aichi 4428507, Japan. RI Sasano, Yasuhiro/C-2927-2009; Koike, Makoto/F-4366-2011; Kondo, Yutaka/D-1459-2012; Wetzel, Gerald/A-7065-2013; Oelhaf, Hermann/A-7895-2013 OI Sasano, Yasuhiro/0000-0001-7470-5642; NR 28 TC 21 Z9 21 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D24 AR 8206 DI 10.1029/2001JD001304 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 637BN UT WOS:000180491900002 ER PT J AU Jensen, EJ Toon, OB Tabazadeh, A Drdla, K AF Jensen, EJ Toon, OB Tabazadeh, A Drdla, K TI Impact of polar stratospheric cloud particle composition, number density, and lifetime on denitrification SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE denitrification ID NITRIC-ACID; ARCTIC STRATOSPHERE; WINTER; MODEL AB One-dimensional simulations of polar stratospheric clouds (PSCs) composed of nitric acid trihydrate (NAT) and nitric acid dihydrate (NAD) particles are used to investigate vertical redistribution of nitric acid by clouds with these compositions. We find that for typical Arctic PSC lifetimes of a few days or less the net depletion of HNO3 is well below 50%, regardless of the NAT or NAD particle number density. With cloud lifetimes of a week or longer, greater than 50% denitrification is possible even with relatively low NAT particle number densities (as low as 1 x 10(-3) cm(-3)). Denitrification is most efficient with NAT particle number densities of about 3 x 10(-3) cm(-3) to 10(-2) cm(-3). For a given temperature history the degree of denitrification by NAD clouds is much less severe than that by NAT clouds. The clouds also cause a local maximum in HNO3 mixing ratios at the cloud base where the cloud particles sublimate. Our simulations suggest that repeated short-lived PSC events do not build up the denitrification beyond about 50%; however, the depth of the denitrified layer increases with each successive PSC event. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Colorado, Dept Atmospher & Ocean Sci, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. RP Jensen, EJ (reprint author), NASA, Ames Res Ctr, MS 254-4, Moffett Field, CA 94035 USA. NR 24 TC 21 Z9 21 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8284 DI 10.1029/2001JD000440 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200058 ER PT J AU Jiang, JH Wu, DL Eckermann, SD AF Jiang, JH Wu, DL Eckermann, SD TI Upper Atmosphere Research Satellite (UARS) MLS observation of mountain waves over the Andes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GRAVITY-WAVES; MIDDLE ATMOSPHERE; NUMBER SPECTRA; EL-NINO; STRATOSPHERE; WINDS; FLUCTUATIONS; DRAG AB Stratospheric air temperature (radiance) fluctuations over the Andes observed by the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS) are presented. The MLS radiance variances show strong annual variability over the Andes mountains in South America, which is closely correlated to the background wind conditions associated with mountain wave generation and propagation. The variances are significantly larger in southern hemispheric winter when the winds in the troposphere and stratosphere over the Andes are both westerly and mountain wave critical levels (zero-wind lines) are absent. The annual variation of MLS radiance variance agrees well with data from radiosondes and output from the Naval Research Laboratory (NRL) Mountain Wave Forecast Model (MWFM) over the same region and period. The amplitude of the radiance variances seems to correlate well with the intensity of surface wind at upstream positions westward of the Andes, which is also related to the meridional temperature gradient in the region. Horizontal scale analysis suggests that mountain waves over the Andes might have two preferential horizontal wavelengths at similar to110 and similar to400 km. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. USN, Res Lab, Middle Atmosphere Dynam Sect, Washington, DC 20375 USA. RP Jiang, JH (reprint author), CALTECH, Jet Prop Lab, Mail Stop 183-701,4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Wu, Dong/D-5375-2012 NR 29 TC 50 Z9 50 U1 2 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8273 DI 10.1029/2002JD002091 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200038 ER PT J AU Jucks, KW Johnson, DG Chance, KV Traub, WA Margitan, JM Stachnik, R Sasano, Y Yokota, T Kanzawa, H Shibasaki, K Suzuki, M Ogawa, T AF Jucks, KW Johnson, DG Chance, KV Traub, WA Margitan, JM Stachnik, R Sasano, Y Yokota, T Kanzawa, H Shibasaki, K Suzuki, M Ogawa, T TI Validation of ILAS v5.2 data with FIRS-2 balloon observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LIMB-ATMOSPHERIC-SPECTROMETER; HALOGEN OCCULTATION EXPERIMENT; UARS PLATFORM; STRATOSPHERE; OZONE; HO2; H2O AB [1] Comparisons of remote sensing stratospheric mixing ratio profiles for O-3,H2O, N2O, HNO3, and NO2 are shown between data (version 5.2) obtained by the Improved Limb Atmospheric Spectrometer (ILAS) on board the Japanese Advanced Earth Observing Satellite (ADEOS) and the Smithsonian Astrophysical Observatory far-infrared spectrometer (FIRS)-2 balloon-borne spectrometer from a flight on 30 April 1997 originating in Fairbanks, Alaska. Submillimeter wave remote sensing and UV in situ observations of mixing ratios of O-3 from Jet Propulsion Laboratory (JPL) instruments obtained on board the same balloon gondola are also used for comparison with ILAS mixing ratios of O-3. The remote sensing balloon observations occurred roughly 5 latitude, and the in situ 2 latitude, north of the nearest ILAS observations and were taken between 0700 and 1300 local solar time (LST), while the ILAS data were taken at the previous local sunset (near 2100 LST). Back trajectories from the locations and times of balloon data sets to the prior local sunset were within 2 latitude and 10 longitude of the nearest ILAS occultation; the validation therefore effectively occurred in very nearly the same air mass as was observed with ILAS, and well within a 1-day time interval. The mixing ratio profiles of all of the compared molecules (O-3, HNO3,N2O, H2O, and NO2) agree to within the combined uncertainties with only minor systematic offsets. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Jet Propuls Lab, Pasadena, CA USA. Japan Environm Agcy, Natl Inst Environm Studies, Tsukuba, Ibaraki 305, Japan. Kokugakuin Univ, Shibuya Ku, Tokyo 1508440, Japan. NASDA, Earth Observat Res Ctr, Tokyo, Japan. RP Jucks, KW (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Sasano, Yasuhiro/C-2927-2009; Johnson, David/F-2376-2015 OI Sasano, Yasuhiro/0000-0001-7470-5642; Johnson, David/0000-0003-4399-5653 NR 26 TC 6 Z9 6 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D24 AR 8207 DI 10.1029/2001JD000578 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 637BN UT WOS:000180491900003 ER PT J AU Kato, S Loeb, NG Rutledge, CK AF Kato, S Loeb, NG Rutledge, CK TI Estimate of top-of-atmosphere albedo for a molecular atmosphere over ocean using Clouds and the Earth's Radiant Energy System measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aerosol radiative forcing; ocean surface reflectance; planetary albedo; molecular atmosphere ID RADIATIVE-TRANSFER; PLANETARY-ATMOSPHERES; LIGHT-FIELD; POLARIZATION; SCATTERING; APPROXIMATION; SIMULATION; INSTRUMENT; AERONET; MATRIX AB [1] The shortwave broadband albedo at the top of a molecular atmosphere over ocean between 40degreesN and 40degreesS is estimated using radiance measurements from the Clouds and the Earth's Radiant Energy System (CERES) instrument and the Visible Infrared Scanner (VIRS) aboard the Tropical Rainfall Measuring Mission satellite. The albedo monotonically increases from 0.059 at a solar zenith angle of 10degrees to 0.107 at a solar zenith angle of 60degrees. The estimated uncertainty in the albedo is 3.5 x 10(-3) caused by the uncertainty in CERES-derived irradiances, uncertainty in VIRS-derived aerosol optical thicknesses, variations in surface wind speed and variations in ozone and water vapor. The estimated uncertainty is similar in magnitude to the standard deviation of 0.003 that is derived from 72 areas which are divided by 20degrees latitude by 20degrees longitude grid boxes. The empirically estimated albedo is compared with the modeled albedo using a radiative transfer model combined with an ocean surface bidirectional reflectivity model. The modeled albedo with standard tropical atmosphere is 0.061 and 0.111 at the solar zenith angles of 10degrees and 60degrees, respectively. The empirically estimated albedo can be used to estimate the direct radiative effect of aerosols at the top of the atmosphere over oceans. C1 Analyt Serv & Mat Inc, Hampton, VA 23681 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. RP Kato, S (reprint author), NASA, Langley Res Ctr, Mail Stop 420, Hampton, VA 23681 USA. NR 46 TC 8 Z9 8 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D19 AR 4396 DI 10.1029/2001JD001309 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 635YT UT WOS:000180428300063 ER PT J AU Koike, M Kondo, Y Takegawa, N Lefevre, F Ikeda, H Irie, H Hunton, HDE Viggiano, AA Miller, TM Ballenthin, JO Sachse, GW Anderson, BE Avery, M Masui, Y AF Koike, M Kondo, Y Takegawa, N Lefevre, F Ikeda, H Irie, H Hunton, HDE Viggiano, AA Miller, TM Ballenthin, JO Sachse, GW Anderson, BE Avery, M Masui, Y TI Redistribution of reactive nitrogen in the Arctic lower stratosphere in the 1999/2000 winter SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE reactive nitrogen; NOy; Arctic; ozone; denitrification; nitrification ID 3-DIMENSIONAL MODEL SIMULATIONS; POLAR VORTEX; OZONE LOSS; NITRIC-ACID; TRACER CORRELATIONS; AIRCRAFT MEASUREMENTS; POTENTIAL VORTICITY; CLOUD AEROSOL; TOTAL WATER; AASE-II AB Total reactive nitrogen (NOy) in the Arctic lower stratosphere was measured from the NASA DC-8 aircraft during the SAGE III Ozone Loss and Validation Experiment (SOLVE) in the winter of 1999/2000. NOy-N2O correlations obtained at altitudes of 10-12.5 km in December 1999 and January 2000 are comparable to the reported reference correlation established using the MkIV balloon measurements made during SOLVE prior to the onset of denitrification. Between late February and mid-March, NOy values obtained from the DC-8 were systematically higher than those observed in December and January by up to 1 part per billion by volume, although a compact correlation between NOy and N2O was maintained. Greater increases in NOy were generally observed in air masses with lower N2O values. The daily minimum temperatures at 450-500 K potential temperature (similar to20-22 km) in the Arctic fell below the ice saturation temperature between late December and mid-January. Correspondingly, intense denitrification and nitrified air masses were observed from the ER-2 at 17-21 km and below 18 km, respectively, in January and March. The increases in NOy observed from the DC-8 in late February/March indicate that influence from nitrification extended as low as 10-12.5 km over a wide area by that time. We show in this paper that the vertical structure of the temperature field during the winter was a critical factor in determining the vertical extent of the NOy redistribution. Results from the Reactive Processes Ruling the Ozone Budget in the Stratosphere (REPROBUS) three-dimensional chemistry transport model, which reproduced the observed general features only when the NOy redistribution process is included, are also presented. C1 Univ Tokyo, Dept Earth & Planetary Sci, Grad Sch Sci, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Adv Sci & Technol Res Ctr, Tokyo 1538904, Japan. Inst Pierre Simon Laplace, Serv Aeron, F-75252 Paris 05, France. Natl Inst Environm Studies, Satellite Remote Sensing Res Team, Tsukuba, Ibaraki 3058506, Japan. USAF, Res Lab, Space Vehicles Directorate, Bedford, MA 01731 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Univ Tokyo, Dept Earth & Planetary Sci, Grad Sch Sci, Bunkyo Ku, Hongo 7-3-1, Tokyo 1130033, Japan. EM koike@eps.s.u-tokyo.ac.jp; kondo@atmos.rcast.u-tokyo.ac.jp; takegawa@stelab.nagoya-u.ac.jp; franck.lefevre@aero.jussieu.fr; hibiki@atmos.rcast.u-tokyo.ac.jp; irie.hitoshi@nies.go.jp; donald.hunton@hanscom.af.mil; albert.viggiano@hanscom.af.mil; thomas.miller@hanscom.af.mil; john.ballenthin@hanscom.af.mil; g.w.sachse@larc.nasa.gov; b.e.anderson@larc.nasa.gov; m.a.avery@larc.nasa.gov; masui@aos.eps.s.u-tokyo.ac.jp RI Koike, Makoto/F-4366-2011; Kondo, Yutaka/D-1459-2012 NR 57 TC 14 Z9 14 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8275 DI 10.1029/2001JD001089 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200040 ER PT J AU Kourtidis, K Zerefos, C Rapsomanikis, S Simeonov, V Balis, D Perros, PE Thompson, AM Witte, J Calpini, B Sharobiem, WM Papayannis, A Mihalopoulos, N Drakou, R AF Kourtidis, K Zerefos, C Rapsomanikis, S Simeonov, V Balis, D Perros, PE Thompson, AM Witte, J Calpini, B Sharobiem, WM Papayannis, A Mihalopoulos, N Drakou, R TI Regional levels of ozone in the troposphere over eastern Mediterranean SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE tropospheric ozone; regional pollution; eastern Mediterranean ID LONG-RANGE TRANSPORT; AIR-POLLUTANTS; AOT40 CONCEPT; CAMPAIGN; GREECE; LIDAR; FLUCTUATIONS; DIRECTIONS; ATLANTIC; MAXIMUM AB [1] During the last 5 years, information on the regional tropospheric ozone levels over the eastern Mediterranean has become available but was confined to measurements at ground level. Here available information is expanded with measurements at two more rural ground level sites spanning 8 latitude, ozonesonde ascents, lidar observations, ship cruises, and aircraft flights. During wintertime the ozone monthly values are 1020 ppbv higher than values at other European sites, while during summertime the values are comparable. This results in regional ozone background levels in the area that are above the European Union (EU) 32 ppb/ 24 hours phytotoxicity limit during the entire year. Late spring lidar observations show that south and southwestern synoptic flows which are associated with Saharan dust events result in lower ozone above the planetary boundary layer (PBL) by 20-35 ppbv as compared to these during northerly flows, which transport air from continental Europe. These lidar observations along with ship measurements during July show that ozone is enhanced 1.5-2.2 times in the continental outflow, when compared to aged maritime air or air from the African continent. These results along with ozonesonde observations suggest that ozone abatement in the area is largely beyond the control of regional emissions and can be controlled only with emission reductions on a European scale. During September, measured background NO and NO2 levels between 3 and 4.5 km above sea level ranged from 1 to 221 pptv and from 102 to 580 pptv, respectively. The troposphere contains around 40-70 Dobson units of ozone during summer and around 20-30 Dobson units during winter. C1 Aristotle Univ Thessaloniki, Dept Phys, Lab Atmospher Phys, GR-54006 Thessaloniki, Greece. Ecole Polytech Fed Lausanne, Fed Inst Technol, CH-1015 Lausanne, Switzerland. Democritus Univ Thrace, Dept Environm Engn, GR-67100 Xanthi, Greece. Univ Paris 12, Fac Sci & Technol, LISA, F-94010 Creteil, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Egyptian Meteorol Author, Cairo Reg Ozone Ctr, Cairo 11331, Egypt. Natl Tech Univ Athens, Dept Phys, GR-15773 Athens, Greece. Univ Crete, Dept Chem, Environm & Chem Proc Lab, Iraklion, Greece. RP Aristotle Univ Thessaloniki, Dept Phys, Lab Atmospher Phys, Campus Box 149, GR-54006 Thessaloniki, Greece. EM kourtidi@auth.gr; zerefos@auth.gr; rapso@env.duth.gr; valentin.simeonov@epfl.ch; balis@auth.gr; perros@lisa.univ-paris12.fr; thompson@gator1.gsfc.nasa.gov; witte@gavial.gsfc.nasa.gov; calpini@epfl.ch; wafik@nwp.gov.eg; apdlidar@central.ntua.gr; mihalo@chemistry.uoc.gr; kdrakos@otenet.gr RI PAPAYANNIS, Alex/A-7951-2010; Mihalopoulos, Nikolaos/H-5327-2016; Thompson, Anne /C-3649-2014; OI Mihalopoulos, Nikolaos/0000-0002-1282-0896; Thompson, Anne /0000-0002-7829-0920; Balis, Dimitris/0000-0003-1161-7746 NR 44 TC 53 Z9 53 U1 3 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP PY 2002 VL 107 IS D18 AR 8140 DI 10.1029/2000JD000140 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 635YH UT WOS:000180427400021 ER PT J AU Lait, LR Schoeberl, MR Newman, PA McGee, T Burris, J Browell, EV Richard, E Braathen, GO Bojkov, BR Goutail, F von der Gathen, P Kyro, E Vaughan, G Kelder, H Kirkwood, S Woods, P Dorokhov, V Zaitcev, I Litynska, Z Kois, B Benesova, A Skrivankova, P De Backer, H Davies, J Jorgensen, T Mikkelsen, IS AF Lait, LR Schoeberl, MR Newman, PA McGee, T Burris, J Browell, EV Richard, E Braathen, GO Bojkov, BR Goutail, F von der Gathen, P Kyro, E Vaughan, G Kelder, H Kirkwood, S Woods, P Dorokhov, V Zaitcev, I Litynska, Z Kois, B Benesova, A Skrivankova, P De Backer, H Davies, J Jorgensen, T Mikkelsen, IS TI Ozone loss from quasi-conservative coordinate mapping during the 1999-2000 SOLVE/THESEO 2000 campaigns SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERIC POLAR VORTEX; WINTER; RECONSTRUCTION; TRANSPORT; DEPLETION; TRENDS; FIELDS; ER-2 AB Ozone observations made by the Airborne Raman Ozone, Temperature, and Aerosol Lidar (AROTEL) and Differential Absorption Lidar (DIAL) on board the NASA DC-8 aircraft, the NOAA in situ instrument on board the NASA ER-2 aircraft, and Third European Stratospheric Experiment on Ozone 2000 (THESEO 2000) ozonesondes are analyzed by applying a quasi-conservative coordinate mapping technique. Measurements from the late winter/early spring SAGE III Ozone Loss and Validation Experiment (SOLVE) period (January through March 2000) are incorporated into a time-varying composite field in a potential vorticity-potential temperature coordinate space; ozone loss rates are calculated both with and without diabatic effects. The average loss rate from mid-January to mid-March near the 450 K isentropic surface in the polar vortex is found to be approximately 0.03 ppmv/d. C1 Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20071 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Boulder, CO 80309 USA. Norwegian Inst Air Res, Tromso, Norway. CNRS, F-75700 Paris, France. Alfred Wegener Inst Polar & Marine Res, Potsdam, Germany. Finnish Meteorol Inst, Sodankyla, Finland. Univ Wales, Aberystwyth, Dyfed, Wales. Royal Netherlands Meteorol Inst, KNMI, NL-3730 AE De Bilt, Netherlands. Swedish Inst Space Phys, Uppsala, Sweden. Natl Phys Lab, Teddington TW11 0LW, Middx, England. Cent Aerol Observ, Moscow, Russia. Inst Meteorol & Water Management, Legionowo, Poland. Czech Hydrometeorol Inst, Prague, Czech Republic. Royal Meteorol Inst Belgium, KMI, IRM, Brussels, Belgium. Meteorol Serv Canada, Downsview, ON, Canada. Danish Meteorol Inst, Copenhagen, Denmark. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Lait, LR (reprint author), Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RI von der Gathen, Peter/B-8515-2009; Newman, Paul/D-6208-2012; McGee, Thomas/G-4951-2013; Vaughan, Geraint/O-2459-2015 OI von der Gathen, Peter/0000-0001-7409-1556; Newman, Paul/0000-0003-1139-2508; Vaughan, Geraint/0000-0002-0885-0398 NR 32 TC 9 Z9 9 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8274 DI 10.1029/2001JD000998 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200039 ER PT J AU Martin, RV Chance, K Jacob, DJ Kurosu, TP Spurr, RJD Bucsela, E Gleason, JF Palmer, PI Bey, I Fiore, AM Li, QB Yantosca, RM Koelemeijer, RBA AF Martin, RV Chance, K Jacob, DJ Kurosu, TP Spurr, RJD Bucsela, E Gleason, JF Palmer, PI Bey, I Fiore, AM Li, QB Yantosca, RM Koelemeijer, RBA TI An improved retrieval of tropospheric nitrogen dioxide from GOME SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OZONE MONITORING EXPERIMENT; ABSORPTION CROSS-SECTIONS; SENSING REFERENCE DATA; MARINE BOUNDARY-LAYER; 231-794 NM RANGE; REACTIVE NITROGEN; RAMAN-SCATTERING; UNITED-STATES; NORTH-AMERICA; MODEL AB We present a retrieval of tropospheric nitrogen dioxide (NO2) columns from the Global Ozone Monitoring Experiment (GOME) satellite instrument that improves in several ways over previous retrievals, especially in the accounting of Rayleigh and cloud scattering. Slant columns, which are directly fitted without low-pass filtering or spectral smoothing, are corrected for an artificial offset likely induced by spectral structure on the diffuser plate of the GOME instrument. The stratospheric column is determined from NO2 columns over the remote Pacific Ocean to minimize contamination from tropospheric NO2. The air mass factor (AMF) used to convert slant columns to vertical columns is calculated from the integral of the relative vertical NO2 distribution from a global 3-D model of tropospheric chemistry driven by assimilated meteorological data (Global Earth Observing System (GEOS)-CHEM), weighted by altitude-dependent scattering weights computed with a radiative transfer model (Linearized Discrete Ordinate Radiative Transfer), using local surface albedos determined from GOME observations at NO2 wavelengths. The AMF calculation accounts for cloud scattering using cloud fraction, cloud top pressure, and cloud optical thickness from a cloud retrieval algorithm (GOME Cloud Retrieval Algorithm). Over continental regions with high surface emissions, clouds decrease the AMF by 20-30% relative to clear sky. GOME is almost twice as sensitive to tropospheric NO2 columns over ocean than over land. Comparison of the retrieved tropospheric NO2 columns for July 1996 with GEOS-CHEM values tests both the retrieval and the nitrogen oxide radical (NOx) emissions inventories used in GEOS-CHEM. Retrieved tropospheric NO2 columns over the United States, where NOx emissions are particularly well known, are within 18% of GEOS-CHEM columns and are strongly spatially correlated (r = 0.78, n = 288, p < 0.005). Retrieved columns show more NO2 than GEOS-CHEM columns over the Transvaal region of South Africa and industrial regions of the northeast United States and Europe. They are lower over Houston, India, eastern Asia, and the biomass burning region of central Africa, possibly because of biases from absorbing aerosols. C1 Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Space Res Org Netherlands, NL-3584 Utrecht, Netherlands. RP Harvard Univ, Div Engn & Appl Sci, G3D Pierce Hall,29 Oxford St, Cambridge, MA 02138 USA. EM rvmartin@fas.harvard.edu RI Martin, Randall/A-2051-2008; Palmer, Paul/F-7008-2010; Gleason, James/E-1421-2012; Martin, Randall/C-1205-2014; Chem, GEOS/C-5595-2014 OI Martin, Randall/0000-0003-2632-8402; NR 73 TC 210 Z9 223 U1 3 U2 29 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 4437 DI 10.1029/2001JD001027 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200100 ER PT J AU Negri, AJ Adler, RF Xu, L AF Negri, AJ Adler, RF Xu, L TI A TRMM-calibrated infrared rainfall algorithm applied over Brazil SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE Amazon; rainfall; TRMM; satellite; precipitation ID PASSIVE MICROWAVE TECHNIQUE; GOES PRECIPITATION INDEX; GLOBAL PRECIPITATION; CONVECTIVE CLOUDINESS; CLIMATOLOGY; INFORMATION; RESOLUTION; DATASET; SENSORS; CYCLE AB [1] The development of a satellite infrared technique for estimating convective and stratiform rainfall and its application in studying the diurnal variability of rainfall in Amazonia are presented. The convective-stratiform technique (CST), calibrated by coincident, physically retrieved rain rates from the TRMM microwave imager (TMI), is applied during January-April 1999 over northern South America. The diurnal cycle of rainfall, as well as the division between convective and stratiform rainfall, is presented. Results compare well (a 1-hour lag) with the diurnal cycle derived from TOGA radar-estimated rainfall in Rondonia. The satellite estimates reveal that the convective rain constitutes, in the mean, 24% of the rain area while accounting for 67% of the rain volume. Estimates of the diurnal cycle for the entire Amazon Basin are in agreement with those from the TRMM precipitation radar, despite the limited sampling of the latter. The effects of geography (rivers, lakes, coasts) and topography on the diurnal cycle of convection are examined. In particular, the Amazon River, downstream of Manaus, is shown to both enhance early morning rainfall and inhibit afternoon convection. Monthly estimates from this technique, dubbed CST/TMI, are verified over a dense rain gage network in the state of Ceara, in northeast Brazil. The CST/TMI showed a high bias equal to +33% of the gage mean, indicating that possibly the TMI estimates alone are also high. The root-mean-square difference (after removal of the bias) equaled 36.6% of the gage mean. The correlation coefficient was 0.77 based on 72 station months. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. RP Negri, AJ (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 912, Greenbelt, MD 20771 USA. NR 29 TC 38 Z9 38 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8048 DI 10.1029/2000JD000265 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200005 ER PT J AU Newman, PA Harris, NRP Adriani, A Amanatidis, GT Anderson, JG Braathen, GO Brune, WH Carslaw, KS Craig, MS DeCola, PL Guirlet, M Hipskind, RS Kurylo, MJ Kullmann, H Larsen, N Megie, GJ Pommereau, JP Poole, LR Schoeberl, MR Stroh, F Toon, OB Trepte, CR Van Roozendael, M AF Newman, PA Harris, NRP Adriani, A Amanatidis, GT Anderson, JG Braathen, GO Brune, WH Carslaw, KS Craig, MS DeCola, PL Guirlet, M Hipskind, RS Kurylo, MJ Kullmann, H Larsen, N Megie, GJ Pommereau, JP Poole, LR Schoeberl, MR Stroh, F Toon, OB Trepte, CR Van Roozendael, M TI An overview of the SOLVE/THESEO 2000 campaign SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE SOLVE; THESEO 2000; ozone; ozone loss; stratosphere; polar vortex ID ARCTIC POLAR VORTEX; MICROWAVE LIMB SOUNDER; HALOGEN OCCULTATION EXPERIMENT; ATMOSPHERE RESEARCH SATELLITE; CHEMICAL OZONE LOSS; STRATOSPHERIC CLOUDS; WINTER 1999/2000; BALLOON-BORNE; NITRIC-ACID; NORTHERN-HEMISPHERE AB Between November 1999 and April 2000, two major field experiments, the Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE) and the Third European Stratospheric Experiment on Ozone (THESEO 2000), collaborated to form the largest field campaign yet mounted to study Arctic ozone loss. This international campaign involved more than 500 scientists from over 20 countries. These scientists made measurements across the high and middle latitudes of the Northern Hemisphere. The main scientific aims of SOLVE/THESEO 2000 were to study (1) the processes leading to ozone loss in the Arctic vortex and (2) the effect on ozone amounts over northern midlatitudes. The campaign included satellites, research balloons, six aircraft, ground stations, and scores of ozonesondes. Campaign activities were principally conducted in three intensive measurement phases centered on early December 1999, late January 2000, and early March 2000. Observations made during the campaign showed that temperatures were below normal in the polar lower stratosphere over the course of the 1999-2000 winter. Because of these low temperatures, extensive polar stratospheric clouds (PSC) formed across the Arctic. Large particles containing nitric acid trihydrate were observed for the first time, showing that denitrification can occur without the formation of ice particles. Heterogeneous chemical reactions on the surfaces of the PSC particles produced high levels of reactive chlorine within the polar vortex by early January. This reactive chlorine catalytically destroyed about 60% of the ozone in a layer near 20 km between late January and mid-March 2000, with good agreement being found between a number of empirical and modeling studies. The measurements made during SOLVE/THESEO 2000 have improved our understanding of key photochemical parameters and the evolution of ozone-destroying forms of chlorine. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. European Ozone Res Coordinating Unit, Cambridge CB2 1HE, England. CNR, ISAC, Inst Fis Atmosfera, I-00133 Rome, Italy. European Commiss, Res DG, B-1049 Brussels, Belgium. Harvard Univ, Dept Chem, Anderson Grp CCB, Cambridge, MA 02138 USA. Norsk Inst Luftforskning, N-2027 Kjeller, Norway. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Univ Leeds, Sch Environm, Leeds LS2 9JT, W Yorkshire, England. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA Headquarters, Washington, DC 20546 USA. ACRI ST, F-06904 Sophia Antipolis, France. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Bremen, Inst Environm Phys, D-28334 Bremen, Germany. Danish Meteorol Inst, Middle Atmospher Res Div, DK-2100 Copenhagen, Denmark. Inst Pierre Simon Laplace, Serv Aeron, Paris, France. CNRS, Serv Aeron, F-91371 Verrieres Le Buisson, France. NASA, Langley Res Ctr, Radiat & Aerosols Branch, Hampton, VA 23681 USA. Forschungszentrum Julich, Inst Stratosphar Chem, D-52425 Julich, Germany. Univ Colorado, Program Atmospher & Ocean Sci, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Belgian Inst Space & Aeron BIRA IASB, B-1180 Brussels, Belgium. RP NASA, Goddard Space Flight Ctr, Code 910,Greenbelt Rd, Greenbelt, MD 20771 USA. EM newman@notus.gsfc.nasa.gov; Neil.Harris@ozone-sec.ch.cam.ac.uk; adriani@ifa.rm.cnr.it; georgios.amanatidis@cec.eu.int; anderson@huarp.harvard.edu; geir@nilu.no; brune@ems.psu.edu; carslaw@env.leeds.ac.uk; mcraig@mail.arc.nasa.gov; pdecola@hq.nasa.gov; mag@acri-st.fr; shipskind@mail.arc.nasa.gov; mkurylo@hq.nasa.gov; hkuell@physik.uni-bremen.de; nl@dmi.dk; gerard.megie@cnrs-dir.fr; pommereau@aerov.jussieu.fr; l.r.poole@larc.nasa.gov; schom@hyperion.gsfc.nasa.gov; f.stroh@fz-juelich.de; toon@lasp.colorado.edu; c.r.trepte@larc.nasa.gov; michelv@oma.be RI Stroh, Fred/A-6505-2009; Newman, Paul/D-6208-2012; Kurylo, Michael/H-2201-2012; Carslaw, Ken/C-8514-2009; Larsen, Niels/G-3145-2014; OI Stroh, Fred/0000-0002-4492-2977; Newman, Paul/0000-0003-1139-2508; Carslaw, Ken/0000-0002-6800-154X; Adriani, Alberto/0000-0003-4998-8008 NR 77 TC 72 Z9 72 U1 1 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8259 DI 10.1029/2001JD001303 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200105 ER PT J AU Northway, MJ Gao, RS Popp, PJ Holecek, JC Fahey, DW Carslaw, KS Tolbert, MA Lait, LR Dhaniyala, S Flagan, RC Wennberg, PO Mahoney, MJ Herman, RL Toon, GC Bui, TP AF Northway, MJ Gao, RS Popp, PJ Holecek, JC Fahey, DW Carslaw, KS Tolbert, MA Lait, LR Dhaniyala, S Flagan, RC Wennberg, PO Mahoney, MJ Herman, RL Toon, GC Bui, TP TI An analysis of large HNO3-containing particles sampled in the Arctic stratosphere during the winter of 1999/2000 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE polar stratospheric clouds; particles; denitrification; HNO3; NAT; NOy ID NITRIC-ACID TRIHYDRATE; POLAR VORTEX; OZONE LOSS; REACTIVE NITROGEN; CLOUD PARTICLES; DENITRIFICATION; HNO3; AEROSOL; CONDENSATION; CHEMISTRY AB Large (>2 mum diameter) HNO3-containing polar stratospheric cloud (PSC) particles were measured in situ by the NOAA NOy instrument on board the NASA ER-2 aircraft during seven flights in the 1999/2000 Arctic winter vortex. Here we discuss the detection of these large PSC particles, their spatial distribution, the ambient conditions under which they were detected, and our methods for interpreting NOy time series with respect to particle sizes and number concentrations. The particles were observed through the use of two NOy inlets on a particle separator extending below the ER-2 aircraft. The particle phase is assumed to be nitric acid trihydrate (NAT) or nitric acid dihydrate (NAD). Over a 48-day period, particles were sampled in the Arctic vortex over a broad range of latitudes (60-85degreesN) and altitudes (15-21 km). Typically, regions of the atmosphere up to 4 km above the observed large particle clouds were saturated with respect to NAT. Occasionally, large particles were measured in air subsaturated with respect to NAT, suggesting ongoing particle evaporation. Vortex minimum temperatures in the observation period suggest that synoptic-scale ice saturation conditions are not required for the formation of this type of particle. Three analytical methods are used to estimate size and number concentrations from the NOy time series. Results indicate particle sizes between 5 and 20 mum diameter and concentrations from 10(-5) to 10(-3) cm(-3). These low number concentrations imply a selective nucleation mechanism. Particle sizes and number concentrations were greater during the midwinter flights than the late winter flights. Knowledge of the geographical extent of large particles, actual sampling conditions, and particle size distributions offers multiple constraints for atmospheric models of PSC formation, which will lead to a better understanding of the process of denitrification and improvements in modeling future ozone loss. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Leeds, Sch Environm, Leeds LS2 9JT, W Yorkshire, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Ames Res Ctr, Atmospher Chem & Dynam Branch, Moffett Field, CA 94035 USA. RP NOAA, Aeron Lab, 325 Broadway,R-AL6, Boulder, CO 80305 USA. EM northway@al.noaa.gov RI Carslaw, Ken/C-8514-2009; Chipperfield, Martyn/H-6359-2013; Gao, Ru-Shan/H-7455-2013; Fahey, David/G-4499-2013; Wennberg, Paul/A-5460-2012; Herman, Robert/H-9389-2012 OI Carslaw, Ken/0000-0002-6800-154X; Chipperfield, Martyn/0000-0002-6803-4149; Fahey, David/0000-0003-1720-0634; Herman, Robert/0000-0001-7063-6424 NR 62 TC 73 Z9 73 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8298 DI 10.1029/2001JD001079 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200095 ER PT J AU Oberheide, J Lehmacher, GA Offermann, D Grossmann, KU Manson, AH Meek, CE Schmidlin, FJ Singer, W Hoffmann, P Vincent, RA AF Oberheide, J Lehmacher, GA Offermann, D Grossmann, KU Manson, AH Meek, CE Schmidlin, FJ Singer, W Hoffmann, P Vincent, RA TI Geostrophic wind fields in the stratosphere and mesosphere from satellite data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CRYOGENIC INFRARED SPECTROMETERS; RESOLUTION DOPPLER IMAGER; MIDDLE ATMOSPHERE; IMAGING INTERFEROMETER; LOWER THERMOSPHERE; TEMPERATURE DATA; DIURNAL TIDE; CRISTA; TELESCOPES; VARIABILITY AB [1] Daily maps of horizontally resolved zonal and meridional geostrophic wind fields in the altitude range of 20-90 km were obtained from the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) experiment during November 1994 and August 1997. Results are compared with zonal mean zonal winds from climatological sources and with assimilated data from standard analyses. Correlative data from ground-based and balloon- and rocket-borne measurements are used to validate the CRISTA winds. The comparisons show that geostrophic wind fields from high spatial resolution satellite-borne temperature measurements are a good approximation for the winds in the middle atmosphere up to mesopause heights. Therefore, they may be used as input for further modeling efforts particularly in the mesosphere, where no wind data from standard analyses are available. C1 Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany. Western Kentucky Univ, Dept Phys & Astron, Bowling Green, KY 42101 USA. Univ Saskatchewan, Inst Space & Atmospher Studies, Saskatoon, SK S7N 0W0, Canada. NASA, Goddard Space Flight Ctr, Lab Hydrostat Proc, Observat Sci Branch, Wallops Isl, VA 23337 USA. Leibniz Inst Atmospharenphys, Kuhlungsborn, Germany. Univ Adelaide, Dept Phys & Math Phys, Adelaide, SA 5005, Australia. RP Oberheide, J (reprint author), Natl Ctr Atmospher Res, High Altitude Observ, Pob 3000, Boulder, CO 80307 USA. RI Oberheide, Jens/C-6156-2011; Lehmacher, Gerald/F-2653-2013; Hagan, Maura/C-7200-2008 OI Oberheide, Jens/0000-0001-6721-2540; Hagan, Maura/0000-0002-8866-7429 NR 40 TC 75 Z9 77 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D23 AR 8175 DI 10.1029/2001JD000655 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 637AT UT WOS:000180490000002 ER PT J AU Offermann, D Schaeler, B Riese, M Langfermann, M Jarisch, M Eidmann, G Schiller, C Smit, HGJ Read, WG AF Offermann, D Schaeler, B Riese, M Langfermann, M Jarisch, M Eidmann, G Schiller, C Smit, HGJ Read, WG TI Water vapor at the tropopause during the CRISTA 2 mission SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE water vapor; tropopause; CRISTA; trace gas variability; constituent transport; middle atmosphere dynamics ID CRYOGENIC INFRARED SPECTROMETERS; ICE-SUPERSATURATED REGIONS; UPPER TROPOSPHERE; LOWER STRATOSPHERE; RELATIVE-HUMIDITY; TROPICAL TROPOPAUSE; SEASONAL-VARIATIONS; SUBVISIBLE CIRRUS; HALOE DATA; OZONE AB [1] Water vapor mixing ratios at the tropopause are derived as a new Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) data product from limb scan measurements of the second mission. Global maps are obtained on a daily basis. Data loss due to high clouds is found to be moderate. Good agreement with in situ airplane measurements (Fast In Situ Stratospheric Hygrometer (FISH)) is obtained for these Version 1 data. A number of different analyses are performed to show the research potential of the data product: the CRISTA data are compared to measurements of the Microwave Limb Sounder (MLS) instrument on the Upper Atmosphere Research Satellite (UARS). Version 4.9 climatology data and Version 5 coincident measurements are used. Good agreement of CRISTA and Version 4.9 data is obtained, whereas there are differences with respect to the Version 5.0 data. CRISTA finds vapor mixing ratios to be highly variable. Only a small part of this is instrumental. Variability is structured, and a scaling behavior is observed. Relation to convectively generated gravity waves is discussed. Relative humidity (RH) is determined on the basis of the CRISTA data. Suitability for supersaturation statistics is discussed and appears to be limited. CRISTA water vapor data are assimilated into a 3D transport model driven by UK Meteorological Office (UKMO) winds. Results are discussed in terms of meridional transports and atmospheric diffusivities. Diffusivities appear to be connected with the water vapor variances in a simple manner. C1 Univ Wuppertal, Dept Phys, Wuppertal, Germany. Res Ctr Juelich GmbH, Inst Chem & Dynam Geosphere, Julich, Germany. Dornier Syst GmbH, Daimler Benz Aerosp, D-7990 Friedrichshafen, Germany. Vacuumschmelze & CoKG, Hanau, Germany. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Offermann, D (reprint author), Univ Wuppertal, Dept Phys, Wuppertal, Germany. RI Smit, Herman/J-2397-2012; Schiller, Cornelius/B-1004-2013; Riese, Martin/A-3927-2013 OI Smit, Herman/0000-0002-2268-4189; Riese, Martin/0000-0001-6398-6493 NR 49 TC 16 Z9 16 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D23 AR 8176 DI 10.1029/2001JD000700 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 637AT UT WOS:000180490000003 ER PT J AU Pereira, AJ Dias, MAFS Albrecht, RI Pereira, LGP Gandu, AW Massambani, O Tokay, A Rutledge, S AF Pereira, AJ Dias, MAFS Albrecht, RI Pereira, LGP Gandu, AW Massambani, O Tokay, A Rutledge, S TI Multisensor analysis of a squall line in the Amazon Region SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE cloud microphysics; cold pool; squall line; Amazon; remote sensing; mesoscale dynamics ID AMERICA; AIR; PRECIPITATION; STRATIFORM; SHEAR; RAIN AB Mesoscale features of the 26 January 1999 squall line are described with measurements made during the field experiment in Rondonia, Brazil, in the wet season (WET) of the Amazon region (AMC) as part of the Large-Scale Biosphere-Atmosphere Experiment in the Amazon (LBA) and the Tropical Rainfall Measurement Mission (TRMM); henceforth referred to as the WET AMC and TRMM-LBA field experiment. The squall line moved through the experiment area from northeast to southwest with high rainfall rates in its leading edge and a poorly defined trailing stratiform precipitating area. Polarimetric and Doppler measurements from the Portable Polarimetric S-band Radar (S-POL) were analyzed in conjunction with surface and upper level data, satellite visible (VIS) and infrared (IR) measurements. These remote and local measurements of variables such as cloud spatial and temporal distribution, pressure, temperature, moisture, precipitation, and wind fields are consistent with each other as well as with similar mesoscale dynamics and thermodynamics features measured, analyzed, and modeled elsewhere [e. g., Rotunno et al., 1988; Garstang et al., 1994; Houze et al., 1990]. This tropical squall line is similar to its cousins in the midlatitudes with finer-scale structural and dynamic features such as rotation and divergence. Results suggest that the cold pool has its origins in midlevels between 400 and 600 hPa from where evaporative cooling and drop-dragging bring down colder air to the surface. The convective region is dominated by warm microphysics, while the stratiform region is dominated by cold microphysics. Moreover, both regions are characterized by monomodal drop spectra centered around 2.0 and 1.0 mm, respectively. Horizontal circulation associated with strong updrafts tends to increase cloud growth efficiency in the leading edge of the squall line. C1 Univ Sao Paulo, Dept Atmospher Sci, BR-05508900 Sao Paulo, Brazil. NASA, Goddard Space Flight Ctr, Trop Rainfall Measurement Miss Off, Greenbelt, MD 20771 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RP Pereira, AJ (reprint author), Univ Sao Paulo, Dept Atmospher Sci, Rua Matao 1226, BR-05508900 Sao Paulo, Brazil. RI Albrecht, Rachel/D-9311-2012 OI Albrecht, Rachel/0000-0003-0582-6568 NR 47 TC 4 Z9 4 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8084 DI 10.1029/2000JD000305 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200064 ER PT J AU Poli, P Joiner, J Kursinski, ER AF Poli, P Joiner, J Kursinski, ER TI 1DVAR analysis of temperature and humidity using GPS radio occultation refractivity data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE GPS; radio occultation; refractivity; data assimilation; radiosonde; 1DVAR ID GLOBAL POSITIONING SYSTEM; ESTIMATION INVERSE METHOD; TROPOSPHERIC WATER-VAPOR; DATA ASSIMILATION; VARIATIONAL ANALYSIS; EARTHS ATMOSPHERE; SURFACE PRESSURE; FORECAST BIAS; INFORMATION; VOYAGER-2 AB The constellation of Global Positioning System (GPS) satellites provides a source of continuous, phase-stable electromagnetic signals available for radio occultation observations of our planet. The atmospheric-induced bending of the transmitted rays observed during each occultation can be converted into a refractivity profile using an Abel transform. Since refractivity is related to temperature and humidity, it may potentially be used in global data assimilation for numerical weather prediction (NWP) and for creating climate data sets. We first compare GPS/Meteorology (GPS/MET) 1995 refractivity with various backgrounds and verify that the best expected background presents generally the best fit with the observed refractivity. We implement here an efficient one-dimensional variational (1DVAR) analysis of GPS refractivity that enables retrieving temperature, humidity, and sea-level pressure using the finite volume data assimilation system background. 1DVAR analyses with GPS/MET 1995 data are compared with collocated radiosondes. They show an excellent capacity of the GPS measurements to resolve the tropopause. In the Northern Hemisphere, we demonstrate a net reduction of temperature bias and standard deviation, as compared with the background. The 1DVAR humidity presents reduced standard deviation as compared to the background between 550 and 400 hPa. However, a refractivity bias between the observations and the background in the lower troposphere systematically shifts the 1DVAR humidity downward. A refractivity bias over the whole profile is transformed into a 1DVAR sea-level pressure bias. This study represents a step toward using the GPS radio occultation data in data assimilation systems to improve NWP forecasts and representation of Earth's climate in models. C1 NASA, Goddard Space Flight Ctr, Data Assimilat Off, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Arizona, Dept Atmospher Sci, Tucson, AZ 85721 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. Ctr Natl Rech Meteorol GMAP, Meteo France, Toulouse, France. CALTECH, NASA Jet Prop Lab, Pasadena, CA 91125 USA. RP Poli, P (reprint author), NASA, Goddard Space Flight Ctr, Data Assimilat Off, Atmospheres Lab, Code 910-3, Greenbelt, MD 20771 USA. RI Joiner, Joanna/D-6264-2012; OI Poli, Paul/0000-0002-8392-6524 NR 50 TC 30 Z9 37 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 4448 DI 10.1029/2001JD000935 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200120 ER PT J AU Potter, C Brooks-Genovese, V Klooster, S Torregrosa, A AF Potter, C Brooks-Genovese, V Klooster, S Torregrosa, A TI Biomass burning emissions of reactive gases estimated from satellite data analysis and ecosystem modeling for the Brazilian Amazon region SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NDVI DATA SET; SCAR-B; CHARCOAL FORMATION; NUTRIENT POOLS; SOUTH-AMERICA; AVHRR DATA; CARBON; FIRE; NITROGEN; FOREST AB To produce a new daily record of trace gas emissions from biomass burning events for the Brazilian Legal Amazon, we have combined satellite advanced very high resolution radiometer (AVHRR) data on fire counts together for the first time with vegetation greenness imagery as inputs to an ecosystem biomass model at 8 km spatial resolution. This analysis goes beyond previous estimates for reactive gas emissions from Amazon fires, owing to a more detailed geographic distribution estimate of vegetation biomass, coupled with daily fire activity for the region (original 1 km resolution), and inclusion of fire effects in extensive areas of the Legal Amazon (defined as the Brazilian states of Acre, Amapa, Amazonas, Maranhao, Mato Grosso, Para, Rondonia, Roraima, and Tocantins) covered by open woodland, secondary forests, savanna, and pasture vegetation. Results from our emissions model indicate that annual emissions from Amazon deforestation and biomass burning in the early 1990s total to 102 Tg yr(-1) carbon monoxide (CO) and 3.5 Tg yr(-1) nitrogen oxides (NOx). Peak daily burning emissions, which occurred in early September 1992, were estimated at slightly more than 3 Tg d(-1) for CO and 0.1 Tg d(-1) for NOx flux to the atmosphere. Other burning source fluxes of gases with relatively high emission factors are reported, including methane (CH4), nonmethane hydrocarbons (NMHC), and sulfur dioxide (SO2), in addition to total particulate matter (TPM). We estimate the Brazilian Amazon region to be a source of between one fifth and one third for each of these global emission fluxes to the atmosphere. The regional distribution of burning emissions appears to be highest in the Brazilian states of Maranhao and Tocantins, mainly from burning outside of moist forest areas, and in Para and Mato Grosso, where we identify important contributions from primary forest cutting and burning. These new daily emission estimates of reactive gases from biomass burning fluxes are designed to be used as detailed spatial and temporal inputs to computer models and data analysis of tropospheric chemistry over the tropical region. C1 NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Moffett Field, CA 94035 USA. Calif State Univ Monterey Bay, Seaside, CA USA. RP Potter, C (reprint author), NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Mail Stop 242-4, Moffett Field, CA 94035 USA. OI Torregrosa, Alicia/0000-0001-7361-2241 NR 58 TC 9 Z9 9 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8056 DI 10.1029/2000JD000250 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200013 ER PT J AU Quinn, PK Coffman, DJ Bates, TS Miller, TL Johnson, JE Welton, EJ Neususs, C Miller, M Sheridan, PJ AF Quinn, PK Coffman, DJ Bates, TS Miller, TL Johnson, JE Welton, EJ Neususs, C Miller, M Sheridan, PJ TI Aerosol optical properties during INDOEX 1999: Means, variability, and controlling factors SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aerosol chemical composition; aerosol mass extinction efficiencies; aerosol mass fractions; aerosol optical depth ID INDIAN-OCEAN EXPERIMENT; BOUNDARY-LAYER AEROSOL; UNITED-STATES; LIGHT-SCATTERING; CARBONACEOUS AEROSOLS; ATMOSPHERIC AEROSOLS; RADIATIVE PROPERTIES; MASS CONCENTRATIONS; STRONG ELECTROLYTES; REFRACTIVE-INDEX AB [1] As part of the Indian Ocean Experiment (INDOEX) 1999 Intensive Field Phase, measurements of aerosol properties were made on board the R/V Ronald H. Brown in the Indian Ocean north and south of the Intertropical Convergence Zone (ITCZ) in the Arabian Sea and in the Bay of Bengal. On the basis of air mass trajectories, eight air mass source regions were identified including the southern hemisphere Atlantic; southern hemisphere Indian Ocean; northern hemisphere Indian Ocean; east Indian subcontinent where trajectories came from near Calcutta, through the southern portion of India, and then to the ship; Indian subcontinent where trajectories came from across central India to the ship; Arabia; Arabia/Indian subcontinent, a mixed region where lower-level trajectories came from Arabia and upper-level trajectories came from India; and Arabian Sea/coastal India where trajectories came from along the coast of India to the ship. Properties of the aerosol measured in the marine boundary layer included chemical composition, number size distribution, and scattering and absorption coefficients. In addition, vertical profiles of aerosol backscatter and optical depth were measured. Presented here as a function of air mass source region are the concentrations and mass fractions of the dominant aerosol chemical components, the fraction of the extinction measured at the surface due to each component, mass extinction efficiencies of the individual components, aerosol scattering and absorption coefficients, single scattering albedo, Angstrom exponent, and optical depth. All results except aerosol optical depth are reported at the measurement relative humidity of 55 +/- 5%. For air masses that originated from the two southern hemisphere marine regions (southern hemisphere Atlantic and Indian Ocean), sea salt dominated the extinction by sub-1 mum and sub-10 mum aerosol particles. The ratios of sub-1 mum to sub-10 mum extinction were the lowest measured of all air mass source regions (mean values of 28 and 40%) due to the dominance of the aerosol mass by supermicron sea salt. In addition, aerosol optical depths were the lowest measured averaging 0.06 +/- 0.03. Non-sea-salt (nss) sulfate aerosol concentrations in air masses from the northern hemisphere Indian Ocean were a factor of 6 higher than those in southern hemisphere air masses, while submicron sea-salt concentrations were comparable. Sulfate aerosol made up 40% of the sub-1 mum extinction, while sea salt dominated the sub-10 mum extinction. Aerosol optical depths for this source region averaged 0.10 +/- 0.03. A mean single scattering albedo near 0.89 and detectable black carbon (BC) concentrations (0.14 +/- 0.05 mug m(-3)) indicated the transport of continentally derived aerosol to the ITCZ. The two regions influenced by low-level (500 m) airflow from Arabia had higher concentrations of submicron nss sulfate, particulate organic matter (POM), and inorganic oxidized material (IOM) than were observed in the marine regions. Concentrations of supermicron IOM were comparable to supermicron sea-salt concentrations. Nss sulfate aerosol dominated the sub-1 mum extinction and made significant contributions to the sub-10 mum extinction. Sea salt dominated the supermicron extinction. Mean BC contributions to submicron extinction were 8 and 12%. Single scattering albedo values averaged 0.93 +/- 0.02 and 0.89 +/- 0.02 for these two source regions. Aerosol optical depths averaged 0.19 +/- 0.12 and 0.38 +/- 0.07 with the higher value due to upper-level (2500 m) flow from India. Regions influenced by low-level airflow from the Indian subcontinent had the Supermicron sea-salt concentrations were lower than or comparable to supermicron nitrate concentrations. Sub-1 mum and sub-10 mum extinction were dominated by nss sulfate aerosol although a burning component consisting of BC, KNO3, and K2SO4 made a nearly equivalent contribution. These regions had a mean single scattering albedo of 0.85 +/- 0.01, the lowest measured for any region. Mean aerosol optical depths were highest (0.3 to 0.4) for regions with low-level or upperlevel airflow from the Indian subcontinent. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. Inst Tropospher Res, D-04318 Leipzig, Germany. Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP Quinn, PK (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. RI Welton, Ellsworth/A-8362-2012; Bates, Timothy/L-6080-2016; Quinn, Patricia/R-1493-2016 OI Quinn, Patricia/0000-0003-0337-4895 NR 73 TC 69 Z9 69 U1 0 U2 21 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D19 AR 8020 DI 10.1029/2000JD000037 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 635YT UT WOS:000180428300014 ER PT J AU Randall, CE Lumpe, JD Bevilacqua, RM Hoppel, KW Shettle, EP Rusch, DW Gordley, LL Kreher, K Pfeilsticker, K Boesch, H Toon, G Goutail, F Pommereau, JP AF Randall, CE Lumpe, JD Bevilacqua, RM Hoppel, KW Shettle, EP Rusch, DW Gordley, LL Kreher, K Pfeilsticker, K Boesch, H Toon, G Goutail, F Pommereau, JP TI Validation of POAM IIINO2 measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HALOGEN OCCULTATION EXPERIMENT; UV-VISIBLE SPECTROMETERS; SOLAR-OCCULTATION; POLAR OZONE; STRATOSPHERIC NO2; ATMOS EXPERIMENT; TRACE-GAS; INSTRUMENT; NITROGEN; SPECTRA AB We describe the Polar Ozone and Aerosol Measurement (POAM) III NO2 measurements and associated errors and compare the POAM III data to correlative measurements obtained from satellite-, balloon-, and ground-based instruments. POAM III NO2 densities are retrieved from 20 to 45 km, with a vertical resolution of about 1.5-2.5 km at altitudes below 40 km and increasing to more than 7 km at an altitude of 45 km. Predicted random errors are on the order of 5% in this altitude range. Sunspots and high aerosol extinction can cause errors in the NO2 retrievals but generally affect only about 10% of the data or less, depending on the altitude. The agreement between POAM III NO2 data and correlative observations is excellent, demonstrating that the POAM III measurements are reasonable in terms of their magnitude, profile structure, and temporal variations. The largest number of comparisons was made with the Halogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite. On average, POAM and HALOE agree to within about 0.2 ppbv from 20 to 33 km or within about 6% at most of these altitudes, with no systematic bias. Differences increase to about 0.7 ppbv (17%, POAM higher than HALOE) by 40 km. This difference decreases to about 12% after accounting for a recently discovered error in the HALOE retrievals. Differences decrease above 40 km and are slightly negative (0.1-0.2 ppbv on average) at 45 km, the top edge of the valid POAM III NO2 altitude range. We conclude that the POAM III NO2 profiles from 20 to 45 km are appropriate for scientific analysis and for the validation of NO2 measurements from other instruments. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Computat Phys Inc, Springfield, VA 22151 USA. USN, Res Lab, Washington, DC 20375 USA. GATS, Newport News, VA 23606 USA. NIWA, Omakau 9182, Otago, New Zealand. Univ Heidelberg, Inst Environm Phys, Heidelberg, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CNRS, Serv Aeron, F-91371 Verrieres Les Buissons, France. RP Randall, CE (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Campus Box 392, Boulder, CO 80309 USA. RI Boesch, Hartmut/G-6021-2012 NR 31 TC 26 Z9 27 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 4432 DI 10.1029/2001JD001520 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200090 ER PT J AU Randall, CE Lumpe, JD Bevilacqua, RM Hoppel, KW Fromm, MD Salawitch, RJ Swartz, WH Lloyd, SA Kyro, E von der Gathen, P Claude, H Davies, J DeBacker, H Dier, H Molyneux, MJ Sancho, J AF Randall, CE Lumpe, JD Bevilacqua, RM Hoppel, KW Fromm, MD Salawitch, RJ Swartz, WH Lloyd, SA Kyro, E von der Gathen, P Claude, H Davies, J DeBacker, H Dier, H Molyneux, MJ Sancho, J TI Reconstruction of three-dimensional ozone fields using POAM III during SOLVE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE POAM; ozone; reconstruction; SOLVE; potential vorticity; data assimilation ID POLAR VORTEX; POTENTIAL VORTICITY; WINTER STRATOSPHERE; ARCTIC WINTER; TRANSPORT; ER-2; BREAKING; DYNAMICS; POCKETS AB In this paper we demonstrate the utility of the Polar Ozone and Aerosol Measurement (POAM) III data for providing semiglobal three-dimensional ozone fields during the Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE) winter. As a solar occultation instrument, POAM III measurements were limited to latitudes of 63degreesN to 68degreesN during the SOLVE campaign but covered a wide range of potential vorticity. Using established mapping techniques, we have used the relation between potential vorticity and ozone measured by POAM III to calculate three-dimensional ozone mixing ratio fields throughout the Northern Hemisphere on a daily basis during the 1999/2000 winter. To validate the results, we have extensively compared profiles obtained from ozonesondes and the Halogen Occultation Experiment to the proxy O-3 interpolated horizontally and vertically to the correlative measurement locations. On average, the proxy O-3 agrees with the correlative observations to better than similar to5%, at potential temperatures below about 900 K and latitudes above about 30degreesN, demonstrating the reliability of the reconstructed O-3 fields in these regions. We discuss the application of the POAM proxy ozone profiles for calculating photolysis rates along the ER-2 and DC-8 flight tracks during the SOLVE campaign, and we present a qualitative picture of the evolution of polar stratospheric ozone throughout the winter. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. USN, Res Lab, Washington, DC 20375 USA. Computat Phys Inc, Springfield, VA 22151 USA. Jet Prop Lab, Pasadena, CA 91109 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. Finnish Meteorol Inst, Sodankyla Observ, FIN-99600 Sodankyla, Finland. Alfred Wegener Inst Polar & Marine Res, D-14473 Potsdam, Germany. Deutsch Wetterdienst, Hohenpeissenberg Observ, D-82383 Hohenpeissenberg, Germany. Environm Canada, Toronto, ON M3H 5T4, Canada. Royal Meteorol Inst Belgium, B-1180 Brussels, Belgium. Deutsch Wetterdienst Meteorol Observ Lindenberg, D-15864 Lindenberg, Germany. Meteorol Off, Wokingham RG40 3DN, Berks, England. Izana Atmospher Observ, Santa Cruz de Tenerife, Spain. RP Randall, CE (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Campus Box 392, Boulder, CO 80309 USA. RI Salawitch, Ross/B-4605-2009; Fromm, Michael/F-4639-2010; von der Gathen, Peter/B-8515-2009; Swartz, William/A-1965-2010; Sancho, Juan Manuel/G-5603-2015; Randall, Cora/L-8760-2014 OI Salawitch, Ross/0000-0001-8597-5832; von der Gathen, Peter/0000-0001-7409-1556; Swartz, William/0000-0002-9172-7189; Sancho, Juan Manuel/0000-0002-9750-9860; Randall, Cora/0000-0002-4313-4397 NR 33 TC 23 Z9 23 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8299 DI 10.1029/2001JD000471 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200104 ER PT J AU Rapp, M Lubken, FJ Mullemann, A Thomas, GE Jensen, EJ AF Rapp, M Lubken, FJ Mullemann, A Thomas, GE Jensen, EJ TI Small-scale temperature variations in the vicinity of NLC: Experimental and model results SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE polar summer mesopause region; noctilucent clouds; mesospheric aerosol particles; gravity waves ID ENERGY-DISSIPATION RATES; MESOSPHERE SUMMER ECHOES; IN-SITU MEASUREMENTS; NOCTILUCENT CLOUDS; MIDDLE ATMOSPHERE; GRAVITY-WAVES; WATER-VAPOR; DENSITY-FLUCTUATIONS; INSITU MEASUREMENTS; LOWER THERMOSPHERE AB [1] Gravity waves (GWs) are a ubiquitious dynamical feature of the polar summer mesopause region. During three summer campaigns, in 1991, 1993 and 1994, we launched seven sounding rockets from the north Norwegian island Andoya. Each of these payloads carried an ionization gauge capable of measuring the total atmospheric density at a high spatial resolution. From these measurements, temperature profiles were determined for altitudes between 70 and 110 km, with an altitude resolution of 200 m. The temperature profiles reveal significant rms variations that are as large as 6 K at 80 km, 10 K at 85 km, and even 20 K at 95 km. During three out of the seven launches a bright noctilucent cloud (NLC) was simultaneously detected by our ground-based lidar and by rocket-borne in situ experiments. During these flights, the NLC is located close to a local temperature minimum below the mesopause. We then estimated gravity wave parameters from accompanying falling sphere and chaff wind observations and found signatures that the wave periods during the NLC cases were on the order of 7-9 hours, with corresponding horizontal wavelengths of 600-1000 km. Motivated by these observations, we used a microphysical model of NLC generation and growth to study the interaction between GWs and NLC. Based on recently measured and modeled temperatures and water vapor mixing ratios, and our gravity wave parameter estimates, we find that the NLC layer indeed follows the motion of the cold phase of the wave by means of a complex interplay between ice crystal sedimentation, transport by the vertical wind, and simultaneous growth. It turns out that the history of individual particles significantly influences the observed properties of NLC. Furthermore, we find that GWs with periods longer than 6.5 hours amplify NLC while waves with shorter periods tend to destroy NLC. In addition, we can only find a correlation between local temperature minima and the location of the NLC provided that the wave periods are longer than similar to6 hours, which is consistent with our wave parameter estimates. C1 Leibniz Inst Atmospher Phys eV, D-18225 Kuhlungsborn, Germany. Univ Colorado, Lab Atmospher & Space Sci, Boulder, CO 80309 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Rapp, M (reprint author), Leibniz Inst Atmospher Phys eV, Schlossstr 6, D-18225 Kuhlungsborn, Germany. RI Rapp, Markus/K-6081-2015 OI Rapp, Markus/0000-0003-1508-5900 NR 59 TC 107 Z9 108 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D19 AR 4392 DI 10.1029/2001JD001241 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 635YT UT WOS:000180428300059 ER PT J AU Reichardt, J Reichardt, S Yang, P McGee, TJ AF Reichardt, J Reichardt, S Yang, P McGee, TJ TI Retrieval of polar stratospheric cloud microphysical properties from lidar measurements: Dependence on particle shape assumptions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SMALL ICE CRYSTALS; T-MATRIX METHOD; LIGHT-SCATTERING; DIELECTRIC PARTICLES; AEROSOL MEASUREMENTS; REFRACTIVE-INDEXES; OZONE DEPLETION; CLIMATE-CHANGE; SIZE; DOMAIN AB Computational simulations have been performed to deduce the dependence of the microphysical analysis of polar stratospheric cloud (PSC) optical data measured with lidar on the assumptions made about particle shape. In a forward model, PSCs are modeled as crystalline and liquid particles in order to generate synthetic optical properties. The parameterization scheme of the PSC microphysical properties allows for coexistence of up to three different particle types with size-dependent shapes; optical properties of individual crystals, specifically hexagonal and asymmetric polyhedral crystals, are determined using the finite difference time domain (FDTD) method. The set of calculated PSC optical properties is selected based on the wavelengths and measurement capabilities of lidar instruments that are typically used to monitor stratospheric aerosols, such as the Airborne Raman Ozone and Temperature Lidar (AROTEL) and the NASA Langley Differential Absorption Lidar (DIAL) onboard the NASA DC-8 during the Stratospheric Aerosol and Gas Experiment (SAGE) Ozone Loss Validation Experiment (SOLVE) campaign in winter 1999/2000. The retrieval process then inverts these synthetic measurement data using a model approach in which the PSC particles are represented purely by an ensemble of spheroids, and the differences between initial and retrieved microphysical properties are examined. The model simulations show that under the assumption of spheroidal particle shapes, surface area density and volume density of leewave PSCs are systematically smaller by, respectively, similar to10-30% and similar to5-25% than the values found for mixtures of droplets, asymmetric polyhedra, and hexagons. C1 Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. RP Reichardt, J (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. RI Yang, Ping/B-4590-2011; McGee, Thomas/G-4951-2013 NR 61 TC 14 Z9 14 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8282 DI 10.1029/2001JD001021 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200054 ER PT J AU Remsberg, E Deaver, L Wells, J Lingenfelser, G Bhatt, P Gordley, L Thompson, R McHugh, M Russell, JM Keckhut, P Schmidlin, F AF Remsberg, E Deaver, L Wells, J Lingenfelser, G Bhatt, P Gordley, L Thompson, R McHugh, M Russell, JM Keckhut, P Schmidlin, F TI An assessment of the quality of Halogen Occultation Experiment temperature profiles in the mesosphere based on comparisons with Rayleigh backscatter lidar and inflatable falling sphere measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE mesospheric temperatures; Rayleigh backscatter lidar; inflatable falling sphere; HALOE temperature comparisons ID MIDDLE ATMOSPHERE; CLIMATOLOGY; VALIDATION; ROCKETSONDE; INVERSION; TIDES AB Bias errors for retrieved temperature profiles T(p) from the Halogen Occultation Experiment (HALOE) are evaluated by pairing with nearby soundings from ground-based Rayleigh lidar and from inflatable falling spheres. Findings for the mesosphere must be based on large sets of pairings because an individual HALOE T( p) measurement is somewhat noisy and may not view the same atmospheric structure. Simulated estimates of total bias errors for the HALOE profiles are of the order of 2% (or 5 K). The average biases with the lidar profiles at 44degreesN, 6degreesE are within 3 K from 33 to 66 km and 4 K to 74 km, at least when zonal easterlies (and reduced wave activity) prevail. Tidal effects can account for most of that difference. Comparisons with shipboard lidar soundings that begin near 100 km indicate no significant bias even in the 77 to 85 km range. Similar comparisons with falling sphere profiles at Cape Canaveral and Wallops Island indicate no significant bias from 40 to 66 km and 71 to 85 km. HALOE profiles are warmer than sphere values from 67 to 70 km, but this is also the altitude region where the sphere profile has greater uncertainties. For those months when the lidar soundings indicate inversion layers the sets of profiles paired with lidar indicate that the HALOE T( p) is somewhat colder in the upper mesosphere, in part owing to the effects of limb path averaging of horizontal structure by HALOE and its inability to completely resolve the inversion layer maximum. On the basis of the combined sets of findings it is concluded that most of the error in a single HALOE T(p) is random, except where there is a sharp inversion. Daily zonal averages of the HALOE profiles are accurate and useful for defining the seasonal and longer-term variations of T(p) in the mesosphere. C1 NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23681 USA. Sci Applicat Int Corp, Hampton, VA USA. GATS Inc, Newport News, VA USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. CNRS, Serv Aeron, Inst Pierre Simon Laplace, F-91371 Verrieres Les Buissons, France. NASA, Goddard Space Flight Ctr, Observ Sci Branch, Wallops Flight Facil, Wallops Isl, VA 23337 USA. RP Remsberg, E (reprint author), NASA, Langley Res Ctr, Div Atmospher Sci, Mail Code 401-B,Room 222,Bldg 1250,21 Langley Blv, Hampton, VA 23681 USA. NR 28 TC 24 Z9 25 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 4447 DI 10.1029/2001JD001521 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200119 ER PT J AU Remsberg, EE Bhatt, PP Deaver, LE AF Remsberg, EE Bhatt, PP Deaver, LE TI Seasonal and longer-term variations in middle atmosphere temperature from HALOE on UARS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE temperature climatology; middle atmosphere; satellite observations; regression analysis ID QUASI-BIENNIAL OSCILLATION; OCCULTATION EXPERIMENT; SOLAR-CYCLE; INTERANNUAL VARIABILITY; LOWER STRATOSPHERE; COOLING TREND; LIDAR DATA; MODEL; OZONE; QBO AB [1] The 9.5-year temperature time series from the Halogen Occultation Experiment (HALOE) aboard the Upper Atmosphere Research Satellite (UARS) has been analyzed for 40degreesN, 30degreesN, 20degreesN, Tropics, 20degreesS, 30degreesS, and 40degreesS using multiple linear regression techniques at 12 pressure levels from 5 to 0.01 hPa. The HALOE sunset and sunrise temperature profiles have good vertical resolution and are representative of the variations of the zonal average state. Vertical profiles with latitude of the average sunset/sunrise differences agree qualitatively with that expected from the effects of tides. Periodic seasonal (annual and semiannual) terms are sampled well in the time series, and the seasonal cycle from HALOE at 40degreesN agrees well with the local variations reported from measurements with the ground- based Rayleigh lidar instrument at 44degreesN, 6degreesE. Significant quasi-biennial oscillation (QBO)-like variations occur at most latitudes of the upper stratosphere in the HALOE data, and their phases are nearly symmetric about the equator. There is also a clear subbiennial (688-day) cycle at Northern Hemisphere (NH) midlatitudes at those same pressure altitudes due to the interaction of the QBO and annual cycles. The solar cycle temperature term is in-phase with the UV flux forcing in the upper stratosphere but lags it by a year or so in the upper mesosphere at NH midlatitudes. There is also a significant cooling trend for the HALOE time series that is of order 1.0 to 1.6 K per decade in the midmesosphere at 20degreesN and at 1 hPa in the tropics. The seasonal terms may be combined with the constant and autoregressive (AR) terms (or annual average distribution that we provided) in order to generate the monthly zonal average HALOE "climatology'' of middle atmosphere temperature for the decade of the 1990s. Comparisons between the HALOE and CIRA climatologies for the upper stratosphere suggest a cooling of order 2.5 K per decade from the mid-1970s to the mid-1990s. HALOE/CIRA differences for the mesosphere change sign with altitude, an indication of bias errors in one or both. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Sci Applicat Int Corp, Hampton, VA USA. RP Remsberg, EE (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 42 TC 30 Z9 30 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D19 AR 4411 DI 10.1029/2001JD001366 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 635YT UT WOS:000180428300079 ER PT J AU Rex, M Salawitch, RJ Harris, NRP von der Gathen, P Braathen, GO Schulz, A Deckelmann, H Chipperfield, M Sinnhuber, BM Reimer, E Alfier, R Bevilacqua, R Hoppel, K Fromm, M Lumpe, J Kullmann, H Kleinbohl, A Bremer, H von Konig, M Kunzi, K Toohey, D Vomel, H Richard, E Aikin, K Jost, H Greenblatt, JB Loewenstein, M Podolske, JR Webster, CR Flesch, GJ Scott, DC Herman, RL Elkins, JW Ray, EA Moore, FL Hurst, DF Romashkin, P Toon, GC Sen, B Margitan, JJ Wennberg, P Neuber, R Allart, M Bojkov, BR Claude, H Davies, J Davies, W De Backer, H Dier, H Dorokhov, V Fast, H Kondo, Y Kyro, E Litynska, Z Mikkelsen, IS Molyneux, MJ Moran, E Nagai, T Nakane, H Parrondo, C Ravegnani, F Skrivankova, P Viatte, P Yushkov, V AF Rex, M Salawitch, RJ Harris, NRP von der Gathen, P Braathen, GO Schulz, A Deckelmann, H Chipperfield, M Sinnhuber, BM Reimer, E Alfier, R Bevilacqua, R Hoppel, K Fromm, M Lumpe, J Kullmann, H Kleinbohl, A Bremer, H von Konig, M Kunzi, K Toohey, D Vomel, H Richard, E Aikin, K Jost, H Greenblatt, JB Loewenstein, M Podolske, JR Webster, CR Flesch, GJ Scott, DC Herman, RL Elkins, JW Ray, EA Moore, FL Hurst, DF Romashkin, P Toon, GC Sen, B Margitan, JJ Wennberg, P Neuber, R Allart, M Bojkov, BR Claude, H Davies, J Davies, W De Backer, H Dier, H Dorokhov, V Fast, H Kondo, Y Kyro, E Litynska, Z Mikkelsen, IS Molyneux, MJ Moran, E Nagai, T Nakane, H Parrondo, C Ravegnani, F Skrivankova, P Viatte, P Yushkov, V TI Chemical depletion of Arctic ozone in winter 1999/2000 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ozone; stratosphere; Match ID IN-SITU MEASUREMENTS; STRATOSPHERIC OZONE; POLAR VORTEX; LOSS RATES; CHEMISTRY; TRENDS; HOLE; CLO AB During Arctic winters with a cold, stable stratospheric circulation, reactions on the surface of polar stratospheric clouds (PSCs) lead to elevated abundances of chlorine monoxide (ClO) that, in the presence of sunlight, destroy ozone. Here we show that PSCs were more widespread during the 1999/2000 Arctic winter than for any other Arctic winter in the past two decades. We have used three fundamentally different approaches to derive the degree of chemical ozone loss from ozonesonde, balloon, aircraft, and satellite instruments. We show that the ozone losses derived from these different instruments and approaches agree very well, resulting in a high level of confidence in the results. Chemical processes led to a 70% reduction of ozone for a region similar to1 km thick of the lower stratosphere, the largest degree of local loss ever reported for the Arctic. The Match analysis of ozonesonde data shows that the accumulated chemical loss of ozone inside the Arctic vortex totaled 117 +/- 14 Dobson units (DU) by the end of winter. This loss, combined with dynamical redistribution of air parcels, resulted in a 88 +/- 13 DU reduction in total column ozone compared to the amount that would have been present in the absence of any chemical loss. The chemical loss of ozone throughout the winter was nearly balanced by dynamical resupply of ozone to the vortex, resulting in a relatively constant value of total ozone of 340 +/- 50 DU between early January and late March. This observation of nearly constant total ozone in the Arctic vortex is in contrast to the increase of total column ozone between January and March that is observed during most years. C1 Alfred Wegener Inst Polar & Marine Res, D-14401 Potsdam, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Cambridge, European Ozone Res Coordinating Unit, Cambridge CB2 1HE, England. Norsk Inst Luftforskning, N-2007 Kjeller, Norway. Univ Leeds, Leeds LS2 9JT, W Yorkshire, England. Free Univ Berlin, Inst Meteorol, D-12165 Berlin, Germany. USN, Res Lab, Washington, DC 20375 USA. Computat Phys Inc, Springfield, VA 22151 USA. Univ Bremen, Inst Environm Phys, D-28334 Bremen, Germany. Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Boulder, CO 80303 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. KNMI, NL-3730 AE De Bilt, Netherlands. Deutscher Wetterdienst, Observ Hohenpeissenberg, D-82383 Hohenpeissenberg, Germany. Atmospher Environm Serv, Toronto, ON M3H 5T4, Canada. Univ Wales, Dept Phys, Aberystwyth SY23 3BZ, Dyfed, Wales. Royal Meteorol Inst Belgium, B-1180 Brussels, Belgium. Meteorol Observ Lindenberg, D-15864 Lindenberg, Germany. CAO, Dolgoprudnyi 141700, Russia. Nagoya Univ, Solar Terr Environm Lab, Toyokawa, Aichi, Japan. Sodankyla Meteorol Observ, Sodankyla, Finland. Ctr Aerol, Legionowo, Poland. Danish Meteorol Inst, DK-2100 Copenhagen, Denmark. UK Met Off, Bracknell RG11 2SZ, Berks, England. IMS, Valentia Observ, Kerry, Ireland. Meteorol Res Inst, Tsukuba, Ibaraki 3050052, Japan. Natl Inst Environm Studies, Tsukuba, Ibaraki 3050053, Japan. INTA, Madrid, Spain. CNR, Ist Fisbat, I-40126 Bologna, Italy. Czech Hydromet Inst, Prague 14306, Czech Republic. SMI, CH-1530 Payerne, Switzerland. RP Rex, M (reprint author), Alfred Wegener Inst Polar & Marine Res, POB 600149, D-14401 Potsdam, Germany. RI Rex, Markus/A-6054-2009; Salawitch, Ross/B-4605-2009; Fromm, Michael/F-4639-2010; Ravegnani, Fabrizio/A-7800-2009; von der Gathen, Peter/B-8515-2009; Toohey, Darin/A-4267-2008; Kondo, Yutaka/D-1459-2012; Herman, Robert/H-9389-2012; Sinnhuber, Bjorn-Martin/A-7007-2013; Sinnhuber, Miriam/A-7252-2013; Chipperfield, Martyn/H-6359-2013; Ray, Eric/D-5941-2013; Aikin, Kenneth/I-1973-2013; Neuber, Roland/B-4923-2014; Hurst, Dale/D-1554-2016 OI Rex, Markus/0000-0001-7847-8221; Salawitch, Ross/0000-0001-8597-5832; Ravegnani, Fabrizio/0000-0003-0735-9297; von der Gathen, Peter/0000-0001-7409-1556; Toohey, Darin/0000-0003-2853-1068; Herman, Robert/0000-0001-7063-6424; Sinnhuber, Bjorn-Martin/0000-0001-9608-7320; Chipperfield, Martyn/0000-0002-6803-4149; Ray, Eric/0000-0001-8727-9849; Neuber, Roland/0000-0001-7382-7832; Hurst, Dale/0000-0002-6315-2322 NR 38 TC 74 Z9 74 U1 3 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8276 DI 10.1029/2001JD000533 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200041 ER PT J AU Riese, M Manney, GL Oberheide, J Tie, X Spang, R Kull, V AF Riese, M Manney, GL Oberheide, J Tie, X Spang, R Kull, V TI Stratospheric transport by planetary wave mixing as observed during CRISTA-2 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOUTHERN-HEMISPHERE; SIMULATION; TEMPERATURE; EVOLUTION; NORTHERN; SYSTEM; WINTER; OZONE AB [1] Planetary waves drive the mean meridional circulation of the stratosphere and at the same time facilitate quasi-horizontal mixing of trace gases. This paper presents significant day-to-day variability of stratospheric trace gas fields associated with large planetary wave activity observed during the second mission of the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) experiment. Geopotential height data of the UK Met Office show that the CRISTA-2 observations in the Southern Hemisphere winter were made during a period of extremely large amplitudes of both wave-1 and wave-2. The planetary wave-1, usually a quasi-stationary feature, moved eastward with the traveling planetary wave-2. The large amplitudes of both wave-1 and wave-2 led to a significant displacement of the edge of the polar vortex toward the tropics (down to 30 S). As a result of the large wave amplitudes and favorable phase alignment, the anticyclone drawing up tropical air was unusually strong, and thus considerable wave-induced trace gas flux from the tropics toward midlatitudes was observed, mainly in the form of a pronounced planetary-scale tongue advected out of the tropics around the vortex and into the anticyclone. Quantitative transport calculations based on a sequential data assimilation system highlight the importance of such transport events for trace gas eddy-flux in the Southern Hemisphere winter stratosphere. C1 Berg Univ Wuppertal, Dept Phys, D-42097 Wuppertal, Germany. CALTECH, Jet Prop Lab, Pasadena, CA USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Forschungszentrum Julich, ICGI, Postfach 1913, D-52425 Julich, Germany. EM m.riese@fz-juelich.de RI Oberheide, Jens/C-6156-2011; Spang, Reinhold/A-2738-2013; Riese, Martin/A-3927-2013 OI Oberheide, Jens/0000-0001-6721-2540; Spang, Reinhold/0000-0002-2483-5761; Riese, Martin/0000-0001-6398-6493 NR 20 TC 29 Z9 32 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D23 AR 8179 DI 10.1029/2001JD000629 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 637AT UT WOS:000180490000006 ER PT J AU Rozwadowska, A Cahalan, RF AF Rozwadowska, A Cahalan, RF TI Plane-parallel biases computed from inhomogeneous Arctic clouds and sea ice SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE SHEBA; FIRE/ACE; plane-parallel bias; cloud trasmittance; cloud albedo; Arctic ID LIQUID WATER DISTRIBUTIONS; SOLAR RADIATIVE FLUXES; MARINE STRATOCUMULUS; BEAUFORT-SEA; INDEPENDENT PIXEL; SCALE-INVARIANCE; STRATUS CLOUDS; SURFACE; FIELDS; ALBEDO AB [1] Monte Carlo simulations of the expected influence of nonuniformity in cloud structure and surface albedo on shortwave radiative fluxes in the Arctic atmosphere are presented. In particular, plane-parallel biases in cloud albedo and transmittance are studied for nonabsorbing, low-level, all-liquid stratus clouds over sea ice. The "absolute bias'' is defined as the difference between the cloud albedo or transmittance for the uniform or plane-parallel case, and the albedo or transmittance for nonuniform conditions with the same mean cloud optical thickness and the same mean surface albedo, averaged over a given area (i.e., bias > 0 means plane-parallel overestimates). Ranges of means and standard deviations of input parameters typical of Arctic conditions are determined from the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment Artic Cloud Experiment (FIRE/ACE)/Surface Heat Budget of the Arctic Ocean (SHEBA)/ Atmospheric Radiation Measurement Program (ARM) experiment, a cooperative effort of the Department of Energy, NASA, NSF, the National Oceanic and Atmospheric Administration, the Office of Naval Research, and the Atmospheric Environment Service. We determine the sensitivity of the bias with respect to the following: domain averaged means and spatial variances of cloud optical thickness and surface albedo, shape of the surface reflectance function, presence of a scattering layer under the clouds, and solar zenith angle. The simulations show that the biases in Arctic conditions are generally lower than in subtropical stratocumulus. The magnitudes of the absolute biases are unlikely to exceed 0.02 for albedo and 0.05 for transmittance. The "relative bias'' expresses the absolute bias as a percentage of the actual cloud albedo or transmittance. The magnitude of the relative bias in albedo is typically below 2% over the reflective Arctic surface, while the magnitude of the relative bias in transmittance can exceed 10%. C1 Polish Acad Sci, Inst Oceanol, PL-81712 Sopot, Poland. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Polish Acad Sci, Inst Oceanol, Powstancow Warszawy 55, PL-81712 Sopot, Poland. EM ania@iopan.gda.pl RI Cahalan, Robert/E-3462-2012 OI Cahalan, Robert/0000-0001-9724-1270 NR 53 TC 4 Z9 4 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D19 AR 4384 DI 10.1029/2002JD002092 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 635YT UT WOS:000180428300051 ER PT J AU Salawitch, RJ Margitan, JJ Sen, B Toon, GC Osterman, GB Rex, M Elkins, JW Ray, EA Moore, FL Hurst, DF Romashkin, PA Bevilacqua, RM Hoppel, KW Richard, EC Bui, TP AF Salawitch, RJ Margitan, JJ Sen, B Toon, GC Osterman, GB Rex, M Elkins, JW Ray, EA Moore, FL Hurst, DF Romashkin, PA Bevilacqua, RM Hoppel, KW Richard, EC Bui, TP TI Chemical loss of ozone during the Arctic winter of 1999/2000: An analysis based on balloon-borne observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ozone depletion; Arctic ozone loss ID IN-SITU MEASUREMENTS; POLAR VORTEX AIR; ER-2 AIRCRAFT; LOWER STRATOSPHERE; TRACE GASES; DENITRIFICATION; TRANSPORT; N2O; SIMULATIONS; MODEL AB Simultaneous balloon-borne observations of ozone (O-3) and nitrous oxide (N2O), a long-lived tracer of dynamical motion, are used to quantify the chemical loss of ozone in the Arctic vortex during the winter of 1999/2000. Chemical loss of ozone occurred between altitudes of about 14 and 22 km ( pressures from similar to120 to 30 mbar) and resulted in a 61 +/- 13 Dobson unit reduction in total column ozone between late November 1999 and 5 March 2000 (the date of the last balloon-borne measurement considered here). This loss estimate is valid for the core of the vortex during the time period covered by the observations. It is shown that the observed changes in the O-3 versus N2O relation were almost entirely due to chemistry and could not have been caused by dynamics. The chemical loss of column ozone inferred from the balloon-borne measurements using the "ozone versus tracer" technique is shown to compare well with estimates of chemical loss found using both the Match technique (as applied to independent ozonesonde data) and the "vortex-averaged descent" technique (as applied to Polar Ozone and Aerosol Measurement (POAM) III satellite measurements of ozone). This comparison establishes the validity of each approach for estimating chemical loss of column ozone for the Arctic winter of 1999/2000. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NOAA, Aeron Lab, Boulder, CO 80305 USA. Alfred Wegener Inst Polar & Marine Res, D-14401 Potsdam, Germany. NOAA, Aeron Lab, Boulder, CO 80303 USA. USN, Res Lab, Washington, DC 20375 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 183-601, Pasadena, CA 91109 USA. EM Ross.J.Salawitch@jpl.nasa.gov; James.J.Margitan@jpl.nasa.gov; Bhaswar.Sen@jpl.nasa.gov; Geoffrey.C.Toon@jpl.nasa.gov; Gregory.B.Osterman@jpl.nasa.gov; mrex@awi-potsdam.de; James.W.Elkins@noaa.gov; eray@al.noaa.gov; Fred.Moore@noaa.gov; Dale.Hurst@noaa.gov; Pavel.Romashkin@noaa.gov; bevilacqua@nrl.navy.mil; Karl.Hoppel@nrl.navy.mil; Erik.C.Richard@noaa.gov; pbui@mail.arc.nasa.gov RI Rex, Markus/A-6054-2009; Salawitch, Ross/B-4605-2009; Ray, Eric/D-5941-2013; Hurst, Dale/D-1554-2016 OI Rex, Markus/0000-0001-7847-8221; Salawitch, Ross/0000-0001-8597-5832; Ray, Eric/0000-0001-8727-9849; Hurst, Dale/0000-0002-6315-2322 NR 51 TC 36 Z9 36 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8269 DI 10.1029/2001JD000620 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200030 ER PT J AU Schafer, JS Holben, BN Eck, TF Yamasoe, MA Artaxo, P AF Schafer, JS Holben, BN Eck, TF Yamasoe, MA Artaxo, P TI Atmospheric effects on insolation in the Brazilian Amazon: Observed modification of solar radiation by clouds and smoke and derived single scattering albedo of fire aerosols SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PHOTOSYNTHETICALLY ACTIVE RADIATION; SKY RADIANCE MEASUREMENTS; OPTICAL-PROPERTIES; FOREST-FIRES; IRRADIANCE; CLIMATE; AERONET; POLLUTION; RAINWATER; NETWORK AB Five aerosol and solar flux monitoring sites were established in Brazil for the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) project. The first two sites were developed in the states of Rondonia and Mato Grosso in January 1999, while the others were initiated in September 1999 in Amazonas, Para, and near Brasilia (later relocated to Acre). Daily insolation [photosynthetically active radiation (PAR) and total solar] for 1999 and 9 months of 2000 was determined from flux measurements, and the daily fraction of theoretical cloud-free, background-aerosol insolation, f(B(day)), was evaluated for each site. Observed daily shortfall (MJ m(-2) d(-1)) of PAR insolation due to clouds and aerosols (relative to modeled values for background aerosol), and the instantaneous reductions of PAR irradiance due to high aerosol optical thickness (AOT) smoke events are presented for 1999 at Alta Floresta. The ratio of PAR flux to total solar flux (PAR fraction) was examined for all atmospheric conditions during 1999, and the observed dependence of this parameter on column water vapor and smoke AOT was quantified. No significant relationship with cloud amount (as quantified) was found. Instantaneous PAR irradiance measurements and concurrent, cloud-cleared aerosol data from collocated CIMEL sunphotometers were used with a radiative transfer model to investigate the optical properties of smoke aerosols during the burning season. In particular, the single scattering albedo (SSA) was evaluated in the PAR spectral range for AOT(440 nm) values ranging from 0.8 to 3.0. These estimates were compared with the operational retrievals of the same parameter from algorithms developed by AERONET for CIMEL sunphotometer radiance measurements. C1 SSAI, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Catonsville, MD USA. Univ Sao Paulo, Dept Fis Aplicada, Inst Fis, BR-05508900 Sao Paulo, Brazil. RP SSAI, Lanham, MD 20706 USA. EM jschafer@aeronet.gsfc.nasa.gov RI Schafer, Joel/A-3978-2010; ECK, THOMAS/D-7407-2012; Yamasoe, Marcia/L-3667-2013; Artaxo, Paulo/E-8874-2010 OI Yamasoe, Marcia/0000-0003-3066-9146; Artaxo, Paulo/0000-0001-7754-3036 NR 37 TC 22 Z9 23 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8074 DI 10.1029/2001JD000428 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200035 ER PT J AU Spang, R Eidmann, G Riese, M Offermann, D Preusse, P Pfister, L Wang, PH AF Spang, R Eidmann, G Riese, M Offermann, D Preusse, P Pfister, L Wang, PH TI CRISTA observations of cirrus clouds around the tropopause SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CRYOGENIC INFRARED SPECTROMETERS; TROPICAL TROPOPAUSE; AIRCRAFT OBSERVATIONS; DATASET; STRATOSPHERE; TEMPERATURE; SATELLITE; TROPOSPHERE; VARIABILITY; TELESCOPES AB [1] The Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) instrument observed thin cirrus clouds at and above the tropopause during its two missions in November 1994 and August 1997. A simple cloud detection scheme was developed for extinctions greater than 2 x 10(-3) km(-1) through analysis of the measured infrared spectra in the 12-mum range. Horizontal and vertical distributions of cloud occurrence frequencies are in good agreement with the Stratospheric Aerosol and Gas Experiment (SAGE) II subvisual cirrus cloud (SVC) climatology as well as SAGE measurements for the 1997 period. Seasonal variations, strong longitudinal variability, and indications of enhanced cloud occurrence frequencies in separated regions caused by El Nino events were detected in the CRISTA data set. A substantial day-to-day variability could be found throughout the tropics, and several regions with enhanced variability have been identified. In addition, a significant amount of cloud was found above the midlatitude tropopause. Backward trajectories in relation to outgoing longwave radiation (OLR) measurements and cloud observation in the troposphere by meteorological satellites suggest that about three fourths of the high clouds (> 15 km) observed by CRISTA in the tropics stem from deep convection systems and the outflow of these systems. This would imply that on the order of at least one fourth of the observed cloud events are originated by other mechanisms, such as in situ formation due to cooling events on synoptic and/or gravity wave scales. For the convective generated cirrus clouds, a maximum lifetime of around 3-4 days was estimated over a wide range of latitudes. Such a long lifetime could be important for modeling the impact of cirrus clouds on radiation budget (climate) and heterogeneous chemical processes around the tropopause. C1 Berg Univ Gesamthsch Wuppertal, Dept Phys, D-42097 Wuppertal, Germany. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Sci & Technol Corp, Hampton, VA 23666 USA. RP Spang, R (reprint author), Univ Leicester, Space Res Ctr, EOS, Leicester LE1 7RH, Leics, England. RI Spang, Reinhold/A-2738-2013; Preusse, Peter/A-1193-2013; Riese, Martin/A-3927-2013 OI Spang, Reinhold/0000-0002-2483-5761; Preusse, Peter/0000-0002-8997-4965; Riese, Martin/0000-0001-6398-6493 NR 48 TC 42 Z9 42 U1 2 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D23 AR 8174 DI 10.1029/2001JD000698 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 637AT UT WOS:000180490000001 ER PT J AU Strahan, S AF Strahan, S TI Influence of planetary wave transport on Arctic ozone as observed by Polar Ozone and Aerosol Measurement (POAM) III SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE stratospheric ozone; Arctic vortex; transport; interannual variability; sudden warming; probability distribution function ID STRATOSPHERIC TRANSPORT; VALIDATION; VORTEX; MODEL AB Interannual differences in Arctic ozone are investigated using data from the Polar Ozone and Aerosol Measurement (POAM) III instrument obtained between May 1998 and April 2001. These three winters were unusually warm or cold relative to the 1979-2001 mean, resulting in years with either a warm, disturbed vortex or a cold, quiet vortex. Contours of probability distribution functions (PDFs) of the POAM data are used to identify seasonal and interannual variations in the transport processes controlling ozone. A major warming in December, 1998, displaced the middle stratospheric vortex from the pole for nearly a month, dissipating it. The vortex reformed in January, 1999, filled with high O-3 air from lower latitudes, which then cooled and descended. By the end of winter 1999, ozone at 500 K in the vortex was 0.5-1.0 ppm higher than in the subsequent cold winter. The winter of 2000-2001 had frequent wave disturbances, beginning with a fairly large event in November. However, at the end of this event, the high potential vorticity (PV) core of the vortex was intact, and by February, O-3 in the vortex looked the same as in 2000. Transport in these winters is inferred from the PDFs and supported by potential vorticity analyses. This study demonstrates that variability in the O-3-PV relationship can be caused by transport, independent of loss by polar stratospheric clouds (PSCs). Ozone in the vortex in a very disturbed winter can be unusually high due to transport and will not represent O-3 levels expected in the absence of PSCs in other years. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Strahan, S (reprint author), NASA, Goddard Space Flight Ctr, Code 910 3, Greenbelt, MD 20771 USA. RI Strahan, Susan/H-1965-2012 NR 22 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 4417 DI 10.1029/2002JD002189 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200071 ER PT J AU Strawa, AW Drdla, K Fromm, M Pueschel, RF Hoppel, KW Browell, EV Hamill, P Dempsey, DP AF Strawa, AW Drdla, K Fromm, M Pueschel, RF Hoppel, KW Browell, EV Hamill, P Dempsey, DP TI Discriminating types Ia and Ib polar stratospheric clouds in POAM satellite data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE polar stratopheric clouds; stratosphere; ozone loss; satellite measurement remote sensing; cloud properties ID ARCTIC STRATOSPHERE; NITRIC-ACID; LIDAR OBSERVATIONS; SULFURIC-ACID; WINTER; DENITRIFICATION; OZONE; AEROSOL; DISTRIBUTIONS; PARTICLES AB A method for discriminating Types Ia and Ib Polar Stratospheric Clouds (PSCs) from Polar Ozone and Aerosol Measurement (POAM) satellite occultation measurements of aerosol extinction coefficient is described. The method has been validated by applying several statistical tests to the results and by using Differential Absorption Lidar (DIAL) and Ozone Lidar Experiment (OLEX) lidar observations made during Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment/Third European Stratospheric Experiment on Ozone II (SOLVE/THESEO 2000). Type Ia PSCs are believed to be composed of large nitric-acid-containing particles that will sediment out of the stratosphere, causing denitrification and facilitating ozone depletion. Type Ib PSCs are believed to be much smaller and will not sediment out of the stratosphere. Discriminating between these two types of PSCs is significant because it will permit a better understanding of ozone depletion today and predict the fate and effect of PSCs using the more continuous temporal coverage and larger areal coverage that can be obtained from satellites. The method is made possible by the character of POAM observations when plotted as normalized extinction versus wavelength dependence. As the extinction increases, observations of Types Ia and Ib PSCs bifurcate. This behavior is also observed in idealized simulations of the formation of Supercooled Ternary Solutions (STS) and nitric acid trihydrate (NAT) particles, which are believed to make up Types Ib and Ia PSCs, respectively. Analysis of POAM observations from the 1999/2000 Arctic winter using the PSC discrimination algorithm revealed that the number of PSC observations peaked in January. In November, December, and January, the ratio of Type Ia to Ib PSCs was about 3. In February and March, this ratio was about 0.3. The average altitude of Type Ia PSCs descended more than the Type Ib, especially in the spring where the Type Ia observations were 2-3 km below the Type Ib observations. This is consistent with observations of denitrification during the 1999/2000 winter. The PSC discrimination algorithm is applicable to previous winters in both hemispheres and will work with SAGE III observations as well. This will permit a more extensive study of the statistical significance of some features of the PSCs observed during the 1999/2000 Arctic winter. It is our belief that the present method of analyzing satellite data to discriminate Type I PSCs will be of great utility in the study of PSCs and ozone depletion. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Computat Phys Inc, Springfield, VA 22151 USA. USN, Res Lab, Washington, DC 20375 USA. NASA, Langley Res Ctr, Hampton, VA 23666 USA. San Jose State Univ, Dept Phys, San Jose, CA 95192 USA. San Francisco State Univ, Dept Meteorol, San Francisco, CA 94132 USA. RP Strawa, AW (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RI Fromm, Michael/F-4639-2010 NR 38 TC 22 Z9 22 U1 2 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8291 DI 10.1029/2001JD000458 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200069 ER PT J AU Sugita, T Yokota, T Nakajima, H Kanzawa, H Nakane, H Gernandt, H Yushkov, V Shibasaki, K Deshler, T Kondo, Y Godin, S Goutail, F Pommereau, JP Camy-Peyret, C Payan, S Jeseck, P Renard, JB Bosch, H Fitzenberger, R Pfeilsticker, K von Konig, M Bremer, H Kullmann, H Schlager, H Margitan, JJ Stachnik, B Toon, GC Jucks, K Traub, WA Johnson, DG Murata, I Fukunishi, H Sasano, Y AF Sugita, T Yokota, T Nakajima, H Kanzawa, H Nakane, H Gernandt, H Yushkov, V Shibasaki, K Deshler, T Kondo, Y Godin, S Goutail, F Pommereau, JP Camy-Peyret, C Payan, S Jeseck, P Renard, JB Bosch, H Fitzenberger, R Pfeilsticker, K von Konig, M Bremer, H Kullmann, H Schlager, H Margitan, JJ Stachnik, B Toon, GC Jucks, K Traub, WA Johnson, DG Murata, I Fukunishi, H Sasano, Y TI Validation of ozone measurements from the Improved Limb Atmospheric Spectrometer SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ILAS; solar occultation; stratosphere; ozone ID HALOGEN OCCULTATION EXPERIMENT; GAS EXPERIMENT-II; STRATOSPHERIC AEROSOL; POLAR OZONE; POAM-II; SOLAR OCCULTATION; HETERODYNE MEASUREMENTS; VERTICAL-DISTRIBUTION; NORTHERN EUROPE; TRACE-GAS AB [1] Vertical profiles of ozone concentration in the high latitudes were observed by the Improved Limb Atmospheric Spectrometer (ILAS) aboard the Advanced Earth Observing Satellite (ADEOS) from November 1996 to June 1997. The ozone data obtained by the version 5.20 ILAS retrieval algorithm are compared with those obtained by the version 19 Halogen Occultation Experiment (HALOE), the version 6 Stratospheric Aerosol and Gas Experiment (SAGE) II, and the version 6 Polar Ozone and Aerosol Measurement (POAM) II retrieval algorithms. The ILAS data are also compared with ozone data measured by ozonesondes, instruments on board balloons or an aircraft, and ground-based instruments. The ILAS ozone data generally agree with its correlative data between 11 and 64 km with some exceptions. Quantitatively, the median value of the relative difference (absolute difference divided by its mean value) for these comparisons was within +/-10%. Relative differences (18%) exceeding the combined measurement errors were found around 45-55 km altitude from comparisons with the HALOE and SAGE II data in January 1997 in the Southern Hemisphere (SH). Larger relative differences (around 50%) were also found below 15 km from comparisons with the HALOE and POAM II data in November 1996 in the SH, but these absolute differences were 0.10-0.16 ppmv as the median value. The ozone data processed by the version 5.20 were improved compared to the former version 3.10, which is available to the general public. The version 5.20 ozone data can be used for scientific analysis purposes based on the accuracy of the data in comparison with these other instruments. C1 Natl Inst Environm Studies, Ozone Layer Res Project, Tsukuba, Ibaraki 3058506, Japan. Alfred Wegener Inst Polar & Marine Res, D-2850 Bremerhaven, Germany. Cent Aerol Observ, Dolgoprudnyi, Russia. Kokugakuin Univ, Fac Letters, Tokyo, Japan. Univ Wyoming, Dept Atmospher Sci, Laramie, WY 82071 USA. Univ Tokyo, Adv Sci & Technol Res Ctr, Tokyo, Japan. CNRS, Serv Aeron, Paris, France. CNRS, Lab Phys Mol & Applicat, Paris, France. CNRS, Lab Phys & Chim Environm, F-45071 Orleans, France. Univ Heidelberg, Inst Umweltphys, D-6900 Heidelberg, Germany. Univ Bremen, Inst Umweltphys, Bremen, Germany. DLR, Inst Phys Atmosphare, Oberpfaffenhofen, Germany. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Tohoku Univ, Dept Geophys, Sendai, Miyagi 980, Japan. RP Sugita, T (reprint author), Natl Inst Environm Studies, Ozone Layer Res Project, 16-2 Onogawa, Tsukuba, Ibaraki 3058506, Japan. RI Sasano, Yasuhiro/C-2927-2009; Kondo, Yutaka/D-1459-2012; Sinnhuber, Miriam/A-7252-2013; Johnson, David/F-2376-2015; Boesch, Hartmut/G-6021-2012 OI Sasano, Yasuhiro/0000-0001-7470-5642; Johnson, David/0000-0003-4399-5653; NR 59 TC 24 Z9 25 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D24 AR 8212 DI 10.1029/2001JD000602 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 637BN UT WOS:000180491900010 ER PT J AU Swartz, WH Yee, JH Vervack, RJ Lloyd, SA Newman, PA AF Swartz, WH Yee, JH Vervack, RJ Lloyd, SA Newman, PA TI Photochemical ozone loss in the Arctic as determined by MSX/UVISI stellar occultation observations during the 1999/2000 winter SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ozone loss; photochemical; Arctic; stellar occultation; MSX/UVISI; SOLVE ID UV-VISIBLE SPECTROMETER; POLAR VORTEX; POTENTIAL VORTICITY; SPACE EXPERIMENT; STRATOSPHERE; INSTRUMENT; DEPLETION; STARS; O-3 AB The combined SAGE III Ozone Loss and Validation Experiment and Third European Stratospheric Experiment on Ozone 2000 (SOLVE/THESEO 2000) campaign during winter 1999/2000 sought, in part, to quantify ozone loss within the Arctic polar vortex using a variety of aircraft-, balloon-, ground-, and space-based instrument platforms. The Midcourse Space Experiment/Ultraviolet and Visible Imagers and Spectrographic Imagers (MSX/UVISI) suite of instruments performed 31 stellar occultation observations from 23 January through 4 March 2000 in and near the Arctic polar vortex. Using a newly developed combined extinctive-refractive algorithm, ozone mixing ratio profiles, along with profiles of total density, pressure, and temperature, were retrieved. Retrieved temperature and ozone profiles are shown to agree well with other measurements. Diabatic trajectory calculations are used to remove the effects of subsidence within the vortex, allowing photochemical ozone loss to be inferred from these occultation measurements. A maximum ozone loss of about 1 ppmv is found at 400-500 K (similar to16-21 km) during the 41-day period for which occultation data are available, in agreement with several other ozone loss analyses of the campaign. This corresponds to an average daily loss rate of similar to0.024 ppmv/day. The combined extinctive-refractive stellar occultation technique is demonstrated to accurately measure stratospheric ozone loss during polar winter. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. RP Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA. EM bill.swartz@jhuapl.edu; jeng-hwa.yee@jhuapl.edu; ron.vervack@jhuapl.edu; steven.lloyd@jhuapl.edu; newman@notus.gsfc.nasa.gov RI Newman, Paul/D-6208-2012; Swartz, William/A-1965-2010; Vervack, Ronald/C-2702-2016 OI Newman, Paul/0000-0003-1139-2508; Swartz, William/0000-0002-9172-7189; Vervack, Ronald/0000-0002-8227-9564 NR 37 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8296 DI 10.1029/2001JD000933 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200093 ER PT J AU Toon, G Sen, B Blavier, JF Sasano, Y Yokota, T Kanzawa, H Ogawa, T Suzuki, M Shibasaki, K AF Toon, G Sen, B Blavier, JF Sasano, Y Yokota, T Kanzawa, H Ogawa, T Suzuki, M Shibasaki, K TI Comparison of ILAS and MkIV profiles of atmospheric trace gases measured above Alaska in May 1997 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE stratosphere; composition; infrared; spectrometry; solar; occultation ID OZONE; SPECTROMETER; STRATOSPHERE; VERSION-3.10; VALIDATION; BALLOON; VORTEX AB [1] Vertical profiles of the gases O-3, HNO3,NO2,N2O, H2O, and CH4, measured above Fairbanks, Alaska, during a May 1997 balloon flight of the JPL MkIV interferometer are compared with version 5.20 profiles measured by the ILAS instrument on board the ADEOS satellite. Both the ILAS and MkIV instruments employ the solar occultation technique, and for many of these gases, use the same absorption bands in their analyses. The results show good agreement for nearly all of these gases, after taking into account the slight differences in the potential vorticities of the sampled air masses and considering the error bars on the measurements. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Natl Inst Environm Studies, Tsukuba, Ibaraki 3058506, Japan. Natl Space Dev Agcy Japan, Earth Observat Res Ctr, Tokyo 1046023, Japan. RP Toon, G (reprint author), CALTECH, Jet Prop Lab, MS 183-601,4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Sasano, Yasuhiro/C-2927-2009 OI Sasano, Yasuhiro/0000-0001-7470-5642 NR 20 TC 10 Z9 10 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D24 AR 8211 DI 10.1029/2001JD000640 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 637BN UT WOS:000180491900007 ER PT J AU Wagner, T Wittrock, F Richter, A Wenig, M Burrows, JP Platt, U AF Wagner, T Wittrock, F Richter, A Wenig, M Burrows, JP Platt, U TI Continuous monitoring of the high and persistent chlorine activation during the Arctic winter 1999/2000 by the GOME instrument on ERS-2 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ozone hole; polar stratospheric ozone; satellite observations; GOME; chlorine activation; polar stratospheric clouds ID OPTICAL-ABSORPTION SPECTROSCOPY; STRATOSPHERIC OZONE DEPLETION; MICROWAVE LIMB SOUNDER; ANTARCTIC OZONE; POLAR VORTEX; OCLO MEASUREMENTS; MLS OBSERVATIONS; HNO3; CLO; SATELLITE AB Measurements of OClO total column amounts during the cold Arctic winter 1999/2000 retrieved from observations by the satellite instrument Global Ozone Monitoring Experiment (GOME) are presented. OClO is formed as a minor product of the reaction of BrO + ClO and thus serves as an indicator for a stratospheric chlorine activation. As a result of the good spatial and temporal coverage of GOME, it is possible to follow the temporal development of the stratospheric chlorine activation during the winter and spring on a daily basis. An initial weak chlorine activation was observed during mid November, shortly after stratospheric temperatures were sufficiently low that formation of polar stratospheric clouds resulted. Strong chlorine activation started around 22 December, when PSC formation was possible over a large altitude range. Chlorine activation was significant and large until the beginning of March, peaking mid February. In the middle of March the chlorine activation steeply decreased and ended around 20 March, when the polar vortex broke up. The duration and the magnitude of the chlorine activation in the Arctic winter 1999/2000 were higher than during all previous Arctic winters since the launch of the GOME instrument in April 1995. C1 Univ Heidelberg, Inst Umweltphys, D-69120 Heidelberg, Germany. Univ Bremen, Inst Environm Phys, D-28334 Bremen, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Wagner, T (reprint author), Univ Heidelberg, Inst Umweltphys, D-69120 Heidelberg, Germany. RI Wittrock, Folkard/B-6959-2008; Richter, Andreas/C-4971-2008; Wenig, Mark/K-7279-2012 OI Wittrock, Folkard/0000-0002-3024-0211; Richter, Andreas/0000-0003-3339-212X; NR 62 TC 15 Z9 18 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8267 DI 10.1029/2001JD000466 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200043 ER PT J AU Welton, EJ Voss, KJ Quinn, PK Flatau, PJ Markowicz, K Campbell, JR Spinhirne, JD Gordon, HR Johnson, JE AF Welton, EJ Voss, KJ Quinn, PK Flatau, PJ Markowicz, K Campbell, JR Spinhirne, JD Gordon, HR Johnson, JE TI Measurements of aerosol vertical profiles and optical properties during INDOEX 1999 using micropulse lidars SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aerosols; lidar; extinction; backscatter; Indian Ocean ID TROPICAL INDIAN-OCEAN; MARINE BOUNDARY-LAYER; 6-WAVELENGTH LIDAR; TRANSPORT; SECTION; RATIO; ACE-1; MODEL AB [1] Micropulse lidar (MPL) systems were used to measure aerosol properties during the Indian Ocean Experiment (INDOEX) 1999 field phase. Measurements were made from two platforms: the NOAA ship R/V Ronald H. Brown, and the Kaashidhoo Climate Observatory (KCO) in the Maldives. Sun photometers were used to provide aerosol optical depths (AOD) needed to calibrate the MPL. This study focuses on the height distribution and optical properties (at 523 nm) of aerosols observed during the campaign. The height of the highest aerosols (top height) was calculated and found to be below 4 km for most of the cruise. The marine boundary layer (MBL) top was calculated and found to be less than 1 km. MPL results were combined with air mass trajectories, radiosonde profiles of temperature and humidity, and aerosol concentration and optical measurements. Humidity varied from approximately 80% near the surface to 50% near the top height during the entire cruise. The average value and standard deviation of aerosol optical parameters were determined for characteristic air mass regimes. Marine aerosols in the absence of any continental influence were found to have an AOD of 0.05+/-0.03, an extinction-to-backscatter ratio (S ratio) of 33+/-6 sr, and peak extinction values around 0.05 km(-1) (near the MBL top). The marine results are shown to be in agreement with previously measured and expected values. Polluted marine areas over the Indian Ocean, influenced by continental aerosols, had AOD values in excess of 0.2, S ratios well above 40 sr, and peak extinction values approximately 0.20 km(-1) (near the MBL top). The polluted marine results are shown to be similar to previously published values for continental aerosols. Comparisons between MPL derived extinction near the ship (75 m) and extinction calculated at ship level using scattering measured by a nephelometer and absorption using a particle soot absorption photometer were conducted. The comparisons indicated that the MPL algorithm (using a constant S ratio throughout the lower troposphere) calculates extinction near the surface in agreement with the ship-level measurements only when the MBL aerosols are well mixed with aerosols above. Finally, a review of the MPL extinction profiles showed that the model of aerosol vertical extinction developed during an earlier INDOEX field campaign (at the Maldives) did not correctly describe the true vertical distribution over the greater Indian Ocean region. Using the average extinction profile and AOD obtained during marine conditions, a new model of aerosol vertical extinction was determined for marine atmospheres over the Indian Ocean. A new model of aerosol vertical extinction for polluted marine atmospheres was also developed using the average extinction profile and AOD obtained during marine conditions influenced by continental aerosols. C1 Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Univ Warsaw, Inst Geophys, PL-02093 Warsaw, Poland. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Welton, EJ (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. RI Welton, Ellsworth/A-8362-2012; Campbell, James/C-4884-2012; Voss, Kenneth /A-5328-2013; Flatau, Piotr/E-2219-2011; Quinn, Patricia/R-1493-2016 OI Campbell, James/0000-0003-0251-4550; Voss, Kenneth /0000-0002-7860-5080; Quinn, Patricia/0000-0003-0337-4895 NR 28 TC 104 Z9 111 U1 4 U2 22 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D19 AR 8019 DI 10.1029/2000JD000038 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 635YT UT WOS:000180428300013 ER PT J AU Williams, E Rosenfeld, D Madden, N Gerlach, J Gears, N Atkinson, L Dunnemann, N Frostrom, G Antonio, M Biazon, B Camargo, R Franca, H Gomes, A Lima, M Machado, R Manhaes, S Nachtigall, L Piva, H Quintiliano, W Machado, L Artaxo, P Roberts, G Renno, N Blakeslee, R Bailey, J Boccippio, D Betts, A Wolff, D Roy, B Halverson, J Rickenbach, T Fuentes, J Avelino, E AF Williams, E Rosenfeld, D Madden, N Gerlach, J Gears, N Atkinson, L Dunnemann, N Frostrom, G Antonio, M Biazon, B Camargo, R Franca, H Gomes, A Lima, M Machado, R Manhaes, S Nachtigall, L Piva, H Quintiliano, W Machado, L Artaxo, P Roberts, G Renno, N Blakeslee, R Bailey, J Boccippio, D Betts, A Wolff, D Roy, B Halverson, J Rickenbach, T Fuentes, J Avelino, E TI Contrasting convective regimes over the Amazon: Implications for cloud electrification SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE lightning; convention; aerosol; regimes; radar; precipitation ID SUPERCOOLED LIQUID WATER; VERTICAL VELOCITY EVENTS; CONDENSATION NUCLEI; OCEANIC CONVECTION; CHARGE; INTENSITY; INDICATOR; SYSTEMS; RADAR; MODEL AB Four distinct meteorological regimes in the Amazon basin have been examined to distinguish the contributions from boundary layer aerosol and convective available potential energy (CAPE) to continental cloud structure and electrification. The lack of distinction in the electrical parameters (peak flash rate, lightning yield per unit rainfall) between aerosol-rich October and aerosol-poor November in the premonsoon regime casts doubt on a primary role for the aerosol in enhancing cloud electrification. Evidence for a substantial role for the aerosol in suppressing warm rain coalescence is identified in the most highly polluted period in early October. The electrical activity in this stage is qualitatively peculiar. During the easterly and westerly wind regimes of the wet season, the lightning yield per unit of rainfall is positively correlated with the aerosol concentration, but the electrical parameters are also correlated with CAPE, with a similar degree of scatter. Here cause and effect are difficult to establish with available observations. This ambiguity extends to the "green ocean" westerly regime, a distinctly maritime regime over a major continent with minimum aerosol concentration, minimum CAPE, and little if any lightning. C1 MIT, Parsons Lab, Cambridge, MA 02139 USA. Hebrew Univ Jerusalem, Jerusalem, Israel. NASA, Goddard Space Flight Ctr, Wallops Isl Flight Facil, Wallops Isl, VA 23337 USA. Univ State Sao Paulo, IPMET, BR-17033360 Bauru, Brazil. Ctr Tecn Aeroesp, BR-12228904 Sao Paulo, Brazil. Univ Sao Paulo, BR-05389970 Sao Paulo, Brazil. Max Planck Inst Chem, D-55128 Mainz, Germany. Univ Arizona, Tucson, AZ 85721 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Virginia, Charlottesville, VA USA. EMBRATEL, Velho, Rondonia, Brazil. RP MIT, Parsons Lab, 48-211, Cambridge, MA 02139 USA. EM Earlew@ll.mit.edu; ntmadden@yahoo.com; John.C.Gerlach.1@gsfc.naa.gov; Mauricio@www.radar.ipmet.unesp.br; Machado@iae.cta.br; Artaxo@if.usp.br; greg@fiji.ucsd.edu; Renno@soar.atmo.arizona.edu; Rich.Blakeslee@msfc.nasa.gov; Jeff.bailey@msfc.nasa.gov; Dennis.Boccippio@msfc.nasa.gov; Akbetts@aol.com; Halverson@agnes.gsfc.nasa.gov; Ricken@trmm.gsfc.nasa.gov; jf6s@unic.mail.virginia.edu; e.avelino@uol.com.br RI Rosenfeld, Daniel/F-6077-2016; Machado, Luiz/C-4314-2012; Artaxo, Paulo/E-8874-2010 OI Rosenfeld, Daniel/0000-0002-0784-7656; Machado, Luiz/0000-0002-8243-1706; Artaxo, Paulo/0000-0001-7754-3036 NR 54 TC 213 Z9 224 U1 1 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP-OCT PY 2002 VL 107 IS D20 AR 8082 DI 10.1029/2001JD000380 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636PY UT WOS:000180466200056 ER PT J AU Zerefos, CS Kourtidis, KA Melas, D Balis, D Zanis, P Katsaros, L Mantis, HT Repapis, C Isaksen, I Sundet, J Herman, J Bhartia, PK Calpini, B AF Zerefos, CS Kourtidis, KA Melas, D Balis, D Zanis, P Katsaros, L Mantis, HT Repapis, C Isaksen, I Sundet, J Herman, J Bhartia, PK Calpini, B TI Photochemical Activity and Solar Ultraviolet Radiation (PAUR) Modulation Factors: An overview of the project SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE total ozone; tropospheric ozone; aerosols; UVB radiation; photochemistry; east Mediterranean ID LONG-RANGE TRANSPORT; SAHARAN DUST EVENT; CAMPAIGN; AEROSOLS; OZONE; MODEL; DEPOSITION AB [1] The Photochemical Activity and Ultraviolet Radiation (PAUR) II project (a continuation of an earlier PAUR I project) had the purpose of studying the interrelationships between changes in total ozone, tropospheric aerosols, UV radiation and photochemical activity. As part of PAUR II project, a campaign took place in Greece and Italy during May-June 1999, with the participation of 15 European and 3 American research institutions. A variety of radiation and gaseous and aerosol atmospheric composition and optical characteristics measurements were made during the campaign. Radiative transfer models and three-dimensional(3-D) regional chemistry transport models (CTM) were applied and compared to the available data set of PAUR II. The present overview paper gives an introduction to the project and to the meteorological and environmental conditions that prevailed and outlines some results that are extensively described in the subsequent papers which form this special section. The modulation of the UVB field in the presence of different types of aerosols, its transmittance and role in the photochemistry of the particular eastern Mediterranean environment is overviewed. Using a 3-D CTM, it is shown that even a 50% reduction in Greek anthropogenic emissions has only a small effect in reducing the ozone levels over the eastern Mediterranean in summer. The environmental conditions, which prevailed during the PAUR I and PAUR II campaigns, offered cases of background conditions over the Aegean Sea as well as conditions with Saharan dust episodes and extremes in total ozone. C1 Aristotle Univ Thessaloniki, Dept Phys, Lab Atmospher Phys, GR-54006 Thessaloniki, Greece. Acad Athens, Res Ctr Atmospher Phys & Climatol, Athens 11251, Greece. Univ Oslo, Dept Geophys, N-0315 Oslo, Norway. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Ecole Polytech Fed Lausanne, Air Pollut Lab, CH-1015 Lausanne, Switzerland. RP Aristotle Univ Thessaloniki, Dept Phys, Lab Atmospher Phys, Campus Box 149, GR-54006 Thessaloniki, Greece. EM zerefos@auth.gr; kourtidi@auth.gr; melas@auth.gr; balis@auth.gr; zanis@auth.gr; phatmcli@otenet.gr; i.s.a.isaksen@geofysikk.uio.no; j.k.sundet@geofysikk.uio.no; herman@tparty.gsfc.nasa.gov; bhartia@champman.gsfc.nasa.gov RI Zanis, Prodromos/B-5598-2015; Bhartia, Pawan/A-4209-2016; OI Bhartia, Pawan/0000-0001-8307-9137; Herman, Jay/0000-0002-9146-1632; Balis, Dimitris/0000-0003-1161-7746 NR 41 TC 64 Z9 64 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP PY 2002 VL 107 IS D18 AR 8134 DI 10.1029/2000JD000134 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 635YH UT WOS:000180427400020 ER PT J AU Zhao, Y Strong, K Kondo, Y Koike, M Matsumi, Y Irie, H Rinsland, CP Jones, NB Suzuki, K Nakajima, H Nakane, H Murata, I AF Zhao, Y Strong, K Kondo, Y Koike, M Matsumi, Y Irie, H Rinsland, CP Jones, NB Suzuki, K Nakajima, H Nakane, H Murata, I TI Spectroscopic measurements of tropospheric CO, C2H6, C2H2,and HCN in northern Japan SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE infrared; remote sensing; tropospheric species; biomass burning ID VERTICAL COLUMN ABUNDANCES; INFRARED SOLAR SPECTRA; HYDROGEN-CYANIDE HCN; PEM-WEST-B; CARBON-MONOXIDE; KITT PEAK; JUNGFRAUJOCH STATION; SEASONAL-VARIATIONS; PACIFIC-OCEAN; UV-RADIATION AB [1] Tropospheric column amounts and mixing ratios of CO, C2H6, C2H2, and HCN were retrieved from ground-based infrared solar spectra using a vertical profile retrieval algorithm (SFIT2). The spectra were recorded with high spectral resolution Fourier transform infrared (FTIR) spectrometers at Moshiri (44.4degreesN) and Rikubetsu (43.5degreesN) in northern Japan from May 1995 to June 2000. The retrievals show significant seasonal variations in the tropospheric content of the four molecules over northern Japan with maxima in winter-spring (February-April) for CO, C2H6, and C2H2 and in summer (May-July) for HCN. Good correlations between CO, C2H6, and C2H2 indicated that they had similar sources and underwent similar dilution processes. Deviation of HCN relative to its seasonal mean value (DeltaHCN) is correlated with the similar deviation of CO (DeltaCO), indicating that enhancements of CO and HCN above the mean levels were probably due to the same sources. Linear trends in tropospheric CO, C2H6, and C2H2 from May 1995 to June 2000 (excluding 1998) were (-2.10 +/- 0. 30), (-2.53 +/- 0.30), and (-3.99 +/- 0.57)%/yr, respectively, while the trend of (-0.93 +/- 0. 49)%/yr in HCN was relatively small. Abnormally high tropospheric amounts of the four molecules were recorded in 1998. HCN amounts were found to be much higher than its seasonal mean value throughout 1998 with a 65% maximum increase in August 1998. Significant increases of CO, C2H6, and C2H2 took place in August-October 1998. Trajectory calculations, global fire maps, and satellite smoke images revealed that biomass burning in eastern Siberia from mid-July to early October 1998 was the major cause of the elevated levels in tropospheric CO, C2H6, C2H2, and HCN observed in northern Japan in 1998. C1 Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, Tokyo 1538904, Japan. Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. Nagoya Univ, Solar Terr Environm Lab, Toyokawa 4428507, Japan. NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23681 USA. Natl Inst Water & Atmospher Res, Lauder, New Zealand. Yokohama Natl Univ, Fac Educ & Human Sci, Hodogaya Ku, Yokohama, Kanagawa 2408501, Japan. Natl Inst Environm Studies, Tsukuba, Ibaraki 3050053, Japan. Tohoku Univ, Grad Sch Sci, Dept Geophys & Astron, Sendai, Miyagi 9808578, Japan. RP Zhao, Y (reprint author), Univ Calif Davis, 1 Shields Ave, Davis, CA 95616 USA. RI Koike, Makoto/F-4366-2011; Strong, Kimberly/D-2563-2012; Kondo, Yutaka/D-1459-2012; Jones, Nicholas/G-5575-2011; OI Jones, Nicholas/0000-0002-0111-2368; Nakane, Hideaki/0000-0002-9032-6105 NR 41 TC 45 Z9 45 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP PY 2002 VL 107 IS D18 AR 4343 DI 10.1029/2001JD000748 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 635YH UT WOS:000180427400009 ER PT J AU Hakkinen, S AF Hakkinen, S TI Surface salinity variability in the northern North Atlantic during recent decades SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ICE-OCEAN SYSTEM; INTERPENTADAL VARIABILITY; THERMOHALINE CIRCULATION; HEAT; TEMPERATURE; SIMULATION; GREENLAND; TRANSPORT; MODEL AB [1] The sea surface salinity (SSS) variability in the North Atlantic is investigated using numerical model simulations for the last 50 years based on atmospheric forcing variability from the Comprehensive Atmosphere Ocean Data Set (COADS) and National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis. The focus here is the SSS variability in the subpolar region. The seasonality of the subpolar surface salinity variability is prominent with the maximum standard deviation (SD) occurring in the summer/fall period so that the amplitude of the summer SSS anomalies far exceed those of the wintertime. The interannual SSS variability in the subpolar gyre can be attributed mainly to excess ice melt, while the longer-term (decadal) variability is associated with meridional overturning variability. In these two hindcasts, the deep mixing (which drives overturning changes) is forced by heat flux variability so that weak subpolar heat loss and subsequent weak overturning are usually manifested in fresh surface conditions in the subpolar gyre within 2 years. This is because the role of deep convection is to mix down the net fresh water input received by the high latitudes. Hence, at the lack of widespread deep mixing, a signal of slowing down overturning, the fresh water input that would be expected based on climatology would accumulate at the surface. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hakkinen, S (reprint author), NASA, Goddard Space Flight Ctr, Code 971,Bldg 33,Room A221, Greenbelt, MD 20771 USA. RI Hakkinen, Sirpa/E-1461-2012 NR 29 TC 18 Z9 18 U1 2 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP-NOV PY 2002 VL 107 IS C12 AR 8003 DI 10.1029/2001JC000812 PG 12 WC Oceanography SC Oceanography GA 638ME UT WOS:000180574100003 ER PT J AU Jo, YH Yan, XH Pan, JY He, MX Liu, WT AF Jo, YH Yan, XH Pan, JY He, MX Liu, WT TI Calculation of the Bowen ratio in the tropical Pacific using sea surface temperature data SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE Bowen ratio; El Nino; latent heat flux; sensible heat flux; West Pacific Warm Pool; TAO ID LATENT-HEAT FLUX; EQUATORIAL PACIFIC; OCEAN AB [1] The equilibrium Bowen ratio (Bo*) can be estimated empirically from the sea surface temperature (SST) only when the air is saturated with water vapor at the sea surface. However, since most of the sea surface is not saturated with water vapor, several studies have been conducted for the empirical Bowen ratio (Bo(E) = Bo*(SST)), which was formulated with many sources of data from many areas. Hicks and Hess' [1977] linear regression formula for the BoE as a function of SST alone was used to estimate the empirical Bowen ratio in the tropical Pacific. Climatological and long-term time series Optimum Interpolation Sea Surface Temperature (OISST) data was used for the climatological study of the BoE. The climatological mean Bowen ratio showed the regions, where the latent heat flux was most dominant. The Bowen ratio in the western Pacific warm pool (WPWP) area (O (0.04)) was 10% smaller than those in the upwelling coastal areas (O (0.14)). Along 5degreesN and 5degreesS, a 0.7 correlation coefficient between the Bo(E) and the bulk formulated Bowen ratio (Bo(B)), using climatological data, was found in the weak wind zone of the doldrums. Bo(B) is the ratio of the bulk formulated sensible heat flux to the bulk formulated latent heat flux. EOF analysis was used to find out dominant temporal and spatial signals of the Bo(E). The first temporal EOF of the Bo(E), using 156 months (1986-1999) of OISST anomaly was related to El Nino events with an approximate 12-month lag when compared to the El Nino-Southern Oscillation (ENSO) index (SOI). The second and third temporal EOF showed annual and interannual signals, respectively. In order to estimate the discrepancy between the Bo(E) and the Bo(B) and to correct for the wind effect and the humidity effect, long-term time series of Tropical Atmosphere Ocean (TAO) data was used. Our results showed that the eastern Pacific demonstrated a stronger correlation between the Bo(B) and the Bo(E) than the western Pacific. However, the Bowen ratio differences (Bo(D) =| Bo(E) - Bo(B)|) were small in the western Pacific, and a larger margin of error was found at the eastern Pacific, where ocean dynamics perturb the upper ocean heat balance. The sensitivity of the humidity and the winds on the Bo(E) was tested using linear correlation of the Bo(D) while varying the winds and humidity. The Bo(D) was small, especially in the southwest Pacific, where there are weak winds and high levels of the humidity. Thus the BoE in our study will be more useful to study involving heat fluxes in the WPWP area rather than those in the eastern Pacific. The correction of the humidity and the wind was applied using a linear regression of the humidity and the winds. After the corrections, the Bo(D) was reduced by an average of 70.2%. Using TAO data, we obtained Bo(E) = 0. 033Bo* in the western Pacific with Bo* 's standard deviation of 0. 008 at sea surface temperature 29.27 degreesC +/- 0.54 degreesC. C1 Univ Delaware, Grad Coll Marine Studies, Ctr Remote Sensing, Newark, DE 19716 USA. Ocean Univ Qingdao, Ocean Remote Sensing Inst, Qingdao 266003, Peoples R China. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jo, YH (reprint author), Univ Delaware, Grad Coll Marine Studies, Ctr Remote Sensing, 209C Robinson Hall, Newark, DE 19716 USA. NR 20 TC 2 Z9 2 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP PY 2002 VL 107 IS C9 AR 3134 DI 10.1029/2001JC001150 PG 16 WC Oceanography SC Oceanography GA 638AM UT WOS:000180546200017 ER PT J AU Kwok, R Cunningham, GF AF Kwok, R Cunningham, GF TI Seasonal ice area and volume production of the Arctic Ocean: November 1996 through April 1997 SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SEA-ICE; IMAGERY; MOTION; MODEL; SAR AB [1] The RADARSAT Geophysical Processor System (RGPS) produces estimates of sea ice motion, deformation, and thickness of the Arctic Ocean sea ice cover from time-sequential synthetic aperture radar (SAR) imagery acquired by RADARSAT. Based on these products, we summarize the evolution of a region of the Arctic Ocean ice cover in terms of its area change, ice volume production, and multiyear ice coverage over a 6-month period between 7 November 1996 through 30 April 1997. This region encompasses a large part of the Western Arctic Ocean. The initial ice area covers similar to2.52 x 10(6) km(2). At the end of April, this region covers similar to2.59 x 10(6) km(2), a net divergence of similar to3%. Over the period, thin ice (0-20 cm) typically covers <2% of this area. The RGPS estimates only the thickness distribution of sea ice volume produced by openings and closings of the ice cover since the initial observation. Thus, only the ice volume of the seasonal ice cover can be determined. Between November 1996 and April 1997, &SIM;1000 km(3) (&SIM;0.4 m) of sea ice is produced. The amount stored in undeformed ice and ridged ice is dependent on the character of the redistribution function. The RGPS products also provide estimates of multiyear ice coverage. From the time-series of multiyear ice coverage, we estimate that nearly 83% of the area is covered by multiyear ice. For more detailed examination of the regional dependence of ice-cover deformation, volume production, and MY ice coverage, the larger region is divided into five subregions. Where possible, we provide an analysis of the errors in the above estimates. In cases where quantification of the uncertainty is not feasible, we list the potential error sources. There are remaining sources of uncertainty in these calculations that remain unquantified, but at this time, there are no adequate in situ or remote-sensing data for comprehensive evaluation of the above estimates. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kwok, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 16 TC 31 Z9 31 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP-OCT PY 2002 VL 107 IS C10 AR 8038 DI 10.1029/2000JC000469 PG 17 WC Oceanography SC Oceanography GA 638JN UT WOS:000180568000004 ER PT J AU Rabbette, M Pilewskie, P AF Rabbette, M Pilewskie, P TI Principal component analysis of Arctic solar irradiance spectra SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID RADIATION BUDGET; CLOUD; CLIMATE; FLUX AB [1] During the First International Satellite Cloud Climatology Regional Experiment Phase III (FIRE III) Arctic Cloud Experiment (ACE) and coincident Surface Heat Budget of the Arctic Ocean (SHEBA) campaign, detailed moderate-resolution solar spectral measurements were made to study the radiative energy budget of the coupled Arctic Ocean-atmosphere system. The National Aeronautics and Space Administration (NASA) Ames Solar Spectral Flux Radiometers (SSFR) were used to measure moderate-resolution solar spectral irradiance in the spectral range 380-2200 nm on board the NASA ER-2 (flying at 21 km) and on the surface at the SHEBA ice camp. Principal Component Analysis (PCA) of SSFR spectra was used to quantify the variability in the data, to determine its causes, to assess our ability to separate cloud and surface effects, and to compare PCA in the Arctic with similar analysis of spectra obtained at a midlatitude continental site. For both the upwelling and downwelling spectra, nearly all of the variance was contained in the first six principal components (PC). The variability in the Arctic downwelling solar irradiance spectra was explained by a few fundamental components including cloud absorption, surface reflectance, molecular scattering, water vapor, and ozone. PCA of the SSFR upwelling spectra separated the influence of the ice surface from that of clouds. C1 Bay Area Environm Res Inst, San Francisco, CA 94122 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Rabbette, M (reprint author), Bay Area Environm Res Inst, San Francisco, CA 94122 USA. NR 21 TC 6 Z9 6 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP-OCT PY 2002 VL 107 IS C10 AR 8049 DI 10.1029/2000JC000566 PG 13 WC Oceanography SC Oceanography GA 638JN UT WOS:000180568000057 ER PT J AU Richter-Menge, JA McNutt, SL Overland, JE Kwok, R AF Richter-Menge, JA McNutt, SL Overland, JE Kwok, R TI Relating arctic pack ice stress and deformation under winter conditions SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE sea ice; stress; deformation; remote sensing ID GENERAL-CIRCULATION MODEL; SEA-ICE; CO2 SENSITIVITY; CLIMATE MODEL; BEAUFORT SEA; DYNAMICS; SIMULATION; MECHANICS; THICKNESS; SYSTEM AB [1] Together, thermodynamic and dynamic processes determine the thickness distribution of the ice cover on polar oceans, which governs the exchange of energy between the atmosphere and the ocean. Key to the dynamic processes is the mechanical behavior of the ice cover. During the Surface Heat Budget of the Arctic Ocean (SHEBA) field experiment, we deployed sensors to measure the internal ice stress at several locations within a 15 x 15 km area. These measurements are combined with satellite- derived ice motion and imagery products. The objective is to make a first step toward using these data sources for evaluating sea ice dynamics models by assessing whether the stress signal can be qualitatively linked to the regional-scale (10-100 km) deformation activity. Four case studies are presented, each with distinguishing characteristics: consolidation of the seasonal ice zone against the Alaskan coast (5-7 December 1997); advancement of the consolidation zone into the perennial ice pack (11-13 December); extreme divergence (14-17 January); and consolidation of the pack against Wrangel Island and the Siberian coast (20-23 February). The results of this analysis (1) demonstrate that stress measurements are related to the regional deformation behavior of the ice cover, (2) confirm that regional-scale ice dynamics is primarily a function of coastal geometry and sustained, large-scale wind direction and magnitude, (3) provide continued evidence that the ice pack behaves as a granular hardening plastic, and (4) encourage pursuit of efforts to use direct measurements of ice stress and deformation in the formulation and development of sea ice dynamics models. C1 CRREL, Erdc, Hanover, NH 03755 USA. Univ Alaska Fairbanks, Fairbanks, AK 99775 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Richter-Menge, JA (reprint author), CRREL, Erdc, 72 Lyme Rd, Hanover, NH 03755 USA. RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 39 TC 48 Z9 49 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP-OCT PY 2002 VL 107 IS C10 AR 8040 DI 10.1029/2000JC000477 PG 15 WC Oceanography SC Oceanography GA 638JN UT WOS:000180568000007 ER PT J AU Signorini, SR Cavalieri, DJ AF Signorini, SR Cavalieri, DJ TI Modeling dense water production and salt transport from Alaskan coastal polynyas SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE Arctic coastal polynyas; sea ice; dense water production; salt transport; modeling Alaskan polynyas ID SEA-ICE DRIFT; ARCTIC-OCEAN; OFFSHORE TRANSPORT; BERING STRAIT; WAVELET ANALYSIS; SHELF; FLOW; PARAMETERIZATION; STRATIFICATION; VARIABILITY AB [1] A three-dimensional primitive equation model was used to assess the effects of dense water formation from winter (1996/1997) polynyas on the ambient stratification, salt transport, and circulation in the vicinity of Barrow Canyon. The model, which includes ambient stratification and bottom topography, is forced by time-varying surface heat flux, surface salt flux, and coastal flow. The influence of sea ice drift on the circulation and salt transport is also analyzed by prescribing ice water stress at the sea surface. The surface fluxes and ice drift are derived from satellite observations (Special Sensor Microwave Imager (SSM/I) and NASA scatterometer (NSCAT) sensors). The coastal flow (Alaska coastal current), which is an extension of the Bering Sea throughflow, is formulated in the model by using a wind-transport regression. One set of experiments was forced by strong and persistent polynyas, simulated by 20-day averaged heat and salt fluxes originating from the largest events. In this set of experiments both strong and weak steady coastal currents were imposed. The amount of salt exported from the generation area depended on the strength of the current. Another set of experiments was forced by weaker and less persistent polynyas using time-varying forcing. The experiments with time-varying polynya forcing were conducted with two ambient vertical stratifications, one representing fall conditions and one representing winter conditions. The amount of salt retained on the shelf was found to be quite sensitive to the initial stratification. Weaker vertical stratification promotes a deeper mixed layer, which develops 20 times faster than the horizontal advective timescale of the coastal current, thus increasing the residence time of the salt generated by the polynya on the shelf. The time-varying northeastward coastal current, combined with the offshore Ekman transport, can export 29-73% of the salt produced by polynyas upstream of Barrow Canyon, depending upon the ambient vertical stratification. The inclusion of ice water stress in the model makes the coastal current much wider due to the resulting offshore Ekman transport and also doubles the amount of salt exported. C1 Sci Applicat Int Corp, Beltsville, MD 20705 USA. NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Signorini, SR (reprint author), Sci Applicat Int Corp, 4600 Powder Mill Rd, Beltsville, MD 20705 USA. NR 34 TC 7 Z9 7 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP PY 2002 VL 107 IS C9 AR 3136 DI 10.1029/2000JC000491 PG 15 WC Oceanography SC Oceanography GA 638AM UT WOS:000180546200019 ER PT J AU Warren, SG Brandt, RE Grenfell, TC McKay, CP AF Warren, SG Brandt, RE Grenfell, TC McKay, CP TI Snowball Earth: Ice thickness on the tropical ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE Snowball Earth; sea ice; marine ice; solar radiation; albedo; ice shelf ID SEA-ICE; OPTICAL-PROPERTIES; SOLAR-RADIATION; SOUTH-POLE; DEEP ICE; ABSORPTION-COEFFICIENTS; LIGHT TRANSMISSION; GREEN ICEBERGS; ANTARCTICA; BENEATH AB [1] On the tropical oceans of a neo-Proterozoic Snowball Earth, snow-free ice would have existed in regions of net sublimation. Photosynthesis could have continued beneath this bare ice if it was sufficiently thin and sufficiently clear. The steady state ice thickness is determined by the necessity to balance the upward conduction of heat with three subsurface heating rates: the heat flux from the ocean to the ice base, the latent heat of freezing to the ice base, and the solar energy absorbed within the ice. A preliminary study, using a broadband model for solar radiation and assuming a large freezing rate, had indicated that tropical ice might be only a few meters thick. Here we show that the vertical throughput of ice by surface sublimation and basal freezing would be too slow to keep the ice thin and that the broadband model had exaggerated the absorption depth of sunlight. We use a spectral model for solar absorption, computing radiative transfer at 60 wavelengths, considering absorption by the ice, and scattering by bubbles. With the spectral model, the computed ice thickness is much greater. For a solar flux of 320 W m(-2) at the equatorial surface and expected albedo of 0.5 for bare sea ice, we find that surface temperatures below 12 degreesC generate ice layers too thick for photosynthesis (> 100 m). If the albedo were as low as 0.4, thick ice would occur only for surface temperatures below 25 degreesC, but such low temperatures would be difficult to maintain with such low albedo. For surface temperatures warmer than these limits, the ice becomes thin (< 1 m) and is unlikely to represent a coherent ice layer. However, glacial deformation of thick floating ice from nearby oceanic regions may preclude the existence of thin or ice-free patches. C1 Univ Washington, Dept Atmospher Sci, Seattle, WA 98196 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Warren, SG (reprint author), Univ Washington, Dept Atmospher Sci, Box 351640, Seattle, WA 98196 USA. NR 61 TC 77 Z9 79 U1 2 U2 26 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP-OCT PY 2002 VL 107 IS C10 AR 3167 DI 10.1029/2001FC001123 PG 18 WC Oceanography SC Oceanography GA 638JN UT WOS:000180568000044 ER PT J AU Zang, XY Fu, LL Wunsch, C AF Zang, XY Fu, LL Wunsch, C TI Observed reflectivity of the western boundary of the equatorial Pacific Ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE western boundary reflection; equatorial Rossby waves; equatorial Kelvin waves; sea level variations; El Nino ID ROSSBY WAVES; TROPICAL PACIFIC; MODEL; VARIABILITY; MOTIONS; ENSO AB [1] Published claims that the reflectivity of the western boundary of the equatorial Pacific is near 100% are examined by using TOPEX/Poseidon data from October 1992 to February 2000. We perform a Fourier analysis of sea surface height measurements and define the variability consistent with the Rossby wave and Kelvin wave dispersion relationship as the energy of Rossby wave and Kelvin wave, respectively. Basin-scale Rossby waves dominate in the period ranges of 180-250 and 270-450 days. Their largest amplitudes are at 4degrees and 6degreesN, respectively. Kelvin waves dominate in distinguishable period ranges of 67-76 and 106-170 days. Because the wavelengths of the Kelvin waves generated from the reflection of low-frequency Rossby waves are much longer than the width of the basin, they cannot be readily differentiated from large-scale forced motions. An upper bound on the reflection coefficient of the Rossby wave is thus estimated as 31% for Rossby waves with periods of 180-250 days. The duration of TOPEX/Poseidon data is too short for studying the reflectivity of the lower-frequency Rossby waves. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. RP Zang, XY (reprint author), MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. NR 28 TC 15 Z9 15 U1 2 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP-OCT PY 2002 VL 107 IS C10 AR 3150 DI 10.1029/2000JC000719 PG 12 WC Oceanography SC Oceanography GA 638JN UT WOS:000180568000026 ER PT J AU Grant, JA Parker, TJ AF Grant, JA Parker, TJ TI Drainage evolution in the Margaritifer Sinus region, Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Mars; water; valleys; channels; rainfall; sapping ID MARTIAN IMPACT CRATERS; ISIDIS BASIN; VALLEYS; DEGRADATION; SURFACE; WATER; AGE AB [1] Margaritifer Sinus, Mars, records a complex history of water transport, storage, and release extending from the late Noachian into at least the mid-Hesperian. Collection, transport, and discharge of water were accomplished by systems of differing character flanking opposite sides of the Chryse Trough. Drainage on the western side of the trough was via the segmented Uzboi-Ladon-Margaritifer mesoscale outflow system that heads in Argyre Basin and incises and fills as it crosses ancient multiringed impact basins. By contrast, Samara and Parana-Loire Valles, two of the largest and best integrated valley systems on Mars, dominated drainage on the eastern trough flank. Valley morphometry suggests formation was due to precipitation-recharged groundwater sapping. All systems discharged into Margaritifer Basin, located along the Chryse Trough axis, and caused ponding that persisted into the early Hesperian. The Uzboi-Ladon-Margaritifer system dominated discharge that was coincident with widespread geomorphic activity on Mars. As channel and valley formation ended, some water in Margaritifer Basin infiltrated the subsurface. Collapse and release of water began shortly thereafter and persisted into mid-Hesperian times, thereby forming Margaritifer and Iani Chaos and incising Ares Vallis. C1 Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Grant, JA (reprint author), Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. NR 54 TC 58 Z9 58 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD SEP PY 2002 VL 107 IS E9 AR 5066 DI 10.1029/2001JE001678 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 639LP UT WOS:000180630500004 ER PT J AU Maguire, WC Pearl, JC Smith, MD Conrath, BJ Kutepov, AA Kaelberer, MS Winter, E Christensen, PR AF Maguire, WC Pearl, JC Smith, MD Conrath, BJ Kutepov, AA Kaelberer, MS Winter, E Christensen, PR TI Observations of high-altitude CO2 hot bands in Mars by the orbiting Thermal Emission Spectrometer SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE MGS/TES; non-LTE; carbon dioxide; hot band; seasons limb ID ACCELERATED LAMBDA ITERATION; RADIATIVE-TRANSFER MODEL; NATURAL LASER-EMISSION; INFRARED EMISSIONS; VIBRATIONAL LEVELS; ATMOSPHERES; VENUS; POPULATIONS; MESOSPHERES AB [1] We present limb spectral measurements of the Martian atmosphere for four seasonal periods produced from data acquired by the Mars Global Surveyor/Thermal Emission Spectrometer. Between the altitudes of approximately 50 and 90 km, nonlocal thermodynamic equilibrium (non-LTE) emission from CO2 hot bands is observed at 10 mum. The centroids of these emissions vary in latitude and height with season, and their emission regions extend approximately 120degrees in latitude. The emission is considerably stronger in the southern summer/northern winter season than in the corresponding northern summer/southern winter season due to large solar flux variations resulting from the eccentricity of the Martian orbit. Modeling of this emission explains its observed altitude, solar zenith angle, and seasonal dependence. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Arizona State Univ, Dept Geol, Tempe, AZ 85287 USA. Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. Max Planck Inst Extraterr Phys, D-37075 Garching, Germany. Emergent Inc, Lanham, MD USA. RP Maguire, WC (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Mail Code 693, Greenbelt, MD 20771 USA. EM william.maguire@gsfc.nasa.gov; phil.christensen@asu.edu RI Smith, Michael/C-8875-2012 NR 16 TC 13 Z9 13 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD SEP PY 2002 VL 107 IS E9 AR 5063 DI 10.1029/2001JE001516 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 639LP UT WOS:000180630500001 ER PT J AU Rubincam, DP Rowlands, DD Ray, RD AF Rubincam, DP Rowlands, DD Ray, RD TI Is asteroid 951 Gaspra in a resonant obliquity state with its spin increasing due to YORP? SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE asteroid; Gaspra; rotation; spin; Yarkovsky; YORP ID DYNAMICAL EVOLUTION; FRAGMENTS; ENCOUNTER AB [1] Asteroid 951 Gaspra appears to be in an obliquity resonance with its spin increasing due to the Yarkovsky-O'Keefe-Radzievskii-Paddack effect (YORP effect, for short). Gaspra, an asteroid 5.8 km in radius, is a prograde rotator with a rotation period of 7.03 hours. A 3 x 10(6) year integration indicates that its orbit is stable over at least this time span. From its known shape and spin axis orientation and assuming a uniform density, Gaspra's axial precession period turns out to be nearly commensurate with its orbital precession period, which leads to a resonance condition with consequent huge variations in its obliquity. At the same time, its shape is such that the YORP effect is increasing its spin rate. YORP may be a reason for small asteroids entering resonances in the first place: they speed up or slow down and fall into resonances. The continued action of YORP probably ultimately causes asteroids to leave resonances, so that they are quasi-stable states. C1 NASA, Goddard Space Flight Ctr, Geodynam Branch, Terr Phys Lab, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, Geodynam Branch, Terr Phys Lab, Code 921, Greenbelt, MD 20771 USA. EM rubincam@core2.gsfc.nasa.gov RI Rowlands, David/D-2751-2012; Rubincam, David/D-2918-2012; Ray, Richard/D-1034-2012 NR 24 TC 11 Z9 11 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD SEP PY 2002 VL 107 IS E9 AR 5065 DI 10.1029/2001JE001813 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 639LP UT WOS:000180630500003 ER PT J AU Williams, DA Radebaugh, J Keszthelyi, LP McEwen, AS Lopes, RMC Doute, S Greeley, R AF Williams, DA Radebaugh, J Keszthelyi, LP McEwen, AS Lopes, RMC Doute, S Greeley, R TI Geologic mapping of the Chaac-Camaxtli region of Io from Galileo imaging data SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Io; geologic mapping; lava flows; paterae; planetary volcanism; Galileo mission ID JUPITERS SATELLITE IO; SULFUR FLOWS; ACTIVE VOLCANISM; SURFACE; IRRADIATION; IMAGES; ANALOG; COLOR; PLUME; MOON AB [1] We produced a geologic/geomorphologic map of the Chaac-Camaxtli region of Io's leading anti-Jovian hemisphere using regional resolution (186 m/pixel) Galileo imaging data collected during orbit I27 (February 2000) integrated with lower resolution (1.4 km/ pixel) color data, along with other Galileo imaging and spectral data. This is the first regional map of Io made from Galileo data. Nine color and geomorphologic units have been mapped, and the close proximity of dark and various colored bright materials suggests that there is an intimate interaction between ( presumably) silicate magmas and sulfur-bearing volatile materials that produced a variety of explosive and effusive deposits in the recent geologic past. This region of Io is dominated by 11 volcanic centers, most of which are paterae that are analogous in morphology to terrestrial calderas but larger in size. Mapping of structural features indicates that most of the active regions occur in topographic lows, and less active or inactive paterae are associated with topographic highs. This indicates that crustal thickness variations influence magma access to the surface. Surface changes in this region since the Voyager flybys (1979) are relatively minor (additional bright and dark flows, color changes), although several active vents have migrated within paterae. This observation, along with the identification of the relatively regular spacing of paterae (similar to100-150 km) along a line, may indicate there are multiple interlacing fractures in the crust that serve as magma conduits from the interior. This connection between volcanism and tectonism may have implications for tidal heating mechanisms and their effect on Io's lithosphere. Some inactive patera floors may be evolving into bright plains material, which, if composed of silicates, might explain the strength of Io's crust to support steep patera walls and tall mountains. C1 Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Arizona State Univ, Dept Geol Sci, Box 871404, Tempe, AZ 85287 USA. EM williams@dione.la.asu.edu RI Lopes, Rosaly/D-1608-2016 OI Lopes, Rosaly/0000-0002-7928-3167 NR 61 TC 19 Z9 19 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD SEP PY 2002 VL 107 IS E9 AR 5068 DI 10.1029/2001JE001821 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 639LP UT WOS:000180630500006 ER PT J AU Carpenter, DL Spasojevic, MA Bell, TF Inan, US Reinisch, BW Galkin, IA Benson, RF Green, JL Fung, SF Boardsen, SA AF Carpenter, DL Spasojevic, MA Bell, TF Inan, US Reinisch, BW Galkin, IA Benson, RF Green, JL Fung, SF Boardsen, SA TI Small-scale field-aligned plasmaspheric density structures inferred from the Radio Plasma Imager on IMAGE SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE plasmasphere; plasmapause; radio sounding; spread echoes; field-aligned irregularities ID ELECTRON-DENSITY; FINE-STRUCTURE; MAGNETOSPHERE; IRREGULARITIES; WHISTLERS; REGION; INSTABILITY; MOTIONS; WAVES; MODEL AB [1] Among the objectives of the Radio Plasma Imager (RPI) on IMAGE is the observation of the Earth's plasmasphere from the satellite's polar orbit, with apogee approximate to8 R-E geocentric distance and perigee near 1200 km altitude. This objective is here pursued by (1) remote sounding from high-altitude regions outside the main plasmasphere, (2) sounding within the plasmasphere, and (3) in situ passive measurements of natural wave activity. During sounding of the plasmasphere from both outside and inside the plasmapause, RPI echoes that follow non-field-aligned ray paths are usually not the discrete traces on range-versus-frequency records (plasmagrams) that are predicted by ray-tracing simulations in smooth magnetospheric density models. Instead, such RPI echoes exhibit various amounts of spreading, from approximate to0.5 R-E to approximate to2 R-E in virtual range (range assuming free-space speed of light propagation). The range spreading is attributed to scattering from, partial reflection from, and propagation along geomagnetic field-aligned electron density irregularities. There exists a substantial body of theoretical work on mechanisms that might explain the appearance of such irregularities both within and beyond the plasmasphere. That the spread-producing irregularities are field-aligned is suggested by the efficiency with which RPI excites discrete echoes that propagate along the geomagnetic field, sometimes into both hemispheres. The spatial distributions and scale sizes of the spread-producing irregularities remain to be investigated. The RPI echo data, however, coupled with earlier evidence from topside sounders and whistler mode instruments, suggest that they can have cross-field scale sizes within a range from approximate to200 m to over 10 km and electron densities within approximate to10% of background. RPI is found capable of detecting plasmapause locations from distances of approximate to3 R-E or more. When minimal signal integration is used, the location and range of density values of a steep plasmapause can be determined from distances of order 1 R-E, and echoes can at times be returned from points extending inward from the plasmapause to locations where the electron density reaches approximate to3000 cm(-3), which is usually at L < 3. C1 Stanford Univ, Space Telecommun & Radiosci Lab, Stanford, CA 94305 USA. Univ Massachusetts, Ctr Atmospher Res, Lowell, MA 01854 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. L3 Commun Analyt Corp, Vienna, VA 22180 USA. RP Carpenter, DL (reprint author), Stanford Univ, Space Telecommun & Radiosci Lab, Stanford, CA 94305 USA. RI Fung, Shing/F-5647-2012 NR 80 TC 44 Z9 44 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP PY 2002 VL 107 IS A9 AR 1258 DI 10.1029/2001JA009199 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634MN UT WOS:000180343700034 ER PT J AU Cattell, C Johnson, L Bergmann, R Klumpar, D Carlson, C McFadden, J Strangeway, R Ergun, R Sigsbee, K Pfaff, R AF Cattell, C Johnson, L Bergmann, R Klumpar, D Carlson, C McFadden, J Strangeway, R Ergun, R Sigsbee, K Pfaff, R TI FAST observations of discrete electrostatic waves in association with down-going ion beams in the auroral zone SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE aurora; ion beams; lower hybrid waves; downward field-aligned current ID CYCLOTRON HARMONIC-WAVES; HYDROGEN CYCLOTRON; VIKING SATELLITE; PLASMA; REGION; H+ AB [1] Ion beams flowing downward, into the ionosphere, along the Earth's magnetic field have frequently been observed by the FAST satellite in the auroral zone. These discrete downward moving ion beams (DFI) have been characterized by Klumpar et al. [1999] who interpreted the horseshoe-shaped distributions as being consistent with acceleration in a parallel potential drop above the satellite, followed by motion into a region of increased magnetic field strength. The down-flowing ion beams are associated with an intense narrowband electrostatic emission at the lower hybrid frequency, polarized perpendicular to the geomagnetic field. Hydrogen cyclotron harmonics both above and below the lower hybrid frequency are also very common. These are the first observations of down-flowing ions and associated waves outside of the cusp, and the physical mechanism producing the ions is very different from the one associated with cusp ion injections. The DFI events that had a monotonic increase in energy were associated with a clear field-aligned current signature. The DFI densities were usually similar to5-10/cc, whereas the background plasma had densities up to 100/cc. The wave and DFI observations are consistent with linear dispersion relation calculations and simulations with ion ring distributions that show that the instability is due to coupling of the ion Bernstein waves to the lower hybrid wave. In addition, for a few events, electrostatic ion cyclotron waves were observed. Such waves are usually associated with up-going ion beams and have not previously been seen with DFI, which have a very different shape in the distribution. C1 Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Eastern Illinois Univ, Dept Phys, Charleston, IL 61920 USA. Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Angeles, Inst Phys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Colorado, Dept Astrophys & Planetary Sci, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Univ Minnesota, Sch Phys & Astron, 116 Church St SE, Minneapolis, MN 55455 USA. EM cattell@fields.space.umn.edu; cfrab@eiu.edu; klump@physics.montana.edu; ccc@ssl.berkeley.edu; mcfadden@ssl.berkeley.edu; strange@igpp.ucla.edu; ree@fast.colorado.edu; Kristine.M.Sigsbee.1@gsfc.nasa.gov; rob.pfaff@gsfc.nasa.gov RI Pfaff, Robert/F-5703-2012; OI Pfaff, Robert/0000-0002-4881-9715; Sigsbee, Kristine/0000-0001-8727-380X; Cattell, Cynthia/0000-0002-3805-320X NR 25 TC 45 Z9 45 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP PY 2002 VL 107 IS A9 AR 1238 DI 10.1029/2001JA000254 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634MN UT WOS:000180343700014 ER PT J AU Farrugia, CJ Popecki, M Mobius, E Jordanova, VK Desai, MI Fitzenreiter, RJ Ogilvie, KW Matsui, H Lepri, S Zurbuchen, T Mason, GM Lawrence, GR Burlaga, LF Lepping, RP Dwyer, JR McComas, D AF Farrugia, CJ Popecki, M Mobius, E Jordanova, VK Desai, MI Fitzenreiter, RJ Ogilvie, KW Matsui, H Lepri, S Zurbuchen, T Mason, GM Lawrence, GR Burlaga, LF Lepping, RP Dwyer, JR McComas, D TI Wind and ACE observations during the great flow of 1-4 May 1998: Relation to solar activity and implications for the magnetosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE magnetic clouds; solar energetic particles; composition; size of solar footprint of connected flux rope; space weather ID CORONAL MASS EJECTIONS; ELECTRON HEAT-FLUX; INTERPLANETARY MAGNETIC CLOUD; GEOMAGNETIC-ACTIVITY; EARTHS MAGNETOSPHERE; ENERGETIC PARTICLES; PROTON TEMPERATURE; OCTOBER 18-20; IONIC CHARGE; POLAR RAIN AB [1] Using magnetic field, plasma, and energetic particle data from Wind and ACE, we analyze interplanetary features associated with the first strongly geoeffective interval in the rising phase of solar cycle 23, which affected Earth on 1-4 May 1998. As shown by Skoug et al. [1999], the configuration consisted of a compound stream made up of an interplanetary coronal mass ejection (ICME) containing a magnetic cloud and being trailed by a hot, faster flow. In addition, we find that the front boundary of the ICME is a rotational discontinuity and the leading edge of the fast stream has a zero normal magnetic field component and is followed by a magnetic field which is strongly enhanced (by a factor of 4) and whose fluctuations lie in a plane approximately parallel to the leading edge. Energetic particle and composition observations confirm that the field lines of the magnetic cloud were connected to at least two different flare sites in the same active region. We infer a lower limit for the size of the solar footprint of the connected flux tube of 0.02 R-s(2), i. e., similar to10(10) km(2). A dramatic weakening of the halo electron distribution occurred during 3 May at the time when other experimenters have documented the presence of prominence material. We hypothesize that the solar wind halo population was scattered by enhanced frequency of Coulomb collisions in the dense and very cold plasma. We discuss our energetic particle observations in terms of local acceleration at interplanetary shocks and field discontinuities as well as in terms of acceleration in flares and CME-driven shocks. We also compare, in a specific formulation, the power and energy input of the May 1998 configuration to the magnetosphere with other much studied geoeffective events. We find that the power input far exceeded that in all previous geoeffective events in our sample and attribute this to the fact that the 1-4 May 1998 event consisted of a compound stream structure with an unprecedented power input during a 3-hour burst of high-speed flow on 4 May. A statistical survey using the OMNI database for the 6-year period 1995-2000 confirms these inferences and indicates further approximate saturation levels for energy and power input of 10 J m(-2) and 0.3 mW m(-2), only exceeded in exceptional events such as May 1998 and July 2000. The solar energetic particle event at the leading edge of the fast stream might be the only advance warning the Earth would receive of the approach of a configuration of such a concentrated geoeffective potential. C1 Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ Maryland, Dept Phys, College Pk, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Florida Inst Technol, Dept Phys & Space Sci, Melbourne, FL 32901 USA. SW Res Inst, San Antonio, TX 78228 USA. Univ Birmingham, Dept Phys & Astrophys, Birmingham B15 2TT, W Midlands, England. RP Farrugia, CJ (reprint author), Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. RI Lepri, Susan/I-8611-2012; OI Moebius, Eberhard/0000-0002-2745-6978; Jordanova, Vania/0000-0003-0475-8743 NR 62 TC 20 Z9 20 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP PY 2002 VL 107 IS A9 AR 1240 DI 10.1029/2001JA000188 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634MN UT WOS:000180343700016 ER PT J AU Krymskii, AM Breus, TK Ness, NF Acuna, MH Connerney, JEP Crider, DH Mitchell, DL Bauer, SJ AF Krymskii, AM Breus, TK Ness, NF Acuna, MH Connerney, JEP Crider, DH Mitchell, DL Bauer, SJ TI Structure of the magnetic field fluxes connected with crustal magnetization and topside ionosphere at Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE Mars; ionosphere; paleomagnetism; magnetosphere ID SOLAR-WIND; ELECTRON REFLECTOMETER; MARTIAN IONOSPHERE; MODEL; TEMPERATURE AB [1] The magnetic fluxes associated with the Martian crustal remanent magnetization have been studied in order to investigate the global structure of the magnetic field in and above the level of the Martian ionosphere. The intensely and nonuniformly magnetized crustal sources generate an effective large-scale magnetic field. Reconnection with the interplanetary magnetic field can possibly take place in many localized regions. This will permit solar wind (SW) and more energetic particles to precipitate into and heat the neutral atmosphere by impact ionization. This may occur not only in cusp-like field structures above nearly vertical field anomalies but also in halos extending several hundreds of kilometers from these sources. Numerous cusp-like regions may exist above the many crustal anomalies in the southern hemisphere. The large-scale horizontal magnetic fields due to the crustal sources and induced by the SW interaction are responsible for controlling the detailed structure of the Martian ionosphere. Radio occultation observations in the southern hemisphere show relatively constant and low average values of the electron density scale height and zero dependence on zenith angle in contrast to that of nonmagnetic Venus. C1 Rostov Don State Univ, Dept Astrophys, Rostov Na Donu 344104, Russia. Russian Acad Sci, Space Res Lab, Moscow 117810, Russia. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Graz Univ, IGAM, A-8010 Graz, Austria. RP Krymskii, AM (reprint author), Rostov Don State Univ, Dept Astrophys, Ul Zorge 5, Rostov Na Donu 344104, Russia. RI connerney, john/I-5127-2013; Hurley, Dana/F-4488-2015; OI Hurley, Dana/0000-0003-1052-1494; Bauer, Siegfried/0000-0003-4213-2047 NR 23 TC 57 Z9 58 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP PY 2002 VL 107 IS A9 AR 1245 DI 10.1029/2001JA000239 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634MN UT WOS:000180343700021 ER PT J AU Ostgaard, N Germany, G Stadsnes, J Vondrak, RR AF Ostgaard, N Germany, G Stadsnes, J Vondrak, RR TI Energy analysis of substorms based on remote sensing techniques, solar wind measurements, and geomagnetic indices SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE energy budget of substorms; X-ray and UV imaging; particle precipitation; Joule heating; ring current; solar wind ID ULTRAVIOLET IMAGER; MAGNETOSPHERE; STORM; ELECTRON; THERMOSPHERE; IONOSPHERE; EMISSIONS; UVI; AE AB [1] Observations from the Polar Ionospheric X-ray Imaging Experiment (PIXIE) and the Ultraviolet Imager (UVI) on board the Polar satellite have been used to examine the energy deposition in the Northern Hemisphere by precipitating electrons for seven substorms during 1997. By combining the results from these two remote sensing techniques we derive the 5 min average electron energy distributions from 100 eV to 100 keV with a spatial resolution of similar to700 km. During growth phase we find that most of the energy is carried by electrons below 10 keV. The study shows that the maximum intensity of the substorm is mostly defined by the flux of electrons below 10 keV. In contrast, the electrons above 10 keV show a greater intensification at substorm onset and are more confined azimuthally during the expansion phase. By using the most appropriate parameterized methods to estimate the energy increase of the ring current (U-R) and the Joule heating rate in both hemispheres (U-J) and by adding the rate of energy deposition in both hemispheres by precipitating electrons (U-A), we estimate the total energy dissipation rate during substorms (U-T). Our estimate of U-A is a factor 2-4 larger than that reported in earlier studies. We find that the contributions to the total time-integrated energy dissipation over the duration of the substorm, W(U-T), from W(U-R), W(U-J), and W(U-A) on average are 15%, 56%, and 29%. Comparing W(U-T) and the time-integrated epsilon parameter, W(epsilon), which approximates the solar wind input due to dayside reconnection, we find that the parameter does not always provide enough energy into the magnetosphere to balance W(U-T). An additional energy transfer mechanism is needed to balance the energy budget. We find that a viscous interaction that transfers 0.17% of the solar wind kinetic energy in addition to the energy transfer due to dayside reconnection, estimated by the epsilon parameter, is sufficient to balance the total energy dissipation U-T. C1 Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA. Univ Bergen, Dept Phys, N-5007 Bergen, Norway. Univ Oslo, Dept Phys, Oslo, Norway. RP Ostgaard, N (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Code 690,Bldg 2, Greenbelt, MD 20771 USA. NR 49 TC 30 Z9 31 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP PY 2002 VL 107 IS A9 AR 1233 DI 10.1029/2001JA002002 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634MN UT WOS:000180343700009 ER PT J AU Ostgaard, N Vondrak, RR Gjerloev, JW Germany, G AF Ostgaard, N Vondrak, RR Gjerloev, JW Germany, G TI A relation between the energy deposition by electron precipitation and geomagnetic indices during substorms SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE geomagnetic indices; particle precipitation; substorms; X-rays; UV emissions; imaging ID IONOSPHERIC CONDUCTANCE; AURORAL IONOSPHERE; MODEL; FIELD; FLUX; AE AB [1] Observations from the Polar Ionospheric X-ray Imaging Experiment (PIXIE) and the Ultraviolet Imager (UVI) on board the Polar satellite have been used to derive the total energy dissipation (U-A) in the Northern Hemisphere by electron precipitation in the energy range from 100 eV to 100 keV. Comparing with geomagnetic indices, we find that during substorms, U-A is linearly related to the quick look AE(QL)(1/2) and AL(QL)(1/2) indices. The best correlation (0.86) is found between the energy flux above 10 keV and the AL(QL) index, which reflects that the energetic electron precipitation modulates the westward electrojet intensity by affecting the Hall conductance. The AU(QL) index which reflects the eastward electrojet intensity shows poor correlation with U-A, either for soft or energetic electrons. This is consistent with an electric field dominance in the dusk sector and a minor role for auroral conductance in the eastward electrojet. On the basis of ionospheric electrodynamics, we argue that a nonlinear relation between U-A and AE (and AL) is more appropriate than a linear relation. We show that the linear relations reported by others do not fit our data set and that they provide U-A values which are too low. For the total electron energy flux (0.1-100 keV) we find the best fit to be U-A[GW] = 4.4 AL(QL)(1/2)-7.6, with a correlation coefficient of 0.83, which is slightly better than that for the AE(QL) index (0.77). By time-integrating the U-A derived from AL(QL), we obtain estimates of the total deposited energy during substorms within +/-20% of the time-integrated U-A derived from UV and X rays. C1 Univ Oslo, Dept Phys, Oslo, Norway. Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Ostgaard, N (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Code 690,Bldg 2, Greenbelt, MD 20771 USA. NR 25 TC 29 Z9 30 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP PY 2002 VL 107 IS A9 AR 1246 DI 10.1029/2001JA002003 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 634MN UT WOS:000180343700022 ER PT J AU Bar-Itzhack, IY Harman, RR AF Bar-Itzhack, IY Harman, RR TI In-space calibration of a skewed gyro quadruplet SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID ANGULAR-RATE ESTIMATION AB A new approach to gyro calibration is presented, where the spacecraft dynamics equation, attitude measurements, and the gyro outputs are used in a pseudolinear Kalman filter that estimates the calibration parameters. Also an algorithm is presented for calibrating a skewed quadruplet rather than the customary triad gyro set aligned along the body coordinate axes. In particular, a new misalignment error model is derived for this case. The new calibration algorithm is applied to the EOS-AQUA satellite gyros. The effectiveness of the new algorithm is demonstrated through simulations. C1 NASA, Goddard Space Flight Ctr, Natl Res Council Resident Res Associate, Flight Dynam Anal Branch,Guidance Navigat & Contr, Greenbelt, MD 20771 USA. RP Bar-Itzhack, IY (reprint author), NASA, Goddard Space Flight Ctr, Natl Res Council Resident Res Associate, Flight Dynam Anal Branch,Guidance Navigat & Contr, Code 572, Greenbelt, MD 20771 USA. NR 13 TC 9 Z9 9 U1 1 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD SEP-OCT PY 2002 VL 25 IS 5 BP 852 EP 859 DI 10.2514/2.4978 PG 8 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 593WE UT WOS:000178016800003 ER PT J AU Marzocca, P Librescu, L Silva, WA AF Marzocca, P Librescu, L Silva, WA TI Flutter, postflutter, and control of a supersonic wing section SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID AEROELASTIC ANALYSIS AB A number of issues related to the flutter and postflutter of two-dimensional supersonic lifting surfaces are addressed. Among them there are the 1) investigation of the implications of the nonlinear unsteady aerodynamics and structural nonlinearities on the stable/unstable character of the limit cycle and 2) study of the implications of the incorporation of a control capability on both the flutter boundary and the postflutter behavior. To this end, a powerful methodology based on the Lyapunov first quantity is implemented. Such a treatment of the problem enables one to get a better understanding of the various factors involved in the nonlinear aeroelastic problem, including the stable and unstable limit cycle. In addition, it constitutes a first step toward a more general investigation of nonlinear aeroclastic phenomena of three-dimensional lifting surfaces. C1 Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. NASA, Langley Res Ctr, Aeroelastic Branch,Struct & Mat Competency, Hampton, VA 23681 USA. RP Marzocca, P (reprint author), Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. NR 26 TC 30 Z9 31 U1 1 U2 7 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD SEP-OCT PY 2002 VL 25 IS 5 BP 962 EP 970 DI 10.2514/2.4970 PG 9 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 593WE UT WOS:000178016800016 ER PT J AU Qu, TD Lindstrom, EJ AF Qu, TD Lindstrom, EJ TI A climatological interpretation of the circulation in the Western South Pacific SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID EAST AUSTRALIAN CURRENT; TOTAL GEOSTROPHIC CIRCULATION; GREAT BARRIER-REEF; EQUATORIAL PACIFIC; INTERMEDIATE WATER; OCEAN CIRCULATION; PHILIPPINE COAST; FLOW PATTERNS; WORLD OCEAN; TRANSPORTS AB Time-averaged circulation is examined using historical hydrographic data near the Australia and Papua New Guinea coast in the Pacific. By averaging the data along isopycnal surfaces in a 0.5degrees x 0.5degrees grid, the authors are able to show many detailed phenomena associated with the narrow western boundary currents, including the vertical structure of the bifurcation latitude of the South Equatorial Current (SEC) and the connection between the Solomon and Coral Seas. The bifurcation latitude of the SEC is found to move southward from about 15degreesS near the surface to south of 22degreesS in the intermediate layers. The origin of the Great Barrier Reef Undercurrent (GBRUC) is identified to be at about 22degreesS. Farther to the north, the GBRUC intensifies underlying the surface East Australian Current, and merges with the North Queensland Current (NQC) at about 15degreesS. The NQC turns eastward to flow along the Papua New Guinea coast and feeds into the New Guinea Coastal Undercurrent (NGCUC) through the Louisiade Archipelago. Further analysis shows that there is a strong water property connection between the Coral and Solomon Seas, confirming the earlier speculation on the water mass origins of the NGCUC. C1 Univ Hawaii Manoa, Int Pacific Res Ctr, SOEST, Honolulu, HI 96822 USA. NASA, Off Earth Sci, Washington, DC 20546 USA. RP Qu, TD (reprint author), Univ Hawaii Manoa, Int Pacific Res Ctr, SOEST, 2525 Correa Rd, Honolulu, HI 96822 USA. EM tangdong@soest.hawaii.edu NR 49 TC 57 Z9 59 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD SEP PY 2002 VL 32 IS 9 BP 2492 EP 2508 DI 10.1175/1520-0485-32.9.2492 PG 17 WC Oceanography SC Oceanography GA 588GX UT WOS:000177694700005 ER PT J AU Hansen, DL Stolte, WC Hemmers, O Guillemin, R Lindle, DW AF Hansen, DL Stolte, WC Hemmers, O Guillemin, R Lindle, DW TI Anion formation moderated by post-collision interaction following core-level photoexcitation of CO SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID INNER-SHELL PHOTOIONIZATION; POST-COLLISION INTERACTION; AR L-SHELL; AUGER DECAY; K-EDGE; SPECTROSCOPY; EXCITATION; PHOTOFRAGMENTATION; FRAGMENTATION; RECAPTURE AB The photon-energy dependence of the oxygen-anion (O-) yield has been measured following photoexcitation of CO just above both the C and 0 K-shell ionization thresholds. The observed exponentially decaying yields above both edges are attributed to a post-collision interaction (PCI) between the emitted photoelectron and the CO molecule. Using a modified semi-classical atomic model, the near-threshold spectra can be reproduced if an energy shift is included. The shift in photon energy above the C K edge is greater than above the 0 K edge. The difference is attributed to a site-dependent PCI effect related to the polarity of the valence orbitals of the CO molecule. C1 Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. Univ Nevada, Dept Chem, Las Vegas, NV 89154 USA. RP Hansen, DL (reprint author), Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. NR 27 TC 22 Z9 22 U1 1 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD SEP PY 2002 VL 35 IS 17 BP L381 EP L386 AR PII S0953-4075(02)36688-4 DI 10.1088/0953-4075/35/17/101 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 703XH UT WOS:000184307300001 ER PT J AU Jenkins, C AF Jenkins, C TI Introduction: Design of Gossamer spacecraft SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Editorial Material C1 S Dakota Sch Mines & Technol, Rapid City, SD USA. NASA, Marshall Space Flight Ctr, Huntsville, AL USA. RP Jenkins, C (reprint author), S Dakota Sch Mines & Technol, Rapid City, SD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2002 VL 39 IS 5 BP 645 EP 645 DI 10.2514/2.3866 PG 1 WC Engineering, Aerospace SC Engineering GA 605LL UT WOS:000178679300001 ER PT J AU Jenkins, CH Schur, WW AF Jenkins, CH Schur, WW TI Gore/seam architectures for gossamer structures SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 42nd Structures, Structural Dynamics, and Materials Conference CY APR 16-19, 2001 CL SEATTLE, WASHINGTON SP Amer Inst Aeronatu & Astronaut, ASME, ASCE, AHS, ASC ID MEMBRANES AB Gossamer spacecraft are ultra-low-mass (areal densities <1 kg/m(2)) structures with applications in communications, imaging, and propulsion. Often large, for example, diameters greater than 10 m, aperture architectures can be either filled (monolithic) or sparse (segmented). Although filled apertures provide the greatest performance, manufacture of large monolithic, that is, seamless, apertures is extremely challenging. Gore/seam architectures provide a compromise for fabrication of gossamer spacecraft. Segments (gores) are manufactured and then assembled into a continuous aperture by seaming together the gores. A similar process was chosen for the Inflatable Antenna Experiment and has been used for decades in the fabrication of large high-altitude scientific balloons. The architecture options for design and fabrication of gossamer spacecraft are reviewed, with particular emphasis on precision applications in communications and imaging. The near-term inevitability of seaming as a fabrication method is emphasized, and the point of view is taken of using seams to advantage. The possibility of "active seams" to mitigate some of the aforementioned issues is discussed and extended to go further to find other uses for the active seams. Lessons learned from NASA's high-altitude balloon program are reviewed in improving structural integrity through use of novel gore/seam design. C1 S Dakota Sch Mines & Technol, Compliant Struct Lab, Dept Engn Mech, Rapid City, SD 57701 USA. NASA, Wallops Flight Facil, Lab Phys Sci, Wallops Isl, VA 23337 USA. RP Jenkins, CH (reprint author), S Dakota Sch Mines & Technol, Compliant Struct Lab, Dept Engn Mech, Rapid City, SD 57701 USA. NR 6 TC 7 Z9 7 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2002 VL 39 IS 5 BP 669 EP 673 DI 10.2514/2.3888 PG 5 WC Engineering, Aerospace SC Engineering GA 605LL UT WOS:000178679300005 ER PT J AU Lake, MS Peterson, LD Levine, MB AF Lake, MS Peterson, LD Levine, MB TI Rationale for defining structural requirements for large space telescopes SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 42nd Structures, Structural Dynamics, and Materials Conference CY APR 16-19, 2001 CL SEATTLE, WASHINGTON SP Amer Inst Aeronatu & Astronaut, ASME, ASCE, AHS, ASC AB A rationale is presented for defining structural requirements for future large space telescope systems. The rationale is based on bounding linear analyses for the deformation of telescope mirrors in response to expected on-orbit disturbance loads and consideration of active control systems that partially compensate for these deformations. It is shown that the vibration frequency of the telescope structure, independent of telescope size, determines the passive structural stability and requirements for an active control system. This means that future large telescopes with low vibration frequencies will necessarily allocate increased active control error budget in proportion to the square of the vibration frequency. Parametric analyses are also presented for the vibration response of two representative mirror architectures: a tensioned membrane mirror and a truss-supported segmented mirror. These examples demonstrate that meeting a specified frequency requirement will require a trade between structural mass fraction and depth of the primary mirror support structure regardless of the structural architecture. C1 Composite Technol Dev Inc, Lafayette, CO 80026 USA. Univ Colorado, Dept Aerosp Engn Sci, Boulder, CO 80309 USA. CALTECH, Jet Prop Lab, Sci & Technol Dev Sect, Pasadena, CA 91109 USA. RP Lake, MS (reprint author), Composite Technol Dev Inc, 1505 Coal Creek Dr, Lafayette, CO 80026 USA. NR 11 TC 6 Z9 6 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2002 VL 39 IS 5 BP 674 EP 681 DI 10.2514/2.3889 PG 8 WC Engineering, Aerospace SC Engineering GA 605LL UT WOS:000178679300006 ER PT J AU Lou, M Fang, HF Hsia, LM AF Lou, M Fang, HF Hsia, LM TI Self-rigidizable space inflatable boom SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 42nd Structures, Structural Dynamics, and Materials Conference CY APR 16-19, 2001 CL SEATTLE, WASHINGTON SP Amer Inst Aeronatu & Astronaut, ASME, ASCE, AHS, ASC AB Development of inflatable structures for space applications has progressed rapidly in the past few years. Noticeable advances have been achieved in several key technology areas, such as system concepts, analysis tools, material selection and characterization, and inflation deployment control. However, many challenges remain to be overcome before the inflatable structures can be actually incorporated into space flight systems. One of these challenges is the development of suitable in-space rigidization methods, and many researchers in the space inflatables community are currently working toward this goal. The concept and development of a new type of space inflatable/self-rigidizable structures, called the spring-tape-reinforced. aluminum laminate booms is described. Analysis and test results related to buckling capability, effects of stowage, modal characteristics, and dynamic responses of spring-tape-reinforced aluminum laminate booms are presented and discussed. C1 CALTECH, Jet Prop Lab, Mech Syst Engn & Res Div, Pasadena, CA 91109 USA. Calif State Univ Los Angeles, Dept Engn Mech, Los Angeles, CA 90032 USA. RP Lou, M (reprint author), CALTECH, Jet Prop Lab, Mech Syst Engn & Res Div, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 8 Z9 8 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2002 VL 39 IS 5 BP 682 EP 690 DI 10.2514/2.3890 PG 9 WC Engineering, Aerospace SC Engineering GA 605LL UT WOS:000178679300007 ER PT J AU Jenkins, C AF Jenkins, C TI Introduction: Analysis of gossamer spacecraft SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Editorial Material C1 S Dakota Sch Mines & Technol, Rapid City, SD USA. NASA, Marshall Space Flight Ctr, Huntsville, AL USA. RP Jenkins, C (reprint author), S Dakota Sch Mines & Technol, Rapid City, SD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2002 VL 39 IS 5 BP 710 EP 710 DI 10.2514/2.3868 PG 1 WC Engineering, Aerospace SC Engineering GA 605LL UT WOS:000178679300011 ER PT J AU Salama, M Fang, H Lou, M AF Salama, M Fang, H Lou, M TI Resistive deployment of inflatable structures using Velcro SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 42nd Structures, Structural Dynamics, and Materials Conference CY APR 16-19, 2001 CL SEATTLE, WASHINGTON SP Amer Inst Aeronatu & Astronaut, ASME, ASCE, AHS, ASC ID STRENGTH AB To explain the dynamics of Velcro-controlled deployment of inflatable structures, we first examine various mechanisms involved in Velcro delamination. Unlike adhesive joints, it is found that Velcro has unique characteristics, wherein multiple load-carrying mechanisms are sequentially engaged to resist separation. Both tests and analysis suggest that a strength criterion based on the strain energy density dissipated during separation can best capture these mechanisms. A finite element model of Velcro interfaces is also used, along with a finite volume inflation model, to simulate the deployment behavior of Velcro-controlled inflatable structures. Although it is essential to determine whether a selected type of Velcro will deploy, it is of equal interest to the designer to assess the rate of deployment. To this end, simulation results show that, consistent with the proposed strength criterion, the average rate of energy dissipation at the Velcro interface also seems to be the most sensitive measure of the rate of Velcro-controlled deployment. C1 CALTECH, Jet Prop Lab, Mech Engn Sect, Pasadena, CA 91109 USA. CALTECH, Jet Prop Lab, Gossamer Syst Grp, Pasadena, CA 91109 USA. CALTECH, Jet Prop Lab, Mech Syst & Res Div, Pasadena, CA 91109 USA. RP Salama, M (reprint author), CALTECH, Jet Prop Lab, Mech Engn Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 4 Z9 7 U1 2 U2 6 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2002 VL 39 IS 5 BP 711 EP 716 DI 10.2514/2.3869 PG 6 WC Engineering, Aerospace SC Engineering GA 605LL UT WOS:000178679300012 ER PT J AU Blandino, JR Johnston, JD Dharamsi, UK AF Blandino, JR Johnston, JD Dharamsi, UK TI Corner wrinkling of a square membrane due to symmetric mechanical loads SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 42nd Structures, Structural Dynamics, and Materials Conference CY APR 16-19, 2001 CL SEATTLE, WASHINGTON SP Amer Inst Aeronatu & Astronaut, ASME, ASCE, AHS, ASC AB Thin-film membrane structures are under consideration for use in many future gossamer spacecraft systems. Examples include sunshields for large-aperture telescopes, solar sails, and membrane optics. The development of capabilities for testing and analyzing pretensioned, thin-film membrane structures is an important and challenging aspect of gossamer spacecraft technology development. Results are presented from experimental and computational studies performed to characterize the wrinkling behavior of thin-film membranes under mechanical loading. The test article is a 500-mm-square Kapton((R)) membrane subjected to symmetric corner loads. Data are presented for loads ranging from 0.49 to 4.91 N. The experimental results show that as the load increases the number of wrinkles increases, while the wrinkle amplitude decreases. The computational model uses a finite element implementation of Stein-Hedgepeth membrane wrinkling theory to predict the behavior of the membrane. Comparisons were made with experimental results for the wrinkle angle and wrinkled region. There was reasonably good agreement between the measured wrinkle angle and the predicted directions of the major principle stresses. The shape of the wrinkled region predicted by the finite element model matches that observed in the experiments; however, the size of the predicted region is smaller that that determined in the experiments. C1 James Madison Univ, Integrated Sci & Technol Program, MSC 4102, Harrisonburg, VA 22807 USA. NASA, Goddard Space Flight Ctr, Mech Syst Anal & Simulat Branch, Greenbelt, MD 20771 USA. RP Blandino, JR (reprint author), James Madison Univ, Integrated Sci & Technol Program, MSC 4102, Harrisonburg, VA 22807 USA. NR 17 TC 27 Z9 29 U1 0 U2 6 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2002 VL 39 IS 5 BP 717 EP 724 DI 10.2514/2.3870 PG 8 WC Engineering, Aerospace SC Engineering GA 605LL UT WOS:000178679300013 ER PT J AU Smalley, KB Tinker, ML AF Smalley, KB Tinker, ML TI Nonlinear pressurization and modal analysis procedure for dynamic modeling of inflatable structures SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 42nd Structures, Structural Dynamics, and Materials Conference CY APR 16-19, 2001 CL SEATTLE, WASHINGTON SP Amer Inst Aeronatu & Astronaut, ASME, ASCE, AHS, ASC ID POWER AB An introduction and set of guidelines for finite element dynamic modeling of nonrigidized inflatable structures are provided. A two-step approach is presented, involving 1) nonlinear static pressurization of the structure and updating of the stiffness matrix and 2) linear normal modes analysis using the updated stiffness. Advantages of this approach are that it provides physical realism in modeling of pressure stiffening and it maintains the analytical convenience of a standard linear eigensolution once the stiffness has been modified. Demonstration of the approach is accomplished through the creation and test verification of an inflated cylinder model using a large commercial finite element code. Good frequency and mode shape comparisons are obtained with test data and previous modeling efforts, verifying the accuracy of the technique. Problems encountered in the application of the approach, as well as their solutions, are discussed in detail. C1 Clarkson Univ, Potsdam, NY 13699 USA. NASA, George C Marshall Space Flight Ctr, Struct Dynam & Loads Grp ED21, Huntsville, AL 35812 USA. RP Smalley, KB (reprint author), Clarkson Univ, Potsdam, NY 13699 USA. NR 37 TC 5 Z9 9 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2002 VL 39 IS 5 BP 732 EP 739 DI 10.2514/2.3872 PG 8 WC Engineering, Aerospace SC Engineering GA 605LL UT WOS:000178679300015 ER PT J AU Farrell, WM Tribble, AC Steinberg, JT AF Farrell, WM Tribble, AC Steinberg, JT TI Similarities in the plasma wake of the moon and space shuttle SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID ELECTRON-TEMPERATURE ENHANCEMENT; LUNAR WAKE; EXPANSION; ORBITER; SATELLITE; VACUUM AB As a result of the Wind spacecraft encounters with the moon, a new view of the lunar wake in the high-density solar wind plasma has emerged. Specifically, the lunar wake was considered to be magnetosonic in nature but is now demonstrated to be a kinetically driven structure filling in via ion sonic disturbances. The structure appears to be determined via kinetic plasma microinstabilities, rather than a bulk magnetohydrodynamic shock. Examining the specific structure, it becomes apparent that the lunar wake and that of the space shuttle have many similarities, suggesting that the shuttle wake is also driven via kinetic instabilities. Comparisons of the two wakes are presented in detail, illustrating the dominance of the kinetic phenomena in the replenishment of both plasma voids. The general concepts presented in this study have applications to other structures immersed in a plasma How, including the space station. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Rockwell Collins, Ctr Adv Technol, Cedar Rapids, IA 52498 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Farrell, WM (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RI Farrell, William/I-4865-2013 NR 23 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2002 VL 39 IS 5 BP 749 EP 754 DI 10.2514/2.3874 PG 6 WC Engineering, Aerospace SC Engineering GA 605LL UT WOS:000178679300017 ER PT J AU Boardsen, SA Kessel, RL AF Boardsen, SA Kessel, RL TI Spin index determination of the Hawkeye spacecraft SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB We have developed a method to despin data from the Hawkeye spacecraft (1974-1978) that involves analyzing the variation of solar array voltage with sun phase angle. This new method is needed because the optical aspect system on the Hawkeye spacecraft failed four months into its mission, after which the spacecraft spin index could be determined only for limited periods using two other methods. Adding our new solar array technique nearly doubles the available data. The Hawkeye mission was designed to study high-latitude, high-altitude magnetosphere (exterior cusp, surrounding magnetopause and boundary layers, the polar cap, and Auroral field lines). The scientific payload was designed to measure the in situ plasma, magnetic, and electric fields. Besides Hawkeye, only the Highly Eccentric Orbiting Satellite-2 (HEOS-2) systematically explored this region of the Earth's geospace. Determining the spin index for the rest of the data, and subsequently despinning these data and representing them in a geophysically meaningful coordinate system, is still important due to the uniqueness of Hawkeye's orbit. The solar array method presented is based on searching parameter space for the solution that results in the best self-organization in spin index of the solar array voltage measurements. The spin index computed using this method is compared against the spin index determined from other methods. The resulting despun magnetic field data are compared with magnetic field models and with in situ magnetic field measurements in the solar wind made by the IMP-8 spacecraft. C1 NASA, Goddard Space Flight Ctr, Branch 632, L3 Commun Analyt Corp, Greenbelt, MD 20770 USA. RP Boardsen, SA (reprint author), NASA, Goddard Space Flight Ctr, Branch 632, L3 Commun Analyt Corp, Greenbelt, MD 20770 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2002 VL 39 IS 5 BP 780 EP 787 DI 10.2514/2.3879 PG 8 WC Engineering, Aerospace SC Engineering GA 605LL UT WOS:000178679300021 ER PT J AU Tartabini, PV Wurster, KE Korte, JJ Lepsch, RA AF Tartabini, PV Wurster, KE Korte, JJ Lepsch, RA TI Multidisciplinary analysis of a lifting body launch vehicle SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT 38th Aerospace Sciences Meeting CY JAN 10-13, 2000 CL RENO, NEVADA ID DESIGN; PROPULSION; SELECTION AB As part of phase 2 of the X-33 Program, NASA selected an integrated lifting body/aerospike engine configuration as the study vehicle for the conceptual analysis of a single-stage-to-orbit reusable launch vehicle. A team at NASA Langley Research Center participated in the screening and evaluation of a number of proposed vehicle configurations in the early phases of the conceptual design process. The performance analyses that supported these studies were conducted to assess the effect of the vehicle's lifting capability, linear aerospike engine, and metallic thermal protection system on the weight and performance of the vehicle. These performance studies were conducted in a multidisciplinary fashion that indirectly linked the trajectory optimization with weight estimation and aerothermal analysis tools. This approach was necessary to develop optimized ascent and entry trajectories that met all vehicle design constraints. Significant improvements in ascent performance were achieved when the vehicle Hew a lifting trajectory and varied the engine mixture ratio during flight. Also, a considerable reduction in empty weight was possible by adjusting the total oxidizer-to-fuel and liftoff thrust-to-weight ratios. However, the optimal ascent flight profile had to be altered to ensure that the vehicle could be trimmed in pitch using only the How diverting capability of the aerospike engine. Likewise, the optimal entry trajectory had to be tailored to meet thermal protection system heating rate and transition constraints while satisfying a crossrange requirement. C1 NASA, Langley Res Ctr, Vehicle Anal Branch, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Multidisciplinary Optimizat Branch, Hampton, VA 23681 USA. RP Tartabini, PV (reprint author), NASA, Langley Res Ctr, Vehicle Anal Branch, Mail Stop 365, Hampton, VA 23681 USA. NR 19 TC 8 Z9 8 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2002 VL 39 IS 5 BP 788 EP 795 DI 10.2514/2.3880 PG 8 WC Engineering, Aerospace SC Engineering GA 605LL UT WOS:000178679300022 ER PT J AU Librescu, L Marzocca, P Silva, WA AF Librescu, L Marzocca, P Silva, WA TI Supersonic/hypersonic flutter and postflutter of geometrically imperfect circular cylindrical panels SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID AEROELASTIC ANALYSIS; SUPERSONIC FLUTTER; COMPOSITE PANELS; FLOW AB A theoretical investigation of the flutter and postflutter of infinitely long thin-walled circular cylindrical panels in a supersonic/hypersonic flowfield is presented. In this context, third-order piston theory and shock wave aerodynamics are used in conjunction with the geometrically nonlinear shell theory to obtain the pertinent aeroelastic governing equations. The effects of in-plane edge restraints and small initial geometric imperfections are also considered in the model. The objective is twofold: 1) to analyze the implications of nonlinear unsteady aerodynamics and structural nonlinearities on the character of the flutter instability boundary and 2) to outline the effects played, in the same respect, by a number of important geometrical, physical, and aerodynamic parameters characterizing the aeroelastic system. As a by-product of this analysis, the implications of these parameters on the linearized flutter instability behavior of the system are captured and emphasized. The behavior of the aeroelastic system in the vicinity of the flutter boundary is studied via the use of an encompassing methodology based on the Lyapunov first quantity. Numerical illustrations, supplying pertinent information on the implications of geometric and aerodynamic nonlinearities, as well as of other effects, such as curvature and thickness ratios, on the flutter instability and on the character of the flutter boundary are examined, and pertinent conclusions are outlined. C1 Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. NASA, Langley Res Ctr, Aeroelastic Branch, Struct & Mat Competency, Hampton, VA 23681 USA. RP Librescu, L (reprint author), Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. NR 47 TC 29 Z9 33 U1 0 U2 4 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2002 VL 39 IS 5 BP 802 EP 812 DI 10.2514/2.3882 PG 11 WC Engineering, Aerospace SC Engineering GA 605LL UT WOS:000178679300024 ER PT J AU Street, KW Hovanitz, ES Chi, SL AF Street, KW Hovanitz, ES Chi, SL TI Lead removal from synthetic leachate matrices by a novel ion-exchange material SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article ID SOLID-PHASE SPECTROPHOTOMETRY; FILMS AB This paper discusses the application of a novel polyacrylate-based ion-exchange material for the removal of Pb ions from water. Preliminary testing includes the establishment of the operating pH range, capacity information, and the effect of Ca2+ and anions in the matrix. Batch testing with powder indicates slightly different optimal operational conditions from those used for column testing. The ion-exchanger is excellent for removing Pb from aqueous solutions. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Englehard Corp, Elyria, OH USA. Eli Lily & Co, Clinton, IN USA. RP Street, KW (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 17 TC 3 Z9 3 U1 0 U2 1 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA ONE GATEWAY CENTER, THIRD FL, PITTSBURGH, PA 15222 USA SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD SEP PY 2002 VL 52 IS 9 BP 1075 EP 1082 PG 8 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 592JE UT WOS:000177933800009 PM 12269668 ER PT J AU Ottens, AK Harrison, WW Griffin, TP Helms, WR AF Ottens, AK Harrison, WW Griffin, TP Helms, WR TI Real-time quantitative analysis of H-2, He, O-2 and Ar by quadrupole ion trap mass spectrometry SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID PAUL TRAP AB The use of a quadrupole ion trap mass spectrometer (QITMS) for quantitative analysis of hydrogen and helium as well as of other permanent gases is demonstrated. Like commercial instruments, the customized QITMS uses mass selective instability; however, this instrument operates at a greater trapping frequency and without a buffer gas. Thus, a useable mass range from 2 to over 50 daltons (Da) is achieved. The performance of the ion trap is evaluated using part-per-million (ppm) concentrations of hydrogen, helium, oxygen, and argon mixed into a nitrogen gas stream, as outlined by the National Aeronautics and Space Administration (NASA), which is interested in monitoring for cryogenic fuel leaks within the Space Shuttle during launch preparations. When quantitating the four analytes, relative accuracy and precision were better than the NASA-required minimum of 10% error and 5% deviation, respectively. Limits of detection were below the NASA requirement of 25-ppm hydrogen and 100-ppm helium; those for oxygen and argon were within the same order of magnitude as the requirements. These results were achieved at a fast data recording rate, and demonstrate the utility of the QITMS as a real-time quantitative monitoring device for permanent gas analysis. (J Am Soc Mass Spectrom 2002, 13, 1120-1128) (C) 2002 American Society for Mass Spectrometry. C1 Univ Florida, Dept Chem, Gainesville, FL 32611 USA. Dynacs Inc, Kennedy Space Ctr, FL USA. NASA, Kennedy Space Ctr, FL USA. RP Univ Florida, Dept Chem, POB 117200, Gainesville, FL 32611 USA. EM harrison@chem.ufl.edu RI Ottens, Andrew/K-3352-2012 NR 21 TC 10 Z9 11 U1 1 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1044-0305 EI 1879-1123 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD SEP PY 2002 VL 13 IS 9 BP 1120 EP 1128 AR PII S1044-0305(02)00431-2 DI 10.1016/S1044-0305(02)00431-2 PG 9 WC Biochemical Research Methods; Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Biochemistry & Molecular Biology; Chemistry; Spectroscopy GA 594ZW UT WOS:000178083200011 PM 12322959 ER PT J AU Randel, WJ Wu, F Stolarski, R AF Randel, WJ Wu, F Stolarski, R TI Changes in column ozone correlated with the stratospheric EP flux SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Article; Proceedings Paper CT International Symposium on Stratospheric Variations and Climate CY NOV 12-15, 2002 CL FUKUOKA, JAPAN ID GLOBAL VARIATIONS; VARIABILITY; TEMPERATURE; SIMULATION; DEPLETION; TRENDS; N2O AB Variability in planetary wave forcing from the troposphere to the stratosphere is reflected in changes in ozone transport, due. to fluctuations in the stratospheric Brewer-Dobson circulation and eddy mixing. This work examines the space-time patterns of correlations between column ozone tendency and planetary wave Eliassen-Palm (EP) flux into the lower stratosphere, using monthly mean data for 1979-2000. Strong correlations are found during winter-spring in both hemispheres, with out-of-phase ozone changes between the tropics and middle-high latitudes. Springtime polar ozone is strongly influenced by wave forcing in both the Arctic and Antarctic. The ozone tendency-wave forcing correlations are combined with observed variations in EP flux to estimate the dynamic contribution to decadal-scale NH ozone trends. These calculations suggest that interannual. changes in EP flux contribute similar to20-30% of the observed trends in column ozone over 35-60degreesN during the past two decades. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Randel, WJ (reprint author), Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. RI Stolarski, Richard/B-8499-2013; Randel, William/K-3267-2016 OI Stolarski, Richard/0000-0001-8722-4012; Randel, William/0000-0002-5999-7162 NR 30 TC 118 Z9 127 U1 0 U2 9 PU METEOROLOGICAL SOC JPN PI TOKYO PA C/O JPN METEOROL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO, JAPAN SN 0026-1165 J9 J METEOROL SOC JPN JI J. Meteorol. Soc. Jpn. PD SEP PY 2002 VL 80 IS 4B BP 849 EP 862 DI 10.2151/jmsj.80.849 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 615FN UT WOS:000179235300007 ER PT J AU Rind, D Lonergan, P Balachandran, NK Shindell, D AF Rind, D Lonergan, P Balachandran, NK Shindell, D TI 2 x CO2 and solar variability influences on the troposphere through wave-mean flow interactions SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Article; Proceedings Paper CT International Symposium on Stratospheric Variations and Climate CY NOV 12-15, 2002 CL FUKUOKA, JAPAN ID MIDDLE ATMOSPHERE MODEL; CLIMATE-CHANGE; EXTRATROPICAL CIRCULATION; STRATOSPHERE SYSTEM; NORTHERN-HEMISPHERE; CYCLE VARIABILITY; UV VARIABILITY; GREENHOUSE-GAS; ANNULAR MODES; WINTER AB A variety of climate forcings are now thought to be able to influence planetary wave dynamics in the troposphere by affecting the propagation of planetary waves out of the troposphere. However, this propagation pattern is sensitive to the details of the corresponding zonal wind changes. Here we discuss two forcing mechanisms that alter zonal winds and subsequent tropospheric responses: changes in atmospheric CO2 concentrations, and solar forcing in conjunction with the QBO. Increased atmospheric CO2 concentrations can be shown to influence planetary wave refraction so as to produce an intensified residual circulation in the subtropical lower stratosphere (which increases transport of tropospheric species into the stratosphere). In our GCM experiments, the low latitude response appears qualitatively robust over a wide range of tropical warming magnitudes, although the quantitative circulation change depends upon the degree of tropical warming as influenced by convection and cloud cover changes;it varies by a factor of three with a factor of three change in tropical warming. At higher latitudes, this equatorward planetary wave refraction has been associated with an increase in the high phase of the Arctic Oscillation. In the model experiments, the extratropical response depends upon the magnitude of both low and high latitude warming in the troposphere; with SST and sea ice changes that result in a weaker Hadley Cell and greater high latitude warming, the Arctic Oscillation phase change may be negative. The QBO alters the latitudinal gradient of the zonal wind in the stratosphere, and solar heating, in association with ozone response, alters the vertical gradient of the zonal wind. Both gradients affect the refractive properties of planetary waves uniquely for each individual combination of tropical east/west winds and solar maximum/minimum activity. In the model, when we consider solar maximum compared to solar minimum conditions, the east (west) phase of the QBO results in a relative high (low) phase of the Arctic Oscillation with corresponding temperature changes. Observed and modeled surface air temperature variations calculated between the solar cycle extremes in the different QBO phases are similar in magnitude to those derived from regression of monthly data on the AO, both being on the order of observed interannual variations. C1 Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Rind, D (reprint author), Columbia Univ, NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. RI Shindell, Drew/D-4636-2012 NR 28 TC 19 Z9 19 U1 0 U2 1 PU METEOROLOGICAL SOC JPN PI TOKYO PA C/O JPN METEOROL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO, JAPAN SN 0026-1165 J9 J METEOROL SOC JPN JI J. Meteorol. Soc. Jpn. PD SEP PY 2002 VL 80 IS 4B BP 863 EP 876 DI 10.2151/jmsj.80.863 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 615FN UT WOS:000179235300008 ER PT J AU Guerra, A Schmidt, C McClure, JC Murr, LE Nunes, AC AF Guerra, A Schmidt, C McClure, JC Murr, LE Nunes, AC TI Flow patterns during friction stir welding SO MATERIALS CHARACTERIZATION LA English DT Article DE friction stir welding; transitional zone; rotational zone; flow ID HYPERVELOCITY IMPACT; COPPER AB Friction stir welding (FSW) is a relatively new technique for welding that uses a cylindrical pin or nib inserted along the weld seam. The nib (usually threaded) and the shoulder in which it is mounted are rapidly rotated and advanced along the seam. Extreme deformation takes place, leaving a fine equiaxed structure in the weld region. The flow of metal during FSW is investigated using a faying surface tracer and a nib frozen in place during welding. It is shown that the material is transported by two processes. The first is a wiping of material from the advancing front side of the nib onto a zone of material that rotates and advances with the nib. The material undergoes a helical motion within the rotational zone that both rotates, advances, and descends in the wash of the threads on the nib and rises on the outer part of the rotational zone. After one or more rotations, this material is sloughed off in its wake of the nib, primarily on the advancing side. The second process is an entrainment of material from the front retreating side of the nib that fills in between the sloughed off pieces from the advancing side. (C) 2002 Elsevier Science Inc. All rights reserved. C1 Univ Texas, Dept Met & Mat Engn, El Paso, TX 79968 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Murr, LE (reprint author), Univ Texas, Dept Met & Mat Engn, El Paso, TX 79968 USA. OI Murr, Lawrence/0000-0001-5942-8376 NR 16 TC 76 Z9 76 U1 4 U2 21 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1044-5803 J9 MATER CHARACT JI Mater. Charact. PD SEP PY 2002 VL 49 IS 2 BP 95 EP 101 DI 10.1016/S1044-5803(02)00362-5 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Materials Science; Metallurgy & Metallurgical Engineering GA 655YK UT WOS:000181580700002 ER PT J AU Harris, JD Eckles, WE Hepp, AF Duraj, SA Fanwick, PE Richardson, J Gordon, EM AF Harris, JD Eckles, WE Hepp, AF Duraj, SA Fanwick, PE Richardson, J Gordon, EM TI Room temperature dissolution of metal powders by thiourea: a novel route to transition metal isothiocyanate complexes (vol 22, pg 625, 2001) SO MATERIALS & DESIGN LA English DT Correction C1 Cleveland State Univ, Dept Chem, Cleveland, OH 44115 USA. NASA, Glenn Res Ctr, Thin Film Technol Grp, Cleveland, OH 44135 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. Univ Louisville, Dept Chem, Louisville, KY 40292 USA. Wilberforce Univ, Div Nat Sci, Wilberforce, OH 45384 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0261-3069 J9 MATER DESIGN JI Mater. Des. PD SEP PY 2002 VL 23 IS 6 BP 581 EP 581 AR PII S0261-3069(01)00094-2 DI 10.1016/S0261-3069(01)00094-2 PG 1 WC Materials Science, Multidisciplinary SC Materials Science GA 596HC UT WOS:000178158000010 ER PT J AU Brown, J Sorkin, S Latombe, JC Montgomery, K Stephanides, M AF Brown, J Sorkin, S Latombe, JC Montgomery, K Stephanides, M TI Algorithmic tools for real-time microsurgery simulation SO MEDICAL IMAGE ANALYSIS LA English DT Article; Proceedings Paper CT Conference on Medical Image Computing and Computer-Assisted Intervention CY OCT, 2001 CL UTRECHT, NETHERLANDS DE microsurgery; computer simulation; surgical training ID COLLISION DETECTION; VIRTUAL-REALITY; SURGERY; DEFORMATIONS; MODEL AB Today, there is growing interest in computer surgical simulation to enhance surgeons' training. This paper presents a simulation system based on novel algorithms for animating instruments interacting with deformable tissue in real-time. The focus is on computing the deformation of a tissue subject to external forces, and detecting collisions among deformable and rigid objects. To achieve real-time performance, the algorithms take advantage of several characteristics of surgical training: (1) visual realism is more important than accurate, patient-specific simulation; (2) most tissue deformations are local; (3) human-body tissues are well damped; and (4) surgical instruments have relatively slow motions. Each key algorithm is described in detail and quantitative performance-evaluation results are given. The specific application considered in this paper is microsurgery, in which the user repairs a virtual severed blood vessel using forceps and a suture (micro-anastomosis). Microsurgery makes it possible to demonstrate several facets of the simulation algorithms, including the deformations of the blood vessel and the suture, and the collisions and interactions between the vessel, the forceps, and the suture. Validation of the overall microsurgery system is based on subjective analysis of the simulation's visual realism by different users. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Dept Comp Sci, Stanford, CA 94305 USA. NASA, Natl Biocomputat Ctr, Stanford, CA USA. RP Stanford Univ, Dept Comp Sci, Stanford, CA 94305 USA. EM jbrown@cs.stanford.edu FU NLM NIH HHS [NLM-3506] NR 34 TC 30 Z9 35 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1361-8415 EI 1361-8423 J9 MED IMAGE ANAL JI Med. Image Anal. PD SEP PY 2002 VL 6 IS 3 BP 289 EP 300 AR PII S1361-8415(02)00086-5 DI 10.1016/S1361-8415(02)00086-5 PG 12 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging SC Computer Science; Engineering; Radiology, Nuclear Medicine & Medical Imaging GA 612CJ UT WOS:000179056400010 PM 12270233 ER PT J AU Schneider, SM Watenpaugh, DE Lee, SMC Ertl, AC Williams, WJ Ballard, RE Hargens, AR AF Schneider, SM Watenpaugh, DE Lee, SMC Ertl, AC Williams, WJ Ballard, RE Hargens, AR TI Lower-body negative-pressure exercise and bed-rest-mediated orthostatic intolerance SO MEDICINE AND SCIENCE IN SPORTS AND EXERCISE LA English DT Article DE blood pressure; catecholamines; microgravity; epinephrine ID UPRIGHT EXERCISE; CARDIAC ATROPHY; SPACEFLIGHT; RESPONSES; TOLERANCE; ASTRONAUTS AB Purpose: Supine, moderate exercise is ineffective in maintaining orthostatic tolerance after bed rest (BR). Our purpose was to test the hypothesis that adding an orthostatic stress during exercise would maintain orthostatic function after BR. Methods: Seven healthy men completed duplicate 15-d 6degrees head-down tilt BR using a crossover design. During one BR, subjects did not exercise (CON). During another BR, subjects exercised for 40 min(.)d(-1) on a supine treadmill against 50-60 mm Hg LBNP (EX). Exercise training consisted of an interval exercise protocol of 2- to 3-min intervals alternating between 41 and 65% VO2max. Before and after BR, an LBNP tolerance test was performed in which the LBNP chamber was decompressed in 10-mm Hg stages every 3 min until presyncope. Results: LBNP tolerance, as assessed by the cumulative stress index (CSI) decreased after BR in both the CON (830 +/- 144, pre-BR vs 524 +/- 56 mm Hg-min, post-BR) and the EX (949 +/- 118 pre-BR vs 560 +/- 44 mm Hg.min, post-BR) conditions. However, subtolerance (0 to -50 mm Hg LBNP) heart rates were lower and systolic blood pressures were better maintained after BR in the EX condition compared with CON. Conclusion: Moderate exercise performed against LBNP simulating an upright 1-g environment failed to protect orthostatic tolerance after 15 d of BR. C1 Univ New Mexico, Dept Human Performance & Dev, Johnson Ctr, Albuquerque, NM 87131 USA. USN, Submarine Med Res Lab, Groton, CT USA. Wyle Life Sci Inc, Houston, TX USA. Vanderbilt Univ, Nashville, TN 37240 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif San Diego, San Diego, CA 92103 USA. RP Schneider, SM (reprint author), Univ New Mexico, Dept Human Performance & Dev, Johnson Ctr, Room 126, Albuquerque, NM 87131 USA. NR 31 TC 26 Z9 26 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0195-9131 J9 MED SCI SPORT EXER JI Med. Sci. Sports Exerc. PD SEP PY 2002 VL 34 IS 9 BP 1446 EP 1453 DI 10.1249/01.MSS.0000027761.31366.06 PG 8 WC Sport Sciences SC Sport Sciences GA 593MR UT WOS:000177995700008 PM 12218737 ER PT J AU Potter, AE Killen, RM Morgan, TH AF Potter, AE Killen, RM Morgan, TH TI The sodium tail of Mercury SO METEORITICS & PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT Workshop on Mercury CY OCT 04-05, 2001 CL FIELD MUSEUM, CHICAGO, ILLINOIS HO FIELD MUSEUM ID ATMOSPHERES; EXOSPHERE AB Mercury is difficult to observe because it is so close to the Sun. However, when the angle of the ecliptic is near maximum in the northern hemisphere, and Mercury is near its greatest eastern elongation, it can be seen against the western sky for about a half hour after sunset. During these times, we were able to map sodium D-2 emission streaming from the planet, forming a long comet-like tail. On 2001 May 26 (U.T.) we mapped the tail downstream to a distance of similar to40 000 km. Sodium velocities in the tail increased to similar to11 km s(-1) at 40 000 km as the result of radiation pressure acceleration. On 2000 June 5 (U.T.) we mapped the cross-sectional extent of the tail at a distance of similar to17 500 km downstream. At this distance, the half-power full-width of the emission was similar to20 000 km. We estimated the transverse velocity of sodium in the tail to range from 2 to 4 km s(-1). The velocities we observed imply source velocities from the planet surface of the order of 5 km s(-1), or 4 eV. Particle sputtering is a likely candidate for production of sodium atoms at these velocities. The total flux of sodium in the tail was similar to1 x 10(23) atoms s(-1), which corresponds to 1 to 10% of the estimated total production rate of sodium on the planet. C1 Natl Solar Observ, Tucson, AZ 85726 USA. SW Res Inst, San Antonio, TX 78228 USA. NASA Headquarters, Washington, DC 20546 USA. RP Potter, AE (reprint author), Natl Solar Observ, POB 26732,950 N Cherry Ave, Tucson, AZ 85726 USA. RI Morgan, Thomas/I-5943-2013 NR 17 TC 59 Z9 59 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2002 VL 37 IS 9 BP 1165 EP 1172 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 598FU UT WOS:000178265900002 ER PT J AU Peale, SJ Phillips, RJ Solomon, SC Smith, DE Zuber, MT AF Peale, SJ Phillips, RJ Solomon, SC Smith, DE Zuber, MT TI A procedure for determining the nature of Mercury's core SO METEORITICS & PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT Workshop on Mercury CY OCT 04-05, 2001 CL FIELD MUSEUM, CHICAGO, IL HO FIELD MUSEUM ID EARTHS CORE; VISCOSITY; MISSION; FIELD AB We review the assertion that the precise measurement of the second degree gravitational harmonic coefficients, the obliquity, and the amplitude of the physical libration in longitude, C-20, C-22, theta, and phi(0), for Mercury are sufficient to determine whether or not Mercury has a molten core (Peale, 1976). The conditions for detecting the signature of the molten core are that such a core not follow the 88-day physical libration of the mantle induced by periodic solar torques, but that it does follow the 250 000-year precession of the spin axis that tracks the orbit precession within a Cassini spin state. These conditions are easily satisfied if the coupling between the liquid core and solid mantle is viscous in nature. The alternative coupling mechanisms of pressure forces on irregularities in the core-mantle boundary (CMB), gravitational torques between an axially asymmetric mantle and an assumed axially asymmetric solid inner core, and magnetic coupling between the conducting molten core and a conducting layer in the mantle at the CMB are shown for a reasonable range of assumptions not to frustrate the first condition while making the second condition more secure. Simulations have shown that the combination of spacecraft tracking and laser altimetry during the planned MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, Ranging) orbiter mission to Mercury will determine C-20, C-22, and theta to better than 1% and phi(0) to better than 8%-sufficient precision to distinguish a molten core and constrain its size. The possible determination of the latter two parameters to 1% or less with Earth-based radar experiments and MESSENGER determination of C-20 and C-22 to 0.1% would lead to a maximum uncertainty in the ratio of the moment of inertia of the mantle to that of the whole planet, C-m/C, of similar to2% with comparable precision in characterizing the extent of the molten core. C1 Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Carnegie Inst Sci, Dept Terr Magnetism, Washington, DC 20015 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. RP Peale, SJ (reprint author), Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. EM peale@io.physics.ucsb.edu NR 40 TC 62 Z9 62 U1 0 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1086-9379 EI 1945-5100 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2002 VL 37 IS 9 BP 1269 EP 1283 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 598FU UT WOS:000178265900011 ER PT J AU Brown, P Campbell, M Suggs, R Cooke, W Theijsmeijer, C Hawkes, RL Jones, J Ellis, KJ AF Brown, P Campbell, M Suggs, R Cooke, W Theijsmeijer, C Hawkes, RL Jones, J Ellis, KJ TI Video and radar observations of the 2000 Leonids: evidence for a strong flux peak associated with 1932 ejecta? SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE techniques : radar astronomy; meteors, meteoroids ID METEOR AB Video and radar observations of the 2000 Leonid shower are presented. We find strong evidence that the first peak in the shower on 2000 November 17 near 8 ut resulting from 1932 ejecta is much stronger than previously recognized and larger than the broader peak on November 18 resulting from 1866 and 1733 ejecta. In particular, we find a TV-radar average peak flux value on November 17 at solar longitude 235degrees.29 +/- 0degrees.02 near 0.15 +/- 0.02 meteoroid km(-2) h (-1)(M (v) > +6.5), which corresponds to a zenithal hourly rate (ZHR) similar to900 assuming a mass index of 1.7. Similarly, we find the second peak on November 18 to be located at 236degrees.26 +/- 0degrees.02 with a maximum flux value of 0.11 +/- 0.02 meteoroid km(-2) h(-1) corresponding to a ZHR of 600. Evidence for this narrower and stronger early peak on November 17 is present in several other observations by radar/radio, although only for data smoothed over 15-min intervals or less. The implications of this higher early peak for the 2000 Leonids associated with 1932 ejecta for predictions and visual observations of the shower in 2002 are briefly discussed. C1 Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. NASA, George C Marshall Space Flight Ctr, Engn Directorate, Huntsville, AL 35812 USA. Comp Sci Corp, Engn Directorate, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Mt Allison Univ, Dept Phys, Sackville, NB E4L 1E6, Canada. Ctr Commun Res, Ottawa, ON, Canada. RP Brown, P (reprint author), Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. NR 22 TC 9 Z9 9 U1 0 U2 0 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP PY 2002 VL 335 IS 2 BP 473 EP 479 DI 10.1046/j.1365-8711.2002.05637.x PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 590YE UT WOS:000177851600023 ER PT J AU Fabian, AC Vaughan, S Nandra, K Iwasawa, K Ballantyne, DR Lee, JC De Rosa, A Turner, A Young, AJ AF Fabian, AC Vaughan, S Nandra, K Iwasawa, K Ballantyne, DR Lee, JC De Rosa, A Turner, A Young, AJ TI A long hard look at MCG-6-30-15 with XMM-Newton SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : active; galaxies : general; galaxies : individual : MCG-6-30-15; galaxies : Seyfert; X-rays : galaxies ID BLACK-HOLE; GALAXY MCG-6-30-15; EMISSION; LINE; DISK AB We present the first results from a 325-ks observation of the Seyfert 1 galaxy MCG-6-30-15 with XMM-Newton and BeppoSAX. The strong, broad, skewed iron line is clearly detected and is well characterized by a steep emissivity profile within 6r(g) (i.e. 6GM/c(2)) and a flatter profile beyond. The inner radius of the emission appears to lie at about 2r(g), consistent with results reported from both an earlier XMM-Newton observation of MCG-6-30-15 by Wilms et al. and part of an ASCA observation by Iwasawa et al. when the source was in a lower flux state. The radius and steep emissivity profile do depend however on an assumed incident power-law continuum and a lack of complex absorption above 2.5 keV. The blue wing of the line profile is indented, either by absorption at about 6.7 keV or by a hydrogenic iron emission line. The broad iron line flux does not follow the continuum variations in a simple manner. C1 Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. CNR, Ist Astrofis Spaziale, Rome, Italy. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England. EM acf@ast.cam.ac.uk RI Turner, Adrian/A-9539-2009 NR 34 TC 219 Z9 223 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP PY 2002 VL 335 IS 1 BP L1 EP L5 DI 10.1046/j.1365-8711.2002.05740.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 589ZB UT WOS:000177790700001 ER PT J AU Popescu, CC Tuffs, RJ AF Popescu, CC Tuffs, RJ TI The percentage of stellar light re-radiated by dust in late-type Virgo Cluster galaxies SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : clusters : individual : Virgo Cluster; galaxies : fundamental parameters; galaxies : photometry; galaxies : spiral; galaxies : statistics; infrared : galaxies ID SPECTRAL ENERGY-DISTRIBUTION; AREA AB We show that the mean percentage of stellar light re-radiated by dust is similar to30 per cent for the Virgo Cluster late-spirals measured with ISOPHOT by Tuffs et al. A strong dependence of this ratio with morphological type was found, ranging from typical values of similar to15 per cent for early spirals to up to similar to50 per cent for some late spirals. The extreme BCDs can have even higher percentages of their bolometric output re-radiated in the thermal infrared. Luminosity correction factors for the cold dust component are given for general use in converting far-infrared (FIR) luminosities derived from IRAS. C1 Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. CALTECH, Jet Prop Lab, IPAC, Pasadena, CA 91125 USA. Romanian Acad, Astron Inst, Bucharest, Romania. Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. RP Popescu, CC (reprint author), Carnegie Inst Washington Observ, 813 Santa Barbara St, Pasadena, CA 91101 USA. NR 25 TC 42 Z9 42 U1 0 U2 1 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP PY 2002 VL 335 IS 2 BP L41 EP L44 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 590YE UT WOS:000177851600001 ER PT J AU Bowman, RC Fultz, B AF Bowman, RC Fultz, B TI Metallic Hydrides I: Hydrogen storage and other gas-phase applications SO MRS BULLETIN LA English DT Article DE hydrogen storage; metal hydrides; neutron scattering ID THERMODYNAMIC PROPERTIES; SYSTEM; ALLOYS; DEGRADATION; BATTERIES; BEHAVIOR; MG AB A brief survey is given of the various classes of metal alloys and compounds that are suitable for hydrogen-storage and energy-conversion applications. Comparisons are made of relevant properties including hydrogen absorption and desorption pressures, total and reversible hydrogen-storage capacity, reaction-rate kinetics, initial activation requirements, susceptibility to contamination, and durability during long-term thermal cycling. Selected applications are hydrogen storage as a fuel, gas separation and purification, thermal switches, and sorption cryocoolers. C1 CALTECH, Jet Prop Lab, ARCS Project, Pasadena, CA 91109 USA. RP Bowman, RC (reprint author), CALTECH, Jet Prop Lab, ARCS Project, Mail Stop 79-24,4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI Bowman, Robert/0000-0002-2114-1713 NR 30 TC 100 Z9 101 U1 2 U2 17 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD SEP PY 2002 VL 27 IS 9 BP 688 EP 693 DI 10.1557/mrs2002.223 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 595EF UT WOS:000178093300016 ER PT J AU Ng, HT Koehne, JE Stevens, RM Li, J Meyyappan, M Han, J AF Ng, HT Koehne, JE Stevens, RM Li, J Meyyappan, M Han, J TI High density array matrices of polymeric structures by ultrathin interfacial layer-mediated double replication approach SO NANO LETTERS LA English DT Article ID ELASTOMERIC POLYMER; ORDERED STRUCTURES; POLYDIMETHYLSILOXANE; LITHOGRAPHY AB We demonstrate here rapid, efficient and reliable fabrication and replication of high density arrays of polymeric structures using ultrathin layer-mediated processes. Highly uniform polymeric structures with submicrometer to nanometer radius-of-curvatures and consistent vertical profiles could be achieved via sequential replication cycles. Highly controllable dry surface treatment has been used to create a chemically inert and stable interfacial zone between two polymers of the same chemical identities to allow simple replica molding and rapid intact release of highly flexible molded polymeric structures. The approach could, in principle, be extended to other systems with appropriate modification of interfacial surface properties. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RI Li, Jun/H-7771-2013 OI Li, Jun/0000-0002-3689-8946 NR 17 TC 4 Z9 4 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 J9 NANO LETT JI Nano Lett. PD SEP PY 2002 VL 2 IS 9 BP 961 EP 964 DI 10.1021/nl025699g PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 593UA UT WOS:000178010900011 ER PT J AU Sullivan, BM Powell, CA AF Sullivan, BM Powell, CA TI Effects of spectrum shape on subjective preference to broadband jet aircraft interior sounds SO NOISE CONTROL ENGINEERING JOURNAL LA English DT Article ID ROOM NOISE CRITERIA; PROPOSED REVISIONS; SYSTEMS; CURVES AB A series of four tests was conducted at NASA-Langley Research Center in the Aircraft Interior Acoustic Simulator using a range of stimuli whose spectrum shapes represent a wide selection of recordings made during cruise in a variety of jet aircraft. These stimuli were broadband in nature and did not contain any audible tonal components. Preference rankings were found for ten stimuli in the first test. The succeeding two tests were designed to determine sound level differences equivalent to the preference rankings. The fourth test extended the range of spectrum shapes and again determined preference rankings and equivalent level differences. The rankings were found to spread over a range of four phons for sounds set at equal calculated Loudness Levels. Metrics that predicted this effect, after loudness had been taken into account using Loudness Level, included Blazier's Quality Assessment Index (QAI), a measure of spectrum balance used in room acoustics. The preferred spectral shapes discovered fit well with the spectra suggested by Beranek for background noise in building spaces. (C) 2002 Institute of Noise Control Engineering. C1 NASA, Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA. RP Sullivan, BM (reprint author), NASA, Langley Res Ctr, Struct Acoust Branch, Mail Stop 463, Hampton, VA 23681 USA. NR 26 TC 2 Z9 2 U1 0 U2 0 PU INST NOISE CONTROL ENGINEERING PI AMES PA IOWA STATE UNIV, COLLEGE ENGINEERING, 212 MARSTON HALL, AMES, IA 50011-2152 USA SN 0736-2501 J9 NOISE CONTROL ENG J JI Noise Control Eng. J. PD SEP-OCT PY 2002 VL 50 IS 5 BP 160 EP 175 DI 10.3397/1.2839688 PG 16 WC Acoustics; Engineering, Multidisciplinary SC Acoustics; Engineering GA 666VM UT WOS:000182197200002 ER PT J AU Tripathi, RK Wilson, JW Cucinotta, FA AF Tripathi, RK Wilson, JW Cucinotta, FA TI A method for calculating proton-nucleus elastic cross-sections SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID MICROSCOPIC CALCULATION; SCATTERING; COLLISIONS; MATTER AB Recently [Nucl. Instr. and Meth. B 145 (1998) 277; Extraction of in-medium nucleon-nucleon amplitude from experiment, NASA-TP, 1998], we developed a method of extracting nucleon-nucleon (N-N) cross-sections in the medium directly from experiment. The in-medium N-N cross-sections form the basic ingredients of several heavy-ion scattering approaches including the coupled-channel approach developed at the NASA Langley Research Center. We investigated [Proton-nucleus total cross-sections in coupled-channel approach, NASA/TP, 2000; Nucl. Instr. and Meth. B 173-174 (2001) 391] the ratio of real to imaginary part of the two body scattering amplitude in the medium. These ratios are used in combination with the in-medium N-N cross-sections to calculate proton-nucleus elastic cross-sections. The agreement is excellent with the available experimental data. These cross-sections are needed for the radiation risk assessment of space missions. (C) 2002 Elsevier Science B.V. All rights reserved. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Lyndon B Johnson Space Ctr, Houston, TX USA. RP Tripathi, RK (reprint author), NASA, Langley Res Ctr, Mail Stop 188B, Hampton, VA 23681 USA. NR 35 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD SEP PY 2002 VL 194 IS 3 BP 229 EP 236 AR PII S0168-583X(02)00690-0 DI 10.1016/S0168-583X(02)00690-0 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 593XM UT WOS:000178019800003 PM 12214634 ER PT J AU Shu, Y Li, BQ de Groh, IC AF Shu, Y Li, BQ de Groh, IC TI Magnetic damping of g-jitter induced double-diffusive convection SO NUMERICAL HEAT TRANSFER PART A-APPLICATIONS LA English DT Article ID CRYSTAL-GROWTH; GRAVITY; MICROGRAVITY; FIELDS AB This article describes a numerical study of g-jitter driven double-diffusive convective flows and thermal and concentration distributions in binary alloy melt systems subject to an external magnetic field. The study is based on the finite element solution of transient magnetohydrodynamic equations governing the momentum, thermal, and solutal transport in the melt pool. Numerical simulations are conducted using synthesized single- and multi-frequency g-jitter as well as real g-jitter data taken during space flights with or without an applied magnetic field. It is found that for the conditions studied, the main melt flow follows approximately a linear superposition of velocity components induced by individual g-jitter components, regardless of whether a magnetic field exists or not. The flow If, field is characterized by a recirculating double-diffusive convection loop oscillating in time with a defined frequency equal to that of the driving g-jitter force. An applied magnetic field has little effect on the oscillating recirculating pattern, except around the moment when the flow reverses its direction. The field has no effect on the oscillation period, but it changes the phase angle. It is very effective in suppressing the flow intensity, and produces a notable reduction of solute striations and time fluctuations in the melt. For a given magnetic field strength, the magnetic damping effect is more pronounced on the velocity associated with the largest g-jitter component present and/or the g-jitter spiking peaks. A stronger magnetic field is more effective in suppressing the melt convection and also is more helpful in bringing the convection in phase with the g-jitter driving force. The applied field is particularly useful in suppressing the effect of real g-jitter spikes on both flow and solutal distributions. With appropriately selected magnetic fields, the convective flows caused by g-jitter can be reduced sufficiently, and it is possible that diffusion dominates the solutal transport in the melt. C1 Washington State Univ, Sch Mech & Mat Engn, Pullman, WA 99164 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Li, BQ (reprint author), Washington State Univ, Sch Mech & Mat Engn, POB 642920, Pullman, WA 99164 USA. NR 16 TC 22 Z9 22 U1 0 U2 1 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1040-7782 J9 NUMER HEAT TR A-APPL JI Numer. Heat Tranf. A-Appl. PD SEP PY 2002 VL 42 IS 4 BP 345 EP 364 DI 10.1080/10407780290059594 PG 20 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA 586XQ UT WOS:000177611800002 ER PT J AU Maiti, A Andzelm, J Svizhenko, A Anantram, MP Panhuis, MIH AF Maiti, A Andzelm, J Svizhenko, A Anantram, MP Panhuis, MIH TI Atomistic simulations with carbon nanotubes - Classical, quantum, and transport modeling SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 3rd Motorola Workshop on Computational Materials and Electronics CY NOV 14-16, 2001 CL TEMPE, ARIZONA SP Motorola ID FIELD-EMISSION; MOLECULAR MECHANICS; ROOM-TEMPERATURE; FORCE-FIELD; SINGLE; POLYMER; GROWTH; MANIPULATION; COMPOSITES; DISPLAY AB Theoretical modeling of carbon nanotubes continues to provide useful insight and guidance to many experimental efforts toward technological applications. Molecular modeling tools have been used to study important structural, electronic, elastic, transport, and growth properties of nanotubes. We report results from three recent simulations: (i) effect of adsorbates on field emission from a nanotube tip; (ii) effect of mechanical deformation and chirality of nanotubes on electronic transport; and (iii) coating and solubilizing nanotubes by a polymer. The reported simulations are based on first principles density functional theory (DFT), classical molecular mechanics, and tight-binding transport based on the Green's function formalism. C1 Accelrys Inc, San Diego, CA 92121 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Dublin Trinity Coll, Dept Phys, Mat Ireland Polymer Res Ctr, Dublin 2, Ireland. RP Maiti, A (reprint author), Accelrys Inc, 9685 Scranton Rd, San Diego, CA 92121 USA. RI in het Panhuis, Marc/D-2590-2012; OI in het Panhuis, Marc/0000-0002-3259-9295 NR 50 TC 6 Z9 6 U1 1 U2 4 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD SEP PY 2002 VL 233 IS 1 BP 49 EP 58 DI 10.1002/1521-3951(200209)233:1<49::AID-PSSB49>3.0.CO;2-8 PG 10 WC Physics, Condensed Matter SC Physics GA 598QF UT WOS:000178287400010 ER PT J AU Luo, LS Girimaji, SS AF Luo, LS Girimaji, SS TI Lattice Boltzmann model for binary mixtures SO PHYSICAL REVIEW E LA English DT Article ID NONIDEAL GASES; FLUID SYSTEMS; LIQUID-GAS; EQUATION; FLOWS; SIMULATIONS; DIFFUSION; AUTOMATA AB An a priori derivation of the lattice Boltzmann equations for binary mixtures is provided by discretizing the Boltzmann equations that govern the evolution of binary mixtures. The present model leads to a set of two-fluid hydrodynamic equations for the mixture. In existing models, employing the single-relaxation-time approximation, the viscosity and diffusion coefficients are coupled through the relaxation parameter tau, thus limited to unity Prandtl number and Schmidt number. In the present model the viscosity and diffusion coefficient are independently controlled by two relaxation parameters, thus enabling the modeling of mixtures with an arbitrary Schmidt number. The theoretical framework developed here can be readily applied to multiple-species mixing. C1 NASA, ICASE, Langley Res Ctr, Hampton, VA 23681 USA. Texas A&M Univ, Dept Aerosp Engn, TAMU 3141, College Stn, TX 77843 USA. RP Luo, LS (reprint author), NASA, ICASE, Langley Res Ctr, Mail Stop 132C,3 W Reid St,Bldg 1152, Hampton, VA 23681 USA. EM luo@icase.edu; girimaji@aero.tamu.edu RI Luo, Li-Shi/A-4561-2011 OI Luo, Li-Shi/0000-0003-1215-7892 NR 34 TC 59 Z9 61 U1 1 U2 13 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD SEP PY 2002 VL 66 IS 3 AR 035301 DI 10.1103/PhysRevE.66.035301 PN 2A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 604MA UT WOS:000178624100007 PM 12366175 ER PT J AU Vassiliadis, D Chang, T Chapman, SC Davidson, RC AF Vassiliadis, D Chang, T Chapman, SC Davidson, RC TI Special topics section: Modes of transport in geospace - Foreword SO PHYSICS OF PLASMAS LA English DT Editorial Material ID SPACE C1 NASA, USRA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. MIT, Cambridge, MA 02139 USA. Univ Warwick, Coventry CV4 7AL, W Midlands, England. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Vassiliadis, D (reprint author), NASA, USRA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Chapman, Sandra/C-2216-2008 OI Chapman, Sandra/0000-0003-0053-1584 NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD SEP PY 2002 VL 9 IS 9 BP 3664 EP 3664 PG 1 WC Physics, Fluids & Plasmas SC Physics GA 586TG UT WOS:000177600700004 ER PT J AU Horton, W Crabtree, C Doxas, I Weigel, RS AF Horton, W Crabtree, C Doxas, I Weigel, RS TI Geomagnetic transport in the solar wind driven nightside magnetosphere-ionosphere system SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT Conference of the American-Geophysical-Union CY DEC 10-14, 2001 CL SAN FRANCISCO, CALIFORNIA SP Amer Geophys Union ID SUBSTORM ONSETS; MAGNETIC-FIELD; PLASMA SHEET; MODEL AB A spatially resolved nonlinear dynamical model of the solar wind driven geomagnetic tail plasma is developed for the purpose of space weather predictions. The model represents the fluctuating electromagnetic fields and high pressure central plasma sheet by a large number (2Nless than or similar to200) of semiglobal coupled current loops ranging from the near-Earth geosynchronous orbit position for substorm dynamics to deep in the geotail. There is a spectrum of dynamical frequencies ranging from 1 h periods to 1 min and shorter periods. The low-frequency modes are global and lead to the dynamics of the low-dimensional (d=6) WINDMI model. The high-frequency dynamics are nonlinear compressional-rarefraction waves propagating up and down the geotail. The localized pulses start from sites of local reconnection set off either by the tearing mode unloading trigger or by localized solar wind disturbances acting on the nightside magnetopause. Larger unloading events lead to nonlinear steepening of the compressional pulsations which act to trigger secondary convection events under certain conditions. (C) 2002 American Institute of Physics. C1 Univ Texas, Inst Fus Studies, Austin, TX 78712 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Horton, W (reprint author), Univ Texas, Inst Fus Studies, Austin, TX 78712 USA. OI Crabtree, Christopher/0000-0002-6682-9992 NR 24 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD SEP PY 2002 VL 9 IS 9 BP 3712 EP 3720 DI 10.1063/1.1499119 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 586TG UT WOS:000177600700011 ER PT J AU Hergenrother, PM Watson, KA Smith, JG Connell, JW Yokota, R AF Hergenrother, PM Watson, KA Smith, JG Connell, JW Yokota, R TI Polyimides from 2,3,3 ',4 '-biphenyltetracarboxylic dianhydride and aromatic diamines SO POLYMER LA English DT Article DE polyimides; low color thin films; structure property relationship ID FILMS; 1,3-BIS(4-AMINOPHENOXY)BENZENE; CRYSTALLIZATION; COPOLYMER; OXIDE AB A series of new polyimides were prepared from the reaction of 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA) with various aromatic diamines. The properties of the a-BPDA polyimides were compared with those of polyimides prepared from the reaction of 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) with the same aromatic diamines. Films of the a-BPDA polyimides had higher glass transition temperatures (T(g)s) and less color than the corresponding s-BPDA polyimide films. Light transmission at 500 nm, solar absorptivity, and thermal emissivity were determined on certain films. Films of similar polyimides based upon a-BPDA and s-BPDA containing meta linkages and others containing para linkages were each cured at 250, 300, and 350 degreesC. The films were characterized primarily by T-g, color, optical transparency, tensile properties, dynamic mechanical thermal analysis, and coefficient of thermal expansion. The a-BPDA meta linked polyimide films had tensile strengths and moduli higher than films of the a-BPDA para linked polyimide. The same phenomenon was not observed for the s-BPDA meta and para linked polyimides. The chemistry, mechanical, and physical properties of the polymers and films are discussed. (C) 2002 Elsevier Science Ltd All rights reserved. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. RP Hergenrother, PM (reprint author), NASA, Langley Res Ctr, 6A W Taylor St Mail Stop 226, Hampton, VA 23681 USA. NR 28 TC 132 Z9 142 U1 5 U2 32 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD SEP PY 2002 VL 43 IS 19 BP 5077 EP 5093 AR PII S0032-3861(02)00362-2 DI 10.1016/S0032-3861(02)00362-2 PG 17 WC Polymer Science SC Polymer Science GA 592UN UT WOS:000177955400003 ER PT J AU D'Sa, EJ Hu, C Muller-Karger, FE Carder, KL AF D'Sa, EJ Hu, C Muller-Karger, FE Carder, KL TI Estimation of colored dissolved organic matter and salinity fields in case 2 waters using SeaWiFS: Examples from Florida Bay and Florida Shelf SO PROCEEDINGS OF THE INDIAN ACADEMY OF SCIENCES-EARTH AND PLANETARY SCIENCES LA English DT Article; Proceedings Paper CT Pan Ocean Remote Sensing Conference (PORSEC) CY DEC, 2000 CL GOA, INDIA DE remote sensing; SeaWiFS; atmospheric correction; chlorophyll a; CDOM; salinity ID OCEAN-COLOR; ATMOSPHERIC CORRECTION; OPTICAL-ABSORPTION; TURBID COASTAL; IMAGERY; PHYTOPLANKTON; REFLECTANCE; ALGORITHMS; RETRIEVAL; SPECTRA AB Estimates of water quality variables such as chlorophyll a concentration (Chl), colored dissolved organic matter (CDOM), or salinity from satellite sensors are of great interest to resource managers monitoring coastal regions such as the Florida Bay and the Florida Shelf. However, accurate estimates of these variables using standard ocean color algorithms have been difficult due to the complex nature of the light field in these environments. In this study, we process SeaWiFS satellite data using two recently developed algorithms; one for atmospheric correction and the other a semi-. analytic bio-optical algorithm and compare the results with standard SeaWiFS algorithms. Overall, the two algorithms produced more realistic estimates of Chl and CDOM distributions in Florida Shelf and Bay waters. Estimates of surface salinity were obtained from the CDOM absorption field assuming a conservative mixing behavior of these Waters. A comparison of SeaWiFS-derived Chl and CDOM absorption with field measurements in the Florida Bay indicated that although well correlated, CDOM was underestimated, while Chl was overestimated. Bottom reflectance appeared to affect these estimates at the shallow central Bay stations during the winter. These results demonstrate the need for new bio-optical algorithms or tuning of the parameters used in the bio-optical, algorithm for local conditions encountered in the Bay. C1 Univ S Florida, Coll Marine Sci, St Petersburg, FL 33701 USA. RP D'Sa, EJ (reprint author), NASA, GB Tech, Earth Sci Applicat Directorate, Bldg 1100, Stennis Space Ctr, MS 39529 USA. RI hu, chuanmin/J-5021-2012 NR 30 TC 31 Z9 31 U1 3 U2 12 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA P B 8005 C V RAMAN AVENUE, BANGALORE 560 080, INDIA SN 0253-4126 J9 P INDIAN AS-EARTH JI Proc. Indian Acad. Sci.-Earth Planet. Sci PD SEP PY 2002 VL 111 IS 3 BP 197 EP 207 PG 11 WC Geosciences, Multidisciplinary SC Geology GA 593CU UT WOS:000177974500003 ER PT J AU Bailey, S AF Bailey, S TI 'Advances in space photovoltaics (2001/02)' SO PROGRESS IN PHOTOVOLTAICS LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Photovolta & Space Environm Branch, Cleveland, OH 44135 USA. RP Bailey, S (reprint author), NASA, Glenn Res Ctr, Photovolta & Space Environm Branch, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD SEP PY 2002 VL 10 IS 6 BP 381 EP 381 DI 10.1002/pip.467 PG 1 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 596KV UT WOS:000178164800001 ER PT J AU Raffaelle, RP Hepp, AF Landis, GA Hoffman, DJ AF Raffaelle, RP Hepp, AF Landis, GA Hoffman, DJ TI Mission applicability assessment of integrated power components and systems SO PROGRESS IN PHOTOVOLTAICS LA English DT Article; Proceedings Paper CT 17th Space Photovoltaic Research and Technology Conference (SPRAT XVII) CY SEP 11-13, 2001 CL OHIO AEROSPACE INST, CLEVELAND, OHIO HO OHIO AEROSPACE INST ID BATTERIES AB The need for smaller, lightweight, autonomous power systems has increased with the current focus oil micro- and nanosatellites. Small-area, high-efficiency, thin-film batteries and solar cells are an attractive choice for such applications. The NASA Glenn Research Center, Johns Hopkins Applied Physics Laboratory, Lithium Power Technologies, MicroSat Systems, and others, have been working oil the development of autonomous monolithic packages combining these elements, or what are called integrated power supplies (IPS). These supplies call be combined with individual satellite components and are capable of providing continuous power, even under intermittent illumination associated with a spinning or earth-orbiting satellite. This paper discusses the space mission applicability, benefits, and current development efforts associated with IPS components and systems. The characteristics and several mission concepts for an IPS that combines thin-film photovoltaic power generation with thin-film lithium ion energy storage are described. Based oil this preliminary assessment, it is concluded that the most likely and beneficial application of all IPS will be for small 'nanosatellites' or in specialized applications serving as a decentralized or as a distributed power source or uninterruptible power supply. Copyright (C) 2002 John Wiley Sons, Ltd. C1 Rochester Inst Technol, Rochester, NY 14623 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Raffaelle, RP (reprint author), Rochester Inst Technol, 85 Lomb Mem Dr, Rochester, NY 14623 USA. NR 11 TC 1 Z9 1 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD SEP PY 2002 VL 10 IS 6 BP 391 EP 397 DI 10.1002/pip.445 PG 7 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 596KV UT WOS:000178164800003 ER PT J AU Bailey, SG Raffaelle, R Emery, K AF Bailey, SG Raffaelle, R Emery, K TI Space and terrestrial photovoltaics: Synergy and diversity SO PROGRESS IN PHOTOVOLTAICS LA English DT Article; Proceedings Paper CT 17th Space Photovoltaic Research and Technology Conference (SPRAT XVII) CY SEP 11-13, 2001 CL OHIO AEROSPACE INST, CLEVELAND, OHIO HO OHIO AEROSPACE INST ID SOLAR-CELLS; EFFICIENCY AB A historical view of the research and development in photovoltaics from the perspective of both the terrestrial and the space communities is presented from the early days through the 1970s and 1980s, 1990s and beyond. The synergy of both communities, both at the beginning and in the present, and hopefully in the future, are highlighted, with examples of the important features in each program. The space community which was impressed by the light weight and reliability of photovoltaics drove much of the early development. Even today, nearly every satellite and other scientific space probe that has been launched has included some solar power. However, since the cost of these power systems was only a small fraction of the satellite and launch cost, the use of much of this technology in the terrestrial marketplace was not feasible. It was clear that the focus of the terrestrial community would be best served by reducing costs. This would include addressing a variety of manufacturing issues and raising the rate of production. Success in these programs and a resulting globalization of effort resulted in major strides in the reduction of PV module costs and increased production. Although, the space community derived benefit from some of these advances, its focus was on pushing the envelope with regard to cell efficiency. The gap between theoretical efficiencies and experimental efficiencies for silicon, gallium arsenide and indium phosphide became almost nonexistent. Recent work by both communities have focused on the development thin-film cells of amorphous silicon, CuInSe2 and CdTe. These cells hold the promise of lower costs for the terrestrial community as well as possible flexible substrates, better radiation resistance, and higher specific power for the space community. It is predicted that future trends in both communities will be directed toward advances through the application of nanotechnology. A picture is emerging in which the space and terrestrial solar cell communities shall once again share many common goals and, in fact, companies may manufacture both space and terrestrial solar cells in HI-V materials and thin-film materials. Basic photovoltaics research, including these current trends in nanotechnology, provides a valuable service for both worlds in that fundamental understanding of cell processes is still vitally important, particularly with new materials or new cell structures. It is entirely possible that one day we might have one solar array design that will meet the criteria for success in both space and on the Earth or perhaps the Moon or Mars. Published in 2002 by John Wiley Sons, Ltd. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Rochester Inst Technol, Rochester, NY 14623 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Bailey, SG (reprint author), NASA, Glenn Res Ctr, MS 302-1 Lewis Field, Cleveland, OH 44135 USA. NR 20 TC 15 Z9 15 U1 1 U2 8 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD SEP PY 2002 VL 10 IS 6 BP 399 EP 406 DI 10.1002/pip.446 PG 8 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 596KV UT WOS:000178164800004 ER PT J AU Dhere, NG Ghongadi, SR Pandit, MB Jahagirdar, AH Scheiman, D AF Dhere, NG Ghongadi, SR Pandit, MB Jahagirdar, AH Scheiman, D TI CIGS2 thin-film solar cells on flexible foils for space power SO PROGRESS IN PHOTOVOLTAICS LA English DT Article; Proceedings Paper CT 17th Space Photovoltaic Research and Technology Conference (SPRAT XVII) CY SEP 11-13, 2001 CL OHIO AEROSPACE INST, CLEVELAND, OHIO HO OHIO AEROSPACE INST ID PHOTOVOLTAICS AB CuIn1-xGaxS2 (CIGS2) thin-film solar cells on flexible stainless steel foil are of interest for space power because of the near optimum bandgap, potential for higher specific power, and superior radiation resistance. This paper describes development of CIGS2 solar cells on 127-mum and 20-mum-thick, flexible SS foils for space power. A large-area, dual-chamber, deposition system has been fabricated. Cu-rich Cu-Ga/In layers were sputter-deposited on unheated Mo-coated foils. p-type CIGS2 thin films were obtained by etching Cu-rich surface layer from CIGS2 films prepared by sulfurization in Ar:H2S 1:0.04 mixture at 475degreesC for 60 min with all intermediate 30-min annealing step at 135degreesC. Solar cells were completed by deposition of CdS/ ZnO/ZnO.Al layers and Ni/Al contact fingers. AM0 PV parameters of a CIGS2 solar cell on 127-mum-thick SS foil measured at NASA-GRC were: V-OC=802.9mV, Jsc=25-07 mA/cm(2), FF = 60.06%, and efficiency = 8.84%. For this cell, AM1.5 PV parameters measured at NREL were V-OC=763mV, Jsc=20.6 mA/cm(2) FF = 67.4%, and efficiency = 10.4%. Copyright (C) 2002 John Wiley Sons, Ltd. C1 Florida Solar Energy Ctr, Cocoa, FL 32922 USA. NASA, Glenn Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA. RP Dhere, NG (reprint author), Florida Solar Energy Ctr, 1679 Clearlake Rd, Cocoa, FL 32922 USA. NR 12 TC 35 Z9 36 U1 1 U2 7 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD SEP PY 2002 VL 10 IS 6 BP 407 EP 416 DI 10.1002/pip.447 PG 10 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 596KV UT WOS:000178164800005 ER PT J AU Ringel, SA Carlin, JA Andre, CL Hudait, MK Gonzalez, M Wilt, DM Clark, EB Jenkins, P Scheiman, D Allerman, A Fitzgerald, EA Leitz, CW AF Ringel, SA Carlin, JA Andre, CL Hudait, MK Gonzalez, M Wilt, DM Clark, EB Jenkins, P Scheiman, D Allerman, A Fitzgerald, EA Leitz, CW TI Single-junction InGaP/GaAs solar cells grown on Si substrates with SiGe buffer layers SO PROGRESS IN PHOTOVOLTAICS LA English DT Article; Proceedings Paper CT 17th Space Photovoltaic Research and Technology Conference (SPRAT XVII) CY SEP 11-13, 2001 CL OHIO AEROSPACE INST, CLEVELAND, OHIO HO OHIO AEROSPACE INST ID HIGH-QUALITY GAAS; GESI BUFFERS AB Single junction InGaP/GaAs solar cells displaying high efficiency and record high open-circuit voltage values have been grown by metal-organic chemical vapor deposition on Ge/graded SiGe/Si substrates. Open-circuit voltages of 980 in 17 under AM0 conditions have been verified to result from a single GaAs junction, with no evidence of Ge-related sub-cell photoresponse. AM0 efficiencies close to 16% have been measured for a large number of small-area cells, the performance of which is limited by non-fundamental current losses due to significant surface reflection resulting from >10% front-surface metal coverage and wafer handling during the growth sequence for these prototype cells. It is shown that at the material quality currently achieved for GaAs grown on Ge/SiGe/Si substrates, namely a 10 ns minority-carrier lifetime that results from complete elimination of anti-phase domains, and maintaining a threading dislocation density of -8 x 10(5) cm(-2), 19-20% AM0 single-junction GaAs cells are imminent. Experiments show that the high performance is not degraded for larger-area cells, with identical open-circuit voltages and higher short-circuit current (due to reduced front metal coverage) values being demonstrated, indicating that large-area scaling is possible in the near term. Comparison with a simple model indicates that the voltage output of these GaAs-on-Si cells follows the ideal behavior expected for lattice-mismatched devices, demonstrating that unaccounted-for defects and issues that have plagued other methods to epitaxially integrate III-V cells with Si are resolved by using SiGe buffers and proper GaAs nucleation methods. These early results already show the enormous and realistic potential of the virtual SiGe substrate approach for generating high-efficiency, lightweight and strong 111-V solar cells. Copyright (C) 2002 John Wiley Sons, Ltd. C1 Ohio State Univ, Dept Elect Engn, Columbus, OH 43210 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. RP Ringel, SA (reprint author), Ohio State Univ, Dept Elect Engn, Columbus, OH 43210 USA. NR 15 TC 80 Z9 81 U1 2 U2 21 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD SEP PY 2002 VL 10 IS 6 BP 417 EP 426 DI 10.1002/pip.448 PG 10 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 596KV UT WOS:000178164800006 ER PT J AU Raffaelle, RP Castro, SL Hepp, AF Bailey, SG AF Raffaelle, RP Castro, SL Hepp, AF Bailey, SG TI Quantum dot solar cells SO PROGRESS IN PHOTOVOLTAICS LA English DT Article; Proceedings Paper CT 17th Space Photovoltaic Research and Technology Conference (SPRAT XVII) CY SEP 11-13, 2001 CL OHIO AEROSPACE INST, CLEVELAND, OHIO HO OHIO AEROSPACE INST ID CDSE NANOCRYSTALS; EFFICIENCY; FILMS AB We have been investigating the synthesis of quantum dots of CdSe, CuInS2, and CuInSe2 for use in an intermediate bandgap solar cell. We have prepared a variety of quantum dots, using the typical organometallic synthesis routes pioneered by Banwendi et al. in the early 1990s. However, unlike previous work in this area, we have also utilized single-source precursor molecules in the synthesis process. We present XRD, TEM, SEM and EDS characterization of our initial attempts at fabricating these quantum dots. Investigation of the size distributions of these nanoparticles via laser light scattering and scanning electron microscopy is also presented. Theoretical estimates on appropriate quantum dot composition, size, and inter-dot spacing along with potential scenarios for solar cell fabrication is discussed. Copyright (C) 2002 John Wiley Sons, Ltd. C1 Rochester Inst Technol, Rochester, NY 14623 USA. Ohio Aerosp Inst, Brookpark, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Raffaelle, RP (reprint author), Rochester Inst Technol, 85 Lomb Mem Dr, Rochester, NY 14623 USA. NR 23 TC 108 Z9 112 U1 4 U2 40 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD SEP PY 2002 VL 10 IS 6 BP 433 EP 439 DI 10.1002/pip.452 PG 7 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 596KV UT WOS:000178164800008 ER PT J AU Li, L Warren, WH AF Li, L Warren, WH TI Retinal flow is sufficient for steering during observer rotation SO PSYCHOLOGICAL SCIENCE LA English DT Article ID OPTIC FLOW; EYE-MOVEMENTS; MOTION PARALLAX; SELF-MOTION; PERCEPTION; INFORMATION; WALKING; DEPTH; GO AB How do people control locomotion while their eyes are simultaneously rotating? A previous study found that during simulated rotation, they can perceive a straight path of self-motion from the retinal flow pattern, despite conflicting extraretinal information, on the basis of dense motion parallax and reference objects. Here we report that the same information is sufficient for active control of joystick steering. Participants steered toward a target in displays that simulated a pursuit eye movement. Steering was highly inaccurate with a textured ground plane (motion parallax alone), but quite accurate when an array of posts was added (motion parallax plus reference objects). This result is consistent with the theory that instantaneous heading is determined from motion parallax, and the path of self-motion is determined by updating heading relative to environmental objects. Retinal flow is thus sufficient for both perceiving self-motion and controlling self-motion with a joystick; extraretinal and positional information can also contribute, but are not necessary. C1 Brown Univ, Dept Cognit & Linguist Sci, Providence, RI 02912 USA. RP Li, L (reprint author), NASA, Ames Res Ctr, MS 262-2, Moffett Field, CA 94305 USA. FU NEI NIH HHS [R01 EY010923, EY10923]; NIMH NIH HHS [K02 MH001353, K02 MH01353] NR 23 TC 25 Z9 25 U1 0 U2 7 PU BLACKWELL PUBLISHERS PI MALDEN PA 350 MAIN STREET, STE 6, MALDEN, MA 02148 USA SN 0956-7976 J9 PSYCHOL SCI JI Psychol. Sci. PD SEP PY 2002 VL 13 IS 5 BP 485 EP 491 DI 10.1111/1467-9280.00486 PG 7 WC Psychology, Multidisciplinary SC Psychology GA 588GE UT WOS:000177693100016 PM 12219819 ER PT J AU Allen, PA Lien, MC Murphy, MD Sanders, RE Judge, KS McCann, RS AF Allen, PA Lien, MC Murphy, MD Sanders, RE Judge, KS McCann, RS TI Age differences in overlapping-task performance: Evidence for efficient parallel processing in older adults SO PSYCHOLOGY AND AGING LA English DT Article ID PSYCHOLOGICAL REFRACTORY-PERIOD; VISUAL WORD RECOGNITION; DUAL-TASK; MEMORY RETRIEVAL; ALZHEIMER-TYPE; LETTER-LEVEL; FREQUENCY; INTERFERENCE; BOTTLENECK; YOUNG AB Two psychological refractory period (PRP) experiments were conducted to examine overlapping processing in younger and older adults. A shape discrimination task (triangle or rectangle) for Task 1 (T-1) and a lexical-decision task (word or nonword) for Task 2 (T-2) were used. PRP effects, response time for T-2 increasing as stimulus onset synchrony (SOA) decreased, were obtained for both age groups. The effect of word frequency on T-2 was smaller at the short SOA than at the long SOA, reflecting slack effects, which were larger for older than younger adults in both experiments. These results suggest that older adults can perform lexical access of T-2 in parallel with the processing of T-1 at least as efficiently as younger adults. C1 Univ Akron, Dept Psychol, Akron, OH 44325 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Allen, PA (reprint author), Univ Akron, Dept Psychol, 290 E Buchtel Ave, Akron, OH 44325 USA. OI Allen, Philip/0000-0001-8567-2217 FU NIA NIH HHS [AG09282] NR 56 TC 44 Z9 44 U1 7 U2 9 PU AMER PSYCHOLOGICAL ASSOC PI WASHINGTON PA 750 FIRST ST NE, WASHINGTON, DC 20002-4242 USA SN 0882-7974 J9 PSYCHOL AGING JI Psychol. Aging PD SEP PY 2002 VL 17 IS 3 BP 505 EP 519 DI 10.1037//0882-7974.17.3.505 PG 15 WC Gerontology; Psychology, Developmental SC Geriatrics & Gerontology; Psychology GA 593LB UT WOS:000177991800013 PM 12243391 ER PT J AU Conway, EM AF Conway, EM TI Expanding the envelope: Flight research at NACA and NASA SO PUBLIC HISTORIAN LA English DT Book Review C1 NASA Langley Res Ctr, Langley, VA USA. RP Conway, EM (reprint author), NASA Langley Res Ctr, Langley, VA USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CALIF PRESS PI BERKELEY PA C/O JOURNALS DIVISION, 2000 CENTER ST, STE 303, BERKELEY, CA 94704-1223 USA SN 0272-3433 J9 PUBL HISTORIAN JI Public Hist. PD FAL PY 2002 VL 24 IS 4 BP 170 EP 171 PG 2 WC History SC History GA 640FH UT WOS:000180677300032 ER PT J AU Matsu'ura, M Mora, P Donnellan, A Yin, XC AF Matsu'ura, M Mora, P Donnellan, A Yin, XC TI Earthquake processes: Physical modelling, numerical simulation and data analysis - Part II SO PURE AND APPLIED GEOPHYSICS LA English DT Editorial Material C1 Univ Tokyo, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. Univ Queensland, Dept Earth Sci, QUAKES, Brisbane, Qld 4072, Australia. NASA, Jet Prop Lab, Pasadena, CA 91109 USA. Chinese Acad Sci, Inst Mech, Lab Nonlinear Mech, Beijing 100080, Peoples R China. RP Matsu'ura, M (reprint author), Univ Tokyo, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. NR 3 TC 1 Z9 1 U1 0 U2 0 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD SEP PY 2002 VL 159 IS 10 BP 2169 EP 2171 DI 10.1007/s00024-002-8729-4 PG 3 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 592LD UT WOS:000177938400001 ER PT J AU Donnellan, A Parker, JW Peltzer, G AF Donnellan, A Parker, JW Peltzer, G TI Combined GPS and InSAR models of postseismic deformation from the Northridge earthquake SO PURE AND APPLIED GEOPHYSICS LA English DT Article DE earthquake; InSAR; GPS; afterslip; Northridge ID RADAR INTERFEROMETRY; CRUSTAL DEFORMATION; 1994 NORTHRIDGE; VENTURA-BASIN; CALIFORNIA; AFTERSLIP AB Models of combined Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) data collected in the region of the Northridge earthquake indicate that significant afterslip on the main fault occurred following the earthquake. Additional shallow deformation occurred to the west of the main rupture plane. Both data sets are consistent with logarithmic time-dependent behavior following the earthquake indicative of afterslip rather than postseismic relaxation. Aftershocks account for only about 10% of the postseismic motion. The two data sets are complimentary in determining the postseismic processes. Fault afterslip and shallow deformation dominate the deformation field in the two years following the earthquake. Lower crustal deformation may play an important role later in the earthquake cycle. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Univ So Calif, Los Angeles, CA USA. Univ Calif Los Angeles, Los Angeles, CA USA. RP Donnellan, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 19 TC 23 Z9 23 U1 0 U2 3 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD SEP PY 2002 VL 159 IS 10 BP 2261 EP 2270 DI 10.1007/s00024-002-8734-7 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 592LD UT WOS:000177938400006 ER PT J AU Granat, R Donnellan, A AF Granat, R Donnellan, A TI A hidden Markov model based tool for geophysical data exploration SO PURE AND APPLIED GEOPHYSICS LA English DT Article DE HMM; geophysics; annealing; clustering; seismic; gps ID SCIENCE DATA-ANALYSIS; EM ALGORITHM AB Unsupervised learning techniques provide a way of investigating scientific data based on automated generation of statistical models. Because these techniques are not dependent on a priori information, they provide an unbiased method for separating data into distinct types. Thus they can be used as an objective method by which to identify data as belonging to previously known classes or to find previously unknown or rare classes and subclasses of data. Hidden Markov model based unsupervised learning methods are particularly applicable to geophysical systems because time relationships between classes, or states of the system, are included in the model. We have applied a modified version of hidden Markov models which employ a deterministic annealing technique to scientific analysis of seismicity and GPS data from the southern California region. Preliminary results indicate that the technique can isolate distinct classes of earthquakes from seismicity data. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Granat, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 16 TC 17 Z9 17 U1 0 U2 1 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD SEP PY 2002 VL 159 IS 10 BP 2271 EP 2283 DI 10.1007/s00024-002-8735-6 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 592LD UT WOS:000177938400007 ER PT J AU Rundle, JB Rundle, PB Klein, W de sa Martins, J Tiampo, KF Donnellan, A Kellogg, LH AF Rundle, JB Rundle, PB Klein, W de sa Martins, J Tiampo, KF Donnellan, A Kellogg, LH TI GEM plate boundary Simulations for the plate boundary observatory: A program for understanding the physics of earthquakes on complex fault networks via observations, theory and numerical simulation SO PURE AND APPLIED GEOPHYSICS LA English DT Article DE earthquakes; numerical simulations; earthscope ID SAN-ANDREAS FAULT; ROCK FRICTION; STATISTICAL-MECHANICS; SOUTHERN-CALIFORNIA; THRESHOLD SYSTEMS; STRESS TRANSFER; MODELS; SLIP; FLUCTUATIONS; DEPENDENCE AB The last five years have seen unprecedented growth in the amount and quality of geodetic data collected to characterize crustal deformation in earthquake-prone areas such as California and Japan. The installation of the Southern California Integrated Geodetic Network (SCIGN) and the Bay Area Regional Deformation (BARD) network are two examples. As part of the recently proposed Earthscope NSF/GEO/EAR/MRE initiative, the Plate Boundary Observatory (PBO) plans to place more than a thousand GPS, strainmeters, and deformation sensors along the active plate boundary of the western coast of the United States, Mexico and Canada (http://www.earthscope.org/pbo.com.html). The scientific goals of PBO include understanding how tectonic plates interact, together with an emphasis on understanding the physics of earthquakes. However, the problem of understanding the physics of earthquakes on complex fault networks through observations alone is complicated by our inability to study the problem in a manner familiar to laboratory scientists, by means of controlled, fully reproducible experiments. We have therefore been motivated to construct a numerical simulation technology that will allow us to study earthquake physics via numerical experiments. To be considered successful, the simulations must not only produce observables that are maximally similar to those seen by the PBO and other observing programs, but in addition the simulations must provide dynamical predictions that can be falsified by means of observations on the real fault networks. In general, the dynamical behavior of earthquakes on complex fault networks is a result of the interplay between the geometric structure of the fault network and the physics of the frictional sliding process. In constructing numerical simulations of a complex fault network, we will need to solve a variety of problems, including the development of analysis techniques (also called data mining), data assimilation, space-time pattern definition and analysis, and visualization needs. Using simulations of the network of the major strike-slip faults in southern California, we present a preliminary description of our methods and results, and comment upon the relative roles of fault network geometry and frictional sliding in determining the important dynamical modes of the system. C1 Univ Colorado, CIRES, Colorado Ctr Chaos & Complex, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Harvey Mudd Coll, Dept Phys, Claremont, CA 91711 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. Los Alamos Natl Lab, Ctr Nonlinear Sci, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Explorat Syst Auton Div, Pasadena, CA 91109 USA. Univ Calif Davis, Dept Geol, Davis, CA 95616 USA. RP Rundle, JB (reprint author), Univ Colorado, CIRES, Colorado Ctr Chaos & Complex, CB 216, Boulder, CO 80309 USA. RI Kellogg, Louise/J-2171-2012; Tiampo, Kristy/I-1355-2015 OI Kellogg, Louise/0000-0001-5874-0472; Tiampo, Kristy/0000-0002-5500-7600 NR 51 TC 24 Z9 25 U1 0 U2 5 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD SEP PY 2002 VL 159 IS 10 BP 2357 EP 2381 DI 10.1007/s00024-002-8739-2 PG 25 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 592LD UT WOS:000177938400011 ER PT J AU Katz, R Cucinotta, FA AF Katz, R Cucinotta, FA TI Implications of single-particle experiments for track theory, therapy and radiation protection SO RADIATION RESEARCH LA English DT Meeting Abstract ID CELLS C1 Univ Nebraska, Lincoln, NE 68583 USA. NASA, Johnson Space Ctr, Houston, TX 77058 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU RADIATION RESEARCH SOC PI OAK BROOK PA 820 JORIE BOULEVARD, OAK BROOK, IL 60523 USA SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD SEP PY 2002 VL 158 IS 3 BP 374 EP 374 PG 1 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA 588NK UT WOS:000177707400023 ER PT J AU Ponomarev, AL Brenner, DJ Cucinotta, FA Sachs, RK AF Ponomarev, AL Brenner, DJ Cucinotta, FA Sachs, RK TI Large DNA fragment distributions in directly hit cells from low-dose, high-LET radiation SO RADIATION RESEARCH LA English DT Meeting Abstract ID DOUBLE-STRAND BREAKS; CHROMOSOMES; MODELS C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Baylor Coll Med, Dept Med, Houston, TX 77030 USA. Columbia Univ, Ctr Radiol Res, New York, NY 10032 USA. Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU RADIATION RESEARCH SOC PI OAK BROOK PA 820 JORIE BOULEVARD, OAK BROOK, IL 60523 USA SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD SEP PY 2002 VL 158 IS 3 BP 380 EP 380 PG 1 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA 588NK UT WOS:000177707400031 ER PT J AU Roman, CT Raposa, KB Adamowicz, SC James-Pirri, MJ Catena, JG AF Roman, CT Raposa, KB Adamowicz, SC James-Pirri, MJ Catena, JG TI Quantifying vegetation and nekton response to tidal restoration of a New England salt marsh SO RESTORATION ECOLOGY LA English DT Article; Proceedings Paper CT 15th Biennial Meeting of the Estuarine-Research-Federation CY SEP 25-30, 1999 CL NEW ORLEANS, LOUISIANA SP Estuarine Res Federat DE Fundulus heteroclitus; nekton; Phragmites australis; restoration; Rhode Island; salt marsh; Spartina ID FUNDULUS-HETEROCLITUS; PHRAGMITES-AUSTRALIS; POPULATIONS; MUMMICHOGS; SALINITY; WETLAND; USA AB Tidal flow to salt marshes throughout the northeastern United States is often restricted by roads, dikes, impoundments, and inadequately sized culverts or bridge openings, resulting in altered ecological structure and function. In this study we evaluated the response of vegetation and nekton (fishes and decapod crustaceans) to restoration of full tidal flow to a portion of the Sachuest Point salt marsh, Middletown, Rhode Island. A before, after, control, impact study design was used, including evaluations of the tide-restricted marsh, the same marsh after reintroduction of tidal flow (i.e., tide-restored marsh), and an unrestricted control marsh. Before tidal restoration vegetation of the 3.7-ha tide-restricted marsh was dominated by Phragmites australis and was significantly different from the adjacent 6.3-ha Spartina -dominated unrestricted control marsh (analysis of similarities randomization test, p < 0.001). After one growing season vegetation of the tide-restored marsh had changed from its pre-restoration condition (analysis of similarities randomization test, p < 0.005). Although not similar to the unrestricted control marsh, Spartina patens and S. alterniflora abundance increased and abundance and height of Phragmites significantly declined, suggesting a convergence toward typical New England salt marsh vegetation. Before restoration shallow water habitat (creeks and pools) of the unrestricted control marsh supported a greater density of nekton compared with the tide-restricted marsh (analysis of variance, p < 0.001), but after one season of restored tidal flow nekton density was equivalent. A similar trend was documented for nekton species richness. Nekton density and species richness from marsh surface samples were similar between the tide-restored marsh and unrestricted control marsh. Fundulus heteroclitus and Palaemonetes pugio were the numerically dominant fish and decapod species in all sampled habitats. This study provides an example of a quantitative approach for assessing the response of vegetation and nekton to tidal restoration. C1 Univ Rhode Isl, Grad Sch Oceanog, Natl Pk Serv, Narragansett, RI 02882 USA. Univ Rhode Isl, USGS Patuxent Wildlife Res Ctr, Narragansett, RI 02882 USA. Natl Marine Fisheries Serv, NOAA, Gloucester, MA 01930 USA. RP Roman, CT (reprint author), Univ Rhode Isl, Grad Sch Oceanog, Natl Pk Serv, Narragansett, RI 02882 USA. NR 34 TC 56 Z9 60 U1 2 U2 23 PU BLACKWELL PUBLISHING INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 1061-2971 J9 RESTOR ECOL JI Restor. Ecol. PD SEP PY 2002 VL 10 IS 3 BP 450 EP 460 DI 10.1046/j.1526-100X.2002.01036.x PG 11 WC Ecology SC Environmental Sciences & Ecology GA 583AM UT WOS:000177383400005 ER PT J AU Gray, A Simenstad, CA Bottom, DL Cornwell, TJ AF Gray, A Simenstad, CA Bottom, DL Cornwell, TJ TI Contrasting functional performance of juvenile salmon habitat in recovering wetlands of the Salmon River estuary, Oregon, USA SO RESTORATION ECOLOGY LA English DT Article; Proceedings Paper CT 15th Biennial Meeting of the Estuarine-Research-Federation CY SEP 25-30, 1999 CL NEW ORLEANS, LOUISIANA SP Estuarine Res Federat DE dike removal; estuary; juvenile salmon; restoration; salt marsh; wetland function ID SALT-MARSH; RESTORATION; RESIDENCE; CRITERIA AB For an estuarine restoration project to be successful it must reverse anthropogenic effects and restore lost ecosystem functions. Restoration projects that aim to rehabilitate endangered species populations make project success even more important, because if misjudged damage to already weakened populations may result. Determining project success depends on our ability to assess the functional state or "performance" and the trajectory of ecosystem development. Mature system structure is often the desired "end point" of restoration and is assumed to provide maximum benefit for target species; however, few studies have measured linkages between structure and function and possible benefits available from early recovery stages. The Salmon River estuary, Oregon, U.S.A., offers a unique opportunity to simultaneously evaluate several estuarine restoration projects and the response of the marsh community while making comparisons with a concurring undiked portion of the estuary. Dikes installed in three locations in the estuary during the early 1960s were removed in 1978, 1987, and 1996, creating a "space-for-time substitution" chronosequence. Analysis of the marsh community responses enables us to use the development state of the three recovering marshes to determine a trajectory of estuarine recovery over 23 years and to make comparisons with a reference marsh. We assessed the rate and pattern of juvenile salmon habitat development in terms of fish density, available prey resources, and diet composition of wild juvenile Oncorhynchus tshawytscha (chinook salmon). Results from the outmigration of 1998 and 1999 show differences in fish densities, prey resources, and diet composition among the four sites. Peaks in chinook salmon densities were greatest in the reference site in 1998 and in the youngest (1996) site in 1999. The 1996 marsh had higher densities of chironomids (insects; average 864/m(2) ) and lower densities of amphipods (crustaceans; average 8/m(3) ) when compared with the other sites. Fauna differences were reflected in the diets of juvenile chinook with those occupying the 1978 and 1996 marshes based on insects (especially chironomids), whereas those from the 1987 and reference marshes were based on crustaceans (especially amphipods). Tracking the development of recovering emergent marsh ecosystems in the Salmon River estuary reveals significant fish and invertebrate response in the first 2 to 3 years after marsh restoration. This pulse of productivity in newly restored systems is part of the trajectory of development and indicates some level of early functionality and the efficacy of restoring estuarine marshes for juvenile salmon habitat. However, to truly know the benefits consumers experience in recovering systems requires further analysis that we will present in forthcoming publications. C1 Univ Washington, Sch Aquat & Fishery Sci, Wetland Ecosyst Team, Seattle, WA 98195 USA. Oregon State Univ, Hatfield Marine Sci Ctr, NOAA, Natl Marine Fisheries Serv, Newport, OR 97365 USA. Oregon Dept Fish & Wildlife, Div Res, Corvallis, OR 97333 USA. RP Gray, A (reprint author), Univ Washington, Sch Aquat & Fishery Sci, Wetland Ecosyst Team, 1122 Boat St, Seattle, WA 98195 USA. NR 39 TC 54 Z9 56 U1 6 U2 46 PU BLACKWELL PUBLISHING INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 1061-2971 J9 RESTOR ECOL JI Restor. Ecol. PD SEP PY 2002 VL 10 IS 3 BP 514 EP 526 DI 10.1046/j.1526-100X.2002.01039.x PG 13 WC Ecology SC Environmental Sciences & Ecology GA 583AM UT WOS:000177383400010 ER PT J AU Neckles, HA Dionne, M Burdick, DM Roman, CT Buchsbaum, R Hutchins, E AF Neckles, HA Dionne, M Burdick, DM Roman, CT Buchsbaum, R Hutchins, E TI A monitoring protocol to assess tidal restoration of salt marshes on local and regional scales SO RESTORATION ECOLOGY LA English DT Article; Proceedings Paper CT 15th Biennial Meeting of the Estuarine-Research-Federation CY SEP 25-30, 1999 CL NEW ORLEANS, LOUISIANA SP Estuarine Res Federat DE assessment; monitoring protocols; salt marsh; tidal restoration; tidal restrictions ID NEW-ENGLAND ESTUARY; SOUTHERN CALIFORNIA; DECOMPOSITION; SALINITY; WETLAND; MANAGEMENT; MITIGATION; CRITERIA; HABITAT; PLANTS AB Assessing the response of salt marshes to tidal restoration relies on comparisons of ecosystem attributes between restored and reference marshes. Although this approach provides an objective basis for judging project success, inferences can be constrained if the high variability of natural marshes masks differences in sampled attributes between restored and reference sites. Furthermore, such assessments are usually focused on a small number of restoration projects in a local area, limiting the ability to address questions regarding the effectiveness of restoration within a broad region. We developed a hierarchical approach to evaluate the performance of tidal restorations at local and regional scales throughout the Gulf of Maine. The cornerstone of the approach is a standard protocol for monitoring restored and reference salt marshes throughout the region. The monitoring protocol was developed by consensus among nearly 50 restoration scientists and practitioners. The protocol is based on a suite of core structural measures that can be applied to any tidal restoration project. The protocol also includes additional functional measures for application to specific projects. Consistent use of the standard protocol to monitor local projects will enable pooling information for regional assessments. Ultimately, it will be possible to establish a range of reference conditions characterizing natural tidal wetlands in the region and to compare performance curves between populations of restored and reference marshes for assessing regional restoration effectiveness. C1 USGS Patuxent Wildlife Res Ctr, Augusta, ME 04330 USA. Wells Natl Estuarine Res Reserve, Wells, ME USA. Univ New Hampshire, Dept Nat Resources, Jackson Estuarine Lab, Durham, NH 03824 USA. Univ Rhode Isl, USGS Patuxent Wildlife Res Ctr, Narragansett, RI USA. Massachusetts Audubon Soc, Wenham, MA USA. Natl Marine Fisheries Serv, Gloucester, MA USA. RP Neckles, HA (reprint author), USGS Patuxent Wildlife Res Ctr, 26 Ganneston Dr, Augusta, ME 04330 USA. NR 45 TC 54 Z9 63 U1 7 U2 39 PU BLACKWELL PUBLISHING INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 1061-2971 J9 RESTOR ECOL JI Restor. Ecol. PD SEP PY 2002 VL 10 IS 3 BP 556 EP 563 DI 10.1046/j.1526-100X.2002.02033.x PG 8 WC Ecology SC Environmental Sciences & Ecology GA 583AM UT WOS:000177383400013 ER PT J AU Wergin, WP Rango, A Foster, J Erbe, EF Pooley, C AF Wergin, WP Rango, A Foster, J Erbe, EF Pooley, C TI Irregular snow crystals: Structural features as revealed by low temperature scanning electron microscopy SO SCANNING LA English DT Article DE field-emission scanning electron microscopy; low-temperature scanning electron microscopy; snow crystals; irregular crystals; snowflakes; rime; graupel ID ICE AB For nearly 50 years, investigators using light microscopy have vaguely alluded to a unique type of snow crystal that has become known as an irregular snow crystal. However, the limited resolution and depth-of-field of the light microscope has prevented investigators from characterizing these crystals. In this study, a field-emission scanning electron microscope, equipped with a cold stage, was used to document the structural features, physical associations, and atmospheric metamorphosis of irregular snow crystals. The crystals appear as irregular hexagons, measuring 60 to 90 mm across, when viewed from the a-axis. Their length (c-axis) rarely exceeds the diameter. The irregular crystals are occasionally found as secondary particles on other larger forms of snow crystals; however, they most frequently occur in aggregates consisting of more than 100 irregular crystals. In the aggregates, the irregular crystals have their axes oriented parallel to one another and, collectively, tend to form columnar structures. Occasionally, these columnar structures exhibit rounded faces along one side, suggesting atmospheric metamorphoses during formation and descent. In extreme cases of metamorphoses, the aggregates would be difficult to distinguish from graupel. Frost, consisting of irregular crystals, has also been encountered, suggesting that atmospheric conditions that favor their growth can also occur terrestrially. C1 ARS, Soybean Genom & Improvement Lab, USDA, Beltsville, MD 20705 USA. New Mexico State Univ, ARS, USDA, Jornada Expt Range, Las Cruces, NM 88003 USA. NASA, Goddard Space Flight Ctr, Lab Hydrol Sci, Greenbelt, MD 20771 USA. ARS, Hydrol & Remote Sensing Lab, USDA, Beltsville, MD USA. RP Wergin, WP (reprint author), ARS, Soybean Genom & Improvement Lab, USDA, Beltsville, MD 20705 USA. NR 22 TC 10 Z9 10 U1 0 U2 7 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430-0832 USA SN 0161-0457 J9 SCANNING JI Scanning PD SEP-OCT PY 2002 VL 24 IS 5 BP 247 EP 256 PG 10 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA 598ND UT WOS:000178281700005 PM 12392356 ER PT J AU Oliker, L Li, XY Husbands, P Biswas, R AF Oliker, L Li, XY Husbands, P Biswas, R TI Effects of ordering strategies and programming paradigms on sparse matrix computations SO SIAM REVIEW LA English DT Article DE preconditioned conjugate gradient; graph partitioning; reverse Cuthill-McKee; self-avoiding walks; message passing; shared-memory directives; hybrid programming; multi-threading ID UNSTRUCTURED GRIDS; MACHINES; MEMORY AB The conjugate gradient (CG) algorithm is perhaps the best-known iterative technique for solving sparse linear systems that are symmetric and positive definite. For systems that are ill conditioned, it is often necessary to use a preconditioning technique. In this paper, we investigate the effects of various ordering and partitioning strategies on the performance of parallel CG and ILU(0) preconditioned CG (PCG) using different programming paradigms and architectures. Results show that for this class of applications, ordering significantly improves overall performance on both distributed and distributed shared-memory systems, cache reuse may be more important than reducing communication, it is possible to achieve message-passing performance using shared-memory constructs through careful data ordering and distribution, and a hybrid MPI+OpenMP paradigm increases programming complexity with little performance gain. A multithreaded implementation of CG on the Cray NITA does not require special ordering or partitioning to obtain high efficiency and scalability, giving it a distinct advantage for adaptive applications; however, it shows limited scalability for PCG due to a lack of thread-level parallelism. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, NASA Adv Supercomp NAS Div, Moffett Field, CA 94035 USA. RP Oliker, L (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Mail Stop 50F, Berkeley, CA 94720 USA. NR 22 TC 34 Z9 35 U1 0 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1445 J9 SIAM REV JI SIAM Rev. PD SEP PY 2002 VL 44 IS 3 BP 373 EP 393 AR PII S0036144500382076 DI 10.1137/S00361445003820 PG 21 WC Mathematics, Applied SC Mathematics GA 584WN UT WOS:000177491900004 ER PT J AU De Moortel, I Ireland, J Walsh, RW Hood, AW AF De Moortel, I Ireland, J Walsh, RW Hood, AW TI Longitudinal intensity oscillations in coronal loops observed with TRACE - I. Overview of measured parameters SO SOLAR PHYSICS LA English DT Article ID SLOW MAGNETOACOUSTIC WAVES; SUNSPOT TRANSITION REGION; MAGNETIC-FIELD; EXPLORER; PLUMES AB In this paper we aim to give a comprehensive overview of geometric and physical properties of longitudinal oscillations in large coronal loops. The 38 examples of propagating disturbances were obtained from the analysis of high cadence, 171 Angstrom TRACE data (JOP 83 and JOP 144). The majority of these outward propagating oscillations are found in the footpoints of large diffuse coronal loop structures, close to active regions. The disturbances travel outward with a propagation speed of the order of v approximate to 122 +/- 43 km s(-1). The variations in intensity are estimated to be roughly 4.1 +/- 1.5% of the background loop brightness. The propagating disturbances are found to be damped very quickly and are typically only detected in the first 8.9 +/- 4.4 Mm along the loop. Using a wavelet analysis, periods of the order of 282 +/- 93 s are found and the energy flux was estimated as 342 +/- 126 erg cm 2 s(-1). We found highly filamentary behavior in the lower part of the coronal loops and showed that the intensity oscillations can be present for several consecutive hours, with a more or less constant period. It is evident that the longitudinal oscillations are a widespread, regularly occurring coronal phenomena. A companion paper is devoted to the interpretation and discussion of the results. C1 Univ St Andrews, Sch Math & Stat, St Andrews KY16 9SS, Fife, Scotland. NASA, L3Com Analyt Corp, GSFC, Greenbelt, MD 20771 USA. Univ Cent Lancashire, Dept Phys Astron & Maths, Preston PR1 2HE, Lancs, England. RP De Moortel, I (reprint author), Univ St Andrews, Sch Math & Stat, St Andrews KY16 9SS, Fife, Scotland. NR 31 TC 126 Z9 126 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD SEP PY 2002 VL 209 IS 1 BP 61 EP 88 DI 10.1023/A:1020956421063 PG 28 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 610EA UT WOS:000178946700004 ER PT J AU De Moortel, I Hood, AW Ireland, J Walsh, RW AF De Moortel, I Hood, AW Ireland, J Walsh, RW TI Longitudinal intensity oscillations in coronal loops observed with TRACE - II. Discussion of measured parameters SO SOLAR PHYSICS LA English DT Article ID SLOW MAGNETOACOUSTIC WAVES; SOLAR CHROMOSPHERE; ATMOSPHERE; PLUMES AB In this paper, we give a detailed discussion of the parameters of longitudinal oscillations in coronal loops, described in Paper I. We found a surprising absence of correlations between the measured variables, with the exception of a relation between the estimated damping length and the period of the intensity variations. Only for 2 out of the 38 cases presented in Paper I did we find a significant perturbation in the 195 Angstrom TRACE data. The loops supporting the propagating disturbances were typically stable, quiescent loops and the total luminosity of the analyzed structures generally varied by no more than 10%. The observed density oscillations are unlikely to be flare-driven and are probably caused by an underlying driver exciting the loop footpoints. It was demonstrated that the rapid damping of the perturbations could not simply be explained as a consequence of the decreasing intensity along the loops. However, we found that (slightly enhanced) thermal conduction alone could account for the observed damping lengths and wavelengths, and, additionally, explain the correlation between propagation period and damping length. C1 Univ St Andrews, Sch Math & Stat, St Andrews KY16 9SS, Fife, Scotland. NASA, L3Com Analyt Corp, GSFC, Greenbelt, MD 20771 USA. Univ Cent Lancashire, Dept Phys Astron & Maths, Preston PR1 2HE, Lancs, England. RP De Moortel, I (reprint author), Univ St Andrews, Sch Math & Stat, St Andrews KY16 9SS, Fife, Scotland. NR 24 TC 81 Z9 81 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD SEP PY 2002 VL 209 IS 1 BP 89 EP 108 DI 10.1023/A:1020960505133 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 610EA UT WOS:000178946700005 ER PT J AU Gallagher, PT Moon, YJ Wang, HM AF Gallagher, PT Moon, YJ Wang, HM TI Active-region monitoring and flare forecasting - I. Data processing and first results SO SOLAR PHYSICS LA English DT Article ID SOLAR; NETWORK; SYSTEM; RATES AB This paper discusses a near real-time approach to solar active-region monitoring and flare prediction using the Big Bear Solar Observatory Active Region Monitor (ARM). Every hour, ARM reads, calibrates, and analyses a variety of data including: full-disk Halpha images from the Global Ha Network; EUV, continuum, and magnetogram data from the Solar and Heliospheric Observatory (SOHO); and full-disk magnetograms from the Global Oscillation Network Group (GONG). For the first time, magnetic gradient maps derived from GONG longitudinal magnetograms are now available on-line and are found to be a useful diagnostic of flare activity. ARM also includes a variety of active-region properties from the National Oceanic and Atmospheric Administration's Space Environment Center, such as up-to-date active-region positions, GOES 5-min X-ray data, and flare-to-region identifications. Furthermore, we have developed a Flare Prediction System which estimates the probability for each region to produce C-, M-, or X-class flares based on nearly eight years of NOAA data from cycle 22. This, in addition to BBSO's daily solar activity reports, has proven a useful resource for activity forecasting. C1 New Jersey Inst Technol, Big Bear Solar Observ, Big Bear City, CA 92314 USA. Korea Astron Observ, Taejon 305348, South Korea. RP Gallagher, PT (reprint author), NASA, L3 Commun Analyt Corp, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Moon, Yong-Jae/E-1711-2013; Gallagher, Peter/C-7717-2011 OI Gallagher, Peter/0000-0001-9745-0400 NR 21 TC 81 Z9 89 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD SEP PY 2002 VL 209 IS 1 BP 171 EP 183 DI 10.1023/A:1020950221179 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 610EA UT WOS:000178946700010 ER PT J AU Dlugach, ZM Mishchenko, MI Morozhenko, AV AF Dlugach, ZM Mishchenko, MI Morozhenko, AV TI The effect of the shape of dust aerosol particles in the Martian atmosphere on the particle parameters SO SOLAR SYSTEM RESEARCH LA English DT Article ID OPTICAL-PROPERTIES; MARS PATHFINDER; IMAGER AB The influence of the shape of dust aerosol particles in the Martian atmosphere on the imaginary part of the refractive index n(i) as derived from photometric observations during the period of the highest activity of the dust storm in 1971 was studied and exemplified for particles of spherical and oblate spheroidal shape. A similar analysis was performed for mean particle radii r(0) and optical thicknesses tau(0) of the dust layer estimated from polarization observations for periods of high atmospheric transparency. It was demonstrated that the values obtained for these optical parameters are affected by the adopted aerosol shape. Namely, the values of ni, r(0), and tau(0) found for spheroidal particles proved to be nearly twice as large as those for spheres. However, they are still much less than the available estimates of these parameters inferred, in particular, from interpreting space experiments. The reason for this difference needs further investigation. C1 Natl Acad Sci Ukraine, Main Astron Observ, UA-03680 Kiev, Ukraine. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Dlugach, ZM (reprint author), Natl Acad Sci Ukraine, Main Astron Observ, UA-03680 Kiev, Ukraine. RI Mishchenko, Michael/D-4426-2012 NR 28 TC 7 Z9 7 U1 0 U2 1 PU MAIK NAUKA/INTERPERIODICA PI NEW YORK PA C/O KLUWER ACADEMIC-PLENUM PUBLISHERS, 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0038-0946 J9 SOLAR SYST RES+ JI Solar Syst. Res. PD SEP-OCT PY 2002 VL 36 IS 5 BP 367 EP 373 DI 10.1023/A:1020459320523 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 610UC UT WOS:000178978500002 ER PT J AU Loewenstein, M Jost, H Grose, J Eilers, J Lynch, D Jensen, S Marmie, J AF Loewenstein, M Jost, H Grose, J Eilers, J Lynch, D Jensen, S Marmie, J TI Argus: a new instrument for the measurement of the stratospheric dynamical tracers, N2O and CH4 SO SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY LA English DT Article; Proceedings Paper CT 3rd International Conference on Tunable Diode Laser Spectroscopy CY JUL 08-12, 2001 CL ZERMATT, SWITZERLAND SP Russian Acad Sci, Gen Phys Inst, Connecticut Coll, Laser Components GmbH, Laser Components Instrumnts Grp Inc, AeroLaser, Aquila Technologies Grp, EKIPS Technol, Anritsu Corp DE stratosphere; tracers; nitrous oxide; methane; second harmonic spectroscopy ID DIODE-LASER SPECTROMETER; ABSORPTION SPECTROMETER; HIGH-PRECISION; SYSTEM AB We describe here a new instrument for the simultaneous, in situ measurement of the stratospheric tracer molecules, nitrous oxide (N2O) and methane (CH4). Argus is unique in its small size making it well suited for limited payload atmospheric research platforms. Argus employs second harmonic spectroscopy using tunable lead-salt diode lasers emitting in the mid-infrared. We first explain the Argus design philosophy followed by detailed descriptions of the instrument's optical, mechanical, and thermal sub-systems. Argus employs an in-flight calibration system providing real time calibrations and tightly constrained uncertainty estimates of the returned data. Data analysis is carried out using non-linear least-squares model fits to the acquired second harmonic spectra. A sampling of Argus data acquired on a recent stratospheric research campaign in the Arctic winter is presented. (C) 2002 Elsevier Science B.V. All rights reserved. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Loewenstein, M (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 18 TC 29 Z9 29 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1386-1425 J9 SPECTROCHIM ACTA A JI Spectroc. Acta Pt. A-Molec. Biomolec. Spectr. PD SEP PY 2002 VL 58 IS 11 BP 2329 EP 2345 AR PII S1386-1425(02)00048-3 DI 10.1016/S1386-1425(02)00048-3 PG 17 WC Spectroscopy SC Spectroscopy GA 591QG UT WOS:000177891300004 PM 12353683 ER PT J AU Kincaid, RK Weber, M Sobieszczanski-Sobieski, J AF Kincaid, RK Weber, M Sobieszczanski-Sobieski, J TI A bell-curve based algorithm for mixed continuous and discrete structural optimization SO STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION LA English DT Article DE evolutionary optimization; discrete optimization; structures AB An evolutionary based strategy utilizing two normal distributions to generate children is developed to solve mixed integer nonlinear programming problems. This Bell-Curve Based (BCB) evolutionary algorithm is similar in spirit to (mu + mu) evolutionary strategies and evolutionary programs but with fewer parameters to adjust and no mechanism for self adaptation. First, a new version of BCB to solve purely discrete optimization problems is described and its performance tested against a tabu search code for an actuator placement problem. Next, the performance of a combined version of discrete and continuous BCB is tested on two-dimensional shape problems and on a minimum weight hub design problem. In the latter case the discrete portion is the choice of the underlying beam shape (I, triangular, circular, rectangular, or U). C1 Coll William & Mary, Dept Math, Williamsburg, VA 23187 USA. Cigital Inc, Dulles, VA 20166 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Kincaid, RK (reprint author), Coll William & Mary, Dept Math, Williamsburg, VA 23187 USA. NR 13 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1615-147X J9 STRUCT MULTIDISCIP O JI Struct. Multidiscip. Optim. PD SEP PY 2002 VL 24 IS 2 BP 98 EP 105 DI 10.1007/s00158-002-0220-4 PG 8 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mechanics SC Computer Science; Engineering; Mechanics GA 602QR UT WOS:000178516400002 ER PT J AU Hudspeth, QM Nagle, KP Zhao, YP Karabacak, T Nguyen, CV Meyyappan, M Wang, GC Lu, TM AF Hudspeth, QM Nagle, KP Zhao, YP Karabacak, T Nguyen, CV Meyyappan, M Wang, GC Lu, TM TI How does a multiwalled carbon nanotube atomic force microscopy probe affect the determination of surface roughness statistics? SO SURFACE SCIENCE LA English DT Article DE carbon; atomic force microscopy; surface roughening; dendritic and/or fractile surfaces ID SEMICONDUCTORS; RESOLUTION AB Through statistical analysis of atomic force micrographs of sputtered-silicon films, we examine the determination of surface roughness parameters, and how this determination is affected by probe characteristics, such as sharpness and aspect ratio. We compare values for the roughness exponent, alpha, and the lateral correlation length, xi, calculated from micrographs obtained with multiple standard atomic force microscopy (AFM) probes in contact and noncontact modes, as well as from micrographs obtained with a multiwalled-nanotube-enhanced AFM probe. The sharper, lower-aspect-ratio nanotube probe is expected to provide a truer picture of the roughness parameters for these films. Using the nanotube probe, we obtained alpha = 0.61 +/- 0.02, as compared to alpha similar to 0.83 obtained with conventional probes. We have also found the nanotube probe is able to detect a smaller lateral correlation length compared to that of the conventional AFM probes. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA. Middlebury Coll, Dept Phys, Middlebury, VT 05753 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. ELORET Corp, Sunnyvale, CA 94087 USA. RP Hudspeth, QM (reprint author), Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, 110 8th St, Troy, NY 12180 USA. RI Zhao, Yiping/A-4968-2008 NR 14 TC 17 Z9 17 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 1 PY 2002 VL 515 IS 2-3 BP 453 EP 461 AR PII S0039-6028(02)019955-6 DI 10.1016/S0039-6028(02)01955-6 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 590YF UT WOS:000177851700025 ER PT J AU Choi, W Lee, H Grant, WB Park, JH Holton, JR Lee, KM Naujokat, B AF Choi, W Lee, H Grant, WB Park, JH Holton, JR Lee, KM Naujokat, B TI On the secondary meridional circulation associated with the quasi-biennial oscillation SO TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY LA English DT Article ID HALOGEN OCCULTATION EXPERIMENT; EQUATORIAL LOWER STRATOSPHERE; INTERANNUAL VARIABILITY; GENERAL-CIRCULATION; RESIDUAL CIRCULATION; 2-DIMENSIONAL MODEL; MIDDLE ATMOSPHERE; TRACE GASES; OZONE QBO; TRANSPORT AB Concentrations and distributions of stratospheric aerosol, hydrogen fluoride and ozone from the Halogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite (UARS) are used to investigate features associated with transport by the secondary meridional circulation induced by the quasi-biennial oscillation (QBO). The points of maxima in the divergence and convergence of the QBO-induced meridional velocity at the equator are identified from the meridional gradients of the tracers. Such points can be identified from the tracer fields in the westerly shear zones but not in the easterly shear zones. The temporal variation of tracer concentration at the equator is determined mainly by vertical advection, which is significantly larger during the westerly shear phase of the QBO than during the easterly shear phase, since the QBO-induced equatorial sinking motion amplifies the vertical gradient. Thus, the vertical advection associated with the secondary circulation has a stronger influence on the equatorial tracer variation during the westerly shear phase than during the easterly shear phase. C1 Seoul Natl Univ, Coll Nat Sci, Sch Earth & Environm Sci, Seoul 151742, South Korea. NCAR, Div Atmospher Chem, Boulder, CO 80305 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Kyungpook Natl Univ, Dept Astron & Atmospher Sci, Book Gu, Taegu 702701, South Korea. Free Univ Berlin, Inst Meteorol, Stratospher Res Grp, D-12165 Berlin, Germany. RP Choi, W (reprint author), Seoul Natl Univ, Coll Nat Sci, Sch Earth & Environm Sci, Seoul 151742, South Korea. RI Grant, William/B-8311-2009 OI Grant, William/0000-0002-1439-3285 NR 40 TC 14 Z9 14 U1 0 U2 7 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6509 J9 TELLUS B JI Tellus Ser. B-Chem. Phys. Meteorol. PD SEP PY 2002 VL 54 IS 4 BP 395 EP 406 DI 10.1034/j.1600-0889.2002.201286.x PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 596VD UT WOS:000178186400007 ER PT J AU Arbocz, J Starnes, JH AF Arbocz, J Starnes, JH TI Future directions and challenges in shell stability analysis SO THIN-WALLED STRUCTURES LA English DT Review ID RANDOM IMPERFECTIONS; CYLINDRICAL-SHELLS; COLLAPSE AB Recent advances in structural analysis and design technology for buckling-critical shell structures are discussed. These advances include a hierarchical analysis strategy that includes analyses that range from classical analysis methods to high-fidelity nonlinear finite element analysis methods, reliability based design methods, the development of imperfection data bases, and the identification of traditional and nontraditional initial imperfections for composite shell structures. When used judiciously, these advances provide the basis for a viable alternative to the traditional and conservative lower-bound design philosophy of the 1960s. These advances also help answer the question of why, after so many years of concentrated research effort to understand the behavior of buckling-critical thin-walled shells, one has not been able to improve on this conservative lower- bound design philosophy in the past. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Delft Univ Technol, Fac Aerosp Engn, Koiter Inst, NL-2600 Delft, Netherlands. NASA, Langley Res Ctr, Hampton, VA USA. RP Arbocz, J (reprint author), Delft Univ Technol, Fac Aerosp Engn, Koiter Inst, Postbus 5058, NL-2600 Delft, Netherlands. NR 45 TC 77 Z9 78 U1 0 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0263-8231 J9 THIN WALL STRUCT JI Thin-Walled Struct. PD SEP PY 2002 VL 40 IS 9 BP 729 EP 754 AR PII S0263-8231(02)00024-1 DI 10.1016/S0263-8231(02)00024-1 PG 26 WC Engineering, Civil SC Engineering GA 587AF UT WOS:000177617800001 ER PT J AU Busch, MP Stramer, SL Caglioti, S Tobler, LH McAuley, J Glynn, S Dodd, RY AF Busch, MP Stramer, SL Caglioti, S Tobler, LH McAuley, J Glynn, S Dodd, RY TI Error surveillance in blood donor infectious disease screening. SO TRANSFUSION LA English DT Meeting Abstract CT 55th Annual Meeting of the American-Association-of-Blood-Banks CY OCT 26-29, 2002 CL ORLANDO, FL SP Amer Assoc Blood Banks C1 Ames Res Ctr, Gaithersburg, MD USA. Blood Syst Lab, Tempe, AZ USA. Blood Ctr Pacific, San Francisco, CA USA. Blood Syst Lab, Tempe, AZ USA. Amer Red Cross, Rockville, MD USA. Westat Corp, Rockville, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0041-1132 EI 1537-2995 J9 TRANSFUSION JI Transfusion PD SEP PY 2002 VL 42 IS 9 SU S BP 3S EP 3S PG 1 WC Hematology SC Hematology GA 592MP UT WOS:000177941700010 ER PT J AU Northway, MJ Popp, PJ Gao, RS Fahey, DW Toon, GC Bui, TP AF Northway, MJ Popp, PJ Gao, RS Fahey, DW Toon, GC Bui, TP TI Relating inferred HNO3 flux values to the denitrification of the 1999-2000 Arctic vortex SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID POLAR STRATOSPHERIC CLOUDS; WINTER STRATOSPHERE; CONDENSATION; PARTICLES AB Extensive populations of large HNO3-containing particles were observed in situ in the 1999-2000 Arctic winter vortex. Assuming nitric acid trihydrate (NAT) composition, the associated values of instantaneous gravitational flux of HNO3 are between 1.10(8) and 5.10(10) molec cm(-3) km day(-1) and are the largest ever derived from in situ measurements. The relationship between these observed populations and observed denitrification in the 1999-2000 Arctic vortex is developed using constraints of NAT formation and sedimentation. This analysis of the 1999-2000 winter provides a useful guide to interpreting future observations of polar stratospheric clouds and denitrification in the polar regions. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP NOAA, Aeron Lab, Boulder, CO 80305 USA. EM northway@al.noaa.gov RI Fahey, David/G-4499-2013; Gao, Ru-Shan/H-7455-2013 OI Fahey, David/0000-0003-1720-0634; NR 16 TC 7 Z9 7 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 31 PY 2002 VL 29 IS 16 AR 1816 DI 10.1029/2002GL015000 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 622ET UT WOS:000179634100007 ER PT J AU Harris, NRP Rex, M Goutail, F Knudsen, BM Manney, GL Muller, R von der Gathen, P AF Harris, NRP Rex, M Goutail, F Knudsen, BM Manney, GL Muller, R von der Gathen, P TI Comparison of empirically derived ozone losses in the Arctic vortex SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ozone; stratosphere; Arctic; chemical loss; estimate; comparison ID 3-DIMENSIONAL MODEL SIMULATIONS; POLAR VORTEX; LOSS RATES; MATCH OBSERVATIONS; WINTER; DEPLETION; STRATOSPHERE; HALOE; MLS; TEMPERATURES AB A number of studies have reported empirical estimates of ozone loss in the Arctic vortex. They have used satellite and in situ measurements and have principally covered the Arctic winters in the 1990s. While there is qualitative consistency between the patterns of ozone loss, a quantitative comparison of the published values shows apparent disagreements. In this paper we examine these disagreements in more detail. We choose to concentrate on the five main techniques (Match, Systeme d'Analyse par Observation Zenithale (SAOZ)/REPROBUS, Microwave Limb Sounder (MLS), vortex average descent, and the Halogen Occultation Experiment (HALOE) ozone tracer approach). Estimates of the ozone losses in three winters (1994/1995, 1995/1996 and 1996/1997) are recalculated so that the same time periods, altitude ranges, and definitions of the Arctic vortex are used. This recalculation reveals a remarkably good agreement between the various estimates. For example, a superficial comparison of results from Match and from MLS indicates a big discrepancy (2.0+/-0.3 and 0.85 ppmv, respectively, for air ending at similar to460 K in March 1995). However, the more precise comparisons presented here reveal good agreement for the individual MLS periods (0.5+/-0.1 versus 0.5 ppmv; 0.4+/-0.2 versus 0.3-0.4 ppmv; and 0.16+/-0.09 ppmv versus no significant loss). Initial comparisons of the column losses derived for 1999/2000 also show good agreement with four techniques, giving 105 DU (SAOZ/REPROBUS), 80 DU (380-700 K partial column from Polar Ozone and Aerosol Monitoring (POAM)/REPROBUS), 85+/-10 DU (HALOE ozone tracer), and 88+/-13 (400-580 partial column from Match). There are some remaining discrepancies with ozone losses calculated using HALOE ozone tracer relations; it is important to ensure that the initial relation is truly representative of the vortex prior to the period of ozone loss. C1 Univ Cambridge, European Ozone Res Coordinating Unit, Ctr Atmospher Sci, Cambridge CB2 1HE, England. Alfred Wegener Inst, D-14473 Potsdam, Germany. CNRS, Serv Aeron, Paris, France. Danish Meteorol Inst, DK-2100 Copenhagen, Denmark. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. New Mexico Highlands Univ, Dept Phys, Las Vegas, NV USA. Forschungszentrum Julich, D-52425 Julich, Germany. RP Harris, NRP (reprint author), Univ Cambridge, European Ozone Res Coordinating Unit, Ctr Atmospher Sci, 14 Union Rd, Cambridge CB2 1HE, England. EM Neil.Harris@ozone-sec.ch.cam.ac.uk; mrex@awi-potsdam.de; florence.goutail@aerov.jussieu.fr; bk@dmi.dk; manney@mls.jpl.nasa.gov; Ro.Mueller@gfz-juelich.de; gathen@awi-potsdam.de RI Rex, Markus/A-6054-2009; von der Gathen, Peter/B-8515-2009; Muller, Rolf/A-6669-2013; OI Rex, Markus/0000-0001-7847-8221; von der Gathen, Peter/0000-0001-7409-1556; Muller, Rolf/0000-0002-5024-9977; Harris, Neil/0000-0003-1256-3006 NR 51 TC 45 Z9 45 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 31 PY 2002 VL 107 IS D20 AR 8264 DI 10.1029/2001JD000482 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 634ZA UT WOS:000180371300001 ER PT J AU McFarlane, SA Evans, KF Ackerman, AS AF McFarlane, SA Evans, KF Ackerman, AS TI A Bayesian algorithm for the retrieval of liquid water cloud properties from microwave radiometer and millimeter radar data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE remote sensing; clouds; radar; microwave radiometer; Bayes ID MARINE BOUNDARY-LAYER; AVERAGED SOLAR FLUXES; RADIATIVE-TRANSFER; STRATIFORM CLOUDS; STRATUS CLOUD; MICROPHYSICS; MODEL; PARAMETERIZATION; SCATTERING; DRIZZLE AB [1] We present anew algorithm for retrieving optical depth and liquid water content and effective radius profiles of nonprecipitating liquid water clouds using millimeter wavelength radar reflectivity and dual-channel microwave brightness temperatures. The algorithm is based on Bayes' theorem of conditional probability and combines prior information on cloud microphysics with the remote sensing observations. Prior probability distribution functions for liquid water clouds were derived from the second, third, and sixth moments of droplet size distributions measured by in situ aircraft probes in shallow tropical cumuli. The algorithm also calculates error bars for each retrieved parameter. To assess the algorithm, we perform retrieval simulations using radar reflectivity and brightness temperatures simulated from tropical cumulus fields calculated by a large eddy simulation model with explicit microphysics. These retrieval simulations show that the Bayesian algorithm has similar magnitude errors to current retrieval methods for liquid water content and liquid water path retrievals but has much smaller errors for effective radius and optical depth. We also perform retrievals on three months of data from the Atmospheric Radiation Measurement (ARM) Program's site on Nauru in the tropical west Pacific. For nonprecipitating liquid water clouds over Nauru during June-August 1999 we retrieve a mean optical depth of 9.2, mean liquid water content of 0.112 g/m(3), and mean effective radius of 7.8 mum. The Bayesian method is a flexible approach to cloud profile remote sensing and could be expanded to other sites or cloud types. C1 Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP McFarlane, SA (reprint author), Univ Colorado, Program Atmospher & Ocean Sci, Campus Box 311, Boulder, CO 80309 USA. RI McFarlane, Sally/C-3944-2008; Ackerman, Andrew/D-4433-2012 OI Ackerman, Andrew/0000-0003-0254-6253 NR 41 TC 34 Z9 34 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 31 PY 2002 VL 107 IS D16 AR 4317 DI 10.1029/2001JD001011 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 634JG UT WOS:000180335800001 ER PT J AU von Konig, M Bremer, H Kleinbohl, A Kullmann, H Kunzi, KF Goede, APH Browell, EV Grant, WB Burris, JF McGee, TJ Twigg, L AF von Konig, M Bremer, H Kleinbohl, A Kullmann, H Kunzi, KF Goede, APH Browell, EV Grant, WB Burris, JF McGee, TJ Twigg, L TI Using gas-phase nitric acid as an indicator of PSC composition SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID POLAR STRATOSPHERIC CLOUDS; AIRBORNE; TEMPERATURE; TRIHYDRATE; DEPLETION; PARTICLES; PROFILES; LIDAR; OZONE; HCL AB The composition of polar stratospheric cloud particles is investigated using data from several remote sensing instruments: gas-phase HNO3 measured by the Airborne Submillimeter Radiometer (ASUR), temperature measured by the Airborne Raman Ozone, Temperature and Aerosol Lidar (AROTEL), and aerosol backscatter wavelength dependence and depolarization measured by the UV Differential Absorption Lidar (DIAL). All three instruments have been operated onboard the NASA DC-8 during the SOLVE winter 1999/2000. A simple thermodynamical model is used to calculate the gas-phase amount of HNO3 in the presence of polar stratospheric clouds (PSCs) along the flight track of the DC-8 for one flight into the polar vortex on 7 December 1999. Three types of PSCs are considered in the model: nitric acid trihydrate (NAT), nitric acid dihydrate (NAD), and supercooled ternary solutions (STS). The comparison of the modeled and measured gas-phase HNO3 in the presence of PSCs shows a very good agreement if a NAT composition of the particles is assumed. However, sensitivity studies show that while the PSCs observed on this flight are not in agreement with a STS composition, the model is very sensitive to temperature, and a NAD composition of the PSC cannot be ruled out. C1 Univ Bremen, Inst Environm Phys, D-28359 Bremen, Germany. SRON, Utrecht, Netherlands. NASA, Langley Res Ctr, Hampton, VA 23681 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP von Konig, M (reprint author), Univ Bremen, Inst Environm Phys, Kufsteiner Str, D-28359 Bremen, Germany. RI Grant, William/B-8311-2009; Sinnhuber, Miriam/A-7252-2013; McGee, Thomas/G-4951-2013 OI Grant, William/0000-0002-1439-3285; NR 31 TC 7 Z9 7 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 31 PY 2002 VL 107 IS D20 AR 8265 DI 10.1029/2001JD001041 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 634ZA UT WOS:000180371300002 ER PT J AU Matthies, L Xiong, Y Hogg, R Zhu, D Rankin, A Kennedy, B Hebert, M Maclachlan, R Won, C Frost, T Sukhatme, G McHenry, M Goldberg, S AF Matthies, L Xiong, Y Hogg, R Zhu, D Rankin, A Kennedy, B Hebert, M Maclachlan, R Won, C Frost, T Sukhatme, G McHenry, M Goldberg, S TI A portable, autonomous, urban reconnaissance robot SO ROBOTICS AND AUTONOMOUS SYSTEMS LA English DT Article; Proceedings Paper CT 6th International Conference on Intelligent Autonomous Systems (IAS-6) CY JUL 25-27, 2000 CL VENICE, ITALY SP Intelligent Autonomous Syst Soc, Italian Assoc Artificial Intelligence, Italian Assoc Robot DE mobile robots; autonomous navigation; obstacle avoidance; visual servoing; visual stair climbing AB Portable mobile robots, in the size class of 20kg or less, could be extremely valuable as autonomous reconnaissance platforms in urban hostage situations and disaster relief. We have developed a prototype urban robot on a novel chassis with articulated tracks that enable stair climbing and scrambling over rubble. Autonomous navigation capabilities of the robot include stereo vision-based obstacle avoidance, visual servoing to user-designated goals, and autonomous vision-guided stair climbing. The system was demonstrated in an urban reconnaissance mission scenario at Fort Sam Houston in October 1999. A two-axis scanning laser rangefinder has been developed and integrated into the robot for indoor mapping and position estimation. This paper describes the robot, its performance in field trials, and some of the technical challenges that remain to enable fieldable urban reconnaissance robots. (C) 2002 Published by Elsevier Science B.V. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. iRobot, Somerville, MA 01243 USA. Univ So Calif, Los Angeles, CA 90007 USA. RP Matthies, L (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 125-209, Pasadena, CA 91109 USA. NR 9 TC 45 Z9 54 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8890 J9 ROBOT AUTON SYST JI Robot. Auton. Syst. PD AUG 31 PY 2002 VL 40 IS 2-3 BP 163 EP 172 AR PII S0921-8890(02)00241-5 DI 10.1016/S0921-8890(02)00241-5 PG 10 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Robotics SC Automation & Control Systems; Computer Science; Robotics GA 590WR UT WOS:000177847800011 ER PT J AU Knudsen, BM Pommereau, JP Garnier, A Nunes-Pinharanda, M Denis, L Newman, P Letrenne, G Durand, M AF Knudsen, BM Pommereau, JP Garnier, A Nunes-Pinharanda, M Denis, L Newman, P Letrenne, G Durand, M TI Accuracy of analyzed stratospheric temperatures in the winter Arctic vortex from infrared Montgolfier long-duration balloon flights - 2. Results SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE temperature; analyses; accuracy; Arctic; long-duration balloon ID CLOUDS AB [1] Five long-duration flights with the Mongolfier infrared (MIR) balloon lasting 15 days, on average, have been conducted in the Arctic winter stratospheric vortex in 1997, 1999, and 2000. Temperatures from the European Centre for Medium-Range Weather Forecasts (ECMWF), Met Office (MO), National Centers for Environmental Prediction (NCEP), Data Assimilation Office (DAO), and NCEP/NCAR reanalysis (REA) have been compared to the observations from 4 to 146 hPa. Occasional large errors (>14 K) occur in each analysis, mainly above 30 hPa. In 2000 the standard deviations of ECMWF, MO, and DAO with respect to the measured temperatures range from 1.0 to 1.3 K, whereas NCEP and REA have substantially larger errors. In 1999 the flights took place during a major warming, and all operational models had large standard deviations and substantial biases. Preoperational versions of the new ECMWF model with increased stratospheric resolution and assimilation of the advanced microwave sounding unit, which none of the other models assimilated, show small biases and standard deviations. C1 Danish Meteorol Inst, DK-2100 Copenhagen, Denmark. CNRS, Serv Aeron, F-91370 Verrieres Les Buissons, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Ctr Natl Etud Spatiale, Toulouse, France. RP Knudsen, BM (reprint author), Danish Meteorol Inst, Lyngbyvej 100, DK-2100 Copenhagen, Denmark. RI Newman, Paul/D-6208-2012 OI Newman, Paul/0000-0003-1139-2508 NR 28 TC 14 Z9 14 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 30 PY 2002 VL 107 IS D20 AR 4316 DI 10.1029/2001JD001329 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 634YG UT WOS:000180369600001 ER PT J AU Mellqvist, J Galle, B Blumenstock, T Hase, F Yashcov, D Notholt, J Sen, B Blavier, JF Toon, GC Chipperfield, MP AF Mellqvist, J Galle, B Blumenstock, T Hase, F Yashcov, D Notholt, J Sen, B Blavier, JF Toon, GC Chipperfield, MP TI Ground-based FTIR observations of chlorine activation and ozone depletion inside the Arctic vortex during the winter of 1999/2000 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE Arctic; ground-based FTIR; accumulated ozone loss; chlorine activation ID HNO3; HF; STRATOSPHERE; MODELS; HCL AB [1] The time evolution and latitudinal distribution of ozone and chlorine species (HCl, ClONO(2), and ClO) in the Arctic and midlatitude stratosphere have been studied for the winter of 1999/2000. This has been done by the use of ground-based solar absorption Fourier Transform Infrared (FTIR) measurements from four locations: Harestua (60.2degreesN, 10.8degreesE), Kiruna (67.8degreesN, 20.4degreesE), Esrange (67.9degreesN, 21.1degreesE), and Ny. Alesund (79degreesN, 12degreesE). The measurements were normalized with the inert tracer HF to minimize the effects of transport, combined using the concept of equivalent latitude and interpreted using the 3D model SLIMCAT. By late January, there was strong chlorine activation with 33% of the available inorganic chlorine column (HCl + ClONO(2)) being lost, with amounts of ClO greatly enhanced. By the middle of March, the ClO had been deactivated to ClONO(2), which exceeded its original fractional abundance (41%), but HCl stayed low (39%) and the ClO columns were still enhanced. The strong and sustained chlorine activations caused considerable accumulated ozone column loss of (12 +/- 7)% and (31 +/- 4)% by the beginning of February and March, respectively. The model showed only (5 3)% and (23 +/- 5)% column loss for the same time periods. By comparison, the 1998/1999 winter measurements showed no significant loss of column ozone but a 10% loss in the model. C1 Chalmers, S-41296 Gothenburg, Sweden. Forschungszentrum, IMK, Karlsruhe, Germany. Univ Karlsruhe, Karlsruhe, Germany. Swedish Inst Space Phys, Dept Atmospher Phys, S-98128 Kiruna, Sweden. Alfred Wegener Inst Polar & Marine Res, Potsdam, Germany. CALTECH, Jet Prop Lab, Pasadena, CA USA. Univ Leeds, Sch Environm, Leeds, W Yorkshire, England. RP Mellqvist, J (reprint author), Chalmers, S-41296 Gothenburg, Sweden. EM johan.mellqvist@rss.chalmers.se RI Blumenstock, Thomas/K-2263-2012; Hase, Frank/A-7497-2013; Chipperfield, Martyn/H-6359-2013; Galle, Bo/F-7996-2016; Notholt, Justus/P-4520-2016 OI Chipperfield, Martyn/0000-0002-6803-4149; Galle, Bo/0000-0001-9989-809X; Notholt, Justus/0000-0002-3324-885X NR 37 TC 13 Z9 13 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 30 PY 2002 VL 107 IS D20 AR 8263 DI 10.1029/2001JD001080 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 634YG UT WOS:000180369600003 ER PT J AU Arvidson, RE Squyres, SW Baumgartner, EI Schenker, PS Niebur, CS Larsen, KW Seelos, FP Snider, NO Jolliff, BL AF Arvidson, RE Squyres, SW Baumgartner, EI Schenker, PS Niebur, CS Larsen, KW Seelos, FP Snider, NO Jolliff, BL TI FIDO prototype Mars rover field trials, Black Rock Summit, Nevada, as test of the ability of robotic mobility systems to conduct field science SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Mars; rovers; field trials; FIDO; MER; remote sensing ID MISSION; CALIFORNIA; LAKE AB [i] The Field Integration Design and Operations (FIDO) prototype Mars rover was deployed and operated remotely for 2 weeks in May 2000 in the Black Rock Summit area of Nevada. The blind science operation trials were designed to evaluate the extent to which FIDO-class rovers can be used to conduct traverse science and collect samples. FIDO-based instruments included stereo cameras for navigation and imaging, an infrared point spectrometer, a color microscopic imager for characterization of rocks and soils, and a rock drill for core acquisition. Body-mounted "belly" cameras aided drill deployment, and front and rear hazard cameras enabled terrain hazard avoidance. Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) data, a high spatial resolution IKONOS orbital image, and a suite of descent images were used to provide regional- and local-scale terrain and rock type information, from which hypotheses were developed for testing during operations. The rover visited three sites, traversed 30 m, and acquired 1.3 gigabytes of data. The relatively small traverse distance resulted from a geologically rich site in which materials identified on a regional scale from remote-sensing data could be identified on a local scale using rover-based data. Results demonstrate the synergy of mapping terrain from orbit and during descent using imaging and spectroscopy, followed by a rover mission to test inferences and to make discoveries that can be accomplished only with surface mobility systems. C1 Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Arvidson, RE (reprint author), Washington Univ, Dept Earth & Planetary Sci, Campus Box 1169,1 Brookins Dr, St Louis, MO 63130 USA. RI Seelos, Frank/C-7875-2016 OI Seelos, Frank/0000-0001-9721-941X NR 19 TC 0 Z9 0 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD AUG 30 PY 2002 VL 107 IS E11 AR 8003 DI 10.1029/2000JE001464 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 623LL UT WOS:000179704300002 ER PT J AU Li, RX Ma, F Xu, FL Matthies, LH Olson, CF Arvidson, RE AF Li, RX Ma, F Xu, FL Matthies, LH Olson, CF Arvidson, RE TI Localization of Mars rovers using descent and surface-based image data SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Mars rover; localization; mapping; topography; bundle adjustment; navigation AB [1] The planned 2003 Mars Exploration Rover (MER) Mission and follow-on surface activities associated with landed missions will focus on long distance roving and sample return, which require detailed knowledge of vehicle locations in both local and global reference systems. In this paper we argue that this rover localization should be known to within 0.1 of the distance traversed for local coordinate systems. To test the ability to meet this goal using only descent and rover-based data, we conducted experiments with simulated descent images and Field Integrated Design and Operations Rover data collected during field tests at Silver Lake, California, in April 1999. Specifically, an integrated bundle adjustment system incorporating both descent and rover-based images was developed and used to localize the rover positions. On the basis of surveyed ground control points it is demonstrated that the joint analysis produces RMS errors of 0.24, 0.15, and 0.38 m in x, y, and z% directions in a local coordinate system, respectively, for ground points within 500 m from the landing point and 0.23, 0.21, and 0.46 m within a distance of 1.5 km. Results show that it is possible to meet the 0.1 goal using descent and rover-based data only. C1 Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Columbus, OH 43210 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. RP Li, RX (reprint author), Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Columbus, OH 43210 USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD AUG 30 PY 2002 VL 107 IS E11 AR 8005 DI 10.1029/2000JE001443 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 623LL UT WOS:000179704300004 ER PT J AU Rignot, E Thomas, RH AF Rignot, E Thomas, RH TI Mass balance of polar ice sheets SO SCIENCE LA English DT Review ID WEST ANTARCTICA; ELEVATION CHANGE; SATELLITE DATA; PINE ISLAND; GREENLAND; GLACIER; CLIMATE; SHELF; INTERFEROMETRY; RETREAT AB Recent advances in the determination of the mass balance of polar ice sheets show that the Greenland Ice Sheet is losing mass by near-coastal thinning, and that the West Antarctic Ice Sheet, with thickening in the west and thinning in the north, is probably thinning overall. The mass imbalance of the East Antarctic Ice Sheet is likely to be small, but even its sign cannot yet be determined. Large sectors of ice in southeast Greenland, the Amundsen Sea Embayment of West Antarctica, and the Antarctic Peninsula are changing quite rapidly as a result of processes not yet understood. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. EG&G Serv, Wallops Isl Flight Facil, Wallops Isl, VA 23337 USA. RP Rignot, E (reprint author), CALTECH, Jet Prop Lab, Mail Stop 300-235, Pasadena, CA 91109 USA. EM eric@adelie.jpl.nasa.gov; robert_thomas@hotmail.com RI Rignot, Eric/A-4560-2014 OI Rignot, Eric/0000-0002-3366-0481 NR 54 TC 255 Z9 271 U1 7 U2 70 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 30 PY 2002 VL 297 IS 5586 BP 1502 EP 1506 DI 10.1126/science.1073888 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 588JA UT WOS:000177697300043 PM 12202817 ER PT J AU Schoeberl, MR Newman, PA Lait, LR McGee, TJ Burris, JF Browell, EV Grant, WB Richard, EC von der Gathen, P Bevilacqua, R Mikkelsen, IS AF Schoeberl, MR Newman, PA Lait, LR McGee, TJ Burris, JF Browell, EV Grant, WB Richard, EC von der Gathen, P Bevilacqua, R Mikkelsen, IS TI An assessment of the ozone loss during the 1999-2000 SOLVE/THESEO 2000 Arctic campaign SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ozone loss; polar ozone; SOLVE ozone loss ID POLAR VORTEX; POTENTIAL VORTICITY; WINTER; STRATOSPHERE; DEPLETION; SYSTEM; MODEL AB Ozone observations from ozonesondes, the lidars aboard the DC-8, in situ ozone measurements from the ER-2, and satellite ozone measurements from Polar Ozone and Aerosol Measurement III (POAM) were used to assess ozone loss during the Sage III Ozone Loss and Validation Experiment (SOLVE) and Third European Stratospheric Experiment on Ozone (THESEO) 1999-2000 Arctic campaign. Two methods of analysis were used. In the first method a simple regression analysis of the data time series is performed on the ozonesonde and POAM measurements within the vortex. In the second method the ozone measurements from all available ozone data were injected into a free-running diabatic trajectory model and were carried forward in time from 1 December to 15 March. Vortex ozone loss was then estimated by comparing the ozone values of those parcels initiated early in the campaign with those parcels injected later in the campaign. Despite the variety of observational techniques used during SOLVE, the measurements provide a fairly consistent picture. Over the whole vortex the largest ozone loss occurs between 550 and 400 K potential temperatures (similar to23-16 km) with over 1.5 ppmv (similar to55%) lost by 15 March, the end of the SOLVE mission period. An ozone loss rate of 0.04-0.05 ppmv/day was computed for 15 March. The total column loss was between 44 and 57 DU or 11-15%. Ozonesondes launched after 15 March suggest that an additional 0.5 ppmv or more ozone was lost between 15 March and 1 April. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Div Atmospher Sci, Langley Res Ctr, Hampton, VA 23681 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Alfred Wegener Inst Polar & Marine Res, Potsdam, Germany. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. Danish Meteorol Inst, Div Geophys, DK-2100 Copenhagen, Denmark. RP Schoeberl, MR (reprint author), NASA, Goddard Space Flight Ctr, Code 916,Bldg 33,Room E311A, Greenbelt, MD 20771 USA. RI von der Gathen, Peter/B-8515-2009; Grant, William/B-8311-2009; Newman, Paul/D-6208-2012; McGee, Thomas/G-4951-2013 OI von der Gathen, Peter/0000-0001-7409-1556; Grant, William/0000-0002-1439-3285; Newman, Paul/0000-0003-1139-2508; NR 37 TC 19 Z9 19 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 28 PY 2002 VL 107 IS D20 AR 8261 DI 10.1029/2001JD000412 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 634XM UT WOS:000180367800001 ER PT J AU Weimer, DR Ober, DM Maynard, NC Burke, WJ Collier, MR McComas, DJ Ness, NF Smith, CW AF Weimer, DR Ober, DM Maynard, NC Burke, WJ Collier, MR McComas, DJ Ness, NF Smith, CW TI Variable time delays in the propagation of the interplanetary magnetic field SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE interplanetary magnetic field; IMF; space weather; Advanced Composition Explorer; ACE ID WIND PLASMA CORRELATIONS; SOLAR-WIND; IONOSPHERIC CONVECTION; EARTH AB Simultaneous measurements of the interplanetary magnetic field ( IMF) are obtained at various locations with four spacecraft, ACE, Wind, IMP-8, and Geotail. We have devised a technique whereby the exact propagation delay time between ACE, at the L1 orbit, and each of the other three spacecraft can be derived from these measurements. This propagation delay is determined as a continuously varying function of time; when this measured delay is applied to all three components of the IMF measured by ACE, they will match the other satellites' IMF to a degree that is much better than expected. However, the actual time delays can vary by nearly an hour in either direction from the expected advection delays, and the lag times have significant changes that can occur on a timescale of a few minutes. These results are interpreted as due to the effects of tilted phase fronts that are changing orientation with time. We have used the delay measurements between multiple satellites to calculate the three-dimensional orientation and temporal variations of the phase front. The best fit phase front plane usually lies within 4 RE or less from the four-point measurements, indicating a lag resolution of a minute or less. Computer animations of the time-varying phase fronts are used to illustrate their behavior. Orientations can change on short timescales. Our findings have implications for both basic research and "space weather'' predictions. These results give a high confidence that the same IMF that is measured near L1 will most likely impact the Earth's magnetosphere, providing ample justification for use of spacecraft data in halo orbit at L1 for monitoring the upstream solar wind prior to its interacting with the magnetosphere. However, there is strong uncertainty in the timing of the arrival of the detailed IMF structures, and these delays will need to be considered. C1 Mission Res Corp, Nashua, NH 03062 USA. USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. SW Res Inst, San Antonio, TX 78228 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. RP Weimer, DR (reprint author), Mission Res Corp, 589 W Hollis St,Suite 201, Nashua, NH 03062 USA. RI Collier, Michael/I-4864-2013 OI Collier, Michael/0000-0001-9658-6605 NR 25 TC 62 Z9 62 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 28 PY 2002 VL 107 IS A8 AR 1210 DI 10.1029/2001JA009102 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 622FB UT WOS:000179634900004 ER PT J AU Shaman, J Stieglitz, M Engel, V Koster, R Stark, C AF Shaman, J Stieglitz, M Engel, V Koster, R Stark, C TI Representation of subsurface storm flow and a more responsive water table in a TOPMODEL-based hydrology model SO WATER RESOURCES RESEARCH LA English DT Article DE TOPMODEL; storm flow; vadose zone processes; soil porosity profile ID REGIONAL-SCALE HYDROLOGY; CATCHMENT-BASED APPROACH; LAND-SURFACE PROCESSES; VIC-2L MODEL; SOIL; SIMILARITY; GENERATION; PATHWAYS; SLOPE AB [1] This study presents two new modeling strategies. First, a methodology for representing the physical process of subsurface storm flow within a TOPMODEL framework is developed. In using this approach, discharge at quick flow timescales is simulated, and a fuller depiction of hydrologic activity is brought about. Discharge of water from the vadose zone is permitted in a physically realistic manner without a priori assumption of the level within the soil column at which subsurface storm flow saturation can take place. Determination of the subsurface storm flow contribution to discharge is made using the equation for groundwater flow. No new parameters are needed. Instead, regions in excess of field capacity that develop during storm events, producing vertical recharge, are also allowed to contribute to soil zone discharge. These subsurface storm flow contributions to river runoff, as for groundwater flow contributions, are a function of catchment topography and hydraulic conductivity at the depth at which such regions in excess of field capacity occur. The second approach improves groundwater flow response through a reduction of porosity and field capacity with depth in the soil column. Large storm events are better captured and a more dynamic water table develops with application of this modified soil column profile (MSCP). The MSCP predominantly reflects soil depth differences in upland and lowland regions of a watershed. Combined, these two approaches, subsurface storm flow and the MSCP, provide a more accurate representation of the timescales at which discharge responds and a more complete depiction of hydrologic activity. Storm events large and small are better simulated, and some of the biases previously evident in TOPMODEL simulations are reduced. C1 Columbia Univ, Dept Earth & Environm Sci, New York, NY 10027 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. RP Shaman, J (reprint author), Columbia Univ, Dept Earth & Environm Sci, New York, NY 10027 USA. RI Koster, Randal/F-5881-2012 OI Koster, Randal/0000-0001-6418-6383 NR 41 TC 20 Z9 20 U1 1 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD AUG 27 PY 2002 VL 38 IS 8 AR 1156 DI 10.1029/2001WR000636 PG 17 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 622JR UT WOS:000179644400002 ER PT J AU Menzies, RT Tratt, DM Spinhirne, JD Hlavka, DL AF Menzies, RT Tratt, DM Spinhirne, JD Hlavka, DL TI Aerosol layers over the Pacific Ocean: Vertical distributions and optical properties as observed by multiwavelength airborne lidars SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review DE aerosol scattering vertical distribution; Pacific Ocean; Global Backscatter Experiment; airborne lidar; multiwavelength lidar; atmospheric dust ID MARINE BOUNDARY-LAYER; CHARACTERIZATION EXPERIMENT ACE-1; EXPERIMENT-II MEASUREMENTS; SEA-SALT AEROSOL; TROPOSPHERIC AEROSOLS; ATMOSPHERIC AEROSOL; SIZE DISTRIBUTION; NORTH PACIFIC; MAUNA-LOA; RADIATIVE PROPERTIES AB [1] Scattering properties of tropospheric aerosol layers were observed with airborne lidars during the Global Backscatter Experiment (GLOBE) airborne campaigns covering a wide range of latitude and longitude over the Pacific Ocean. Lidar data at 0.532, 1.064, 1.54, and 9.25 mum wavelengths are used to study the vertical profiles and optical properties of the marine boundary layer (MBL) as well as elevated dust layers due to transport of material from Asia. The lidars were calibrated to provide absolute aerosol backscatter coefficients at their respective wavelengths. The lidar data are compared with predictions based on commonly used dust and sea salt aerosol refractive index and size distribution parameters. Published observations of aerosol characteristics from onboard in situ sensors are used to verify locations where mineral dust aerosol dominated the aerosol optical properties in the free troposphere. Relative humidity has a major impact on the observed MBL aerosol scattering characteristics. The multiwavelength observations of the dust layers are consistent with the assumption that for the particle size range that dominates the scattering properties the particle size distribution varies little over 10 3 km transport distances and is not strongly dependent on altitude. A nonsphericity effect on the dust scattering, in particular the suppression of backscattering at the shorter lidar wavelengths, is discussed in the context of data comparisons with model predictions. The observations of the sea salt aerosol scattering in the remote MBL indicate that at altitudes above 150 m in optically clear conditions the influence of the supermicron coarse mode is minor compared with that of the submicron accumulation mode. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Menzies, RT (reprint author), CALTECH, Jet Prop Lab, MS 168-214,4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Tratt, David/A-7884-2009 OI Tratt, David/0000-0002-3942-6848 NR 103 TC 7 Z9 7 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 24 PY 2002 VL 107 IS D16 AR 4292 DI 10.1029/2001JD001196 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 634EJ UT WOS:000180326800004 ER PT J AU Fuselier, SA Collin, HL Ghielmetti, AG Claflin, ES Moore, TE Collier, MR Frey, H Mende, SB AF Fuselier, SA Collin, HL Ghielmetti, AG Claflin, ES Moore, TE Collier, MR Frey, H Mende, SB TI Localized ion outflow in response to a solar wind pressure pulse SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE ionospheric outflow; solar wind interactions; auroral ionosphere; neutral particle imaging ID ENERGY NEUTRAL ATOMS; IONOSPHERE; MAGNETOSPHERE; EVENTS AB Neutrals created by charge-exchange of low-energy (similar to10-100 eV) ion outflow from the ionosphere are imaged by the Low Energy Neutral Atom (LENA) imager on the IMAGE spacecraft. Comparing the neutral flux with changes in the solar wind during an ion outflow event on 24 June 2000 indicates that changes in solar wind density (and therefore dynamic pressure) are associated with episodic bursts of ion outflow. LENA images show that these bursts are confined to the duskside. Simultaneous images of the aurora from the IMAGE FUV Wideband Imaging Camera indicate that these episodic bursts on the duskside are associated with increased duskside auroral emissions. The pitch angle and charge exchange altitude for the ion outflow distributions are estimated by applying field line tracing in a model magnetic field and assuming that the outflow occurs in the auroral zone. The pitch angle information places constraints on the neutral atom images, indicating that the ion outflow observed on the duskside probably consists of high pitch angle conics and that field-aligned ion outflow from other parts of the oval cannot be observed from the IMAGE spacecraft location. C1 Lockheed Martin Adv Technol Ctr, Palo Alto, CA 94304 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Fuselier, SA (reprint author), Lockheed Martin Adv Technol Ctr, 3251 Hanover St,O-L9-42,Bldg 255, Palo Alto, CA 94304 USA. RI Moore, Thomas/D-4675-2012; Collier, Michael/I-4864-2013 OI Moore, Thomas/0000-0002-3150-1137; Collier, Michael/0000-0001-9658-6605 NR 23 TC 24 Z9 24 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 24 PY 2002 VL 107 IS A8 AR 1203 DI 10.1029/2001JA000297 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 622EZ UT WOS:000179634700003 ER PT J AU Kaufman, YJ Kleidman, RG Hall, DK Martins, JV Barton, JS AF Kaufman, YJ Kleidman, RG Hall, DK Martins, JV Barton, JS TI Remote sensing of subpixel snow cover using 0.66 and 2.1 mu m channels SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RESOLUTION; LAND AB Hydrologic models increasingly require knowledge of the amount of snow cover within a pixel in order to provide accurate estimates of snow covered area. Present methods for remote sensing of subpixel snow cover require knowledge of the spectral reflectance properties of the snow as well as the background material, making these methods difficult to apply globally. Similar problems were encountered in global remote sensing of aerosol particles over varying land terrain. Since both aerosol and snow are dark at 2.1 mum, we suggest a method for sub-pixel snow mapping based on experience with remote sensing of aerosols. Here the pixel reflectance at 2.1 mum is used to estimate the reflectance of the non-snow regions in the pixel at 0.66 mum. The difference between the total pixel brightness at 0.66 mum and the derived brightness of the same pixel without the snow is used to estimate the sub-pixel snow cover with an error usually < &PLUSMN;0.05. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. Univ Maryland Baltimore Cty, Baltimore, MD 21250 USA. Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. RP Kaufman, YJ (reprint author), NASA, Goddard Space Flight Ctr, Code 913, Greenbelt, MD 20771 USA. RI Hall, Dorothy/D-5562-2012 NR 15 TC 21 Z9 25 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 23 PY 2002 VL 29 IS 16 AR 1781 DI 10.1029/2001GL013580 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 622DY UT WOS:000179632300001 ER PT J AU Coe, MT Costa, MH Botta, A Birkett, C AF Coe, MT Costa, MH Botta, A Birkett, C TI Long-term simulations of discharge and floods in the Amazon Basin SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WATER-BALANCE; INTERANNUAL VARIABILITY; CLIMATE VARIABILITY; CONTINENTAL-SCALE; BIOSPHERE MODEL; SURFACE CLIMATE; CARBON BALANCE; LAKE CHAD; DEFORESTATION; INUNDATION AB A terrestrial ecosystem model (integrated biosphere simulator (IBIS)) and a hydrological routing algorithm (HYDRA) are used in conjunction with long time series climate data to simulate the river discharge and flooded area of the Amazon/Tocantins River basin over the last 60 years. Evaluating the results of this modeling exercise over the entire basin yields three major results: (1) Observations at 121 stations throughout the basin show that discharge is well simulated for most tributaries originating in Brazil. However, the discharge is consistently underestimated, by greater than 20%, for tributaries draining regions outside of Brazil and the main stem of the Amazon. The discharge underestimation is most likely a result of underestimated precipitation in the data set used as model input. (2) A new flooding algorithm within HYDRA captures the magnitude and timing of the river height and flooded area in relatively good agreement with observations, particularly downstream of the confluence of the Negro and Solimoes Rivers. (3) Climatic variability strongly impacts the hydrology of the basin. Specifically, we find that short (similar to3-4 years) and long (similar to28 years) modes of precipitation variability drive spatial and temporal variability in river discharge and flooded area throughout the Amazon/Tocantins River basins. C1 Univ Wisconsin, Ctr Sustainabil & Global Environm, Gaylord Nelson Inst Environm Studies, Madison, WI 53706 USA. Univ Fed Vicosa, BR-36571000 Vicosa, MG, Brazil. Univ Maryland Coll Pk, ESSIC, NASA GSFC, Greenbelt, MD 20771 USA. RP Coe, MT (reprint author), Univ Wisconsin, Ctr Sustainabil & Global Environm, Gaylord Nelson Inst Environm Studies, 1225 W Dayton St, Madison, WI 53706 USA. EM coe@phoebus.meteor.wisc.edu RI Costa, Marcos/A-5695-2009 OI Costa, Marcos/0000-0001-6874-9315 NR 34 TC 45 Z9 45 U1 1 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 23 PY 2002 VL 107 IS D20 AR 8044 DI 10.1029/2001JD000740 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 634XG UT WOS:000180367300003 ER PT J AU Hahne, GE AF Hahne, GE TI Schrodinger equation for joint bidirectional motion in time SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID COMPREHEND STATISTICAL LAWS; QUANTUM-MECHANICS; ARROWS; NEED AB The conventional time-dependent Schrodinger equation describes only unidirectional time evolution of the state of a physical system, i.e. forward or, less commonly, backward. This paper proposes a generalized quantum dynamics for the description of joint, and interactive, forward and backward time evolution within a physical system. The principal mathematical assumption for bidirectional evolution in general is that the space of states should be taken to be not merely a Hilbert space, but a more restricted entity known as a Krein space, which is a complex Hilbert space with a Hermitian operator that has eigenvalues +1 and -1 only, and that therefore gives rise to an indefinite metric. The vector subspaces of states with positive or negative norm with respect to the indefinite metric will-for open channels-be construed to be states in forward or, respectively, backward evolution along the time axis. The quantum dynamics is generated by a pseudo-Hermitian Hamiltonian operator and conserves inner products with respect to the indefinite metric. Input and output states are defined in physically plausible ways such that the output comprises both reflected and transmitted states from a zone of interaction in time; a unitary transformation between input and output states is obtained from the pseudounitary transformation between the initial and final states. Three applications are studied: (1) a formal theory of collisions in terms of perturbation theory; (2) a relativistically invariant quantum field theory for a system that kinematically comprises the direct sum of two quantized real scalar fields, such that one subfield evolves forward and the other backward in time, and such that there is dynamical coupling between the subfields; (3) an argument that in the latter field theory, the dynamics predicts that in a range of values of the coupling constants, the expectation value of the vacuum energy of the universe is forced to be zero to high accuracy. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hahne, GE (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 54 TC 3 Z9 3 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD AUG 23 PY 2002 VL 35 IS 33 BP 7101 EP 7123 AR PII S0305-4470(02)36841-0 DI 10.1088/0305-4470/35/33/309 PG 23 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 594LP UT WOS:000178051900010 ER PT J AU Hedges, SB Kumar, S AF Hedges, SB Kumar, S TI Vertebrate genomes compared SO SCIENCE LA English DT Editorial Material ID PUFFERFISH C1 Penn State Univ, NASA, Astrobiol Inst, University Pk, PA 16802 USA. Penn State Univ, Dept Biol, Mueller Lab 208, University Pk, PA 16802 USA. Arizona State Univ, Dept Biol, Tempe, AZ 85287 USA. RP Hedges, SB (reprint author), Penn State Univ, NASA, Astrobiol Inst, University Pk, PA 16802 USA. RI Kumar, Sudhir/F-1411-2011 NR 15 TC 78 Z9 81 U1 0 U2 6 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 23 PY 2002 VL 297 IS 5585 BP 1283 EP 1285 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 586FL UT WOS:000177573900026 PM 12193771 ER PT J AU Matsunaga, N Chaban, GM Gerber, RB AF Matsunaga, N Chaban, GM Gerber, RB TI Degenerate perturbation theory corrections for the vibrational self-consistent field approximation: Method and applications SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SPECTROSCOPY CALCULATIONS; POLYATOMIC-MOLECULES; BASIS-SETS; AB-INITIO; RARE-GAS; STATES; ENERGIES; DENSITY; SYSTEMS; SPECTRUM AB A new algorithm for computing anharmonic vibrational states for polyatomic molecules is proposed. The algorithm starts with the vibrational self-consistent field (VSCF) method and uses degenerate perturbation theory to correct for effects of correlation between different vibrational modes. The algorithm is developed in a version that computes the anharmonic vibrational spectroscopy directly from potential energy surface points calculated by using ab initio codes. The method is applied to several molecules where near degeneracies occur for excited vibrational states, including HOOH, HSSH, and HOOOH. The method yields results in very good accordance with experiments and generally provides improvements over nondegenerate perturbation corrections for VSCF. (C) 2002 American Institute of Physics. C1 Long Isl Univ, Dept Chem & Biochem, Brooklyn, NY 11201 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Hebrew Univ Jerusalem, Dept Phys Chem, IL-91904 Jerusalem, Israel. Hebrew Univ Jerusalem, Fritz Harbor Res Ctr, IL-91904 Jerusalem, Israel. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. RP Matsunaga, N (reprint author), Long Isl Univ, Dept Chem & Biochem, Brooklyn, NY 11201 USA. EM Nikita.Matsunaga@liu.edu; chaban@pegasus.arc.nasa.gov; benny@fh.huji.ac.il NR 44 TC 118 Z9 118 U1 0 U2 15 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 22 PY 2002 VL 117 IS 8 BP 3541 EP 3547 DI 10.1063/1.1494978 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 582KZ UT WOS:000177351100003 ER PT J AU Lin, X Fowler, LD Randall, DA AF Lin, X Fowler, LD Randall, DA TI Flying the TRMM Satellite in a general circulation model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE TRMM; sampling; orbit; precipitation; GCM ID ICE-CLOUD MICROPHYSICS; SURFACE PARAMETERIZATION SIB2; OUTGOING LONGWAVE RADIATION; SHALLOW-WATER EQUATIONS; PRESENT-WEATHER REPORTS; MEASURING MISSION TRMM; TIME STOCHASTIC-MODEL; DARWIN RAINFALL DATA; SAMPLING ERROR; DIURNAL CYCLE AB By incorporating the Tropical Rainfall Measurement Mission (TRMM) satellite orbital information into the Colorado State University General Circulation Model (CSU GCM), we are able to "fly'' a satellite in the GCM and sample the simulated atmosphere in the same way as the TRMM sensors sample the real atmosphere. The TRMM-sampled statistics for precipitation and radiative fluxes at annual, intraseasonal, monthly mean, and seasonal-mean diurnal timescales are evaluated by comparing the satellite-sampled against fully sampled simulated atmospheres. The sampling rates of the TRMM sensors are significantly affected by the sensors' swath widths. The TRMM Microwave Imager (TMI) and the Visible Infrared Scanner (VIRS) sample each 2.25degrees x 2.25degrees grid box in the tropics and subtropics about once per day, but at a different local time every day, while the precipitation radar (PR) and the Clouds and the Earth's Radiant Energy System (CERES) sensor visit each grid box about once every 3 days and twice per day, respectively. Besides inadequate samplings resulting from sensors' swath widths, there is a large, systematic diurnal undersampling associated with TRMM's orbital geometry for grid boxes away from the equator. When only 1 month of TRMM data are used, this diurnal undersampling can lead to more daytime samples relative to nighttime samples in one hemisphere and more nighttime samples relative to daytime samples in the other hemisphere. The resulting sampling biases (3-6 W m(-2)) are very pronounced in outgoing longwave radiation (OLR) over the subtropical landmasses. The sampling errors in OLR monthly and seasonal means are less than 8 W m(-2) (5%) for each 2.25degrees x 2.25degrees grid box. The OLR monthly and seasonal means are not sensitive to diurnal undersamplings associated with the TRMM orbits and sensors' swath widths. However, this is not the case for total precipitation. Diurnal undersampling could produce errors as large as 20% in the tropics and 40% in the subtropics, for the zonally averaged monthly mean rain rates. The TRMM orbits sample each 2.25degrees x 2.25degrees grid box in the tropics and subtropics 1-6 times for each hour of the day within a single season. The seasonal-mean diurnal cycles of precipitation and OLR are not well sampled for any one grid box. By either accumulating the satellite data for a long enough period, or averaging the data over a large area with a relatively uniform diurnal signal, the diurnal cycles of precipitation and OLR can be satisfactorily sampled. The effects of TRMM sampling errors on the inferred tropical-mean hydrologic cycle and radiative fluxes are also evaluated. There are strong spurious oscillations associated with TRMM's orbital geometry, with periods of 23 days and 3-4 months, in tropical-mean daily and monthly precipitation. While the relative fluctuations of the sampled OLR are negligible, the relative fluctuations of the sampled precipitation have magnitudes similar to those of the observed climate variability. Caution must therefore be used when applying TRMM observations of tropical-mean precipitation to interpret climate variations at intraseasonal and interannual scales. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RP Lin, X (reprint author), NASA, Goddard Space Flight Ctr, UMBC GEST Data Assimilat Off, Code 910-3, Greenbelt, MD 20771 USA. EM xlin@dao.gsfc.nasa.gov RI Randall, David/E-6113-2011 OI Randall, David/0000-0001-6935-4112 NR 54 TC 12 Z9 12 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 22 PY 2002 VL 107 IS D16 AR 4281 DI 10.1029/2001JD000619 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 634DD UT WOS:000180324000002 ER PT J AU Rickenbach, TM Ferreira, RN Halverson, JB Herdies, DL Dias, MAFS AF Rickenbach, TM Ferreira, RN Halverson, JB Herdies, DL Dias, MAFS TI Modulation of convection in the southwestern Amazon basin by extratropical stationary fronts SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE convection; tropics; Amazon; monsoon; low; level jet; TRMM ID SOUTH-AMERICA; TOGA COARE; LIFE-CYCLE; RADAR; SCALE; VARIABILITY; DISTRIBUTIONS; REFLECTIVITY; CIRCULATION; EVOLUTION AB [1] Regimes of lower tropospheric northwesterly wind observed in southwestern Amazonia during the Tropical Rainfall Measuring Mission Large-Scale Biosphere Atmosphere (TRMM-LBA) field campaign were shown to be local manifestations of stationary frontal systems that extended into the deep Tropics along the South Atlantic Convergence Zone ("SACZ'' regime). Frontal systems were transient and were confined to the subtropics during the interim periods of easterly and weak westerly flow ("non-SACZ'' regime). Observations from surface-based radar in TRMM-LBA suggested that mesoscale convective systems in the SACZ regime were significantly larger in areal coverage, with weaker rainfall intensity and weaker vertical development of the convective cells. The diurnal variation of rain intensity and rain areal coverage generally showed afternoon maxima for both regimes, but with important differences suggesting explosive convective cell growth in the non-SACZ regime and the dominance of nocturnal stratiform rain processes in the SACZ regime. These results had implications for the parameterization (in general circulation models) of subgrid-scale convective processes in Amazonia in terms of the large-scale flow and for improving precipitation and latent heating retrieval from spaceborne platforms such as the TRMM satellite. C1 Univ Maryland, Joint Ctr Earth Technol, Baltimore, MD 21201 USA. NASA, Goddard Space Flight Ctr, Mesoscale Proc Branch, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Seasonal Interannual Predict Proj, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Data Assimilat Off, Greenbelt, MD 20771 USA. Univ Sao Paulo, Inst Astron & Geophys, Dept Atmospher Sci, Sao Paulo, Brazil. RP Rickenbach, TM (reprint author), Univ Maryland, Joint Ctr Earth Technol, Baltimore, MD 21201 USA. RI Herdies, Dirceu/C-6675-2013 OI Herdies, Dirceu/0000-0002-2872-8453 NR 40 TC 55 Z9 56 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 22 PY 2002 VL 107 IS D20 AR 8040 DI 10.1029/2000JD000263 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 634JP UT WOS:000180336500005 ER PT J AU Rannou, P Hourdin, F McKay, CP AF Rannou, P Hourdin, F McKay, CP TI A wind origin for Titan's haze structure SO NATURE LA English DT Article ID GENERAL-CIRCULATION; ATMOSPHERE; AEROSOLS; MODEL; OCCULTATION; SCATTERING; GROWTH AB Titan, the largest moon of Saturn, is the only satellite in the Solar System with a dense atmosphere. Titan's atmosphere is mainly nitrogen with a surface pressure of 1.5 atmospheres and a temperature of 95 K (ref. 1). A seasonally varying(2) haze, which appears to be the main source of heating and cooling that drives atmospheric circulation(3,4), shrouds the moon. The haze has numerous features that have remained unexplained. There are several layers(5), including a 'polar hood'(6-8), and a pronounced hemispheric asymmetry(2). The upper atmosphere rotates much faster than the surface of the moon(9,10), and there is a significant latitudinal temperature asymmetry at the equinoxes(11,12). Here we describe a numerical simulation of Titan's atmosphere, which appears to explain the observed features of the haze. The critical new factor in our model is the coupling of haze formation with atmospheric dynamics, which includes a component of strong positive feedback between the haze and the winds. C1 Univ Paris 06 Univ Versailles St Quentin, Serv Aeron, F-75252 Paris, France. Univ Paris 06, Meteorol Dynam Lab, F-75252 Paris, France. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Rannou, P (reprint author), Univ Paris 06 Univ Versailles St Quentin, Serv Aeron, B102,4 Pl Jussieu, F-75252 Paris, France. EM pra@ccr.jussieu.fr RI RANNOU, Pascal/I-9059-2012 NR 28 TC 84 Z9 84 U1 1 U2 9 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 22 PY 2002 VL 418 IS 6900 BP 853 EP 856 DI 10.1038/nature00961 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 585YR UT WOS:000177555600031 PM 12192403 ER PT J AU Iorio, L Ciufolini, I Pavlis, EC AF Iorio, L Ciufolini, I Pavlis, EC TI Measuring the relativistic perigee advance with satellite laser ranging SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article ID GRAVITY; VERIFICATION; EQUIVALENCE; PRINCIPLE; MERCURY; IMPACT; RADAR; LUNAR AB The pericentric advance of a test body by a central mass is one of the classical tests of general relativity. Today, this effect is measured with radar ranging by the perihelion shift of Mercury and other planets, in the gravitational field of Sun, with a relative accuracy of the order of 10(-2)-10(-3). In this paper, we explore the possibility of a measurement of the pericentric advance in the I gravitational field of Earth by analysing the laser-ranged data of some orbiting, or proposed, laser-ranged geodetic satellites. Such a measurement of the perigee advance would place limits on hypothetical, very weak, Yukawa-type components of the gravitational interaction, with a finite range of the order of 104 km. Thus, we show that, at the I present level of knowledge of the orbital perturbations, the relative accuracy, achievable with suitably combined orbital elements of LAGEOS and LAGEOS II, is of the order of 10(-3). With the corresponding measured value of (2 + 2gamma - beta)/3, by using eta = 4beta - gamma - 3 from lunar laser ranging, we could get an estimate of the PPN parameters gamma and beta with an accuracy of the order of 10(-2)-10(-3). Nevertheless, these accuracies would be substantially improved in the near future with the new Earth gravity field models by the CRAMP and GRACE missions. The use of the perigee of LARES (LAser RElativity Satellite), with a suitable combination of orbital residuals including also the node and the perigee of LAGEOS II, would also further improve the accuracy of the proposed measurement. C1 Univ Bari, Dipartimento Fis, I-70126 Bari, Italy. Univ Lecce, Dipartimento Ingn, I-73100 Lecce, Italy. UMBC, JCET, Joint Ctr Earth Syst Technol, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Univ Bari, Dipartimento Fis, Via Amendola 173, I-70126 Bari, Italy. RI Iorio, Lorenzo/G-5658-2011 OI Iorio, Lorenzo/0000-0003-4949-2694 NR 36 TC 24 Z9 24 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 EI 1361-6382 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD AUG 21 PY 2002 VL 19 IS 16 BP 4301 EP 4309 AR PII S0264-9381(02)37060-6 DI 10.1088/0264-9381/19/16/306 PG 9 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 594CM UT WOS:000178031200006 ER PT J AU Liou, K Wu, CC Lepping, RP Newell, PT Meng, CI AF Liou, K Wu, CC Lepping, RP Newell, PT Meng, CI TI Midday sub-auroral patches (MSPs) associated with interplanetary shocks SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PRECIPITATION; ARCS AB [1] We report a new category of dayside auroral transients using auroral image data from the Polar spacecraft Ultraviolet Imager. The transients are characterized by a sudden brightening of the auroral patch in the midday sub-auroral zone, and thus are named midday sub-auroral patches (MSPs). MSPs were found to occur concurrently with storm sudden commencements in response to the compression of the magnetosphere by interplanetary (IP) shocks. After brightening, the MSP widened and/or moved equatorward. The latitudinal location of an MSP depends on the solar wind dynamic pressure in the shock downstream: a larger dynamic pressure corresponds to a lower latitude. The lifetime of an MSP is short (similar to5-6 min). The magnetospheric source region for the MSPs, as determined with the Defense Meteorological Satellite Program particle data from one fortuitous event, is the central plasma sheet (CPS). Sudden compression of the Earth's magnetic field due to the IP shock impact may change the pitch angles of a pre-existing population of CPS particles, which consequently fall into the loss cone and produce auroral emission. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Liou, K (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. EM kan.liou@jhuapl.edu RI Liou, Kan/C-2089-2016 OI Liou, Kan/0000-0001-5277-7688 NR 9 TC 25 Z9 25 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 21 PY 2002 VL 29 IS 16 AR 1771 DI 10.1029/2001GL014182 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 622DL UT WOS:000179631200001 ER PT J AU Pieri, D Ma, C Simpson, JJ Hufford, G Grindle, T Grove, C AF Pieri, D Ma, C Simpson, JJ Hufford, G Grindle, T Grove, C TI Analyses of in-situ airborne volcanic ash from the February 2000 eruption of Hekla Volcano, Iceland SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SATELLITE-BASED TECHNIQUE; FAILURES AB [1] A McDonnell- Douglas DC-8 NASA research aircraft inadvertently flew into an airborne volcanic ash plume from the 26 February 2000 eruption of Hekla Volcano. Filter samples from the aircraft were compared with "normal use'' and "pristine clean'' filters using SEM, energy-dispersive x-ray spectrometer, and Nicolet FTIR spectrophotometer analyses. These analyses confirm that the DC-8 encountered airborne volcanic ash from Hekla Volcano. This result is supported by independent onboard heated aerosol observations at the time of the encounter. The analyses further demonstrate the ambiguous nature of the dual band thermal IR ("split window'') method for detecting volcanic ash from the point of view of aviation safety. They also highlight the utility of in situ aircraft filter-based observations of volcanic aerosols for scientific purposes. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, Scripps Inst Oceanog, Digital Image Anal Lab, La Jolla, CA 92093 USA. Natl Weather Serv, Anchorage, AK 99513 USA. NASA, Dryden Flight Res Ctr, Edwards AFB, CA 93523 USA. RP CALTECH, Jet Prop Lab, M-S 183-501,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM dave@lithos.jpl.nasa.gov; chi@gps.caltech.edu; jsimpson@ucsd.edu; gary.hufford@noaa.gov; thomas.grindle@mail.dfrc.nasa.gov; cindy@lithos.jpl.nasa.gov NR 11 TC 18 Z9 18 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 21 PY 2002 VL 29 IS 16 AR 1772 DI 10.1029/2001GL013688 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 622DL UT WOS:000179631200002 ER PT J AU Howell, LW AF Howell, LW TI Maximum likelihood estimation of the broken power law spectral parameters with detector design applications SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE cosmic-ray; power law; maximum likelihood; calorimeter; broken power law; spectral break; spectral knee; Cramer-Rao bound AB The method of Maximum Likelihood (ML) is used to estimate the spectral parameters of an assumed broken power law energy spectrum from simulated detector responses. This methodology. which requires the complete specificity of all cosmic-ray detector design parameters, is shown to provide approximately unbiased, minimum variance, and normally distributed spectra information for events detected by an instrument having a wide range of commonly used detector response functions, The ML procedure, coupled with the simulated performance of a proposed space-based detector and its planned life cycle, has proved to be of significant value in the design phase of a new science instrument, The procedure helped make important trade studies in design parameters as a function of the science objectives, which is particularly important for space-based detectors where physical parameters, such as dimension and weight, impose rigorous practical lit-nits to the design envelope. This ML methodology is then generalized to estimate broken power law spectral parameters from real cosmic-ray data sets. (C) 2002 Elsevier Science B.V. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. RP Howell, LW (reprint author), NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. NR 12 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 2002 VL 489 IS 1-3 BP 422 EP 438 AR PII S0168-9002(02)00794-5 DI 10.1016/S0168-9002(02)00794-5 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 592DB UT WOS:000177920500039 ER PT J AU Cai, XC Keyes, DE AF Cai, XC Keyes, DE TI Nonlinearly preconditioned inexact Newton algorithms SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE nonlinear preconditioning; inexact Newton methods; Krylov subspace methods; nonlinear additive Schwarz; domain decomposition; nonlinear equations; parallel computing; incompressible flows ID KRYLOV-SCHWARZ ALGORITHMS; CONVERGENCE; EQUATIONS; SYSTEMS AB Inexact Newton algorithms are commonly used for solving large sparse nonlinear system of equations F (u*) = 0 arising, for example, from the discretization of partial differential equations. Even with global strategies such as linesearch or trust region, the methods often stagnate at local minima of parallel toFparallel to, especially for problems with unbalanced nonlinearities, because the methods do not have built-in machinery to deal with the unbalanced nonlinearities. To find the same solution u*, one may want to solve instead an equivalent nonlinearly preconditioned system F (u*) = 0 whose nonlinearities are more balanced. In this paper, we propose and study a nonlinear additive Schwarz-based parallel nonlinear preconditioner and show numerically that the new method converges well even for some difficult problems, such as high Reynolds number flows, where a traditional inexact Newton method fails. C1 Univ Colorado, Dept Comp Sci, Boulder, CO 80309 USA. Old Dominion Univ, Dept Math & Stat, Norfolk, VA 23529 USA. Lawrence Livermore Natl Lab, ISCR, Livermore, CA 94551 USA. NASA, ICASE, Langley Res Ctr, Hampton, VA 23681 USA. RP Cai, XC (reprint author), Univ Colorado, Dept Comp Sci, Boulder, CO 80309 USA. NR 29 TC 84 Z9 86 U1 0 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD AUG 21 PY 2002 VL 24 IS 1 BP 183 EP 200 AR PII S106482750037620X DI 10.1137/S106482750037620X PG 18 WC Mathematics, Applied SC Mathematics GA 585XU UT WOS:000177552200009 ER PT J AU Liu, CC Carder, KL Miller, RL Ivey, JE AF Liu, CC Carder, KL Miller, RL Ivey, JE TI Fast and accurate model of underwater scalar irradiance SO APPLIED OPTICS LA English DT Article ID ASYMPTOTIC OPTICAL ATTENUATION; OCEAN WATER; MEAN COSINE; LIGHT; ABSORPTION; PHOTOSYNTHESIS; ALGORITHMS; RADIANCE; MATTER; CLOUD AB A spectral model of scalar irradiance with depth is applied to calculations of photosynthetically available radiation for a vertically homogeneous water column. The model runs more than 14,000 times faster than the full Hydrolight code, while it limits the percentage error to 2.20% and the maximum error to less than 4.78%. The distribution of incident sky radiance and the effects of a wind-roughened surface are integrated into this model. It can be applied to case 1 waters as well as to case 2 waters that happen to be gelbstoff rich, and the volume-scattering phase function can be generated dynamically based on the backscatter fraction. This new model is both fast and accurate and is, therefore, suitable for use interactively in models of the oceanic system, such as biogeochemical models or the heat budget part of global circulation models. It can also be applied by use of remote-sensing data to improve light-field calculations as a function of depth, which is needed for the estimation of global ocean carbon production and the ocean heat budget. (C) 2002 Optical Society of America. C1 Univ S Florida, Coll Marine Sci, St Petersburg, FL 33701 USA. RP Liu, CC (reprint author), NASA, Earth Sci Applicat Directorate, Stennis Space Ctr, MS 39529 USA. EM ccliu88@yahoo.com NR 42 TC 20 Z9 23 U1 0 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD AUG 20 PY 2002 VL 41 IS 24 BP 4962 EP 4974 DI 10.1364/AO.41.004962 PG 13 WC Optics SC Optics GA 586AT UT WOS:000177560300004 PM 12206203 ER PT J AU Tripp, TM Jenkins, EB Williger, GM Heap, SR Bowers, CW Danks, AC Dave, R Green, RF Gull, TR Joseph, CL Kaiser, ME Lindler, D Weymann, RJ Woodgate, BE AF Tripp, TM Jenkins, EB Williger, GM Heap, SR Bowers, CW Danks, AC Dave, R Green, RF Gull, TR Joseph, CL Kaiser, ME Lindler, D Weymann, RJ Woodgate, BE TI The heavy-element enrichment of Ly alpha clouds in the Virgo supercluster SO ASTROPHYSICAL JOURNAL LA English DT Review DE galaxies : clusters : individual (Virgo); intergalactic medium; ISM : abundances; quasars : absorption lines; quasars : individual (3C 273) ID TELESCOPE IMAGING SPECTROGRAPH; LINE-OF-SIGHT; ULTRAVIOLET-SPECTROSCOPIC-EXPLORER; HIGH-RESOLUTION SPECTROGRAPH; GALACTIC CHEMICAL EVOLUTION; HOT INTERGALACTIC MEDIUM; OPTICALLY THIN PLASMAS; HUBBLE-SPACE-TELESCOPE; 4 RICH CLUSTERS; LOW-REDSHIFT AB Using high signal-to-noise ratio echelle spectra of 3C 273 obtained with the Space Telescope Imaging Spectrograph (resolution of 7 km s(-1) FWHM), we constrain the metallicities of two Lyalpha clouds in the vicinity of the Virgo Cluster. We detect C II Si II and Si III absorption lines in the Lyalpha absorber at z(abs) = 0.00530. Previous observations with the Far Ultraviolet Spectroscopic Explorer have revealed Lybeta-Lytheta absorption lines at the same redshift, thereby accurately constraining the H I column density. We model the ionization of the gas and derive [C/H] = -1.2(-0.2)(+0.3) [Si/C] = 0.2 +/- 0.1, and log n(H) = 2.8 +/- 0.3. The model implies a small absorber thickness, similar to70 pc, and thermal pressure p/k approximate to 40 cm(-3) K. It is most likely that the absorber is pressure confined by an external medium because gravitational confinement would require a very high ratio of dark matter to baryonic matter. Based on a sample of Milky Way sight lines in which carbon and silicon abundances have been reliably measured in the same interstellar cloud ( including new measurements presented herein), we argue that it is unlikely that the overabundance of Si relative to C is due to depletion onto dust grains. Instead, this probably indicates that the gas has been predominately enriched by ejecta from Type II supernovae. Such enrichment is most plausibly provided by an unbound galactic wind, given the absence of known galaxies within a projected distance of 100 kpc and the presence of galaxies capable of driving a wind at larger distances (e.g., H I 1225+ 01). Such processes have been invoked to explain the observed abundances in the hot, X-ray emitting gas in Virgo. However, the sight line to 3C 273 is more than 10 away from the X-ray emission region. We also constrain the metallicity and physical conditions of the Virgo absorber at z(abs) = 0.00337 in the spectrum of 3C 273 based on detections of O vI and H I and an upper limit on C IV. If this absorber is collisionally ionized, the O VI/C IV limit requires T greater than or similar to 10(5.3) K in the O VI-bearing gas. For either collisional ionization or photoionization, we find that [O/H] greater than or similar to 2.0 at z(abs) = 0.00337. C1 Princeton Univ Observ, Princeton, NJ 08544 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08855 USA. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. RP Tripp, TM (reprint author), Princeton Univ Observ, Peyton Hall, Princeton, NJ 08544 USA. EM tripp@astro.princeton.edu RI Gull, Theodore/D-2753-2012; Woodgate, Bruce/D-2970-2012; heap, sara/E-2237-2012; Jenkins, Edward/P-5684-2014 OI Gull, Theodore/0000-0002-6851-5380; Jenkins, Edward/0000-0003-1892-4423 NR 115 TC 57 Z9 57 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2002 VL 575 IS 2 BP 697 EP 711 DI 10.1086/341338 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 583VF UT WOS:000177430600008 ER PT J AU Tanner, A Ghez, AM Morris, M Becklin, EE Cotera, A Ressler, M Werner, M Wizinowich, P AF Tanner, A Ghez, AM Morris, M Becklin, EE Cotera, A Ressler, M Werner, M Wizinowich, P TI Spatially resolved observations of the Galactic center source IRS 21 SO ASTROPHYSICAL JOURNAL LA English DT Article DE Galaxy : center; infrared : stars ID SAGITTARIUS A-ASTERISK; CENTRAL PARSEC; RESOLUTION OBSERVATIONS; VELOCITY DISPERSION; IONIZED-GAS; 2.2 MICRONS; BLACK-HOLE; MILKY-WAY; STARS; GALAXY AB We present diffraction-limited 2-25 mum images obtained with the W. M. Keck 10 m telescopes that spatially resolve the cool source IRS 21, one of a small group of enigmatic objects in the central parsec of our Galaxy that have eluded classification. Modeled as a Gaussian, the azimuthally averaged intensity pro le of IRS 21 has a half-width at half-maximum (HWHM) size of 650 +/- 80 AU at 2.2 mum and an average HWHM size of 1600 +/- 200 AU at mid-infrared wavelengths. These large apparent sizes imply an extended distribution of dust. The mid-infrared color map indicates that IRS 21 is a self-luminous source rather than an externally heated dust clump as originally suggested. The spectral energy distribution has distinct near- and mid-infrared components. A simple radiative transfer code, which simultaneously fits the near- and mid-infrared photometry and intensity profiles, supports a model in which the near- infrared radiation is scattered and extincted light from an embedded central source, while the mid-infrared emission is from thermally reradiating silicate dust. We argue that IRS 21 ( and by analogy, the other luminous sources along the Northern Arm) is a massive star experiencing rapid mass loss and plowing through the Northern Arm, thereby generating a bow shock, which is spatially resolved in our observations. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. WM Keck Observ, Kamuela, HI 96743 USA. RP Tanner, A (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. EM tanner@astro.ucla.edu NR 48 TC 46 Z9 47 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2002 VL 575 IS 2 BP 860 EP 870 DI 10.1086/341470 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 583VF UT WOS:000177430600021 ER PT J AU Reeh, N Mohr, JJ Krabill, WB Thomas, R Oerter, H Gundestrup, N Boggild, CE AF Reeh, N Mohr, JJ Krabill, WB Thomas, R Oerter, H Gundestrup, N Boggild, CE TI Glacier specific ablation rate derived by remote sensing measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GREENLAND ICE-SHEET; MASS-BALANCE; INTERFEROMETRY; FLOW AB [1] The specific ablation rate in a transect of Storstrommen, a large outlet glacier from the Northeast Greenland ice sheet, is derived by combining airborne laser altimetry measurements with emergence/submergence velocities derived from satellite synthetic aperture radar interferometry (InSAR) and airborne ice-sounding radar measurement of ice thickness. The results are compared with in situ point observations of ablation measured at poles drilled into the glacier. Considering the different measurement periods for the different data sets, the agreement between derived and observed ablation rates is satisfactory. The new method of deriving specific mass balance, particularly ablation rate, by remote sensing measurements alone has the potential to substantially increase the density of observational based ablation rates on ice sheet and ice cap margins. C1 Tech Univ Denmark, Orsted DTU, DK-2800 Kgs Lyngby, Denmark. NASA, Goddard Space Flight Ctr, Wallops Flight Facil,Lab Hydrospher Proc, Observ Sci Branch, Wallops Isl, VA 23337 USA. NASA, Goddard Space Flight Ctr, EG&G Serv, Wallops Isl, VA 23337 USA. Alfred Wegener Inst Polar & Marine Res, D-27515 Bremerhaven, Germany. Geol Survey Denmark & Greenland, DK-2400 Copenhagen NV, Denmark. Niels Bohr Inst Astron Phys & Geophys, Copenhagen, Denmark. RP Reeh, N (reprint author), Tech Univ Denmark, Arctic Technol Ctr, Kgs Lyngby, Denmark. NR 17 TC 0 Z9 0 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 20 PY 2002 VL 29 IS 16 AR 1763 DI 10.1029/2002GL015307 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 622DH UT WOS:000179630900003 ER PT J AU Salawitch, RJ Wennberg, PO Toon, GC Sen, B Blavier, JF AF Salawitch, RJ Wennberg, PO Toon, GC Sen, B Blavier, JF TI Near IR photolysis of HO2NO2: Implications for HOx SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOSPHERE; ABSORPTION AB [1] We report observations and calculations of peroxynitric acid, HO2NO2, in the stratosphere and upper troposphere. The simulations show that photolysis of HO2NO2 via excitation of purely vibrational modes at wavelengths longward of 760 nm (the near IR) can dominate loss of this species. Consideration of this photolytic pathway reduces calculated HO2NO2, resolving a large discrepancy between standard model calculations and observations of HO2NO2 at high-latitude spring. The lower calculated abundance of HO2NO2 reduces the efficiency of the OH + HO2NO2 sink of HOx. Consideration of this process leads to large increases in calculated HOx (20 to 60%) for high-latitude spring and better agreement with observed stratospheric abundances of HOx. Near IR photolysis of HO2NO2 alters the coupling between NOx and HOx in stratospheric and upper tropospheric photochemical models. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. RP Salawitch, RJ (reprint author), CALTECH, Jet Prop Lab, Mail Stop 183-601,4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Salawitch, Ross/B-4605-2009; Wennberg, Paul/A-5460-2012 OI Salawitch, Ross/0000-0001-8597-5832; NR 14 TC 28 Z9 28 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 20 PY 2002 VL 29 IS 16 AR 1762 DI 10.1029/2002GL015006 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 622DH UT WOS:000179630900002 ER PT J AU Ricca, A Drocco, JA AF Ricca, A Drocco, JA TI Interaction of O(2) with a (9,0) carbon nanotube SO CHEMICAL PHYSICS LETTERS LA English DT Article ID GEOMETRY OPTIMIZATION; ELECTRONIC-PROPERTIES; MOLECULAR-MECHANICS; GAS-ADSORPTION; OXYGEN; GRAPHITE AB The physisorption and chemisorption of O(2) on the inner and outer walls of a (9,0) carbon nanotube have been studied using the ONION! method and the MP2 correlation treatment which includes long-range dispersion interactions. We have compared our results with previous theoretical work using density functional theory and with experiment. Physisorption occurs both inside and outside the tube but the binding is weak and very little charge transfer occurs. Chemisorption on the outer wall is energetically favorable but has a very high barrier and is not likely to occur under normal conditions. Dangling bonds must be present at the surface for O(2) to react. (C) 2002 Elsevier Science B.V. All rights reserved. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Ricca, A (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM ricca@pegasus.arc.nasa.gov NR 19 TC 55 Z9 57 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD AUG 19 PY 2002 VL 362 IS 3-4 BP 217 EP 223 AR PII S0009-2614(02)01004-7 DI 10.1016/S0009-2614(02)01004-7 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 588XC UT WOS:000177726600007 ER PT J AU Bean, BD Mollner, AK Choi, P Garland, ER Morrell, C Sander, SP Okumura, M AF Bean, BD Mollner, AK Choi, P Garland, ER Morrell, C Sander, SP Okumura, M TI Measurement of alkoxy radical isomerization rates. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 190-PHYS BP U323 EP U323 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301688 ER PT J AU Brune, W Harder, H Martinez, M Faloona, I Tan, D Simpas, JB Lesher, R Jeagle, L Jacob, D Crawford, J AF Brune, W Harder, H Martinez, M Faloona, I Tan, D Simpas, JB Lesher, R Jeagle, L Jacob, D Crawford, J TI Global atmospheric oxidation chemistry: What are measurements telling us? SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Georgia Inst Technol, Atlanta, GA 30332 USA. Univ Washington, Seattle, WA 98195 USA. Harvard Univ, Cambridge, MA 02138 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RI Crawford, James/L-6632-2013 OI Crawford, James/0000-0002-6982-0934 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 043-PHYS BP U300 EP U300 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301544 ER PT J AU Chaban, GM Salter, LM AF Chaban, GM Salter, LM TI Effects of electronic excitation on hydrogen atom transfer (tautomerization) reactions for the DNA base adenine: Theoretical study. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Tougaloo Coll, Tougaloo, MS 39174 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 333-PHYS BP U345 EP U345 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301830 ER PT J AU Chaban, GM Huo, W Lee, T AF Chaban, GM Huo, W Lee, T TI Infrared spectra of hydrated magnesium salts and their role in the search for possible life conditions on Jupiter moons. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 072-PHYS BP U305 EP U305 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301572 ER PT J AU Chen, B Harmon, JP AF Chen, B Harmon, JP TI Raman study of carbon nanotube composites conductivity. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ S Florida, Dept Chem, Tampa, FL 33620 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 269-COLL BP U438 EP U438 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RL UT WOS:000177422202216 ER PT J AU Christensen, LE Okumura, M Sander, SP AF Christensen, LE Okumura, M Sander, SP TI Reaction kinetics of peroxy radicals. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 CALTECH, Dept Chem, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 209-PHYS BP U326 EP U326 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301707 ER PT J AU Dateo, CE AF Dateo, CE TI Prebiotic processing induced by comet and meteor impact. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Eloret Corp, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 030-PHYS BP U298 EP U298 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301531 ER PT J AU Ferrante, RF Hudson, RL Moore, MH AF Ferrante, RF Hudson, RL Moore, MH TI Spectroscopic studies of N-2-rich ices relevant to Triton and Pluto. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USN Acad, Dept Chem, Annapolis, MD 21402 USA. NASA, Goddard Space Flight Ctr, Astrochem Branch, Greenbelt, MD 20771 USA. Eckerd Coll, Dept Chem, St Petersburg, FL 33733 USA. RI Hudson, Reggie/E-2335-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 013-PHYS BP U295 EP U295 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301514 ER PT J AU Greene, B McClure, MB Johnson, HT AF Greene, B McClure, MB Johnson, HT TI Destruction of hypergolic chemicals in a liquid propellant testing laboratory. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Honeywell Technol Solut Inc, Dept Lab, Las Cruces, NM 88004 USA. NASA, Lyndon B Johnson Space Ctr, White Sands Test Facil, Labs Off RF, Houston, TX 77058 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 015-CHAS BP U279 EP U279 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RL UT WOS:000177422201314 ER PT J AU Han, DW Thompson, CM Moore, JA AF Han, DW Thompson, CM Moore, JA TI Synthesis and characterization of adamantane-containing CARDO poly(enaminonitriles). SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA, Langley Res Ctr, LaRC, Hampton, VA 23681 USA. Rensselaer Polytech Inst, Dept Chem, New York State Ctr Polymer Synth, Troy, NY 12180 USA. RI Moore, James/B-4615-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 141-POLY BP U377 EP U377 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422302017 ER PT J AU Head-Gordon, M Weisman, J Lee, T AF Head-Gordon, M Weisman, J Lee, T TI Electronic structure calculations of the excited states of polycyclic aromatic hydrocarbons. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 069-PHYS BP U304 EP U304 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301569 ER PT J AU Herndon, SC Brown, LR Nelson, DD Zahniser, MS AF Herndon, SC Brown, LR Nelson, DD Zahniser, MS TI Application of tunable diode laser absorption spectroscopy using the 1740 cm-1 band to measure formaldehyde. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Aerodyne Res Inc, Ctr Atmospher & Environm Chem, Billerica, MA 01821 USA. CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 211-PHYS BP U326 EP U326 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301709 ER PT J AU Hudgins, DM AF Hudgins, DM TI From interstellar polycyclic aromatic hydrocarbons to astrobiology. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Astrophys Branch, SSA, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 012-PHYS BP U295 EP U295 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301513 ER PT J AU Jacob, DJ Martin, EV Palmer, PI Jones, DB Heald, CL Chance, KV Bowman, K Worden, J Hoffman, R AF Jacob, DJ Martin, EV Palmer, PI Jones, DB Heald, CL Chance, KV Bowman, K Worden, J Hoffman, R TI Satellite observations of tropospheric chemistry. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Harvard Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Jet Prop Lab, Pasadena, CA USA. RI Palmer, Paul/F-7008-2010; Heald, Colette/A-6813-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 046-PHYS BP U301 EP U301 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301547 ER PT J AU Lambert, JL AF Lambert, JL TI Potential of optical toxicity following "non-invasive" measurement of glucose with raman spectroscopy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ So Calif, Childrens Hosp, Keck Sch Med, Dept Ophthalmol, Los Angeles, CA 90027 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 021-ANYL BP U115 EP U116 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 583RL UT WOS:000177422200446 ER PT J AU Lillehei, PT Park, C Rouse, JH Siochi, EJ AF Lillehei, PT Park, C Rouse, JH Siochi, EJ TI Characterization of carbon nanotube composites via magnetic force microscopy and force spectroscopy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. NASA, Langley Res Ctr, ICASE, Hampton, VA 23681 USA. RI Lillehei, Peter/C-9196-2009 OI Lillehei, Peter/0000-0001-8183-9980 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 094-COLL BP U410 EP U410 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RL UT WOS:000177422202042 ER PT J AU Mattioda, AL Hudgins, DM Bauschlicher, C Allamandola, LJ AF Mattioda, AL Hudgins, DM Bauschlicher, C Allamandola, LJ TI Infrared spectra of matrix-isolated polycyclic aromatic hydrocarbons and their ions: PAHs incorporating the peropyrene structure. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Astrophys Branch, Moffett Field, CA 94035 USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 191-PHYS BP U323 EP U323 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301689 ER PT J AU Meyer, MA AF Meyer, MA TI Astrobiology: From the laboratory to space. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA Headquarters, Solar Syst Explorat Div, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 009-PHYS BP U295 EP U295 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301510 ER PT J AU Okumura, M Bean, BD Nizkorodov, S Mollner, AK Francisco, JS Sander, SP AF Okumura, M Bean, BD Nizkorodov, S Mollner, AK Francisco, JS Sander, SP TI Reactions of OH+NO2: Direct observation of the HOONO channel. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 133-PHYS BP U314 EP U314 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301632 ER PT J AU Pellis, NR AF Pellis, NR TI Space biological research: Unique contributions of microgravity. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA, Johnson Space Ctr, Biol Syst Off, Houston, TX 77058 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 4-SOCED BP U30 EP U30 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RL UT WOS:000177422200025 ER PT J AU Pohorille, A Wilson, MA AF Pohorille, A Wilson, MA TI Peptides at membrane surfaces and their role in the origin of life. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, NASA Ctr Computat Astrobiol, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 051-PHYS BP U301 EP U301 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301552 ER PT J AU Pohorille, A Chipot, C Wilson, MA AF Pohorille, A Chipot, C Wilson, MA TI Protein solvation in membranes and at water-membrane interfaces. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Ctr Computat Astrobiol, Moffett Field, CA 94035 USA. Univ Nancy 1, Chim Theor Lab, F-54013 Nancy, France. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 028-COMP BP U473 EP U473 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RL UT WOS:000177422202355 ER PT J AU Salama, F AF Salama, F TI DIBs: Tracer of interstellar organic materials. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 068-PHYS BP U304 EP U304 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301568 ER PT J AU Salawitch, RJ Wennberg, PO AF Salawitch, RJ Wennberg, PO TI Stratospheric photochemistry: Halogens SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RI Salawitch, Ross/B-4605-2009; Wennberg, Paul/A-5460-2012 OI Salawitch, Ross/0000-0001-8597-5832; NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 108-PHYS BP U310 EP U310 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301607 ER PT J AU Schwenke, DW AF Schwenke, DW TI Theoretical studies of the H+CO reaction. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RI schwenke, david/I-3564-2013 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 099-PHYS BP U309 EP U309 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301598 ER PT J AU Skokova, KA Leiser, DB AF Skokova, KA Leiser, DB TI Characterization of a new refractory oxidative-resistant ceramic carbon insulation material. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, ELORET, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 007-FUEL BP U557 EP U558 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 583RL UT WOS:000177422202838 ER PT J AU Wang, YH Brinson, B Johnson, MP Kittrell, C Sivaram, S Kim, M Miller, M Lavin, G Kono, J Hauge, R Smalley, RE Arepalli, S Nikolaev, P Cui, H Puretzky, AA Eres, G Lupini, A Chisholm, MF Pennycook, SJ Melechko, A Schaaff, TG Lowndes, DH Geohegan, DB AF Wang, YH Brinson, B Johnson, MP Kittrell, C Sivaram, S Kim, M Miller, M Lavin, G Kono, J Hauge, R Smalley, RE Arepalli, S Nikolaev, P Cui, H Puretzky, AA Eres, G Lupini, A Chisholm, MF Pennycook, SJ Melechko, A Schaaff, TG Lowndes, DH Geohegan, DB TI Condense phase growth of carbon nanotubes by annealing C-60/nickel pancake structures. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Rice Univ, Dept Chem, Houston, TX 77005 USA. Rice Univ, Ctr Nanoscale Sci & Technol, Houston, TX 77005 USA. NASA, Lyndon B Johnson Space Ctr, G B Tech, Houston, TX 77058 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RI Hauge, Robert/A-7008-2011; Arepalli, Sivaram/A-5372-2010; Nikolaev, Pavel/B-9960-2009; Puretzky, Alexander/B-5567-2016; Geohegan, David/D-3599-2013; Eres, Gyula/C-4656-2017 OI Hauge, Robert/0000-0002-3656-0152; Puretzky, Alexander/0000-0002-9996-4429; Geohegan, David/0000-0003-0273-3139; Eres, Gyula/0000-0003-2690-5214 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 053-COLL BP U404 EP U404 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RL UT WOS:000177422202001 ER PT J AU Warner, JD Kranbuehl, DE Dean, CJ Knowles, RR Thompson, DW Southward, RE AF Warner, JD Kranbuehl, DE Dean, CJ Knowles, RR Thompson, DW Southward, RE TI Silver-polyimide nanocomposite films with highly reflective surfaces synthesized with the poly(amic acid) and imide forms of 6FDA/4-BDAF. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Coll William & Mary, Dept Appl Sci, Williamsburg, VA 23187 USA. Coll William & Mary, Dept Chem, Williamsburg, VA 23187 USA. NASA, Langley Res Ctr, Struct & Mat Competency, Hampton, VA USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 030-PMSE BP U493 EP U493 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422302671 ER PT J AU Wennberg, PO Salawitch, RJ AF Wennberg, PO Salawitch, RJ TI Stratospheric photochemistry: Nitrogen and hydrogen free radicals SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RI Salawitch, Ross/B-4605-2009; Wennberg, Paul/A-5460-2012 OI Salawitch, Ross/0000-0001-8597-5832; NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 18 PY 2002 VL 224 MA 107-PHYS BP U310 EP U310 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 583RM UT WOS:000177422301606 ER PT J AU Chatfield, RB Guo, Z Sachse, GW Blake, DR Blake, NJ AF Chatfield, RB Guo, Z Sachse, GW Blake, DR Blake, NJ TI The subtropical global plume in the Pacific Exploratory Mission-Tropics A (PEM-Tropics A), PEM-Tropics B, and the Global Atmospheric Sampling Program (GASP): How tropical emissions affect the remote Pacific SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE global pollution; subtropical jet; long-distance transport; biomass burning; pristine atmosphere; cloud venting ID GENERAL-CIRCULATION MODEL; CHEMICAL-TRANSPORT MODEL; CARBON-MONOXIDE; TRACE-A; TROPOSPHERIC OZONE; CO; CHEMISTRY; SATELLITE; CH4; SENSITIVITY AB [1] An extended southern subtropical plume of CO meanders >15,000 km around the world, gradually spreading around 20 S. This southern pollution plume is most noticeable in the burning season, southern spring; a similar subtropical plume appears in the northern spring. We use tracer maps to guide the use of trajectories to trace observations of the plume to their origins. The MM5 mesoscale model provides high-resolution, near-global synoptic reconstructions of the weather. Two situations are analyzed: NASA's airborne Pacific Exploratory Mission-Tropics A (PEM-Tropics A) period, September-October 1996 and the PEM-Tropics B period, March-April 1999. Similar features are noted for a much earlier mission in 1977, which apparently captured the first, but never-recognized, samples of the global pollution of the Southern Hemisphere. For PEM-Tropics A, near-source pieces of the plume are clearly seen in the Total Ozone Mapping Spectrometer (TOMS) absorbing aerosol product and are well simulated. Downwind, the aircraft sampling of several strands deriving from a single plume seems representative and well simulated. A general mechanism of the plume emerges: The southern plume arises in surface accumulation regions in Africa and South America. Thunderstorm-scale venting of pollutants usually lofts the plume; however, synoptic-scale lifting can produce intense outbreaks. The plume flows eastward in the subtropical jet region as a single coherent but articulated current until it is increasingly filamented by storms in the Pacific. A similar northern subtropical plume is described for the PEM-Tropics B period. The 100-km model resolution we used seemed to capture much of the variability. However, the model somewhat under predicted the highest values. C1 NASA, Ames Res Ctr, Div Earth Sci, Moffett Field, CA 94035 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. RP Chatfield, RB (reprint author), NASA, Ames Res Ctr, Div Earth Sci, Moffett Field, CA 94035 USA. NR 49 TC 20 Z9 20 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 17 PY 2002 VL 107 IS D16 AR 4278 DI 10.1029/2001JD000497 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 622HA UT WOS:000179639900003 ER PT J AU Bradley, BA Sakimoto, SEH Frey, H Zimbelman, JR AF Bradley, BA Sakimoto, SEH Frey, H Zimbelman, JR TI Medusae Fossae Formation: New perspectives from Mars Global Surveyor SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Mars; Medusae Fossae Formation; Mars Global Surveyor; layering; volcanism ID ORBITER LASER ALTIMETER; TOPOGRAPHY; THARSIS; RECORD; REGION; CAMERA; ICE AB [1] The nature and origin of the Medusae Fossae Formation (MFF) on Mars has been debated since the return of the first Viking images. The MFF's young age, distinctive surface texture, and lack of obvious source have prompted multiple hypotheses for its origin. This study uses data from the Mars Global Surveyor (MGS) mission to examine the MFF at all available scales. We discuss and quantify observations from Mars Orbiter Laser Altimeter (MOLA) topography and Mars Orbiter Camera (MOC) images to better constrain the origin of the MFF. Topographic grid estimates yield a present extent of 2.1 x 10(6) km(2) and a volume of 1.4 x 10(6) km(3); however, remnant yardang deposits observed far from the thicker lobes of MFF material suggest that it may have once covered up to 5 x 10(6) km(2). We do not find compelling evidence for extensive fluvial reworking of the MFF; however, in several regions, buried channels are apparent in the MFF because the formation is draped over underlying topography. Layering is apparent at all scales, from submeter to hundreds of meters, with variable resistance to weathering. Continuity of layers appears to be local to regional, but not likely formation-wide. Yardangs form both parallel and bidirectional patterns, with resistant layers and jointing probably influencing their orientations. A comparative study of MFF regional topography and surface expression indicates that the MFF is quantitatively dissimilar to Martian polar layered deposits. The material is most likely a friable and irregularly consolidated air fall deposit of probable volcanic origin. C1 NASA, Goddard Space Flight Ctr, Geodynam Branch, GEST, Greenbelt, MD 20771 USA. Smithsonian Inst, Natl Air & Space Museum, CEPS, Washington, DC 20560 USA. RP Bradley, BA (reprint author), Brown Univ, Dept Geol Sci, Box 1846, Providence, RI 02912 USA. RI Bradley, Bethany/B-1964-2008 OI Bradley, Bethany/0000-0003-4912-4971 NR 42 TC 52 Z9 52 U1 3 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD AUG 17 PY 2002 VL 107 IS E8 AR 5058 DI 10.1029/2001JE001537 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 622HP UT WOS:000179641700001 ER PT J AU Elmustafa, AA Stone, DS AF Elmustafa, AA Stone, DS TI Indentation size effect in polycrystalline FCC metals SO ACTA MATERIALIA LA English DT Article DE indentation size effect; geometrically necessary dislocations; activation volume; work hardening; nanoindentation ID STRAIN GRADIENT PLASTICITY; SINGLE-CRYSTALS; HARDNESS; DEFORMATION; COPPER; LAW AB High purity aluminum and alpha brass samples were tested for the indentation size effect (ISE) using a combination of microhardness (high load) and nanoindentation (low load). We employed rate effects to study low temperature deformation mechanisms using nanoindentation creep and load relaxation. Based on these rate effects which are conspicuous in terms of the rate sensitivity of the hardness, partial derivativeH/partial derivativelnepsilon(eff), we calculated the activation volume, V*, and compared data from indentation creep with data from uniaxial loading. The data from nanoindentation for alpha brass when plotted, V* vs H or tau (flow stress), extrapolated into literature data from conventional tensile testing, while the aluminum nanoindentation data exhibited an offset. We propose some mechanisms for this offset. We demonstrate that the trend of V* vs H, resulting from the ISE in a single specimen, concurs with that obtained from testing specimens with various levels of work hardening. This suggests that the ISE is driven by a dislocation mechanism. Additionally, when the results are fitted to a strain gradient plasticity model (SGP), the data at deep indents (microhardness and large nanoindentation) exhibited a straight-line behavior closely identical to literature data. However, for shallow indents (nanoindetation data), the slope of the line severely changes, decreasing by a factor of ten, resulting in a "bilinear behavior". We also propose some possible mechanisms for this behavior. (C) 2002 Published by Elsevier Science Ltd on behalf of Acta Materialia Inc. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. Univ Wisconsin, Madison, WI USA. RP Elmustafa, AA (reprint author), NASA, Langley Res Ctr, Mail Stop 238, Hampton, VA 23665 USA. RI Stone, Donald/A-7496-2016 NR 30 TC 101 Z9 101 U1 5 U2 45 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD AUG 16 PY 2002 VL 50 IS 14 BP 3641 EP 3650 AR PII S1359-6454(02)00175-1 DI 10.1016/S1359-6454(02)00175-1 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 584ZY UT WOS:000177499700009 ER PT J AU Casey, KS Adamec, D AF Casey, KS Adamec, D TI Sea surface temperature and sea surface height variability in the North Pacific Ocean from 1993 to 1999 SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE sea surface temperature (SST); sea surface height (SSH); interannual variability; ENSO; TOPEX/Poseidon; AVHRR ID SINGULAR-VALUE DECOMPOSITION; INTERDECADAL VARIABILITY; SATELLITE; SCALES; ENSO AB [1] Correlations between advanced very high resolution radiometer Pathfinder sea surface temperature (SST) and TOPEX sea surface height (SSH) anomalies are calculated for the 7 year period 1993-1999 in the equatorial and North Pacific. These correlations provide measures of SSH and SST covariability and are obtained using an empirical orthogonal function analysis separately on the two fields and a singular value decomposition (SVD) method on both fields simultaneously. These correlations reveal distinct SST-SSH states: a warm, elevated period from January 1993 to December 1994; a cooler, lower phase spanning January 1995 through December 1996; and the strongly variable El Nino-Southern Oscillation (ENSO) period spanning 1997-1999. The relationships between these SST-SSH states and the dominant interannual and interdecadal modes of Pacific variability are investigated through correlations with indices for the Southern Oscillation, Pacific-North American (PNA) pattern, and Pacific Decadal Oscillation (PDO). When including the tropics, significant correlations between the first SVD mode of the SST-SSH covariability and the interannual ENSO pattern and interdecadal PDO pattern are evident. Restricting the focus to the extratropical North Pacific reveals significant correlations with only the interdecadal PDO pattern. While the first mode reveals connections to the ENSO and PDO patterns, the second SVD mode indicates significant correlations to the PNA pattern for both the tropical and extratropical Pacific. C1 NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Casey, KS (reprint author), NOAA, UCAR, NESDIS, NODC, Silver Spring, MD 20910 USA. RI Casey, Kenneth/D-4065-2013 OI Casey, Kenneth/0000-0002-6052-7117 NR 20 TC 12 Z9 13 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD AUG 15 PY 2002 VL 107 IS C8 AR 3099 DI 10.1029/2001JC001060 PG 12 WC Oceanography SC Oceanography GA 611BH UT WOS:000178996200008 ER PT J AU Gary, SP Goldstein, BE Neugebauer, M AF Gary, SP Goldstein, BE Neugebauer, M TI Signatures of wave-ion interactions in the solar wind: Ulysses observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE solar wind; alpha particles; Alfven waves; Ulysses ID CYCLOTRON ANISOTROPY INSTABILITY; TEMPERATURE ANISOTROPY; PREFERENTIAL ACCELERATION; RESONANT ACCELERATION; INVERSE CORRELATION; HEAVY-IONS; PROTON; MAGNETOSHEATH; TURBULENCE; PLASMA AB [1] Theory and simulations predict that resonant wave-particle scattering by enhanced magnetic fluctuations yields characteristic signatures in properties of solar wind ions. Here Ulysses/Solar Wind Observations Over the Poles of the Sun (SWOOPS) instrument measurements of protons and alpha particles are examined to seek three types of these signatures: (1) a statistical constraint on the proton temperature anisotropy imposed by the electromagnetic proton cyclotron instability; (2) a correlation between the alpha anisotropy and the alpha/proton relative flow speed driven by electromagnetic alpha/proton instabilities; and (3) relationships among the proton anisotropy, the alpha anisotropy, and the alpha/proton speed induced by the cascade of long-wavelength Alfven fluctuations to ion cyclotron resonances at shorter wavelengths. No signatures of alpha/proton instabilities are found. However, the first example of the proton anisotropy constraint in the slow solar wind is demonstrated, and a theoretical prediction for Alfven/cyclotron wave acceleration in the fast wind is similar to a statistical lower bound observed on the alpha/proton speed. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gary, SP (reprint author), Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. NR 46 TC 24 Z9 24 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 15 PY 2002 VL 107 IS A8 AR 1169 DI 10.1029/2001JA000269 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 611HB UT WOS:000179009600022 ER PT J AU Gjerloev, JW Hoffman, RA AF Gjerloev, JW Hoffman, RA TI Currents in auroral substorms SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE auroral substorms; field-aligned currents; auroral electrojets; Harang discontinuity; current closure; substorm current wedge ID FIELD-ALIGNED CURRENTS; IONOSPHERIC ELECTRIC-FIELDS; HEIGHT-INTEGRATED CONDUCTIVITY; TWO-DIMENSIONAL OBSERVATIONS; WESTWARD TRAVELING SURGE; PROTON PRECIPITATION; NIGHTTIME SECTOR; CURRENT SYSTEMS; ZONE CURRENTS; ENERGY FLUX AB [1] We present a model of the three-dimensional current system in the nighttime sector during the expansion phase through early recovery phase for bulge-type aurora substorms. The height-integrated horizontal ionospheric currents are calculated from models of the height-integrated conductivity and convection electric field previously published [Gjerloev and Hoffman, 2000a, 2000b, 2001] that were based on a set of data from the Dynamics Explorer 2 satellite, while the field-aligned currents are deduced from the divergence of the horizontal currents. These model-derived field-aligned currents are then compared with the field-aligned currents determined from magnetometer data from the same data set used to develop the conductance and electric field models. The comparison shows good agreement, thereby serving as an independent verification of the entire self-consistent substorm model. We find that the feeding as well as the drainage of the substorm current wedge component of the westward electrojet is principally due to an imbalance of the downward region 0 and upward region 1 current sheets under which the electrojet is flowing. We do not find evidence of a simple downward current postmidnight and upward current premidnight. The eastward electrojet, which almost entirely originates on the dayside, is partly drained by a poleward current flowing across the Harang region into the westward electrojet at 19-21 magnetic local time (MLT) and partly by net upward field-aligned currents located just prior to midnight. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Gjerloev, JW (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Code 696, Greenbelt, MD 20771 USA. NR 34 TC 23 Z9 23 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 15 PY 2002 VL 107 IS A8 AR 1163 DI 10.1029/2001JA000194 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 611HB UT WOS:000179009600028 ER PT J AU Luhmann, JG Li, Y Arge, CN Gazis, PR Ulrich, R AF Luhmann, JG Li, Y Arge, CN Gazis, PR Ulrich, R TI Solar cycle changes in coronal holes and space weather cycles SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE solar wind sources; coronal holes; solar cycle ID INTERPLANETARY MAGNETIC-FIELD; MASS EJECTIONS; SOURCE-SURFACE; WIND STREAMS; FLUX; EVOLUTION; HELIOSPHERE; STRENGTH; MODEL; SPEED AB [1] Potential field source surface models of the coronal magnetic field, based on Mt. Wilson Observatory synoptic magnetograms, are used to infer the coronal hole sources of low-heliolatitude solar wind over approximately the last three solar cycles. Related key parameters like interplanetary magnetic field and bulk velocity are also calculated. The results illustrate how the evolving contribution of the polar hole sources relative to that from low-latitude and midlatitude active region hole sources can explain solar magnetic field control of long-term interplanetary variations. In particular, the enduring consistent magnetogram record and continuous model displays produce a useful overview of the solar control of interplanetary cycles and trends that affect space weather. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Luhmann, JG (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. EM jgluhmann@ssl.berkeley.edu; yanli@ssl.berkeley.edu; nick.arge@noaa.gov; pgazis@mail.arc.nasa.gov; Ulrich@astro.ucla.edu NR 44 TC 49 Z9 49 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 15 PY 2002 VL 107 IS A8 AR 1154 DI 10.1029/2001JA007550 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 611HB UT WOS:000179009600037 ER PT J AU McDonald, FB Klecker, B McGuire, RE Reames, DV AF McDonald, FB Klecker, B McGuire, RE Reames, DV TI Relative recovery of galactic and anomalous cosmic rays at 1 AU: Further evidence for modulation in the heliosheath SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE anomalous cosmic rays; heliosheath; coronal mass ejections; interplanetary shocks; solar wind; galactic cosmic rays ID WIND TERMINATION SHOCK; WAVY NEUTRAL SHEET; SOLAR-WIND; DRIFT MODEL; ENERGETIC PARTICLES; TRANSPORT; GRADIENT; ACCELERATION; HELIOSPHERE; DECREASES AB [1] For solar cycle 22 the large-scale interplanetary disturbances produced by the intense solar activity of March/June 1991 had a long-term effect on the recovery of galactic cosmic rays throughout the heliosphere that persisted for almost 5 years. At 1 AU, the recovery of 13 MeV/nucleon anomalous cosmic ray oxygen (ACR O+) is much more rapid than that of 265 MeV/nucleon galactic cosmic ray helium (GCR He), consistent with previous observations in the distant heliosphere [McDonald et al., 2000] and strengthening the concept that the region of the heliosheath plays an important role in the modulation of galactic cosmic rays. A comparison of the time histories of GCR He and ACR O+ at 1 and 44 AU observations suggest the recovery moves from the distant heliosphere inward toward 1 AU for this particular phase of the heliomagnetic cycle. There is a very low relative modulation potential, Phi, between 1 and 70 AU of 116 +/- 6 MV for GCR He at solar minimum using the force field approximation. When combined with the small radial intensity gradients in the distant heliosphere, a much lower modulation potential is implied between 1 AU and the termination shock at solar minimum than had been assumed previously. There is no effect on the 13 MeV/nucleon ACR O+ intensity as the inclination of the heliospheric neutral current sheet decreases from 32degrees to its minimum value of 8degrees. C1 Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. NASA, Goddard Space Flight Ctr, Space Phys Data Facil, Greenbelt, MD 20771 USA. RP McDonald, FB (reprint author), Univ Maryland, Inst Phys Sci & Technol, Comp & Space Sci Bldg 3245, College Pk, MD 20742 USA. NR 33 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 15 PY 2002 VL 107 IS A8 AR 1156 DI 10.1029/2001JA000206 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 611HB UT WOS:000179009600035 ER PT J AU Richardson, IG Cane, HV Cliver, EW AF Richardson, IG Cane, HV Cliver, EW TI Sources of geomagnetic activity during nearly three solar cycles (1972-2000) SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE geomagnetic activity; solar cycle variation; solar wind; interplanetary magnetic field ID CORONAL MASS EJECTIONS; LONG-TERM VARIATIONS; MAGNETIC-FIELD; WIND; FLUX; TEMPERATURE; PREDICTION; MINIMUM; REGIONS; PASSAGE AB [1] We examine the contributions of the principal solar wind components (corotating highspeed streams, slow solar wind, and transient structures, i.e., interplanetary coronal mass ejections (CMEs), shocks, and postshock flows) to averages of the aa geomagnetic index and the interplanetary magnetic field (IMF) strength in 1972-2000 during nearly three solar cycles. A prime motivation is to understand the influence of solar cycle variations in solar wind structure on long-term (e. g., approximately annual) averages of these parameters. We show that high-speed streams account for approximately two-thirds of long-term aa averages at solar minimum, while at solar maximum, structures associated with transients make the largest contribution (similar to 50%), though contributions from streams and slow solar wind continue to be present. Similarly, high-speed streams are the principal contributor ( similar to 55%) to solar minimum averages of the IMF, while transient-related structures are the leading contributor ( similar to 40%) at solar maximum. These differences between solar maximum and minimum reflect the changing structure of the near-ecliptic solar wind during the solar cycle. For minimum periods, the Earth is embedded in high-speed streams similar to 55% of the time versus similar to 35% for slow solar wind and similar to 10% for CME-associated structures, while at solar maximum, typical percentages are as follows: high-speed streams similar to 35%, slow solar wind similar to 30%, and CME-associated similar to 35%. These compositions show little cycle-to-cycle variation, at least for the interval considered in this paper. Despite the change in the occurrences of different types of solar wind over the solar cycle (and less significant changes from cycle to cycle), overall, variations in the averages of the aa index and IMF closely follow those in corotating streams. Considering solar cycle averages, we show that high-speed streams account for similar to44%, similar to48%, and similar to40% of the solar wind composition, aa, and the IMF strength,, respectively, with corresponding figures of similar to 22%, similar to 32%, and similar to 25% for CME-related structures, and similar to 33%, similar to 19%, and similar to 33% for slow solar wind. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. AF Res Lab, Hanscom AFB, Bedford, MA USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Univ Tasmania, Sch Math & Phys, Hobart, Tas, Australia. RP Richardson, IG (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. OI Richardson, Ian/0000-0002-3855-3634 NR 35 TC 92 Z9 93 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 15 PY 2002 VL 107 IS A8 AR 1187 DI 10.1029/2001JA000504 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 611HB UT WOS:000179009600004 ER PT J AU Tsyganenko, NA AF Tsyganenko, NA TI A model of the near magnetosphere with a dawn-dusk asymmetry - 1. Mathematical structure SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE inner magnetosphere; geomagnetic field models; partial ring current; field-aligned currents; magnetopause ID INTERPLANETARY MAGNETIC-FIELD; RING CURRENT DEVELOPMENT; BIRKELAND CURRENTS; ALIGNED CURRENTS; QUANTITATIVE MODELS; MAGNETOPAUSE SHAPE; GEOMAGNETIC-FIELD; ELECTRIC-FIELD; CURRENT SHEET; PLASMA SHEET AB [1] A new empirical magnetic field model has been developed, representing the variable configuration of the inner and near magnetosphere for different interplanetary conditions and the ground disturbance levels. This paper describes the mathematical structure of the model, while the results of fitting it to a new set of spacecraft data are presented in a companion paper. The general approach remains the same as in the earlier T96 model, but the mathematical description of all major sources of the magnetospheric field now applies recently developed new methods. In particular, the field deformation technique is extensively used, making it possible to realistically and flexibly represent the fields of the cross-tail current, the ring current, and the Region 1 and 2 Birkeland currents. The new model ring current includes not only the axisymmetric component but also a partial ring current with field-aligned closure currents, a feature absent in earlier data-based models. The field of the cross-tail current includes two modules whose current densities vary along the Sun-Earth line with different rates. The cross-tail current sheet warps in two dimensions in response to the geodipole tilt, its inner edge shifts along the Sun-Earth line with growing disturbance, and its thickness varies along and across the tail. Birkeland currents of Regions 1 and 2 vary in response to interplanetary conditions, so that at ionospheric altitudes they shift in latitude and change their distribution in local time. The magnetospheric boundary is specified using a most recent empirical model [Shue et al., 1998]; its size is controlled by the solar wind ram pressure, and its shape also varies in response to changes of the Earth's dipole tilt angle. The model magnetopause ensures a full confinement of the fields of all sources inside the magnetopause, regardless of its shape and size. The model also includes an interplanetary magnetic field - controlled interconnection field, allowing a finite normal B-n at the magnetopause and hence open magnetospheric configurations. C1 NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Tsyganenko, NA (reprint author), NASA, Goddard Space Flight Ctr, USRA, Code 690-2, Greenbelt, MD 20771 USA. RI Tsyganenko, Nikolai/J-7377-2012 OI Tsyganenko, Nikolai/0000-0002-5938-1579 NR 40 TC 277 Z9 281 U1 4 U2 16 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 15 PY 2002 VL 107 IS A8 AR 1179 DI 10.1029/2001JA000219 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 611HB UT WOS:000179009600012 ER PT J AU Tsyganenko, NA AF Tsyganenko, NA TI A model of the near magnetosphere with a dawn-dusk asymmetry - 2. Parameterization and fitting to observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE inner magnetosphere; geomagnetic field models; partial ring current; field-aligned currents; magnetopause ID MAGNETIC-FIELD EXPERIMENT; GEOMAGNETIC-FIELD; SOLAR-WIND; FLUXGATE MAGNETOMETER; INNER MAGNETOSPHERE; QUANTITATIVE MODELS; CURRENT SHEET; RING-CURRENT; POLAR-CAP; GEOTAIL AB [1] First results are presented of an empirical modeling of the Earth's inner and near magnetosphere (X greater than or equal to -15 R-E), using a new set of data and new methods, described in a companion paper. The modeling database included 5-min average B field data, taken in a wide range of altitudes and latitudes by the International Solar Terrestrial Physics spacecraft Polar (1996-1999) and Geotail (1994-1999), as well as by earlier missions, ISEE 2 (1984-1987), Active Magnetospheric Particle Tracer Explorers (AMPTE)/CCE (1984-1988), AMPTE/Ion Release Module (1984-1986), CRRES (1990-1991), and DE 1 (1984-1990). To take into account the delayed response of the magnetosphere to the solar wind and interplanetary magnetic field (IMF), each data record in the data set was tagged by a "trail'' of 5-min averages of the IMF, solar wind, and Dst field data, covering the preceding 2-hour interval. The axisymmetric ring current (SRC) and the partial one (PRC), both parameterized by the corrected Dst* index and the solar wind pressure P-d, were found to vary in strikingly different ways. While under quiet conditions the PRC is much weaker than the SRC, it dramatically grows in magnitude and rotates to the dusk sector with rising |Dst*| and P-d, significantly exceeding the SRC even during moderate storms, in excellent agreement with recent particle simulations. The innermost part of the cross-tail current is quite sensitive to the southward IMF and yields similar to90% of the tail's contribution to the Dst index, in contrast with the more distant tail current, which responds mainly to the solar wind pressure and provides no appreciable contribution to Dst. In response to southward IMF conditions, Region 1 and 2 Birkeland currents rapidly grow in magnitude and expand to lower latitudes, while their peaks shift slightly in local time toward noon. The coefficient of the IMF penetration inside the magnetosphere was found to dramatically increase with growing IMF clock angle: while quite small (similar to0.1) for northward IMF, it rises to similar to0.6 as the IMF turns southward. Priorities and challenges for future data-based modeling studies are discussed. C1 NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Tsyganenko, NA (reprint author), NASA, Goddard Space Flight Ctr, USRA, Code 690-2, Greenbelt, MD 20771 USA. RI Tsyganenko, Nikolai/J-7377-2012 OI Tsyganenko, Nikolai/0000-0002-5938-1579 NR 42 TC 248 Z9 252 U1 7 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 15 PY 2002 VL 107 IS A8 AR 1176 DI 10.1029/2001JA000220 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 611HB UT WOS:000179009600015 ER PT J AU Valek, PW Perez, JD Jahn, JM Pollock, CJ Wuest, MP Friedel, RHW Moore, TE Peterson, WK AF Valek, PW Perez, JD Jahn, JM Pollock, CJ Wuest, MP Friedel, RHW Moore, TE Peterson, WK TI Outflow from the ionosphere in the vicinity of the cusp SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE ionospheric outflow; cusp boundary ID BOUNDARY-LAYER; PLASMA SHEET; DIPOLE TILT; ION; MAGNETOSPHERE; LATITUDE; PRECIPITATION; INSTRUMENT; MISSION AB [1] Low-energy ion outflows from the ionosphere are known to be an important source of plasma for the magnetosphere. The objective of this study is to describe the spatial relationships between low-energy ionospheric outflows and the cusp. The analysis is similar to that used in superposed epoch analyses, except that a spatial reference is used instead of a temporal one. Data from the Thermal Ion Dynamics Experiment (TIDE) supported by data from the Toroidal Imaging Mass-Angle Spectrograph (TIMAS) and Hydra, during low-altitude, perigee passes over the South Pole by the Polar spacecraft are used. The presence of isotropic ions from the magnetosheath is used to define the equatorward boundary of the cusp. By using this magnetospheric boundary as a reference point instead of invariant latitude, the temporal variability of the cusp location with respect to the Earth is removed. Poleward of this boundary in the cusp proper, observations show ionospheric outflow in addition to the isotropic magnetosheath ions. A technique used to separate the ion distributions originating from the two sources is presented and applied in order to calculate moments of the outflowing ion distribution. Ionospheric outflow is found to occur in the cleft region that extends approximate to1.5degrees equatorward of the low-latitude cusp boundary and in the cusp that extends approximate to5degrees poleward of this boundary. Both the parallel and perpendicular temperatures of the outflowing ions are found to be approximately a factor of 3 larger on the equatorward side of this cusp boundary, i.e., in the cleft. C1 Auburn Univ, Dept Phys, Auburn, AL 36849 USA. SW Res Inst, San Antonio, TX 78228 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Interplanetary Phys Branch, Greenbelt, MD 20771 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. RP Valek, PW (reprint author), SW Res Inst, 6220 Culebra Rd, San Antonio, TX 78228 USA. RI Peterson, WK/A-8706-2009; Friedel, Reiner/D-1410-2012; Moore, Thomas/D-4675-2012 OI Peterson, WK/0000-0002-1513-6096; Valek, Philip/0000-0002-2318-8750; Friedel, Reiner/0000-0002-5228-0281; Moore, Thomas/0000-0002-3150-1137 NR 24 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 15 PY 2002 VL 107 IS A8 AR 1180 DI 10.1029/2001JA000107 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 611HB UT WOS:000179009600011 ER PT J AU Sheng, CY Bozzelli, JW Dean, AM Chang, AY AF Sheng, CY Bozzelli, JW Dean, AM Chang, AY TI Detailed kinetics and thermochemistry of C2H5+O-2: Reaction kinetics of the chemically-activated and stabilized CH3CH2OO center dot adduct SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID THERMODYNAMIC PROPERTIES; REACTION-MECHANISM; PRESSURE-DEPENDENCE; ETHANE COMBUSTION; PEROXYL RADICALS; MOLECULAR-OXYGEN; HEAT-CAPACITIES; ETHYL RADICALS; HARTREE-FOCK; TEMPERATURE AB The kinetics of the chemically activated reaction between the ethyl radical and molecular oxygen are analyzed using quantum Rice-Ramsperger-Kassel (QRRK) theory for k(E) with both a master equation analysis and a modified strong-collision approach to account for collisional deactivation. Thermodynamic properties of species and transition states are determined by ab initio methods at the G2 and CBS-Q/B3LYP/6-31G(d,p) levels of theory and isodesmic reaction analysis. Rate coefficients for reactions of the energized adducts are obtained from canonical transition state theory. The reaction of C2H5 with O-2 forms an energized peroxy adduct with a calculated well depth of 35.3 kcal mol(-1) at the CBS-Q//B3LYP/6-31G(d,p) level of theory. The calculated (VTST) high-pressure limit bimolecular addition reaction rate constant for C2H5 + O-2 is 2.94 x 10(13)T(-0.44). Predictions of the chemically activated branching ratios using both collisional deactivation models are similar. All of the product formation pathways of ethyl radical with O-2, except the direct HO2 elimination from the CH3CH2OO. adduct, involve barriers that are above the energy of the reactants. As a result, formation of the stabilized CH3CH2OO. adduct is important at low to moderate temperatures; subsequent reactions of this adduct should be included in kinetic mechanisms. The temperature and pressure dependent rate coefficients for both the chemically activated reactions of the energized adducts and the thermally activated reactions of the stabilized adducts are assembled into a reaction mechanism. Comparisons of predictions using this mechanism to experiment demonstrate the necessity of including dissociation of the stabilized ethylperoxy adduct. Two channels are particularly important, direct HO2 elimination and reverse reaction to C2H5 + O-2, where the ratio of these rates is a function of temperature and pressure. The predictions, using unadjusted rate coefficients, are consistent with literature observations over extended temperature and pressure ranges. Comparison of a mechanism using 7 x 3 Chebyshev polynomials to represent k(T,P) to a conventional mechanism which used k(T) only (different values for k(T) at different pressures) showed good agreement. The kinetic implications for low-temperature ignition due to the direct formation of ethylene and HO2 from ethylperoxy are discussed. C1 New Jersey Inst Technol, Dept Chem Engn Chem & Environm Sci, Newark, NJ 07102 USA. Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bozzelli, JW (reprint author), New Jersey Inst Technol, Dept Chem Engn Chem & Environm Sci, Newark, NJ 07102 USA. RI Dean, Anthony/A-8590-2009 NR 50 TC 106 Z9 106 U1 1 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD AUG 15 PY 2002 VL 106 IS 32 BP 7276 EP 7293 DI 10.1021/jp014540+ PG 18 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 582LZ UT WOS:000177353700006 ER PT J AU Nussenzveig, HM AF Nussenzveig, HM TI Does the glory have a simple explanation? SO OPTICS LETTERS LA English DT Article ID DIELECTRIC SPHERES; RESONANCES AB The explanation for the meteorological glory provided by the complex angular momentum theory is revisited in response to comments that a simpler physical picture would be desirable. New results that confirm the tunneling origin of the glory and the roles of resonances and surface waves in this phenomenon are presented, and expressions for averaged angular distribution and polarization features are given. (C) 2002 Optical Society of America. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Nussenzveig, HM (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 14 TC 10 Z9 11 U1 0 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD AUG 15 PY 2002 VL 27 IS 16 BP 1379 EP 1381 DI 10.1364/OL.27.001379 PG 3 WC Optics SC Optics GA 584TF UT WOS:000177484300003 PM 18026452 ER PT J AU Leon, R Ibanez, J Marcinkevicius, S Siegert, J Paskova, T Monemar, B Chaparro, S Navarro, C Johnson, SR Zhang, YH AF Leon, R Ibanez, J Marcinkevicius, S Siegert, J Paskova, T Monemar, B Chaparro, S Navarro, C Johnson, SR Zhang, YH TI Defect states in red-emitting InxAl1-xAs quantum dots SO PHYSICAL REVIEW B LA English DT Article ID LEVEL TRANSIENT SPECTROSCOPY; MISFIT DISLOCATIONS; VISIBLE LUMINESCENCE; DEEP LEVELS; SI; EMISSION; SYSTEMS; TRAPS; RECOMBINATION; IRRADIATION AB Optical and transport measurements carried out in pn diodes and Schottky barriers containing multilayers of InAlAs quantum dots embedded in AlGaAs barriers show that while red emission from quantum dot (QD) states is obtained at similar to1.8 eV, defect states dominate the optical properties and transport in these quantum dots. These defects provide nonradiative recombination paths, which shortens the carrier lifetimes in QD's to tens of picoseconds (from similar to1 ns) and produce deep level transient spectroscopy (DLTS) peaks in both p and n type structures. DLTS experiments performed with short filling pulses and bias dependent measurements on InAlAs QD's on n-AlGaAs barriers showed that one of the peaks can be attributed to either QD/barrier interfacial defects or QD electron levels, while other peaks are attributed to defect states in both p and n type structures. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Royal Inst Technol, Dept Microelect & Informat Technol, S-16440 Kista, Sweden. Linkoping Univ, Dept Phys & Measurement Technol, S-58183 Linkoping, Sweden. Arizona State Univ, Ctr Solid State Elect Res, Tempe, AZ 85287 USA. Arizona State Univ, Dept Elect Engn, Tempe, AZ 85287 USA. RP Leon, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Paskova, Tanya/D-2203-2009; Materials, Semiconductor/I-6323-2013; Ibanez-Insa, Jordi/F-6995-2014; Monemar, Bo/B-3718-2016 OI Ibanez-Insa, Jordi/0000-0002-8909-6541; NR 31 TC 1 Z9 1 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD AUG 15 PY 2002 VL 66 IS 8 AR 085331 DI 10.1103/PhysRevB.66.085331 PG 7 WC Physics, Condensed Matter SC Physics GA 593BW UT WOS:000177972500089 ER PT J AU Fujita, M Chao, BF Sanchez, BV Johnson, TJ AF Fujita, M Chao, BF Sanchez, BV Johnson, TJ TI Oceanic torques on solid Earth and their effects on Earth rotation SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article DE Earth rotation; oceanic torque; angular momentum ID ATMOSPHERIC ANGULAR-MOMENTUM; GENERAL-CIRCULATION MODEL; POLAR MOTION; CHANDLER-WOBBLE; EXCITATION; BUDGET; BALANCE; SIGNALS AB [1] We calculate that the oceanic torque vectors (x, y, z components) acting on the solid Earth using the Parallel Ocean Climate Model (POCM) output data at 3-day intervals for the period 1988-1995. This study examined three distinct types of torque, with different physical mechanisms: pressure, gravitational, and frictional. The pressure torque is further divided into two parts: that due to Earth's ellipticity and that due to the ocean bottom topography. According to resultant time series the ellipticity pressure torque causes the largest effect for the x and y components. The gravitational torque and the ellipticity pressure torque are shown numerically to be exactly proportional by a factor of -0.49. The topographic pressure torque is somewhat smaller in overall amplitude than the ellipticity-induced torque (the sum of the ellipticity pressure torque and gravitational torque). The ocean bottom frictional torque is found to be negligible in all three components. To validate the torque calculations, we compare the calculated oceanic torques with effective torque derived from the ocean angular momentum (OAM) variation, both from POCM. It is shown that the effective torque associated with the mass term of the OAM agrees remarkably well with the ellipticity-induced torque as required by theory. For the motion term the effective torque can be explained mostly by the topographic pressure torque in the intraseasonal periods, but the seasonal and longer-period components show significant differences between the two. The difference should theoretically be attributed to the exclusion of the wind frictional torque on the ocean. However, a comparison based on the NASA GEOS-1 atmospheric model shows that the wind frictional torque obtained is insufficient in power in the x and y components. Finally, in the application to the Earth rotation excitation it is found that both the ellipticity and topographic torques have comparable contributions to polar motion excitation for both seasonal and nonseasonal variations. For the length of day variation, our torque approach is presently inadequate because the oceanic contribution is relatively too small to be estimated in the presence of data and model errors. C1 Japan Coast Guard, Hysrog & Oceanog Dept, Chuo Ku, Tokyo 1040045, Japan. NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA. USN Observ, Earth Orientat Dept, Washington, DC 20392 USA. RP Fujita, M (reprint author), Japan Coast Guard, Hysrog & Oceanog Dept, Chuo Ku, 5-3-1 Tsukiji, Tokyo 1040045, Japan. EM masayuki-fujita@kaiho.mlit.go.jp; chao@bowie.gsfc.nasa.gov; bsanchez@santafe.gsfc; tj@casa.usno.navy.mol RI Sanchez, Braulio/I-5952-2013; Chao, Benjamin Fong/N-6156-2013 NR 43 TC 6 Z9 6 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD AUG 14 PY 2002 VL 107 IS B8 AR 2154 DI 10.1029/2001JB000339 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 610ZY UT WOS:000178993000007 ER PT J AU Alter-Gartenberg, R Nolf, SR Davis, RE AF Alter-Gartenberg, R Nolf, SR Davis, RE TI Assessment of the Wiener-Retinex process SO APPLIED OPTICS LA English DT Article ID IMAGES AB We assess the performance of the Retinex transformation, the Wiener restoration, and the combined Wiener-Retinex process in the context of the end-to-end model of color visual-communication channels for near-surface acquisition. We extend the formulations of panchromatic imaging for the nonlinear Retinex transformation and the linear Wiener and Wiener-Retinex restoration filters to color imaging. We further assess the accuracy by which colors are restored in the cases of uniform and spatially varying irradiance levels, and the shadow depth for which color consistency is still possible with reasonable accuracy. Finally, we assess the sensitivity of these processes to perturbations in the visual channel, including the image-gathering design and the spatial support of the Retinex transformation. (C) 2002 Optical Society of America. C1 Comp Sci Corp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Alter-Gartenberg, R (reprint author), Comp Sci Corp, 21 Enterprise Pkwy, Hampton, VA 23666 USA. EM rgartenb@csc.com NR 22 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD AUG 10 PY 2002 VL 41 IS 23 BP 4783 EP 4805 DI 10.1364/AO.41.004783 PG 23 WC Optics SC Optics GA 582AG UT WOS:000177327100004 PM 12197646 ER PT J AU Milman, MH Catanzarite, J Turyshev, SG AF Milman, MH Catanzarite, J Turyshev, SG TI Effect of wave-number error on the computation of path-length delay in white-light interferometry SO APPLIED OPTICS LA English DT Article ID PHASE-SHIFTING INTERFEROMETRY AB We analyze the error in computed optical path-length delay when using a phase-shifting interferometry (PSI) algorithm with an error in the operating wavelength. The delay error decomposes into two terms. The first is the error in the conversion from a phase measurement to the delay because of the incorrect wavelength, and the second is the error made in the phase measurement itself that is due to the wavelength error. The most important aspect of this investigation is to ascertain this latter error. A general characterization is obtained, and a particularly simple formula is developed for the special case of least-squares estimation involving only the ratio of the wave-number error to the wave number and a multiplicative factor that is an a priori computable nonlinear function of the ratio of the modulator stroke length to the operating wavelength. Because the ultimate path-length error is a function of the two terms, a new set of PSI algorithms that compensate the computed phase error to cancel the conversion error is developed. Numerical simulations are presented to validate the analysis and establish the insensitivity of the new algorithms to wave-number error. (C) 2002 Optical Society of America. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Milman, MH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 198-138, Pasadena, CA 91109 USA. EM mark.h.milman@jpl.nasa.gov NR 13 TC 9 Z9 9 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD AUG 10 PY 2002 VL 41 IS 23 BP 4884 EP 4890 DI 10.1364/AO.41.004884 PG 7 WC Optics SC Optics GA 582AG UT WOS:000177327100015 PM 12197657 ER PT J AU Dwek, E Barker, MK AF Dwek, E Barker, MK TI The cosmic radio and infrared backgrounds connection SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; diffuse radiation; infrared : general; radio continuum : general ID SPIRAL GALAXIES; STAR-FORMATION; EMISSION; CONSTRAINTS; MODEL AB We use the radio-infrared ( IR) flux correlation between star-forming galaxies in the local universe to examine the connection between their cumulative contributions to the cosmic IR and radio backgrounds. The general expression relating the intensities of the two backgrounds is complicated and depends on details of the evolution of the galaxies IR luminosity function with redshift. However, in the specific case in which the radio-IR flux correlation is linear, the relation between the intensity of the IR background and the brightness temperature of the radio background reduces to a simple analytical expression that at 178 MHz is I-CIB (nW m(-2) sr(-1)) = 2.7 T-crb (K), where the numerical coefficient was calculated for a radio spectral index of 0.7. This relation is insensitive to the star-formation history of the galaxies that produce the cosmic IR background (CIB). We use the observed CIB intensity to constrain the cosmic star formation history and the relation between the CIB and the cosmic radio background ( CRB) to constrain the relative contribution of star-forming galaxies to the CRB. Current limits on the CIB intensity predict a 178 MHz brightness temperature of similar to18 +/- 9 K, about half of the 37 +/- 8 K inferred for an isotropic radio component. This suggests that star-forming galaxies and active galactic nuclei (AGNs) contribute about equally to the CRB intensity at that frequency. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. RP Dwek, E (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. NR 24 TC 14 Z9 14 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2002 VL 575 IS 1 BP 7 EP 11 DI 10.1086/341143 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 581BH UT WOS:000177270900002 ER PT J AU Schmitt, HR Pringle, JE Clarke, CJ Kinney, AL AF Schmitt, HR Pringle, JE Clarke, CJ Kinney, AL TI The orientation of jets relative to dust disks in radio galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; galaxies : active; galaxies : jets; galaxies : nuclei; galaxies : structure ID SPACE-TELESCOPE OBSERVATIONS; SEYFERT-GALAXIES; ELLIPTIC GALAXIES; VLA OBSERVATIONS; NUCLEAR DISKS; B2 SAMPLE; ACCRETION; HST; GAS; IDENTIFICATIONS AB We use Hubble Space Telescope broadband images and VLA and VLBI continuum data to study the three-dimensional orientation of jets relative to nuclear dust disks in 20 radio galaxies. The comparison between the position angles of the jets and those of the dust disk major axes shows a wide distribution, suggesting that they are not aligned preferentially perpendicular to each other. We use a statistical technique to determine the three-dimensional distribution of angles between jets and dust disk rotation axes. This analysis shows that the observations are consistent with jets homogeneously distributed over a large region, extending over polar caps of 55degrees-77degrees but seeming to avoid lying close to the plane of the dust disks. We argue that the lack of close alignment between jets and dust disks axes is not likely to be caused by feeding the nucleus with gas from mergers originated from random directions. We suggest that the misalignment can be due to a warping mechanism in the accretion disk, such as self-irradiation instability or the Bardeen-Petterson effect, or that the gravitational potential in the inner regions of the galaxy is misaligned with respect to that of the dust disk. C1 Natl Radio Astron Observ, Socorro, NM 87801 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Space Telescope Sci Inst, Baltimore, MD 21218 USA. NASA Headquarters, Washington, DC 20546 USA. RP Schmitt, HR (reprint author), Natl Radio Astron Observ, POB O,1003 Lopezville Rd, Socorro, NM 87801 USA. NR 44 TC 51 Z9 51 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2002 VL 575 IS 1 BP 150 EP 155 DI 10.1086/341211 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 581BH UT WOS:000177270900016 ER PT J AU Jenkins, JM AF Jenkins, JM TI The impact of solar-like variability on the detectability of transiting terrestrial planets SO ASTROPHYSICAL JOURNAL LA English DT Article DE methods : data analysis; planetary systems; techniques : photometric ID HIGH-PRECISION PHOTOMETRY; SUN-LIKE STARS; EXTRASOLAR PLANETS; INNER PLANETS; CM DRACONIS; LIMITS; HD-209458; MISSION; STABILITY; ROTATION AB Transit photometry is a promising method for discovering extrasolar planets as small as Earth from space-based photometers, and several near-term photometric missions are on the drawing board. In particular, NASA's recently selected Kepler mission is devoted primarily to detecting extrasolar planets. The success of these efforts depends in part on the ability to detect transit signatures against the inherent photometric variability of the target stars. While other noise sources such as shot noise and CCD noise are under the control of the instrument designers, this one is not. The photometric variability of solar-like stars presents a fundamental lower limit to the minimum detectable planet radius for a given star and number of observed transits. In this paper we examine the capability of such missions using bolometric data for the only star for which sufficient photometric precision exists to address this question: the Sun. The results indicate that solar-like variability does not prevent the detection of Earth-sized planets even for stars rotating significantly faster than the Sun. Four transits are detectable for m(v) = 12 stars with rotation periods as short as similar to21 days, while six transits allow detection for stellar rotation periods as short as similar to16 days. Indeed, the limits posed by solar-like variability allow for the detection of planets significantly smaller than Earth orbiting Sun-like stars. Planets as small as 0.6 Earth radii exhibiting at least six transits can be detected orbiting bright (m(v) = 10) solar analogs. C1 NASA, SETI Inst, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Jenkins, JM (reprint author), NASA, SETI Inst, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. NR 45 TC 76 Z9 76 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2002 VL 575 IS 1 BP 493 EP 505 DI 10.1086/341136 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 581BH UT WOS:000177270900044 ER PT J AU Beck, JG Gizon, L Duvall, TL AF Beck, JG Gizon, L Duvall, TL TI A new component of solar dynamics: North-south diverging flows migrating toward the equator with an 11 year period SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : atmospheric motions; Sun : rotation ID MICHELSON DOPPLER IMAGER; ZONAL FLOWS; ROTATION; SUN AB Time-distance helioseismology analysis of Dopplergrams provides maps of torsional oscillations and meridional flows. Meridional flow maps show a time-varying component that has a banded structure that matches the torsional oscillations with an equatorward migration over the solar cycle. The time-varying component of meridional flow consists of a flow diverging from the dominant latitude of magnetic activity. These maps are compared with other torsional oscillation maps and with magnetic flux maps, showing a strong correlation with active latitudes. These results demonstrate a strong link between the time-varying component of the meridional flow and the torsional oscillations. C1 Stanford Univ, WW Hansen Expt Phys Lab, Stanford, CA 94305 USA. NASA, Goddard Space Flight Ctr, Lab Astron & Solar Phys, Greenbelt, MD 20771 USA. RP Beck, JG (reprint author), Stanford Univ, WW Hansen Expt Phys Lab, 455 Via Palou, Stanford, CA 94305 USA. RI Gizon, Laurent/B-9457-2008; Duvall, Thomas/C-9998-2012 NR 17 TC 52 Z9 53 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2002 VL 575 IS 1 BP L47 EP L50 DI 10.1086/342636 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 581BJ UT WOS:000177271000011 ER PT J AU Markwardt, CB Swank, JH Strohmayer, TE in 't Zand, JJM Marshall, FE AF Markwardt, CB Swank, JH Strohmayer, TE in 't Zand, JJM Marshall, FE TI Discovery of a second millisecond accreting pulsar: XTE J1751+305 SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; pulsars : general; pulsars : individual (XTE J1751+305); stars : neutron; white dwarfs; X-rays : binaries ID X-RAY BINARIES; SAX J1808.4-3658; RADIO PULSARS; SYSTEM; STARS AB We report the discovery by the Rossi X-Ray Timing Explorer Proportional Counter Array of a second transient accreting millisecond pulsar, XTE J1751-305, during regular monitoring observations of the Galactic bulge region. The pulsar has a spin frequency of 435 Hz, making it one of the fastest pulsars. The pulsations contain the signature of orbital Doppler modulation, which implies an orbital period of 42 minutes, the shortest orbital period of any known radio or X-ray millisecond pulsar. The mass function, f(x) = (1.278 +/- 0.003) x 10(-6) M., yields a minimum mass for the companion of between 0.013 and 0.017 M., depending on the mass of the neutron M star. No eclipses were detected. A previous X-ray outburst in 1998 June was discovered in archival All-Sky Monitor data. Assuming mass transfer in this binary system is driven by gravitational radiation, we constrain the orbital inclination to be in the range 30degrees-85degrees and the companion mass to be 0.013-0.035 M.. The companion M is most likely a heated helium dwarf. We also present results from the Chandra High Resolution Camera-S observations, which provide the best-known position of XTE J1751-305. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Utrecht, Astron Inst, NL-3508 TA Utrecht, Netherlands. SRON, Natl Inst Space Res, NL-3585 CA Utrecht, Netherlands. RP Markwardt, CB (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RI Swank, Jean/F-2693-2012 NR 27 TC 128 Z9 128 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2002 VL 575 IS 1 BP L21 EP L24 DI 10.1086/342612 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 581BJ UT WOS:000177271000005 ER PT J AU Reames, DV Tylka, AJ AF Reames, DV Tylka, AJ TI Energetic particle abundances as probes of an interplanetary shock wave SO ASTROPHYSICAL JOURNAL LA English DT Article DE acceleration of particles; shock waves; Sun : abundances; Sun : coronal mass ejections (CMEs); Sun : particle emission ID CORONAL MASS EJECTIONS; ACCELERATION; EVENTS; INTENSITIES; TRANSPORT; EVOLUTION; SPECTRA; WIND AB We examine the unique abundance variations of Fe/O and He/H in solar energetic particles from a W09 event of 2001 April 10 that have leaked through the flank of an interplanetary shock launched from W04 on April 9. Shock waves from both events reached the Wind spacecraft on April 11. During the second event, both Fe/O and He/H began at low values and rose to maxima near the time of passage of the shock waves, indicating greater scattering for the species with the highest rigidity at a given velocity. Strong modulation of Fe/O suggests preferential scattering and trapping of Fe by the wave spectrum near and behind the intermediate shock. A significant factor may be the residual proton-generated waves from the very hard proton spectrum accelerated by the early shock wave prior to the onset of the second event. Thus, ion abundances from the later event probe the residual wave spectrum at the earlier shock. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP Reames, DV (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. RI Tylka, Allan/G-9592-2014 NR 20 TC 8 Z9 9 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2002 VL 575 IS 1 BP L37 EP L39 DI 10.1086/342529 PN 2 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 581BJ UT WOS:000177271000009 ER PT J AU Okong'o, NA Bellan, J AF Okong'o, NA Bellan, J TI Direct numerical simulation of a transitional supercritical binary mixing layer: heptane and nitrogen SO JOURNAL OF FLUID MECHANICS LA English DT Article ID DENSITY-FUNCTION; TURBULENT-FLOWS; SHEAR; SCALES; PRESSURES; EVOLUTION; BEHAVIOR; NUMBER; DROPS; MODEL AB Direct numerical simulations (DNS) of a supercritical temporal mixing layer are conducted for the purpose of exploring the characteristics of high-pressure transitional mixing behaviour. The conservation equations are formulated according to fluctuation-dissipation (FD) theory, which is consistent with non-equilibrium thermodynamics and converges to kinetic theory in the low-pressure limit. According to FD theory, complementing the low-pressure typical transport properties (viscosity, diffusivity and thermal conductivity), the thermal diffusion factor is an additional transport property which may play an increasingly important role with increasing pressure. The Peng-Robinson equation of state with appropriate mixing rules is coupled to the dynamic conservation equations to obtain a closed system. The boundary conditions are periodic in the streamwise and spanwise directions, and of non-reflecting outflow type in the cross-stream direction. Due to the strong density stratification, the layer is considerably more difficult to entrain than equivalent gaseous or droplet-laden layers, and exhibits regions of high density gradient magnitude that become very convoluted at the transitional state. Conditional averages demonstrate that these regions contain predominantly the higher-density, entrained fluid, with small amounts of the lighter, entraining fluid, and that in these regions the mixing is hindered by the thermodynamic properties of the fluids. During the entire evolution of the layer, the dissipation is overwhelmingly due to species mass flux followed by heat flux effects with minimal viscous contribution, and there is a considerable amount of backscatter in the flow. Most of the species mass flux dissipation is due to the molecular diffusion term with significant contributions from the cross-term proportional to molecular and thermal diffusion. These results indicate that turbulence models for supercritical fluids should primarily focus on duplicating the species mass flux rather than the typical momentum flux, which constitutes the governing dissipation in atmospheric mixing layers. Examination of the passive-scalar probability density functions (PDFs) indicates that neither the Gaussian, nor the beta PDFs are able to approximate the evolution of the DNS-extracted PDF from its inception through transition. Furthermore, the temperature-species PDFs are well correlated, meaning that their joint PDF is not properly approximated by the product of their marginal PDFs; this indicates that the traditional reactive flow modelling based on replacing the joint PDF representing the reaction rate by the product of the marginal PDFs is not appropriate. Finally, the subgrid-scale temperature-species PDFs are also well correlated, and the species PDF exhibits important departures from the Gaussian. These results suggest that classic PDFs used in atmospheric pressure flows would not capture the physics of this supercritical mixing layer, either in an assumed PDF model at the larger scale, or at the subgrid scale. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bellan, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 46 TC 42 Z9 44 U1 0 U2 2 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4221 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD AUG 10 PY 2002 VL 464 BP 1 EP 34 DI 10.1017/S0022112002008480 PG 34 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 584PF UT WOS:000177475500001 ER PT J AU Chaban, GM Huo, WM Lee, TJ AF Chaban, GM Huo, WM Lee, TJ TI Theoretical study of infrared and Raman spectra of hydrated magnesium sulfate salts SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SELF-CONSISTENT-FIELD; ANHARMONIC VIBRATIONAL SPECTROSCOPY; MOLECULAR CALCULATIONS; GALILEAN SATELLITES; BASIS SETS; ROW ATOMS; MINERALS; SYSTEMS; SURFACE; OCEAN AB Harmonic and anharmonic vibrational frequencies, as well as infrared and Raman intensities, are calculated for MgSO(4).nH(2)O (n=1-3). Electronic structure theory at the second order Moller-Plesset perturbation theory level with a triple-zeta+polarization basis set is used to determine the geometry, energetics, charge distributions, and vibrational spectra of pure and hydrated MgSO(4) salts. The direct vibrational self-consistent field method and its correlation corrected extension are used to determine anharmonic corrections to vibrational frequencies and infrared intensities for the pure MgSO(4) and its complex with one water molecule. Very significant differences are found between vibrational spectra of water molecules in complexes with MgSO(4) and pure water. Some of the O-H stretching frequencies are shifted to the red very significantly (by up to 2000 cm(-1)) upon complexation with magnesium sulfate. They should be observed between 1700 and 3000 cm(-1), in a region very different from the corresponding O-H stretch frequency region of pure water (3700-3800 cm(-1)). In addition, the SO(2) stretching vibrations are found at lower frequency regions than the water vibrations. They can serve as unique identifiers for the presence of sulfate salts. The predicted infrared and Raman spectra should be of valuable help in the design of future missions and analysis of observed data from the ice surface of Jupiter's moon Europa that possibly contains hydrated MgSO(4) salts. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Chaban, GM (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM chaban@pauli.nas.nasa.gov RI Lee, Timothy/K-2838-2012 NR 22 TC 29 Z9 29 U1 1 U2 9 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 8 PY 2002 VL 117 IS 6 BP 2532 EP 2537 DI 10.1063/1.1489997 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 577BX UT WOS:000177042800011 ER PT J AU Andriotis, AN Menon, M Srivastava, D AF Andriotis, AN Menon, M Srivastava, D TI Transfer matrix approach to quantum conductivity calculations in single-wall carbon nanotubes SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS SCHEME; TIGHT-BINDING; ELECTRICAL-TRANSPORT; CONDUCTANCE; SYSTEMS; DISORDER; HYDROGEN; DEFECTS; DEVICES; STATES AB We present an efficient transfer matrix formalism for obtaining the quantum conductivity of single-wall carbon nanotubes (SWCN's) based on a nonorthogonal tight-binding scheme. The formalism is used to calculate conductivity in the presence of topological defects and H adsorbates. I-V characteristics show large oscillatory behavior as a function of the number of H adatoms for both (10,0) and (5,5) SWCN's. Furthermore, the conductivity is found to depend sensitively on structural relaxation. (C) 2002 American Institute of Physics. C1 Fdn Res & Technol Hellas, Inst Elect Struct & Laser, Iraklion 71110, Crete, Greece. Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. Univ Kentucky, Ctr Computat Sci, Lexington, KY 40506 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Andriotis, AN (reprint author), Fdn Res & Technol Hellas, Inst Elect Struct & Laser, POB 1527, Iraklion 71110, Crete, Greece. EM andriot@iesl.forth.gr; super250@pop.uky.edu; deepak@nas.nasa.gov RI Andriotis, Antonios/A-2848-2014 NR 49 TC 24 Z9 24 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 8 PY 2002 VL 117 IS 6 BP 2836 EP 2843 DI 10.1063/1.1491406 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 577BX UT WOS:000177042800045 ER PT J AU Cruden, BA Rao, MVVS Sharma, SP Meyyappan, M AF Cruden, BA Rao, MVVS Sharma, SP Meyyappan, M TI Neutral gas temperature estimate in CF4/O-2/Ar inductively coupled plasmas SO APPLIED PHYSICS LETTERS LA English DT Article ID ELECTRON-IMPACT EXCITATION; CARBON-MONOXIDE; STATES; CO; DENSITIES; DIOXIDE AB Neutral temperatures in inductively coupled CF4/O-2/Ar mixture plasmas have been characterized by fitting the rotational envelope of emission spectra in a gaseous electronics conference reference cell. CF and CO are found to present different rotational temperatures with opposite trends with respect to pressure. It is proposed that CF is created as a rotationally and translationally hot molecule due to CF4 dissociation and the disparity in temperatures and temperature trend is indicative of incomplete equilibration of the CF with other neutral species in the plasma. This may have important consequences from the standpoint of understanding neutral reaction chemistries. (C) 2002 American Institute of Physics. C1 NASA, Plasma Res Lab, Ames Res Ctr, Moffett Field, CA 94035 USA. Eloret Corp, Sunnyvale, CA USA. RP Cruden, BA (reprint author), NASA, Plasma Res Lab, Ames Res Ctr, MS 223-2, Moffett Field, CA 94035 USA. NR 19 TC 19 Z9 19 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 5 PY 2002 VL 81 IS 6 BP 990 EP 992 DI 10.1063/1.1497998 PG 3 WC Physics, Applied SC Physics GA 579GZ UT WOS:000177171400014 ER PT J AU Paielli, R AF Paielli, R TI Continuous altitude rule SO AVIATION WEEK & SPACE TECHNOLOGY LA English DT Letter C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Paielli, R (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MCGRAW HILL INC PI NEW YORK PA 1221 AVENUE OF THE AMERICAS, NEW YORK, NY 10020 USA SN 0005-2175 J9 AVIAT WEEK SPACE TEC JI Aviat. Week Space Technol. PD AUG 5 PY 2002 VL 157 IS 6 BP 6 EP 6 PG 1 WC Engineering, Aerospace SC Engineering GA 581GN UT WOS:000177283500002 ER PT J AU Cox, CM Chao, BF AF Cox, CM Chao, BF TI Detection of a large-scale mass redistribution in the terrestrial system since 1998 SO SCIENCE LA English DT Article ID GRAVITATIONAL-FIELD; SATELLITE ALTIMETRY; ICE-SHEET; SEA-LEVEL; CIRCULATION; OCEAN; EARTH; 20TH-CENTURY; GLACIERS; ROTATION AB Earth's dynamic oblateness (J(2)) had been undergoing a decrease, according to space geodetic observations over the past 25 years, until around 1998, when it switched quite suddenly to an increasing trend that has continued to the present. The secular decrease in J(2) resulted primarily from the postglacial rebound in the mantle. The present increase, whose geophysical cause(s) are uncertain, thus signifies a large change in global mass distribution with a J(2) effect that considerably overshadows that of mantle rebound. C1 NASA, Goddard Space Flight Ctr, Raytheon Informat Technol & Sci Serv, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA. RP Cox, CM (reprint author), NASA, Goddard Space Flight Ctr, Raytheon Informat Technol & Sci Serv, Code 926, Greenbelt, MD 20771 USA. EM ccox@stokes.gsfc.nasa.gov RI Chao, Benjamin Fong/N-6156-2013 NR 28 TC 126 Z9 138 U1 4 U2 9 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 2 PY 2002 VL 297 IS 5582 BP 831 EP 833 DI 10.1126/science.1072188 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 579RZ UT WOS:000177192800049 PM 12161652 ER PT J AU Grzanka, E Palosz, B Gierlotka, S Pielaszek, R Bismayer, U Janik, JF Wells, JR Palosz, W Porsch, F AF Grzanka, E Palosz, B Gierlotka, S Pielaszek, R Bismayer, U Janik, JF Wells, JR Palosz, W Porsch, F TI Generation and relaxation of microstrains in GaN nanocrystals under extreme pressures SO ACTA PHYSICA POLONICA A LA English DT Article; Proceedings Paper CT 4th International School and Symposium on Physics in Materials Science (ISSPMS 01) CY SEP 23-29, 2001 CL JASZOWIEC, POLAND SP Inst Atom Energy, Warsaw Univ Technol, Dept Mat Sci & Engn ID GALLIUM NITRIDE AB Nanocrystalline powders of GaN with grain sizes ranging from 2 to 30 nm were examined under high external pressures by in situ diffraction techniques in a diamond anvil cell at DESY (HASYLAB, Station F3). The experiments on densification of pure powders under high pressure were performed without a pressure medium. The mechanism of generation and relaxation of internal strains and their distribution in nanoparticles was deduced from the Bragg reflections recorded in situ under high pressures at room temperature. The microstrain was calculated from the full-width at half-maximum (FWHM) values of the Bragg lines. It was found that microstrains in GaN crystallites are generated and subsequently relaxed by two mechanisms: generation of stacking faults and change of the size and shape of the grains occurring under external stress. C1 High Pressure Res Ctr UNIPRESS, PL-01142 Warsaw, Poland. Warsaw Univ, Inst Expt Phys, Warsaw, Poland. Univ Hamburg, Mineral Petrog Inst, Hamburg, Germany. Stanislaw Staszic Univ Min & Met, PL-30059 Krakow, Poland. Duke Univ, Dept Chem, Durham, NC 27706 USA. NASA, USRA, George C Marshall Space Flight Ctr, Huntsville, AL USA. Univ Bonn, Mineral Petrol Inst, D-5300 Bonn, Germany. RP Grzanka, E (reprint author), High Pressure Res Ctr UNIPRESS, Sokolowska 29-37, PL-01142 Warsaw, Poland. NR 7 TC 2 Z9 2 U1 0 U2 1 PU POLISH ACAD SCIENCES INST PHYSICS PI WARSAW PA AL LOTNIKOW 32-46, 02-668 WARSAW, POLAND SN 0587-4246 J9 ACTA PHYS POL A JI Acta Phys. Pol. A PD AUG PY 2002 VL 102 IS 2 BP 167 EP 174 PG 8 WC Physics, Multidisciplinary SC Physics GA 581AV UT WOS:000177269700002 ER PT J AU Raman, G Envia, E Bencic, TJ AF Raman, G Envia, E Bencic, TJ TI Jet-cavity interaction tones SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 37th Aerospace Sciences Meeting and Exhibit CY JAN 11-14, 1999 CL RENO, NEVADA SP Amer Inst Aeronaut & Astronaut ID OSCILLATIONS; SCREECH; EDGE AB A fundamental study of resonant tones produced by jet-cavity interaction over a wide range of flow conditions covering both subsonic and supersonic speeds is described. Two significant findings emerge. For the jet-cavity configurations investigated, a suitably defined reduced frequency parameter allows for a global classification of all jet-cavity tones into two main types. For the first type, the reduced frequency depends on the jet Mach number, whereas for the second type, the reduced frequency is independent of the jet Mach number. We propose simple correlations for the frequency of both types of tones. Based on earlier research, we had expected that the traditional classifications of cavity flows into the open, transitional, or closed variety would be insensitive to small changes in Mach number and would depend primarily on the cavity's LID ratio. However, use of the novel high-resolution photoluminescent pressure sensitive paint shows that these classifications are actually quite sensitive to the jet Mach number for jet-cavity interactions. However, these classifications provide no guidance for determining tone type, amplitude, or frequency. C1 IIT, Aerosp Engn Mech Mat & Aerosp Engn Dept, Chicago, IL 60616 USA. NASA, John H Glenn Res Ctr, Acoust Branch, Cleveland, OH 44135 USA. NASA, John H Glenn Res Ctr, Opt Instrumentat Technol Branch, Cleveland, OH 44135 USA. RP Raman, G (reprint author), IIT, Aerosp Engn Mech Mat & Aerosp Engn Dept, Chicago, IL 60616 USA. NR 34 TC 12 Z9 13 U1 3 U2 6 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD AUG PY 2002 VL 40 IS 8 BP 1503 EP 1511 DI 10.2514/2.1845 PG 9 WC Engineering, Aerospace SC Engineering GA 580QJ UT WOS:000177245000003 ER PT J AU Khorrami, MR Li, F Choudhari, M AF Khorrami, MR Li, F Choudhari, M TI Novel approach for reducing rotor tip-clearance-induced noise in turbofan engines SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA/CEAS 7th Aeroacoustics Conference CY MAY 28-30, 2001 CL MAASTRICHT, NETHERLANDS SP Amer Inst Aeronaut & Astronaut, CEAS ID NAVIER-STOKES COMPUTATIONS; FLAP AB Rotor tip-clearance induced noise, in the form of both rotor self-noise and rotor-stator interaction noise, constitutes an important component of total fan noise. Innovative yet cost-effective techniques to suppress rotor-generated noise are, therefore, of foremost importance for improving the noise signature of turbofan engines. To that end, the feasibility of a passive porous treatment strategy to modify positively the tip-clearance flowfield is addressed. Accurate viscous flow calculations of the baseline and the treated rotor flowfields are studied. Detailed comparison between the computed baseline solution and experimental measurements shows excellent agreement. Tip-vortex structure, trajectory, strength, and other relevant aerodynamic quantities are extracted from the computed database. Extensive comparison between the untreated and treated tip-clearance flowfields is performed. The effectiveness of the porous treatment for altering the rotor-tip vortex flowfield, in general, and reducing the intensity of the tip vortex, in particular, is demonstrated. In addition, the simulated flowfield for the treated tip clearly shows that substantial reduction in the intensity of both the shear layer rollup and boundary-layer separation on the wall is achieved. C1 High Technol Corp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA. RP Khorrami, MR (reprint author), NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA. RI Choudhari, Meelan/F-6080-2017 OI Choudhari, Meelan/0000-0001-9120-7362 NR 36 TC 12 Z9 13 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD AUG PY 2002 VL 40 IS 8 BP 1518 EP 1528 DI 10.2514/2.1848 PG 11 WC Engineering, Aerospace SC Engineering GA 580QJ UT WOS:000177245000005 ER PT J AU Corona, E Waters, WA Starnes, JH AF Corona, E Waters, WA Starnes, JH TI Collapse of rectangular aluminum plates with axial cracks SO AIAA JOURNAL LA English DT Article AB Results of an experimental and numerical study of the residual strength of compression-loaded rectangular aluminum plates with longitudinal cracks are presented. The paper concentrates first on the experimental results and the numerical simulations of the experiments. The results of a parametric study to determine the effects of varying selected parameters on plate response are also presented. The results indicate that the response of the plates is characterized by a limit load instability that induces collapse. Experimental results show that the collapse loads of the plates depend on the location of the crack and that these loads are lower when the crack is located near a longitudinal edge. The numerical results agree with the experimental results. The results of the parametric study indicate that the dependence of the collapse load on crack length is most significant when the cracks are near a longitudinal edge. The collapse load of plates that are simply supported or clamped on all four edges show the same trends as the crack length increases, although the values are, as expected, different. Plates with edges constrained to remain straight in their planes had higher collapse loads than those with edges free to deform in plane. The degree of geometric imperfection sensitivity of the collapse load is not significantly affected by the presence of cracks for the cases considered. C1 Univ Notre Dame, Dept Aerosp & Mech Engn, Notre Dame, IN 46556 USA. Lockheed Martin Space Operat, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Corona, E (reprint author), Univ Notre Dame, Dept Aerosp & Mech Engn, Notre Dame, IN 46556 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD AUG PY 2002 VL 40 IS 8 BP 1665 EP 1672 DI 10.2514/2.1838 PG 8 WC Engineering, Aerospace SC Engineering GA 580QJ UT WOS:000177245000023 ER PT J AU Samii, VF Les, CM Schulz, KS Keyak, JH Stover, SM AF Samii, VF Les, CM Schulz, KS Keyak, JH Stover, SM TI Computed tomographic osteoabsorptiometry of the elbow joint in clinically normal dogs SO AMERICAN JOURNAL OF VETERINARY RESEARCH LA English DT Article; Proceedings Paper CT 34th Annual Meeting of the American-College-of-Veterinary-Surgeons CY SEP 30-OCT 03, 1999 CL SAN FRANCISCO, CALIFORNIA SP Amer Coll Vet Surgeons ID MEDIAL CORONOID PROCESS; CANINE ELBOW; OSTEOCHONDRITIS DISSECANS; SUBCHONDRAL BONE; MINERAL DENSITY; CUBITAL JOINT; INCONGRUITY; DIAGNOSIS; DISEASES; CT AB Objective-To evaluate subchondral bone density patterns in elbow joints of clinically normal dogs by use of computed tomographic (CT) osteoabsorptiometry. Sample Population-20 cadaver forelimbs from 10 clinically normal dogs. Procedure-Each elbow joint was imaged in parasagittal and transverse planes of 1.5-mm thickness. Slice data were converted to dipotassium phosphate equivalent density (PPED) values. Sagittal, parasagittal, and transverse medial coronoid process topographic maps were constructed. Defined zones were created for each of the 3 CT planes, and confluence and peak PPED values were determined. Results-The lowest PPED value was 340 mg/ml (articular and subchondral confluence), and the highest was 1780 mg/ml (peak subchondral density). Detectable effects of joint laterality were not found in the confluence or peak PPED measurements or in the peak-to-confluence PPED ratio for all 3 CT planes. Significant differences were found among zones in all 3 planes for confluence and peak PPED measurements and between sagittal and transverse planes for peak-to-confluence PPED ratios. Subjectively, the pattern of density distribution among dogs was fairly consistent for the sagittal and parasagittal slices. Three specific patterns of density distribution were apparent on the transverse topographic maps of the medial coronoid process that corresponded to conformational differences. Conclusions and Clinical Relevance-The use of CT osteoabsorptiometry provides a repeatable technique that can be used to noninvasively examine bone density and the effects of stress acting on joints in vivo. Variability in density values for any of the CT planes was not identified among clinically normal dogs. C1 Univ Calif Davis, Sch Vet Med, Dept Surg & Radiol Sci, Davis, CA 95616 USA. Univ Calif Davis, Sch Vet Med, Dept Anat Physiol & Cell Biol, Davis, CA 95616 USA. NASA, Ames Res Ctr, Musculoskeletal Biomech Lab, Moffett Field, CA 94035 USA. UCI Med Ctr, Dept Orthoped Surg, Orange, CA 92868 USA. RP Samii, VF (reprint author), Ohio State Univ, Coll Vet Med, Dept Vet Clin Sci, Columbus, OH 43210 USA. NR 28 TC 27 Z9 27 U1 0 U2 5 PU AMER VETERINARY MEDICAL ASSOC PI SCHAUMBURG PA 1931 N MEACHAM RD SUITE 100, SCHAUMBURG, IL 60173-4360 USA SN 0002-9645 J9 AM J VET RES JI Am. J. Vet. Res. PD AUG PY 2002 VL 63 IS 8 BP 1159 EP 1166 DI 10.2460/ajvr.2002.63.1159 PG 8 WC Veterinary Sciences SC Veterinary Sciences GA 580XG UT WOS:000177261600015 PM 12171171 ER PT J AU Aksnes, A Stadsnes, J Bjordal, J Ostgaard, N Vondrak, RR Detrick, DL Rosenberg, TJ Germany, GA Chenette, D AF Aksnes, A Stadsnes, J Bjordal, J Ostgaard, N Vondrak, RR Detrick, DL Rosenberg, TJ Germany, GA Chenette, D TI Instantaneous ionospheric global conductance maps during an isolated substorm SO ANNALES GEOPHYSICAE LA English DT Article DE ionosphere; auroral ionosphere, particle precipitation; magnetospheric physics; storms and substorms ID HEIGHT-INTEGRATED CONDUCTIVITY; AURORAL SUBSTORMS; ELECTRODYNAMIC PARAMETERS; LATITUDINAL VARIATION; ELECTRIC-FIELDS; ENERGY FLUX; MODEL; PRECIPITATION; IONIZATION; EMISSIONS AB Data from the Polar Ionospheric X-ray Imager (PIXIE) and the Ultraviolet Imager (UVI) on board the Polar satellite have been used to provide instantaneous global conductance maps. In this study, we focus on an isolated substorm event occurring on 31 July 1997. From the PIXIE and the UVI measurements, the energy spectrum of the precipitating electrons can be derived. By using a model of the upper atmosphere, the resulting conductivity values are generated. We present global maps of how the 5 min time-averaged height-integrated Hall and Pedersen conductivities vary every 15 min during this isolated substorm. The method presented here enables us to study the time development of the conductivities, with a spatial resolution of similar to700 km. During the substorm, a single region of enhanced Hall conductance is observed. The Hall conductance maximum remains situated between latitudes 64 and 70 corrected geomagnetic (CGM) degrees and moves eastward. The strongest conductances are observed in the pre-midnight sector at the start of the substorm expansion. Toward the end of the substorm expansion and into the recovery phase, we find the Hall conductance maximum in the dawn region. We also observe that the Hall to Pedersen conductance ratio for the regions of maximum Hall conductance is increasing throughout the event, indicating a hardening of the electron spectrum. By combining PIXIE and UVI measurements with an assumed energy distribution, we can cover the whole electron energy range responsible for the conductances. Electrons with energies contributing most to the Pedersen conductance are well covered by UVI while PIXIE captures the high energetic component of the precipitating electrons affecting the Hall conductance. Most statistical conductance models have derived conductivities from electron precipitation data below approximately 30 keV Since the intensity of the shortest UVI-wavelengths (LBHS) decreases significantly at higher electron energies, the UVI electron energy range is more or less comparable with the energy ranges of the statistical models. By calculating the conductivities from combined PIXIE and UVI measurements to compare with the conductivities from using UVI data only, we observe significant differences in the Hall conductance. The greatest differences are observed in the early evening and the late morning sector. We therefore suggest that the existing statistical models underestimate the Hall conductance. C1 Univ Bergen, Dept Phys, N-5020 Bergen, Norway. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Maryland, College Pk, MD 20742 USA. Univ Alabama, Huntsville, AL 35899 USA. Lockheed Martin Adv Technol Ctr, Palo Alto, CA USA. RP Aksnes, A (reprint author), Univ Bergen, Dept Phys, N-5020 Bergen, Norway. NR 39 TC 24 Z9 24 U1 0 U2 2 PU EUROPEAN GEOPHYSICAL SOC PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 0992-7689 J9 ANN GEOPHYS-GERMANY JI Ann. Geophys. PD AUG PY 2002 VL 20 IS 8 BP 1181 EP 1191 PG 11 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 583XP UT WOS:000177436800006 ER PT J AU Thomas-Keprta, KL Clemett, SJ Bazylinski, DA Kirschvink, JL McKay, DS Wentworth, SJ Vali, H Gibson, EK Romanek, CS AF Thomas-Keprta, KL Clemett, SJ Bazylinski, DA Kirschvink, JL McKay, DS Wentworth, SJ Vali, H Gibson, EK Romanek, CS TI Magnetofossils from ancient Mars: a robust biosignature in the Martian meteorite ALH84001 SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Review ID MAGNETITE CRYSTALS; MAGNETOTACTIC BACTERIA; SNC METEORITES; ALLAN-HILLS-84001; TEMPERATURE; CARBONATES; MINERALS; AGE; MARINE; ORIGIN C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Lockheed Martin, Houston, TX 77058 USA. Iowa State Univ, Dept Microbiol, Ames, IA 50011 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. McGill Univ, Dept Earth & Planetary Sci, Montreal, PQ H3A 2A7, Canada. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Thomas-Keprta, KL (reprint author), NASA, Lyndon B Johnson Space Ctr, Mail Code C23, Houston, TX 77058 USA. RI Vali, Hojatollah/F-3511-2012 OI Vali, Hojatollah/0000-0003-3464-9943 NR 64 TC 62 Z9 68 U1 4 U2 16 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD AUG PY 2002 VL 68 IS 8 BP 3663 EP 3672 DI 10.1128/AEM.68.8.3663-3672.2002 PG 10 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 580WV UT WOS:000177260500001 PM 12147458 ER PT J AU Contursi, A Kaufman, MJ Helou, G Hollenbach, DJ Brauher, J Stacey, GJ Dale, DA Malhotra, S Rubio, M Rubin, RH Lord, SD AF Contursi, A Kaufman, MJ Helou, G Hollenbach, DJ Brauher, J Stacey, GJ Dale, DA Malhotra, S Rubio, M Rubin, RH Lord, SD TI ISO LWS observations of the two nearby spiral galaxies NGC 6946 and NGC 1313 SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 6946, NGC 1313); galaxies : ISM; ISM : HI ID POLYCYCLIC AROMATIC-HYDROCARBONS; LARGE-SCALE DISSOCIATION; SMALL MAGELLANIC CLOUD; SEST KEY PROGRAM; H-II REGIONS; INTERSTELLAR-MEDIUM; MOLECULAR GAS; SMALL GRAINS; PHOTODISSOCIATION REGIONS; IRAS COLORS AB We present the analysis of Infrared Space Observatory long-wavelength spectrometer (LWS) observations of the two nearby late-type galaxies NGC 1313 and NGC 6946. Both galaxies have been fully mapped in the [C III] far-infrared fine-structure line at 158 mum, and some regions have been observed also in the [0 1] 63,um and [N II] 122 mum lines. We use these observations to derive the physical properties of the atomic interstellar medium, to establish how they relate to other interstellar medium components (gas and dust), and to establish how they vary with different galaxy components such as nucleus, spiral arms, and disk. The [C II] line is the main cooling line of the atomic medium. In NGC 6946 and NGC 1313, its emission represents 0.8% of the infrared emission. Moreover, the [C II] emission can be spatially associated with three components: the nucleus, the star-forming regions in spiral arms, and the diffuse galaxy disk. This last component contributes less than or similar to40% in NGC 6946 and similar to30% in NGC 1313 to the total emission. We apply the photodissociation region (PDR) model by Kaufman et al. to derive PDR physical parameters responsible for the neutral atomic gas emission (G(0), n, and T-s). The results do not significantly differ from what Malhotra et al. recently found by modeling the integrated emission of a sample of 60 normal galaxies. This suggests that the emission in each region under the LWS beam in NGC 6946 and NGC 1313 (corresponding to a linear size of similar to 1.5 kpc) is likely to arise from a mixture of components similar to the mixture producing the integrated emission of normal galaxies. However, some regions in NGC 6946 have a G(o)/n ratio similar to2-3 times smaller than the mean value found for the normal galaxy sample (1.3), suggesting that the beam-averaged contribution of a less active component in these regions is higher than its contribution in the integrated emission of normal galaxies or, conversely, that the bulk of the integrated emission of the normal galaxies is dominated by a few active regions probably located in their nuclei. CO(1-0) and [C II] in NGC 6946 are well correlated, and the mean [C II]/CO ratio agrees with the mean integrated ratios of the normal galaxies sample. This value (similar to500) is a factor of similar to2 less than the mean ratio found for a sample of normal galaxies observed with the Kupier Airborne Observatory (KAO) by Stacey et al. This difference is probably due to the fact that the KAO beam (55") is smaller than the LWS beam (75"), such that the Stacey et al. KAO observations are likely to be more biased toward the nucleus of the galaxies and therefore toward more active regions. In NGC 1313 only four LWS regions have been observed in CO(1-0), and three of them were detected. The [C II]/CO(1-0) seems to systematically increase from the northeast to the south, along the S-shaped spiral arm, indicating that the interstellar medium conditions in NGC 1313 are much more inhomogeneous than the conditions in NGC 6946. H I and [C it] in NGC 6946 are completely uncorrelated, probably because they arise from different gas components: [C II] arises principally in dense and warm PDR and H I from diffuse (n less than or similar to 3 x 10(3) cm(-3)) gas. On the other hand, in NGC 1313 we successfully detect two distinct gas components: a cirrus-like component, for which H I and [C II] are weakly correlated as observed in our Galaxy, and a component associated with dense PDRs completely uncorrelated from H I as observed in NGC 6946. Finally, we find that the H I residing in dense gas surrounding the star-forming regions and presumably recently photodissociated constitutes a few percent of the total H I. In turn, this dense gas component produces most of the [C II] emission emitted by the atomic neutral medium, even if its contribution is lower in NGC 1313 than in NGC 6946. On the other hand, the [C II] emission arising from ionized gas is higher in NGC 1313 than in NGC 6946. C1 CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. CALTECH, Downs Lab Phys, Pasadena, CA 91125 USA. San Jose State Univ, Dept Phys, San Jose, CA 95192 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Chile, Dept Astron, Santiago, Chile. RP Contursi, A (reprint author), CALTECH, Ctr Infrared Proc & Anal, MS 100-22, Pasadena, CA 91125 USA. RI Rubio, Monica/J-3384-2016 NR 70 TC 34 Z9 34 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD AUG PY 2002 VL 124 IS 2 BP 751 EP 776 DI 10.1086/341374 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 574KQ UT WOS:000176888900011 ER PT J AU Elmegreen, DM Elmegreen, BG Frogel, JA Eskridge, PB Pogge, RW Gallagher, A Iams, J AF Elmegreen, DM Elmegreen, BG Frogel, JA Eskridge, PB Pogge, RW Gallagher, A Iams, J TI Arm structure in anemic spiral galaxies SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : clusters : individual (Virgo); galaxies : evolution; galaxies : spiral; galaxies : structure ID VIRGO CLUSTER SPIRALS; STAR-FORMATION THRESHOLDS; MOLECULAR GAS; NEUTRAL HYDROGEN; ROTATION CURVES; GALACTIC DISKS; EVOLUTION; COMA; DEFICIENCY; CLASSIFICATION AB Anemic galaxies have less prominent star formation than normal galaxies of the same Hubble type. Previous studies showed they are deficient in total atomic hydrogen but not in molecular hydrogen. Here we compare the combined surface densities of H I and H(2) at mid-disk radii with the Kennicutt threshold for star formation. The anemic galaxies are below the threshold, which explains their lack of prominent star formation, but they are not much different than other early-type galaxies, which also tend to be below threshold. The spiral wave amplitudes of anemic and normal galaxies were also compared, using images in B and J pass-bands from the OSU Bright Spiral Galaxy Survey. Anemic galaxies have normal spiral wave properties too, with the same amplitudes and radial dependencies as other galaxies of the same arm class. Because of the lack of gas, spiral waves in early-type galaxies and anemics do not have a continuous supply of stars with low velocity dispersions to maintain a marginally stable disk. As a result, they are either short lived, evolving toward lenticulars and S0 types in only a few rotations at mid-disk, or they are driven by the asymmetries associated with gas removal in the cluster environment. C1 Vassar Coll, Dept Phys & Astron, Poughkeepsie, NY 12604 USA. IBM Corp, Div Res, TJ Watson Res Ctr, Yorktown Hts, NY 10598 USA. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. NASA Headquarters, Washington, DC 20546 USA. Minnesota State Univ, Dept Phys & Astron, Mankato, MN 56001 USA. Williams Coll, Dept Astron, Williamstown, MA 02167 USA. RP Elmegreen, DM (reprint author), Vassar Coll, Dept Phys & Astron, Poughkeepsie, NY 12604 USA. EM elmegreen@vassar.edu; bge@watson.ibm.com; frogel@astronomy.ohio-state.edu; paul.eskridge@mnsu.edu; pogge@astronomy.ohio-state.edu; angallagher@vassar.edu; jiams1@williams.edu NR 45 TC 16 Z9 16 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD AUG PY 2002 VL 124 IS 2 BP 777 EP 781 DI 10.1086/341613 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 574KQ UT WOS:000176888900012 ER PT J AU Pritzl, BJ Smith, HA Catelan, MR Sweigart, AV AF Pritzl, BJ Smith, HA Catelan, MR Sweigart, AV TI Variable stars in the unusual, metal-rich globular cluster NGC 6388 SO ASTRONOMICAL JOURNAL LA English DT Review DE globular clusters : individual (NGC 6388); RR Lyrae variable ID RR-LYRAE STARS; HORIZONTAL-BRANCH STARS; RED GIANT BRANCH; AGE-METALLICITY RELATION; COLOR-MAGNITUDE DIAGRAM; BVI CCD PHOTOMETRY; OMEGA-CENTAURI; OOSTERHOFF DICHOTOMY; LIGHT CURVES; EVOLUTIONARY SEQUENCES AB We have undertaken a search for variable stars in the metal-rich globular cluster NGC 6388, using time-series BV photometry. Twenty-eight new variables were found in this survey, increasing the total number of variables found near NGC 6388 to similar to57. A significant number of the variables are RR Lyrae (similar to14), most of which are probable cluster members. The periods of the fundamental-mode RR Lyrae are shown to be unusually long compared with metal-rich field stars. The existence of these long-period RRab stars suggests that the horizontal branch of NGC 6388 is unusually bright. This implies that the metallicity-luminosity relationship for RR Lyrae stars is not universal if the RR Lyrae in NGC 6388 are indeed metal-rich. We consider the alternative possibility that the stars in NGC 6388 may span a range in [Fe/H]. Four candidate Population II Cepheids were also found. If they are members of the cluster, NGC 6388 would be the most metal-rich globular cluster to contain Population II Cepheids. The mean V magnitude of the RR Lyrae is found to be 16.85+/-0.05, resulting in a distance of 9.0 to 10.3 kpc for a range of assumed values of for RR Lyrae. We determine the reddening of the cluster to be E(B-V) = 0.40+/-0.03 mag, with differential reddening across the face of the cluster. We discuss the difficulty in determining the Oosterhoff classification of NGC 6388 and NGC 6441 due to the unusual nature of their RR Lyrae and address evolutionary constraints on a recent suggestion that they are of Oosterhoff type II. C1 Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 6904411, Chile. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Natl Opt Astron Observ, POB 26732, Tucson, AZ 85726 USA. EM pritzl@pa.msu.edu; smith@pa.msu.edu; mcatelan@astro.puc.cl; sweigart@bach.gsfc.nasa.gov NR 106 TC 66 Z9 66 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD AUG PY 2002 VL 124 IS 2 BP 949 EP 976 DI 10.1086/341381 PG 28 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 574KQ UT WOS:000176888900026 ER PT J AU Ireland, J De Moortel, I AF Ireland, J De Moortel, I TI Application of wavelet analysis to transversal coronal loop oscillations SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE Sun : activity; Sun : corona; methods : data analysis ID ALFVEN WAVES; HEATING MECHANISMS; MAGNETIC-FIELD; PLASMA; TRACE; MODELS AB There as yet remain few examples of well observed, transversal oscillations in coronal loops. Such oscillations have the potential to yield much information on the nature of the solar corona, as demonstrated by the analysis of Nakariakov et al. (1999) of a transversely oscillating loop observed in the TRACE 171 Angstrom passband on 14th July, 1998. Their analysis extracts a decaying loop oscillation signal from the data which is then considered in the light of the substantial body of theoretically and computationally derived knowledge of the dynamics of coronal loops. The analysis presented in this paper approaches the reduction of the same dataset using wavelet techniques described by De Moortel & Hood (2000) and De Moortel et al. (2002). The authors show that the value of the decay exponent N in a decaying oscillating time series of the form exp(-kt(N)) is measurable from a wavelet transform of the time series (for some decay constant k and time t). The application of these techniques shows that the value of the decay exponent in the 14th July, 1998 event is not well determined by the data, i.e., the associated error is very large. Since the value of the decay exponent implies the presence of particular decay mechanisms and not others, the large error associated with the exponent value implies that a wide range of mechanisms should be considered when discussing the physics behind this event. Comments are also made on the time dependence of the oscillation wavelet scale. Two additional examples of transversal coronal loop oscillations are also analysed. C1 NASA, Goddard Space Flight Ctr, Commun Analytics Corp L3, Greenbelt, MD 20771 USA. Univ St Andrews, Dept Math & Computat Sci, St Andrews KY16 9SS, Fife, Scotland. RP Ireland, J (reprint author), NASA, Goddard Space Flight Ctr, Commun Analytics Corp L3, Code 682-3,Bldg 26,Room G-1, Greenbelt, MD 20771 USA. NR 21 TC 9 Z9 9 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 2002 VL 391 IS 1 BP 339 EP 351 DI 10.1051/0004-6361:20020643 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 581QQ UT WOS:000177304700031 ER PT J AU Villata, M Raiteri, CM Kurtanidze, OM Nikolashvili, MG Ibrahimov, MA Papadakis, IE Tsinganos, K Sadakane, K Okada, N Takalo, LO Sillanpaa, A Tosti, G Ciprini, S Frasca, A Marilli, E Robb, RM Noble, JC Jorstad, SG Hagen-Thorn, VA Larionov, VM Nesci, R Maesano, M Schwartz, RD Basler, J Gorham, PW Iwamatsu, H Kato, T Pullen, C Benitez, E de Diego, JA Moilanen, M Oksanen, A Rodriguez, D Sadun, AC Kelly, M Carini, MT Miller, HR Catalano, S Dultzin-Hacyan, D Fan, JH Ishioka, R Karttunen, H Keinanen, P Kudryavtseva, NA Lainela, M Lanteri, L Larionova, EG Matsumoto, K Mattox, JR Montagni, F Nucciarelli, G Ostorero, L Papamastorakis, J Pasanen, M Sobrito, G Uemura, M AF Villata, M Raiteri, CM Kurtanidze, OM Nikolashvili, MG Ibrahimov, MA Papadakis, IE Tsinganos, K Sadakane, K Okada, N Takalo, LO Sillanpaa, A Tosti, G Ciprini, S Frasca, A Marilli, E Robb, RM Noble, JC Jorstad, SG Hagen-Thorn, VA Larionov, VM Nesci, R Maesano, M Schwartz, RD Basler, J Gorham, PW Iwamatsu, H Kato, T Pullen, C Benitez, E de Diego, JA Moilanen, M Oksanen, A Rodriguez, D Sadun, AC Kelly, M Carini, MT Miller, HR Catalano, S Dultzin-Hacyan, D Fan, JH Ishioka, R Karttunen, H Keinanen, P Kudryavtseva, NA Lainela, M Lanteri, L Larionova, EG Matsumoto, K Mattox, JR Montagni, F Nucciarelli, G Ostorero, L Papamastorakis, J Pasanen, M Sobrito, G Uemura, M TI The WEBT BL Lacertae Campaign 2000 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : active; galaxies : BL Lacertae objects : general; galaxies : BL Lacertae objects : individual : BL Lacertae; galaxies : jets; quasars : general ID 1997 OUTBURST; OPTICAL OBSERVATIONS; RADIO VARIABILITY; OBJECTS; MICROVARIABILITY; PHOTOMETRY; BLAZARS; PERIODICITY; SPECTRUM; GALAXIES AB We present UBVRI light curves of BL Lacertae from May 2000 to January 2001, obtained by 24 telescopes in 11 countries. More than 15 000 observations were performed in that period, which was the extension of the Whole Earth Blazar Telescope (WEBT) campaign originally planned for July-August 2000. The exceptional sampling reached allows one to follow the flux behaviour in fine detail. Two different phases can be distinguished in the light curves: a first, relatively low-brightness phase is followed by an outburst phase, after a more than 1 mag brightening in a few weeks. Both the time duration (about 100 d) and the variation amplitude (roughly 0:9 mag) are similar in the two phases. Rapid flux oscillations are present all the time, involving variations up to a few tenths of mag on hour time scales, and witnessing an intense intraday activity of this source. In particular, a half-mag brightness decrease in about 7 h was detected on August 8-9, 2000, immediately followed by a similar to0.4 mag brightening in 1.7 h. Colour indexes have been derived by coupling the highest precision B and R data taken by the same instrument within 20 min and after subtracting the host galaxy contribution from the fluxes. The 620 indexes obtained show that the optical spectrum is weakly sensitive to the long-term trend, while it strictly follows the short-term flux behaviour, becoming bluer when the brightness increases. Thus, spectral changes are not related to the host galaxy contribution, but they are an intrinsic feature of fast flares. We suggest that the achromatic mechanism causing the long-term flux base-level modulation can be envisaged in a variation of the relativistic Doppler beaming factor, and that this variation is likely due to a change of the viewing angle. Discrete correlation function (DCF) analysis reveals the existence of a characteristic time scale of variability of similar to7 h in the light curve of the core WEBT campaign, while no measurable time delay between variations in the B and R bands is found. C1 Osserv Astron Torino, INAF, I-10025 Pino Torinese, TO, Italy. Abastumani Observ, GE-383762 Abastumani, Rep of Georgia. Astrophys Inst Potsdam, D-14482 Potsdam, Germany. Landessternwarte Heidelberg Konigstuhl, D-69117 Heidelberg, Germany. Uzbek Acad Sci, Ulugh Beg Astron Inst, Tashkent 700052, Uzbekistan. Univ Crete, Dept Phys, Iraklion 71003, Crete, Greece. Fdn Res & Technol Hellas, IESL, Iraklion 71110, Crete, Greece. Osaka Kyoiku Univ, Inst Astron, Kashiwara, Osaka 5828582, Japan. Tuorla Observ, Piikkio 21500, Finland. Univ Perugia, Osservatorio Astron, I-06126 Perugia, Italy. Osserv Astrofis Catania, I-95123 Catania, Italy. Univ Victoria, Dept Phys & Astron, Victoria, BC V8W 3P6, Canada. Boston Univ, Inst Astrophys Res, Boston, MA 02215 USA. St Petersburg State Univ, Inst Astron, St Petersburg 198504, Russia. Isaac Newton Inst Chile, St Petersburg Branch, St Petersburg, Russia. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Univ Missouri, Dept Phys & Astron, St Louis, MO 63121 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Kyoto Univ, Fac Sci, Dept Astron, Kyoto, Japan. Clarke & Coyote Astrophys Observ, Wilton, CA 95693 USA. Univ Nacl Autonoma Mexico, Inst Astron, Mexico City 04510, DF, Mexico. Kyvaskylan Sirus RY, Nyrola Observ, Jyvaskyla 40950, Finland. Guadarrama Observ, Madrid 28409, Spain. Univ Colorado, Dept Phys, Denver, CO 80217 USA. Western Kentucky Univ, Dept Phys & Astron, Bowling Green, KY 42104 USA. Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. Guangzhou Univ, Ctr Astrophys, Guangzhou 510400, Peoples R China. Francis Marion Univ, Dept Chem Phys & Astron, Florence, SC 29501 USA. Univ Turin, Dipartimento Fis Gen, I-10125 Turin, Italy. RP Villata, M (reprint author), Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy. RI de Diego, Jose/B-4093-2009; Papadakis, Iossif/C-3235-2011; Papamastorakis, Ioannis/G-7324-2011; Tosti, Gino/E-9976-2013; Larionov, Valeri/H-1349-2013; Kudryavtseva, Nadezhda/F-2472-2013; Kurtanidze, Omar/J-6237-2014; Larionova, Elena/H-7287-2013; Jorstad, Svetlana/H-6913-2013; Hagen-Thorn, Vladimir/H-3983-2013; OI Villata, Massimo/0000-0003-1743-6946; Frasca, Antonio/0000-0002-0474-0896; Larionov, Valeri/0000-0002-4640-4356; Larionova, Elena/0000-0002-2471-6500; Jorstad, Svetlana/0000-0001-9522-5453; Hagen-Thorn, Vladimir/0000-0002-6431-8590; Ostorero, Luisa/0000-0003-3983-5980; Raiteri, Claudia Maria/0000-0003-1784-2784; Jose A., de Diego/0000-0001-7040-069X; Kudryavtseva, Nadia/0000-0002-1372-0942 NR 59 TC 104 Z9 105 U1 1 U2 3 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 2002 VL 390 IS 2 BP 407 EP 421 DI 10.1051/0004-6361:20020662 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 578KP UT WOS:000177116700002 ER PT J AU Man in't Zand, JJ Markwardt, CB Bazzano, A Cocchi, M Cornelisse, R Heise, J Kuulkers, E Natalucci, L Santos-Lleo, M Swank, J Ubertini, P AF Man in't Zand, JJ Markwardt, CB Bazzano, A Cocchi, M Cornelisse, R Heise, J Kuulkers, E Natalucci, L Santos-Lleo, M Swank, J Ubertini, P TI The nature of the X-ray transient SAX J1711.6-3808 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE accretion, accretion disks; binaries : close; X-rays : stars : individual : SAX J1711.6-3808 ID BLACK-HOLE; ASTRONOMY SATELLITE; RXTE OBSERVATIONS; ENERGY-SPECTRA; XTE J1748-288; ON-BOARD; EMISSION; BEPPOSAX; DISK; LINE AB SAX J1711.6-3808 is an X-ray transient in the Galactic bulge that was active from January through May of 2001 and whose maximum 1-200 keV luminosity was measured to be 5 x 10(-9) erg cm(-2) s(-1) which is less than similar to25% of the Eddington limit, if placed at a distance equal to that of the galactic center. We study the X-ray data that were taken of this moderately bright transient with instruments on BeppoSAX and RXTE. The spectrum shows two interesting features on top of a Comptonized continuum commonly observed in low-state X-ray binaries: a broad emission feature peaking at 7 keV and extending from 4 to 9 keV, and a soft excess with a color temperature below 1 keV which reveals itself only during one week of data. High time-resolution analysis of 412 ksec worth of data fails to show bursts, coherent or high-frequency quasi-periodic oscillations. Given the dynamic range of the flux measurements, this would be unusual if a neutron star were present. SAX J1711.6-3808 appears likely to contain a black hole. No quiescent optical counterpart could be identified in archival data within the 5"-radius XMM error circle, but the limits are not very constraining because of heavy extinction (A(V) = 16). C1 Univ Utrecht, Astron Inst, NL-3508 TA Utrecht, Netherlands. SRON, Natl Inst Space Res, NL-3584 CA Utrecht, Netherlands. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CNR, Ist Astrofis Spaziale, Area Ric Roma Tor Vergata, I-00133 Rome, Italy. XMM Newton Sci Opereat Ctr, Vilspa Satellite Tracking Stn, Madrid, Spain. RP Univ Utrecht, Astron Inst, POB 80000, NL-3508 TA Utrecht, Netherlands. EM jeanz@sron.nl RI Swank, Jean/F-2693-2012; OI Bazzano, Angela/0000-0002-2017-4396 NR 56 TC 0 Z9 0 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 2002 VL 390 IS 2 BP 597 EP 609 DI 10.1051/0004-6361:20020762 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 578KP UT WOS:000177116700017 ER PT J AU Bouret, JC Deleuil, M Lanz, T Roberge, A des Etangs, AL Vidal-Madjar, A AF Bouret, JC Deleuil, M Lanz, T Roberge, A des Etangs, AL Vidal-Madjar, A TI A chromospheric scenario for the activity of beta Pictoris, as revealed by FUSE SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE line : profiles; stars : atmospheres; stars : chromospheres; stars : activity; stars : winds, outflows ID MAIN-SEQUENCE STARS; FALLING EVAPORATING BODIES; YOUNG PLANETARY SYSTEM; HERBIG AE/BE STARS; A-TYPE STARS; CIRCUMSTELLAR DISK; INTERMEDIATE-MASS; CONVECTION ZONES; ULTRAVIOLET; SPECTRA AB We investigate a chromospheric scenario to explain the characteristics of the far-UV emission lines of beta Pictoris, revealed by FUSE spectra of this famous circumstellar disk system. The model assumes a thin region heated up to a few 10(5) K located close to the stellar photosphere. The resonance lines of CIII at 977 Angstrom and OVI at 1032-1037 Angstrom, seen in emission, are produced in this chromosphere-transition region complex. Using complementary data in the mid and near UV (specifically, a resonance doublet of C IV at 1548-1550 Angstrom and MgII h & k), we show that the whole dataset is remarquably well reproduced by the model. In addition, we investigate the properties of the CIII* multiplet at 1176 Angstrom and conclude that this line likely forms in a weak warm wind, originating from the prominent circumstellar disk of beta Pictoris. Finally, radiative losses have been calculated and have provided estimates of the amount of non radiative energy dissipated in the external atmosphere of beta Pictoris, which is a measure of the star's activity level. Such behavior for an A5 V star presents a challenge for both evolution and activity models since the former predict that main-sequence A stars should not be active, while the latter are unable to quantitatively account for the characteristics of the chromospheric heating of beta Pictoris. C1 Traverse Siphon, Lab Astrophys Marseille, F-13376 Marseille 12, France. Univ Aix Marseille 1, Ctr Math & Informat, F-13453 Marseille, France. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. CNRS, Inst Astrophys Paris, F-75014 Paris, France. RP Bouret, JC (reprint author), Traverse Siphon, Lab Astrophys Marseille, BP 8, F-13376 Marseille 12, France. RI Roberge, Aki/D-2782-2012 OI Roberge, Aki/0000-0002-2989-3725 NR 46 TC 25 Z9 25 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 2002 VL 390 IS 3 BP 1049 EP 1061 DI 10.1051/0004-6361:20020741 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 579MR UT WOS:000177182200027 ER PT J AU Peeters, E Hony, S Van Kerckhoven, C Tielens, AGGM Allamandola, LJ Hudgins, DM Bauschlicher, CW AF Peeters, E Hony, S Van Kerckhoven, C Tielens, AGGM Allamandola, LJ Hudgins, DM Bauschlicher, CW TI The rich 6 to 9 mu m spectrum of interstellar PAHs SO ASTRONOMY & ASTROPHYSICS LA English DT Review DE circumstellar matter; stars : pre-main sequence; HII regions; ISM : molecules; planetary nebulae : general; infrared : ISM : lines and bands ID POLYCYCLIC AROMATIC-HYDROCARBONS; INFRARED-EMISSION BANDS; COMPACT HII-REGIONS; INTERMEDIATE-MASS STARS; PROTOPLANETARY NEBULAE; ISO SPECTROSCOPY; REFLECTION NEBULAE; PLANETARY-NEBULAE; SWS SPECTROSCOPY; PHOTODISSOCIATION REGION AB IR spectroscopy provides a valuable tool for the characterisation and identification of interstellar molecular species. Here, we present 6-9 mum spectra of a sample of reflection nebulae, HII regions, YSOs, evolved stars and galaxies that show strong unidentified infrared bands, obtained with the SWS spectrograph on board ISO. The IR emission features in this wavelength region show pronounced variations. 1) The 6.2 mum feature shifts from 6.22 to 6.3 mum and clearly shows profile variations. 2) The 7.7 mum complex is comprised of at least two subpeaks peaking at 7.6 and one longwards of 7.7 mum. In some cases the main peak can apparently shift up to 8 mum. Two sources do not exhibit a 7.7 mum complex but instead show a broad emission feature at 8.22 mum. 3) The 8.6 mum feature has a symmetric profile in all sources and some sources exhibit this band at slightly longer wavelengths. For the 6.2, 7.7 and 8.6 mum features, the sources have been classified independently based on their profile and peak position. The classes derived for these features are directly linked with each other. Sources with a 6.2 mum feature peaking at similar to6.22 mum exhibit a 7.7 mum complex dominated by the 7.6 mum component. In contrast, sources with a 6.2 mum profile peaking longwards of 6.24 mum show a 7.7 mum complex with a dominant peak longwards of 7.7 mum and a 8.6 mum feature shifted toward the red. Furthermore, the observed 6-9 mum spectrum depends on the type of object. All ISM-like sources and a few PNe and Post-AGB stars belong to the first group while isolated Herbig AeBe stars, a few Post-AGB stars and most PNe belong to the second group. We summarise existing laboratory data and theoretical quantum chemical calculations of the modes emitting in this wavelength region of PAH molecules. We discuss the variations in peak position and profile in view of the exact nature of the carrier. We attribute the observed 6.2 mum profile and peak position to the combined effect of a PAH family and anharmonicity with pure PAHs representing the 6.3 mum component and substituted/complexed PAHs representing the 6.2 mum component. The 7.6 mum component is well reproduced by both pure and substituted/complexed PAHs but the 7.8 mum component remains an enigma. In addition, the exact identification of the 8.22 mum feature remains unknown. The observed variations in the characteristics of the IR emission bands are linked to the local physical conditions. Possible formation and evolution processes that may influence the interstellar PAH class are highlighted. C1 Univ Groningen, SRON, Natl Inst Space Res, NL-9700 AV Groningen, Netherlands. Univ Groningen, Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Katholieke Univ Leuven, Inst Sterrenkunde, B-3100 Heverlee, Belgium. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Peeters, E (reprint author), Univ Groningen, SRON, Natl Inst Space Res, POB 800, NL-9700 AV Groningen, Netherlands. EM peeters@astro.rug.nl NR 110 TC 342 Z9 342 U1 3 U2 26 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 2002 VL 390 IS 3 BP 1089 EP 1113 DI 10.1051/0004-6361:20020773 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 579MR UT WOS:000177182200030 ER PT J AU Ruiterkamp, R Halasinski, T Salama, F Foing, BH Allamandola, LJ Schmidt, W Ehrenfreund, P AF Ruiterkamp, R Halasinski, T Salama, F Foing, BH Allamandola, LJ Schmidt, W Ehrenfreund, P TI Spectroscopy of large PAHs - Laboratory studies and comparison to the diffuse interstellar bands SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE molecular data; methods : laboratory; ISM : lines and bands; ISM : molecules ID POLYCYCLIC AROMATIC-HYDROCARBONS; FEATURES; CARRIERS; MOLECULES; EMISSION; CLOUDS; ABSORPTION; SPECTRA; CATIONS; REGION AB Polycyclic Aromatic Hydrocarbons (PAHs) are thought to be the carriers of the ubiquitous infrared emission bands (UIBs). Data from the Infrared Space Observatory (ISO) have provided new insights into the size distribution and the structure of interstellar PAH molecules pointing to a trend towards larger-size PAHs. The mid-infrared spectra of galactic and extragalactic sources have also indicated the presence of 5-ring structures and PAH structures with attached side groups. This paper reports for the first time the laboratory measurement of the UV-Vis-NIR absorption spectra of a representative set of large PAHs that have also been selected for a long duration exposure experiment on the International Space Station ISS. PAHs with sizes up to 600 amu, including 5-ring species and PAHs containing heteroatoms, have been synthesized and their spectra measured using matrix isolation spectroscopy. The spectra of the neutral species and the associated cations and anions measured in this work are also compared to astronomical spectra of Diffuse Interstellar Bands (DIBs). C1 Leiden Observ, NL-2300 RA Leiden, Netherlands. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. ESA, Res Support Div, ESTEC, SCISR, NL-2200 AG Noordwijk, Netherlands. PAH Forsch Inst, D-86926 Greifenberg, Germany. RP Ruiterkamp, R (reprint author), Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands. EM ruiterka@strw.leidenuniv.nl RI Salama, Farid/A-8787-2009 OI Salama, Farid/0000-0002-6064-4401 NR 64 TC 66 Z9 66 U1 1 U2 12 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 2002 VL 390 IS 3 BP 1153 EP 1170 DI 10.1051/0004-6361:20020478 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 579MR UT WOS:000177182200035 ER PT J AU Blasi, P Dick, R Kolb, EW AF Blasi, P Dick, R Kolb, EW TI Ultra-high energy cosmic rays from annihilation of superheavy dark matter SO ASTROPARTICLE PHYSICS LA English DT Article DE dark matter; ultra-high energy cosmic rays ID DEUTERIUM ABUNDANCE; POTENT DENSITY; INFLATION; PARTICLES; UNIVERSE; LIMITS; FIELDS; OMEGA; BARYOGENESIS; CREATION AB We consider the possibility that ultra-high energy cosmic rays originate from the annihilation of relic superheavy dark matter. We find that across-section of similar to 10(-2)6 cm(2) (M-X/10(12) GeV)(3/2) is required to account for the observed rate of super-GZK events if the superheavy dark matter follows a Navarro-Frenk-White density profile. This would require extremely large-l contributions to the annihilation cross-section. We also calculate the possible signature from annihilation in sub-galactic clumps of dark matter and find that the signal from sub-clumps dominates and may explain the observed flux with a much smaller cross-section than if the superheavy dark matter is smoothly distributed. Finally, we discuss the expected anisotropy in the arrival directions of the cosmic rays, which is a characteristic signature of this scenario. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Osserv Astrofis Arcetri, I-50125 Florence, Italy. NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Saskatchewan, Dept Phys & Engn Phys, Saskatoon, SK S7N 5E2, Canada. Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Osserv Astrofis Arcetri, Largo E Fermi 5, I-50125 Florence, Italy. EM blasi@arcetri.astro.it; rainer@sask.usask.ca; rocky.kolb@cern.ch RI Dick, Rainer/H-5182-2011; Blasi, Pasquale/O-9345-2015 OI Blasi, Pasquale/0000-0003-2480-599X NR 57 TC 44 Z9 47 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 EI 1873-2852 J9 ASTROPART PHYS JI Astropart Phys. PD AUG PY 2002 VL 18 IS 1 BP 57 EP 66 AR PII S0927-6505(02)00113-5 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 601KJ UT WOS:000178444600004 ER PT J AU Kaspi, S Brandt, WN George, IM Netzer, H Crenshaw, DM Gabel, JR Hamann, FW Kaiser, ME Koratkar, A Kraemer, SB Kriss, GA Mathur, S Mushotzky, RF Nandra, K Peterson, BM Shields, JC Turner, TJ Zheng, W AF Kaspi, S Brandt, WN George, IM Netzer, H Crenshaw, DM Gabel, JR Hamann, FW Kaiser, ME Koratkar, A Kraemer, SB Kriss, GA Mathur, S Mushotzky, RF Nandra, K Peterson, BM Shields, JC Turner, TJ Zheng, W TI The ionized gas and nuclear environment in NGC 3783. I. Time-averaged 900 kilosecond Chandra grating spectroscopy SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (NGC 3783); galaxies : nuclei; galaxies : Seyfert; techniques : spectroscopic; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; SEYFERT-1 GALAXY NGC-3783; X-RAY-FLUORESCENCE; BROAD-LINE REGION; WARM ABSORBER; ASCA OBSERVATIONS; ULTRAVIOLET; ABSORPTION; EMISSION; IONS AB We present results from a 900 ks exposure of NGC 3783 with the High-Energy Transmission Grating Spectrometer on board the Chandra X-Ray Observatory. The resulting X-ray spectrum, which covers the 0.5-10 keV energy range, has the best combination of signal-to-noise ratio and resolution ever obtained for an AGN. This spectrum reveals absorption lines from H-like and He-like ions of N, O, Ne, Mg, Al, Si, and S. There are also possible absorption lines from H-like and He-like Ar and Ca as well as H-like C. We also identify inner-shell absorption from lower ionization ions such as Si VII-Si XII and S XII-S XIV. The iron absorption spectrum is very rich; L-shell lines of Fe XVII Fe XXIV are detected, as well as probable resonance lines from Fe XXV A strong complex of M-shell lines from iron ions is also detected in the spectrum. The absorption lines are blueshifted relative to the systemic velocity by a mean velocity of -590 +/- 150 km s(-1). We resolve many of the absorption lines, and their mean FWHM is 820 +/- 280 km (s-1). We do not find correlations between the velocity shifts or the FWHMs with the ionization potentials of the ions. Most absorption lines show asymmetry, having more extended blue wings than red wings. In O VII we have resolved this asymmetry to be from an additional absorption system at approximately 1300 km s(-1). The two X-ray absorption systems are consistent in velocity shift and FWHM with the ones identified in the UV lines of C IV N V and H I Equivalent width measurements for all absorption and emission lines are given and column densities are calculated for several ions. We resolve the narrow Fe Kalpha line at 6398.2 +/- 3.3 eV to have an FWHM of 1720+/-360 km s(-1), which suggests that this narrow line may be emitted from the outer part of the broad-line region or the inner part of the torus. We also detect a "Compton shoulder" redward of the narrow Fe Kalpha line, which indicates that it arises in cold, Compton-thick gas. C1 Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Tel Aviv Univ, Sch Phys & Astron, Raymond & Beverly Sackler Fac Exact Sci, IL-69978 Tel Aviv, Israel. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Maryland, Joint Ctr Astrophys, Dept Phys, Baltimore, MD 21250 USA. Georgia State Univ, Dept Phys & Astrophys, Atlanta, GA 30303 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. Johns Hopkins Univ, Ctr Astrophys Sci, Dept Phys & Astron, Baltimore, MD 21218 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Univ Space Res Assoc, Seabrook, MD USA. Ohio Univ, Dept Phys & Astron, Clippinger Res Labs 251B, Athens, OH 45701 USA. RP Kaspi, S (reprint author), Penn State Univ, Dept Astron & Astrophys, 525 Davey Lab, University Pk, PA 16802 USA. RI Brandt, William/N-2844-2015 OI Brandt, William/0000-0002-0167-2453 NR 45 TC 237 Z9 237 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2002 VL 574 IS 2 BP 643 EP 662 DI 10.1086/341113 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 581BC UT WOS:000177270400010 ER PT J AU Gibson, SE Fletcher, L Del Zanna, G Pike, CD Mason, HE Mandrini, CH Demoulin, P Gilbert, H Burkepile, J Holzer, T Alexander, D Liu, Y Nitta, N Qiu, J Schmieder, B Thompson, BJ AF Gibson, SE Fletcher, L Del Zanna, G Pike, CD Mason, HE Mandrini, CH Demoulin, P Gilbert, H Burkepile, J Holzer, T Alexander, D Liu, Y Nitta, N Qiu, J Schmieder, B Thompson, BJ TI The structure and evolution of a sigmoidal active region SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun : activity; Sun : magnetic fields ID CORONAL MASS EJECTIONS; MAGNETIC-FLUX TUBES; WHOLE-SUN-MONTH; MODEL CONVECTION ZONE; SOHO EIT OBSERVATIONS; SOLAR-FLARES; NULL POINTS; YOHKOH SXT; RECONNECTION; HELICITY AB Solar coronal sigmoidal active regions have been shown to be precursors to some coronal mass ejections. Sigmoids, or S-shaped structures, may be indicators of twisted or helical magnetic structures, having an increased likelihood of eruption. We present here an analysis of a sigmoidal region's three-dimensional structure and how it evolves in relation to its eruptive dynamics. We use data taken during a recent study of a sigmoidal active region passing across the solar disk ( an element of the third Whole Sun Month campaign). While S-shaped structures are generally observed in soft X-ray (SXR) emission, the observations that we present demonstrate their visibility at a range of wavelengths including those showing an associated sigmoidal lament. We examine the relationship between the S-shaped structures seen in SXR and those seen in cooler lines in order to probe the sigmoidal region's three-dimensional density and temperature structure. We also consider magnetic field observations and extrapolations in relation to these coronal structures. We present an interpretation of the disk passage of the sigmoidal region, in terms of a twisted magnetic flux rope that emerges into and equilibrates with overlying coronal magnetic field structures, which explains many of the key observed aspects of the region's structure and evolution. In particular, the evolving flux rope interpretation provides insight into why and how the region moves between active and quiescent phases, how the region's sigmoidicity is maintained during its evolution, and under what circumstances sigmoidal structures are apparent at a range of wavelengths. C1 Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland. Univ Cambridge, Dept Appl Math & Theoret Phys, Cambridge CB3 9EW, England. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Inst Astron & Fis Espacio, RA-1428 Buenos Aires, DF, Argentina. Observ Paris, Sect Meudon, DASOP, CNRS,URA 2080, F-92195 Meudon, France. Lockheed Martin Solar & Astrophys Lab, Palo Alto, CA 94304 USA. Stanford Univ, Ctr Space Sci & Astrophys, HEPL, Stanford, CA 94305 USA. New Jersey Inst Technol, Big Bear Solar Observ, Big Bear City, CA 92314 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gibson, SE (reprint author), Natl Ctr Atmospher Res, High Altitude Observ, POB 3000, Boulder, CO 80307 USA. RI Gibson, Sarah/A-9189-2011; Gilbert, Holly/C-7215-2012; Thompson, Barbara/C-9429-2012; OI Demoulin, Pascal/0000-0001-8215-6532 NR 63 TC 77 Z9 77 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2002 VL 574 IS 2 BP 1021 EP 1038 DI 10.1086/341090 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 581BC UT WOS:000177270400042 ER PT J AU Mason, GM Wiedenbeck, ME Miller, JA Mazur, JE Christian, ER Cohen, CMS Cummings, AC Dwyer, JR Gold, RE Krimigis, SM Leske, RA Mewaldt, RA Slocum, PL Stone, EC von Rosenvinge, TT AF Mason, GM Wiedenbeck, ME Miller, JA Mazur, JE Christian, ER Cohen, CMS Cummings, AC Dwyer, JR Gold, RE Krimigis, SM Leske, RA Mewaldt, RA Slocum, PL Stone, EC von Rosenvinge, TT TI Spectral properties of He and heavy ions in He-3-rich solar flares SO ASTROPHYSICAL JOURNAL LA English DT Article DE acceleration of particles; cosmic rays; interplanetary medium; solar wind; Sun : abundances; Sun : flares ID ENERGETIC PARTICLE EVENTS; COROTATING INTERACTION REGIONS; ADVANCED-COMPOSITION-EXPLORER; CORONAL MASS EJECTIONS; FAST MODE WAVES; STOCHASTIC ACCELERATION; ELECTRON ACCELERATION; ISOTOPE SPECTROMETER; CYCLOTRON WAVES; ABUNDANCES AB Using advanced instrumentation on the ACE spacecraft, we have conducted a survey of solar energetic particle spectra in He-3-rich events over a broad energy range similar to80 keV nucleon(-1) to 15 MeV nucleon(-1) during the period 1997 September 2001 March. The spectra of He-4 and heavy ions ( C, N, O, Ne, Mg, Si, S, Ca, Fe) were generally similar over this range but often hardened below similar to1 MeV nucleon(-1). In most of the events there was even stronger hardening of the He-3 spectrum below similar to1 MeV nucleon(-1), leading to an energy-dependent He-3 : He-4 ratio. These observations point to unique and distinct properties of He-3 in these events and place new constraints on models that seek to explain enhancements of He-3 and heavy ions using the same mechanisms. In addition to the events with spectra in the form of power laws or double power laws, there is a second class of event in which the low-energy He-3 and Fe spectra are rounded, while the He-4 remains a power law. In these cases He-3 and Fe spectra can be fitted at low energies by a stochastic acceleration model, but this model does not explain the higher energy portions of these spectra, nor the power-law spectral forms of the He-4. These observations appear to require an additional mechanism, such as acceleration by cascading MHD turbulence. The He-3 enrichment pattern that we observe suggests that all these different spectral features might be due to processes with a common origin but then followed by different acceleration histories. C1 Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Alabama, Huntsville, AL 35899 USA. Aerosp Corp, El Segundo, CA 90245 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CALTECH, Pasadena, CA 91125 USA. Florida Inst Technol, Melbourne, FL 32901 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. RP Mason, GM (reprint author), Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RI Christian, Eric/D-4974-2012 OI Christian, Eric/0000-0003-2134-3937 NR 60 TC 73 Z9 73 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2002 VL 574 IS 2 BP 1039 EP 1058 DI 10.1086/341112 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 581BC UT WOS:000177270400043 ER PT J AU Turner, TJ Mushotzky, RF Yaqoob, T George, IM Snowden, SL Netzer, H Kraemer, SB Nandra, K Chelouche, D AF Turner, TJ Mushotzky, RF Yaqoob, T George, IM Snowden, SL Netzer, H Kraemer, SB Nandra, K Chelouche, D TI Narrow components within the FeK alpha profile of NGC 3516: Evidence of the importance of general relativistic effects? SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (NGC 3516); galaxies : nuclei; galaxies : Seyfert ID ACTIVE GALACTIC NUCLEI; BLACK-HOLE; IRON LINE; SEYFERT-1 GALAXIES; MCG-6-30-15; COMPTONIZATION; EMISSION; DISK; MODEL AB We present results from a simultaneous Chandra High Energy Transmission Grating and XMM-Newton observation of NGC 3516. We find evidence of several narrow components of Fe Kalpha along with a broad line. We consider the possibility that the lines arise in a blob of material ejected from the nucleus with velocity similar to0.25c. We also consider an origin in a neutral accretion disk, suffering enhanced illumination at 35R(g) and 175R(g),perhaps as a result of magnetic reconnection. The presence of these narrow features indicates there is no Comptonizing region along the line of sight to the nucleus. This in turn is compelling support for the hypothesis that broad Fe Kalpha components are, in general, produced by strong gravity. C1 Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophy, Baltimore, MD 21250 USA. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Ctr Astrophys Sci, Bloomberg Ctr, Baltimore, MD 21218 USA. Univ Space Res Assoc, Seabrook, MD 20706 USA. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Catholic Univ Amer, NASA, GSFC, Greenbelt, MD 20771 USA. RP Turner, TJ (reprint author), Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophy, 1000 Hilltop Circle, Baltimore, MD 21250 USA. RI Snowden, Steven/D-5292-2012 NR 30 TC 110 Z9 110 U1 1 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2002 VL 574 IS 2 BP L123 EP L127 DI 10.1086/342504 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 581BF UT WOS:000177270700005 ER PT J AU Tingay, SJ Reynolds, JE Tzioumis, AK Jauncey, DL Lovell, JEJ Dodson, R Costa, ME McCulloch, PM Edwards, PG Hirabayashi, H Murphy, DW Preston, RA Piner, BG Nicolson, GD Quick, JFH Kobayashi, H Shibata, KM AF Tingay, SJ Reynolds, JE Tzioumis, AK Jauncey, DL Lovell, JEJ Dodson, R Costa, ME McCulloch, PM Edwards, PG Hirabayashi, H Murphy, DW Preston, RA Piner, BG Nicolson, GD Quick, JFH Kobayashi, H Shibata, KM TI VSOP space VLBI and geodetic VLBI investigations of southern hemisphere radio sources SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : active; galaxies : jets; quasars : general; radiation mechanisms : nonthermal radio continuum : galaxies; techniques : interferometric ID PEARSON-READHEAD SURVEY; ACTIVE GALACTIC NUCLEI; SCALE STRUCTURE; BRIGHTNESS TEMPERATURES; EGRET IDENTIFICATIONS; GALAXY; GHZ; MORPHOLOGY; EVOLUTION; JET AB We present images from VLBI Space Observatory Programme (VSOP) observations of 14 compact extragalactic southern hemisphere radio sources, including a description of the observations, the data reduction techniques, and the parameters of the resulting images and model fits. These images provide the highest resolution information to date for many of these objects. Comparisons are made between VSOP and previous ground-based VLBI results, including images from data extracted from the geodetic VLBI archive at the United States Naval Observatory. From the VSOP data, we find that the two radio galaxies observed have lower peak brightness temperatures than the 12 quasars. Also, these data show (1) no evidence for obvious differences between the brightness temperature distributions of gamma-ray loud and gamma-ray quiet radio-loud active galactic nuclei and (2) no evidence for obvious correlations between brightness temperature and spectral index, radio polarization, flux density, or month timescale modulation index. These results are consistent with previous work by Lister, Tingay, & Preston, who found that the only observable significantly correlated with VSOP-derived brightness temperature is intraday variability, which is strongly correlated with many relativistic beaming indicators. For one source, PKS 1127-145, we undertake a detailed investigation of the milliarcsecond-scale component positions as a function of time, taking data from the literature and the current work, to estimate proper motions. As a result, we suggest that two components previously reported as stationary, C1 and C2, have apparent transverse speeds of (9.1 +/- 3.8) and (5.3 +/- 2.3) h(-1)c, respectively. We also make the first investigation of the apparent motion in the nearest GHz-peaked spectrum radio galaxy, PKS 1718-649, finding an upper limit on the apparent separation speed of 0.08c. Comparison of geodetic VLBI and VSOP data show no significant detection of component motion in PKS 0208-512, (2.4 +/- 3.1) h(-1)c, and only a tentative detection in PKS 0537-441, ( 2.8 +/-2.2) h(-1)c. A significant detection of component motion is found in PKS 1610-771, solely from the geodetic VLBI data, (9.4 +/- 3.5) h(-1)c. C1 CSIRO, Australia Telescope Natl Facil, Paul Wild Observ, Narrabri, NSW 2390, Australia. CSIRO, Australia Telescope Natl Facil, Epping, NSW 2121, Australia. Univ Tasmania, Dept Phys, Hobart, Tas 7001, Australia. Inst Space & Astronaut Sci, Kanagawa 229, Japan. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Whittier Coll, Dept Phys, Whittier, CA 90608 USA. Hartebeesthoek Radio Astron Observ, ZA-1740 Transval, South Africa. Natl Astron Observ, Tokyo 1818588, Japan. RP Tingay, SJ (reprint author), CSIRO, Australia Telescope Natl Facil, Paul Wild Observ, Narrabri, NSW 2390, Australia. RI Tingay, Steven/B-5271-2013 NR 41 TC 27 Z9 27 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD AUG PY 2002 VL 141 IS 2 BP 311 EP 335 DI 10.1086/340783 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 575ZN UT WOS:000176978500002 ER PT J AU Smith, DA Levine, A Bradt, H Hurley, K Feroci, M Butterworth, P Golenetskii, S Pendleton, G Phengchamnan, S AF Smith, DA Levine, A Bradt, H Hurley, K Feroci, M Butterworth, P Golenetskii, S Pendleton, G Phengchamnan, S TI X-ray light curves of gamma-ray bursts detected with the All-Sky Monitor on RXTE SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE gamma rays : bursts ID SPECTRAL CHARACTERISTICS; BATSE OBSERVATIONS; TEMPORAL STRUCTURE; COSMIC FIREBALLS; INTERNAL SHOCKS; AFTERGLOW; EVOLUTION; BEPPOSAX; VARIABILITY; GINGA AB We present X-ray light curves (1.5-12 keV) for 15 gamma-ray bursts (GRBs) detected by the All-Sky Monitor (ASM) on the Rossi X-Ray Timing Explorer. We compare these soft X-ray light curves with count rate histories obtained by the high-energy (>12 keV) experiments BATSE, Konus-Wind, the BeppoSAX Gamma-Ray Burst Monitor, and the burst monitor on Ulysses. We discuss these light curves within the context of a simple relativistic fireball and synchrotron shock paradigm, and we address the possibility of having observed the transition between a GRB and its afterglow. The light curves show diverse morphologies, with striking differences between energy bands. In several bursts, intervals of significant emission are evident in the ASM energy range with little or no corresponding emission apparent in the high-energy light curves. For example, the final peak of GRB 970815 as recorded by the ASM is detected only in the softest BATSE energy bands. We also study the duration of bursts as a function of energy. Simple, singly peaked bursts seem consistent with the E-0.5 power law expected from an origin in synchrotron radiation, but durations of bursts that exhibit complex temporal structure are not consistent with this prediction. Bursts such as GRB 970828 that show many short spikes of emission at high energies last significantly longer at low energies than the synchrotron cooling law would predict. C1 Univ Michigan, Ann Arbor, MI 48109 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. CNR, Ist Astrofis Spaziale, I-00133 Rome, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Emergent Informat Technol, Largo, MD 20774 USA. Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. COLSA Corp, Huntsville, AL 35806 USA. RP Smith, DA (reprint author), Univ Michigan, Ann Arbor, MI 48109 USA. EM donaldas@umich.edu RI Golenetskii, Sergey/B-3818-2015; OI Feroci, Marco/0000-0002-7617-3421 NR 71 TC 11 Z9 11 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 EI 1538-4365 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD AUG PY 2002 VL 141 IS 2 BP 415 EP 428 DI 10.1086/340328 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 575ZN UT WOS:000176978500005 ER PT J AU Walborn, NR Fullerton, AW Crowther, PA Bianchi, L Hutchings, JB Pellerin, A Sonneborn, G Willis, AJ AF Walborn, NR Fullerton, AW Crowther, PA Bianchi, L Hutchings, JB Pellerin, A Sonneborn, G Willis, AJ TI Far Ultraviolet Spectroscopic Explorer atlas of OB stars in the Magellanic Clouds SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE atlases; Magellanic Clouds; stars : early-type; stars : winds, outflows; ultraviolet : stars ID ON-ORBIT PERFORMANCE; SPECTRAL CLASSIFICATION; STELLAR WINDS; MASS-LOSS; B-STARS; SUPERGIANTS; LINES; COPERNICUS; COMPONENTS; PROFILES AB An atlas of the 900-1200 Angstrom region in the spectra of 47 OB stars in the Large and Small Magellanic Clouds, observed at high resolution by the Far Ultraviolet Spectroscopic Explorer (FUSE), is presented and discussed. The systematic trends in the numerous stellar-wind features in this region, some from species (and ionizations) not represented at longer wavelengths, are charted as a function of the optical spectral types. The FUSE sample is by far the most powerful to date for that purpose. A special effort has been made to verify the spectral types of all stars included in the atlas, in a number of cases with new optical observations that are also illustrated, to avoid uncertainties from that source in the stellar-wind trends. A new O2 star has been found in the process. Most of these stars have been previously observed at longer ultraviolet wavelengths by the Hubble Space Telescope and in the optical from the ground with high-resolution, digital instruments; thus very comprehensive physical modeling of these OB atmospheres and winds now becomes possible. This atlas will serve as a guide to the FUSE Magellanic Cloud OB database for that purpose. The Magellanic Cloud sample provides a very important complement to the FUSE database of Galactic OB counterparts (Pellerin et al. 2002), both because the lower extinction and interstellar H(2) absorption toward the Cloud stars allow a much clearer view of the stellar spectra below 1100 Angstrom, and because of the metallicity differences among the three galaxies. In particular, most wind features in the SMC spectra are seen to be significantly weaker than those in the LMC at the same spectral types. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Victoria, Dept Phys & Astron, Victoria, BC V8W 3P6, Canada. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. UCL, Dept Phys & Astron, London WC1E 6BT, England. Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V8X 4M6, Canada. Univ Laval, Dept Phys Genie Phys & Opt, Quebec City, PQ G1K 7P4, Canada. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Walborn, NR (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. EM walborn@stsci.edu; awf@pha.jhu.edu; pac@star.ucla.ac.uk; bianchi@pha.jhu.edu; john.hutchings@hia.nrc.ca; apelleri@phy.ulaval.ca; sonneborn@stars.gsfc.nasa.gov; ajw@star.ucl.ac.uk OI Crowther, Paul/0000-0001-6000-6920 NR 43 TC 66 Z9 66 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD AUG PY 2002 VL 141 IS 2 BP 443 EP 468 DI 10.1086/340571 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 575ZN UT WOS:000176978500007 ER PT J AU Kozlovsky, B Murphy, RJ Ramaty, R AF Kozlovsky, B Murphy, RJ Ramaty, R TI Nuclear deexcitation gamma-ray lines from accelerated particle interactions SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE acceleration of particles; gamma rays : theory; nuclear reactions, nucleosynthesis, abundances Sun : abundances; Sun : flares; Sun : X-rays, gamma rays ID CROSS-SECTIONS RELEVANT; SOLAR-FLARE; ABUNDANCES; ASTRONOMY; SPECTROSCOPY; C-12; O-16; OXYGEN; SUN AB Total cross sections for the production of gamma-ray lines from nuclear deexcitation as a function of the projectile energy are evaluated and presented. Included are proton and reactions with He, C, N, O, Ne, Mg, Al, Si, S, Ca, and Fe. Such functions are essential for interpretation of gamma-ray line observations of astrophysical sites which contain large fluxes of energetic particles such as solar flares, the Earth's atmosphere, planetary atmospheres and surfaces, the interstellar medium, and galactic nebulae. C1 Tel Aviv Univ, Sch Phys & Astron, Ramat Aviv, Israel. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Kozlovsky, B (reprint author), Tel Aviv Univ, Sch Phys & Astron, Ramat Aviv, Israel. NR 51 TC 61 Z9 62 U1 1 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD AUG PY 2002 VL 141 IS 2 BP 523 EP 541 DI 10.1086/340545 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 575ZN UT WOS:000176978500011 ER PT J AU Cockell, CS Lee, P AF Cockell, CS Lee, P TI The biology of impact craters - a review SO BIOLOGICAL REVIEWS LA English DT Review DE impact crater; succession; lake; hydrothermal; Mars; Haughton; comet; asteroid ID MOUNT-ST-HELENS; DEVON-ISLAND; POLAR DESERT; HYDROTHERMAL ACTIVITY; HAUGHTON FORMATION; VOLCANIC-ERUPTION; PLANT-COMMUNITIES; KRAKATAU-ISLANDS; ARCTIC CANADA; RIES CRATER AB Impact craters contain ecosystems that are often very different from the ecosystems that surround them. On Earth over 150 impact craters have been identified in a wide diversity of biomes. All natural events that can cause localized disruption of ecosystems have quite distinct patterns of recovery. Impact events are unique in that they are the only extraterrestrial mechanism capable of disrupting an ecosystem locally in space and time. Thus, elucidating the chronological sequence of change at the sites of impacts is of ecological interest. In this synthetic review we use the existing literature, coupled with our own observations at the Haughton impact structure, Devon Island, Nunavut, Canada to consider the patterns of biological recovery at the site of impact craters and the ecological characteristics of impact craters. Three phases of recovery are suggested. The Phase of Thermal Biology, a phase associated with the localized, ephemeral thermal anomaly generated by an impact event. The Phase of Impact Succession and Climax, a phase marked by multiple primary and secondary succession events both in the aquatic realm (impact crater-lakes) and terrestrial realm (colonization of paleolacustrine deposits and impact-generated substrata) that are followed by periods of climax ecology. In the case of large-scale impact events (> 10(4) Mt), this latter phase may also be influenced by successional changes in the global environment. Finally, during the Phase of Ecological Assimilation, the disappearance of the surface geological expression of an impact structure results in a concomitant loss of ecological distinctiveness. In extreme cases, the impact structure is buried. Impact succession displays similarities and differences to succession following other agents of ecological disturbance, particularly volcanism. C1 British Antarctic Survey, Cambridge CB3 0ET, England. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. SETI Inst, Moffett Field, CA 94035 USA. RP Cockell, CS (reprint author), British Antarctic Survey, High Cross,Madingley Rd, Cambridge CB3 0ET, England. NR 133 TC 49 Z9 50 U1 5 U2 19 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4221 USA SN 1464-7931 J9 BIOL REV JI Biol. Rev. PD AUG PY 2002 VL 77 IS 3 BP 279 EP 310 DI 10.1017/S146479310100584X PG 32 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 594PC UT WOS:000178058500001 PM 12227518 ER PT J AU Pratt, LR Pohorille, A AF Pratt, LR Pohorille, A TI Hydrophobic effects and modeling of biophysical aqueous solution interfaces SO CHEMICAL REVIEWS LA English DT Review ID MOLECULAR-DYNAMICS SIMULATION; LIQUID-VAPOR INTERFACE; MONTE-CARLO SIMULATION; PERIODIC BOUNDARY-CONDITIONS; SUM-FREQUENCY GENERATION; LIPID BILAYER-MEMBRANES; WATER-HEXANE INTERFACE; TRANSFORM INFRARED-SPECTROSCOPY; LATERAL PRESSURE PROFILE; LENNARD-JONES WALLS C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NASA, Ames Res Ctr, Exobiol Branch, Moffett Field, CA 94035 USA. RP Pratt, LR (reprint author), Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. RI Pratt, Lawrence/H-7955-2012 OI Pratt, Lawrence/0000-0003-2351-7451 NR 280 TC 266 Z9 269 U1 7 U2 86 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2665 J9 CHEM REV JI Chem. Rev. PD AUG PY 2002 VL 102 IS 8 BP 2671 EP 2691 AR UNSP CR000692+ DI 10.1021/cr000692+ PG 21 WC Chemistry, Multidisciplinary SC Chemistry GA 585WZ UT WOS:000177548700004 PM 12175264 ER PT J AU Kang, IS Jin, K Wang, B Lau, KM Shukla, J Krishnamurthy, V Schubert, SD Wailser, DE Stern, WF Kitoh, A Meehl, GA Kanamitsu, M Galin, VY Satyan, V Park, CK Liu, Y AF Kang, IS Jin, K Wang, B Lau, KM Shukla, J Krishnamurthy, V Schubert, SD Wailser, DE Stern, WF Kitoh, A Meehl, GA Kanamitsu, M Galin, VY Satyan, V Park, CK Liu, Y TI Intercomparison of the climatological variations of Asian summer monsoon precipitation simulated by 10 GCMs SO CLIMATE DYNAMICS LA English DT Article ID GENERAL-CIRCULATION MODELS; INTERANNUAL VARIABILITY; HORIZONTAL RESOLUTION; INTRASEASONAL OSCILLATION; CLOUD ENSEMBLE; EAST CHINA; SENSITIVITY; PREDICTABILITY; CONVECTION; PROJECT AB We assesses the overall performance of stateof-the-art atmospheric GCMs in simulating the climatological variations of summer monsoon rainfall over the Asian-Western Pacific region and the systematic errors that are common to a group of GCMs. The GCM data utilized are obtained from 10 GCM groups participated in the CLIVAR/Monsoon GCM Intercomparison Project. The model composite shows that the overall spatial pattern of summer monsoon rainfall is similar to the observed, although the western Pacific rainfall is relatively weak. For the simulated precipitation over the western Pacific, the models can be classified into two categories. The first category of models simulates the precipitation more confined to the equatorial region and weaker precipitation in the subtropical western Pacific compared to the observed. The second category of models simulates large precipitation in the subtropical western Pacific but the region is shifted to the north by 5-10degrees. None of the models realistically reproduce the observed Mei-yu rain band in the region from the East China Sea to the mid Pacific. Most of the models produce a rain band along the continental side of East Asia. The climatological variations of simulated summer rainfall are examined in terms of their amplitude and their principal EOF modes. All models simulate larger amplitudes of the climatological seasonal variation of Indian summer monsoon than the observed, though most models simulate smaller amplitudes in the western Pacific. The ten model composite produces four leading EOF modes over the Asian-western Pacific region, which are remarkably similar to the observed counterparts. The first and second eigenmodes, respectively, represent the smoothed seasonal march of broad-scale monsoon and the onsets of the Indian and East Asian summer monsoon. The third and fourth modes relate to the climatological intraseasonal oscillation (CISO). In contrast to the model composite, several models fail to reproduce the first principal mode, and most models do riot reproduce the observed modes higher than the second. The CISO of precipitation is also examined over the Indian monsoon and the East Asia-western Pacific monsoon regions separately. C1 Seoul Natl Univ, Sch Earth & Environm Sci, Seoul 151742, South Korea. Univ Hawaii, Int Pacific Res Ctr, Honolulu, HI 96822 USA. NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. Inst Global Environm & Soc Inc, Ctr Ocean Land Atmosphere Studies, Calverton, MD USA. NASA, Goddard Space Flight Ctr, Data Adm Off, Greenbelt, MD 20771 USA. SUNY Stony Brook, Inst Terr & Planetary Atmospheres, Stony Brook, NY 11794 USA. Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08544 USA. Meteorol Res Inst, Tsukuba, Ibaraki 305, Japan. Natl Ctr Atmospher Res, Boulder, CO USA. Natl Ctr Environm Predict, Camp Springs, MD USA. Russian Acad Sci, Inst Numer Math, Moscow, Russia. Indian Inst Trop Meteorol, Pune, Maharashtra, India. Korea Meteorol Adm, Climate Predict Div, Seoul, South Korea. Inst Atmospher Phys, Beijing, Peoples R China. RP Kang, IS (reprint author), Seoul Natl Univ, Sch Earth & Environm Sci, Seoul 151742, South Korea. EM kang@climate.snu.ac.kr RI Lau, William /E-1510-2012; 안, 민섭/D-9972-2015 OI Lau, William /0000-0002-3587-3691; NR 46 TC 275 Z9 312 U1 5 U2 37 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD AUG PY 2002 VL 19 IS 5-6 BP 383 EP 395 DI 10.1007/s00382-002-0245-9 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 591FZ UT WOS:000177870200002 ER PT J AU Harm, DL Sandoz, GR Stern, RM AF Harm, DL Sandoz, GR Stern, RM TI Changes in gastric myoelectric activity during space flight SO DIGESTIVE DISEASES AND SCIENCES LA English DT Article DE electrogastrogram; space motion sickness; postprandial responses ID MOTION SICKNESS; ELECTRICAL-ACTIVITY; UNEXPLAINED NAUSEA; SLOW WAVES; ELECTROGASTROGRAM; HUMANS; GASTROPARESIS; TACHYGASTRIA; RECORDINGS; NEUROPATHY AB The purpose of the present study was to examine postprandial myoelectric activity of the stomach and gastric activity associated with space motion sickness using electrogastrography. Three crewmembers participated in this investigation. Preflight, subjects exhibited normal postprandial responses to the ingestion of a meal. Inflight, crewmembers exhibited an abnormal decrease in the power of the normal gastric slow wave after eating on flight day 1, but had a normal postprandial response by flight day 3. Prior to and during episodes of nausea and vomiting, the electrical activity of the stomach became dysrhythmic with 60-80% of the spectral power in the bradygastric and tachygastric frequency ranges. These findings indicate that gastric motility may be decreased during the first few days of space flight. In addition, changes in the frequency of the gastric slow wave associated with space motion sickness symptoms are consistent with those reported for laboratory-induced motion sickness. C1 NASA, Lyndon B Johnson Space Ctr, Neurosci Lab, Houston, TX 77058 USA. Penn State Univ, Dept Psychol, University Pk, PA 16802 USA. Krug Life Sci, Houston, TX 77058 USA. RP NASA, Lyndon B Johnson Space Ctr, Neurosci Lab, Mail Code SK3,2101 Nasa Rd 1, Houston, TX 77058 USA. NR 41 TC 5 Z9 6 U1 3 U2 5 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0163-2116 EI 1573-2568 J9 DIGEST DIS SCI JI Dig. Dis. Sci. PD AUG PY 2002 VL 47 IS 8 BP 1737 EP 1745 AR UNSP 0163-2116/02/0800-1737/0 DI 10.1023/A:1016480109272 PG 9 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA 573BF UT WOS:000176808900010 PM 12184524 ER PT J AU Moisan, JR Moisan, TA Abbott, MR AF Moisan, JR Moisan, TA Abbott, MR TI Modelling the effect of temperature on the maximum growth rates of phytoplankton populations SO ECOLOGICAL MODELLING LA English DT Article DE phytoplankton; temperature; maximum growth rate; population ID SKELETONEMA-COSTATUM BACILLARIOPHYCEAE; LIGHT-INTENSITY; FRESH-WATER; ECOSYSTEM MODEL; TIME-SERIES; MIXED-LAYER; MARINE; PHOTOSYNTHESIS; ADAPTATION; IRRADIANCE AB Functional relationships which parameterize growth based on the Eppley temperature relationship for phytoplankton maximal growth rates are increasingly being used in marine and freshwater ecosystem models. In this paper, we demonstrate the effect of using such generalized relationships in modelling studies. Two suites of numerical experiments are carried out to investigate the sensitivity of models to generalized growth relationships. In each experiment, 100 individual species or groups of phytoplankton are allowed to compete under a variety of growth versus temperature relationships. One suite of experiments is carried out within a simple 'chemostat' type model that is forced with seasonally varying temperature and photosynthetically available radiation (PAR) fields. A second suite of experiments is carried out using a biogeochemical mixed-layer model to demonstrate the sensitivity of these models to various temperature versus growth relationships. The key difference in the biogeochemical mixed-layer simulations is in the timing of the ecosystem response to seasonal variability of the mixed-layer depth and temperature. The Eppley growth versus temperature relationship overestimates phytoplankton growth by as much as 80% during the spring when growth rates are crucial to the timing of the spring blooms. This decrease in growth rates causes a delay in the spring phytoplankton bloom which in turn results in significant changes in all other model constituents. The results from both suites of experiments show that it is important to resolve the intrinsic growth dynamics of a population in order to properly resolve the maximum growth rates of phytoplankton populations. The results also present a possible explanation for why phytoplankton are commonly found growing within water colder than their optimal temperature for growth. A dynamic growth versus temperature model is introduced that is capable of resolving the growth dynamics of a population of phytoplankton under a variety of temperature forcing scenarios. This new growth versus temperature model/relationship will be useful in global biogeochemical models and demonstrates the importance of underlying population dynamics in controlling bulk community growth estimates. (C) 2002 Elsevier Science B.V. All rights reserved. C1 NASA, Lab Hydrospher Proc, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. RP Moisan, JR (reprint author), NASA, Lab Hydrospher Proc, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. RI Moisan, John/B-8762-2016 OI Moisan, John/0000-0002-8078-8939 NR 62 TC 44 Z9 48 U1 3 U2 48 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3800 J9 ECOL MODEL JI Ecol. Model. PD AUG 1 PY 2002 VL 153 IS 3 BP 197 EP 215 AR PII S0304-3800(02)00008-X DI 10.1016/S0304-3800(02)00008-X PG 19 WC Ecology SC Environmental Sciences & Ecology GA 577QB UT WOS:000177071900001 ER PT J AU Biemont, E Dumont, PD Garnir, HP Palmeri, P Quinet, P AF Biemont, E Dumont, PD Garnir, HP Palmeri, P Quinet, P TI Radiative lifetime and oscillator strength determination in Mg-like potassium (K VIII) SO EUROPEAN PHYSICAL JOURNAL D LA English DT Article ID ATOMIC-STRUCTURE CALCULATIONS; ISOELECTRONIC SEQUENCE; CORE-POLARIZATION; TRANSITION-PROBABILITIES; RESONANCE TRANSITIONS; EXCITATION-ENERGIES; HYPERFINE-STRUCTURE; INTERSYSTEM LINE; BEAM-FOIL; SI-III AB Theoretical transition probabilities have been obtained for 54 n = 3 transitions depopulating the 3s3p P-1(o), 3P(2) P-3, D-1, S-1, 3s3d D-1, D-3 and 3p3d P-3(o), D-3(o), F-3(o), F-1(o), D-1(o), P-1(o) levels, including 14 transitions not yet observed. Some of these predictions have been compared with experimental lifetimes obtained by beam-foil spectroscopy for four n = 3 levels of K7+. An excellent agreement is observed between theory and experiment for all the levels. C1 Univ Liege, Inst Phys Nucl Atom & Spect, B-4000 Liege, Belgium. Univ Mons, B-7000 Mons, Belgium. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Biemont, E (reprint author), Univ Liege, Inst Phys Nucl Atom & Spect, Sart Tilman B 15, B-4000 Liege, Belgium. NR 48 TC 12 Z9 12 U1 0 U2 0 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6060 J9 EUR PHYS J D JI Eur. Phys. J. D PD AUG PY 2002 VL 20 IS 2 BP 199 EP 204 DI 10.1140/epjd/e2002-00132-1 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 585PV UT WOS:000177534500005 ER PT J AU Bell, KR AF Bell, KR TI The early evolution of the solar nebula with implications for the formation of primitive material SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 2002 VL 66 IS 15A SU 1 BP A64 EP A64 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 583RX UT WOS:000177423400123 ER PT J AU Brandon, AD AF Brandon, AD TI Os-186-Os-187 systematics of Gorgona komatiites and Iceland picrites SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract C1 NASA, Johnson Space Ctr, Houston, TX 77058 USA. NR 5 TC 1 Z9 1 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 2002 VL 66 IS 15A SU 1 BP A100 EP A100 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 583RX UT WOS:000177423400194 ER PT J AU Brasier, MD Green, OR Jephcoat, AP Kleepe, AK Van Kranendonk, MJ Lindsay, F Steele, A Grassineau, NV AF Brasier, MD Green, OR Jephcoat, AP Kleepe, AK Van Kranendonk, MJ Lindsay, F Steele, A Grassineau, NV TI Questioning the evidence for Earth's oldest fossils SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract C1 Univ Oxford, Dept Earth Sci, Oxford OX1 3PR, England. Geol Survey Western Australia, Perth, WA 6004, Australia. NASA, JSC, Astrobiol Inst, Houston, TX 77058 USA. Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. Royal Holloway Univ London, Dept Geol, Egham TW20 0EX, Surrey, England. RI Van Kranendonk, Martin/J-8755-2012 NR 1 TC 1 Z9 1 U1 0 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 2002 VL 66 IS 15A SU 1 BP A101 EP A101 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 583RX UT WOS:000177423400196 ER PT J AU Charnley, S AF Charnley, S TI Interstellar organic chemistry SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 2002 VL 66 IS 15A SU 1 BP A131 EP A131 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 583RX UT WOS:000177423400254 ER PT J AU Des Marais, DJ AF Des Marais, DJ TI Biogeochemical carbon cycles during the Archean and early Proterozoic SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract C1 Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 2002 VL 66 IS 15A SU 1 BP A178 EP A178 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 583RX UT WOS:000177423400347 ER PT J AU Dixon, ET AF Dixon, ET TI He and Ne ratios in Icelandic basalts SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract ID UPPER-MANTLE; SYSTEMATICS; BEHAVIOR; HELIUM; ARGON C1 NASA, JSC, Houston, TX 77058 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 2002 VL 66 IS 15A SU 1 BP A187 EP A187 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 583RX UT WOS:000177423400364 ER PT J AU Flynn, G Keller, L Wirick, S Jacobsen, C AF Flynn, G Keller, L Wirick, S Jacobsen, C TI The origin of Solar System organic matter: Evidence from IDPs SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract C1 SUNY Coll Plattsburgh, Plattsburgh, NY 12901 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. RI Jacobsen, Chris/E-2827-2015 OI Jacobsen, Chris/0000-0001-8562-0353 NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 2002 VL 66 IS 15A SU 1 BP A237 EP A237 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 583RX UT WOS:000177423400461 ER PT J AU Humayun, A Puchtel, IS Brandon, AD AF Humayun, A Puchtel, IS Brandon, AD TI PGEs in Icelandic picrites SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract C1 Univ Chicago, Chicago, IL 60637 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 2002 VL 66 IS 15A SU 1 BP A347 EP A347 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 583RX UT WOS:000177423400678 ER EF