FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Pella, J Masuda, M AF Pella, J Masuda, M TI Bayesian methods for analysis of stock mixtures from genetic characters SO FISHERY BULLETIN LA English DT Article ID CHAIN MONTE-CARLO; DISTRIBUTIONS; MITOCHONDRIAL; POPULATIONS; FREQUENCY; MARKERS; DNA AB An implementation of Bayesian methods to assess general stock mixtures is described. An informative prior for genetic characters of the separate stocks in a mixture is derived from baseline samples. A neutral, low-information prior is used for the stock proportions in the mixture. A Gibbs sampler-the data augmentation algorithm-is used to alternately generate samples from the posterior distribution for the genetic parameters of the separate stocks and for the stock proportions in the mixture. The posterior distribution incorporates the information about genetic characters in the baseline samples, including relatedness of stocks, with that in the stock-mixture sample to better estimate genotypic composition of the separate stocks. Advantages over usual likelihood methods include greater realism in model assumptions, better flexibility in applications, especially those with missing data, and consequent improved estimation of stock-mixture proportions from the contributing stocks. Two challenging applications illustrate the technique and its advantages. C1 NOAA, Natl Marine Fisheries Serv, Auke Bay Lab, Alaska Fisheries Sci Ctr, Juneau, AK 99801 USA. RP Pella, J (reprint author), NOAA, Natl Marine Fisheries Serv, Auke Bay Lab, Alaska Fisheries Sci Ctr, 11305 Glacier Hwy, Juneau, AK 99801 USA. NR 35 TC 185 Z9 198 U1 1 U2 13 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JAN PY 2001 VL 99 IS 1 BP 151 EP 167 PG 17 WC Fisheries SC Fisheries GA 403VN UT WOS:000167063300013 ER PT J AU Soh, S Gunderson, DR Ito, DH AF Soh, S Gunderson, DR Ito, DH TI The potential role of marine reserves in the management of shortraker rockfish (Sebastes borealis) and rougheye rockfish (S-aleutianus) in the Gulf of Alaska SO FISHERY BULLETIN LA English DT Article ID FISHERIES; DYNAMICS AB Shortraker and rougheye rockfish (Sebastes borealis and S. aleutianus) have been an independent management subgroup of the Gulf of Alaska slope rockfish assemblage since 1991. Special concerns are proposed for the management of these species because they are very slow growing, long-lived, and commercially important. Marine reserves (harvest refugia) have often been proposed as a valuable management tool for mitigating overfishing and maintaining species and habitat diversity. Their effectiveness in fisheries management, however, is poorly understood and concepts regarding their use are largely untested. Our study investigated the potential role of harvest refugia in the management of these two species by using a Geographic Information System (GIS) application to design harvest refugia networks of varying spatial extent. Twenty-year projections employing a population dynamics model were used to compare ending biomass and fishing mortality under the current management system with biomass and fishing mortality under refuge management systems. The results indicate that harvest refugia can be used to greatly reduce discards and serial overfishing of substocks without reducing current catch levels. C1 Univ Washington, Sch Fisheries, Seattle, WA 98195 USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Soh, S (reprint author), Minist Maritime Affairs & Fisheries, Seodaemun Gu, 139 Chungjong 3, Seoul 120715, South Korea. NR 31 TC 7 Z9 7 U1 3 U2 4 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JAN PY 2001 VL 99 IS 1 BP 168 EP 179 PG 12 WC Fisheries SC Fisheries GA 403VN UT WOS:000167063300014 ER PT J AU DeMaster, DP Lowry, LF Frost, KJ Bengtson, RA AF DeMaster, DP Lowry, LF Frost, KJ Bengtson, RA TI The effect of sea state on estimates of abundance for beluga whales (Delphinapterus leucas) in Norton Sound, Alaska SO FISHERY BULLETIN LA English DT Article C1 NOAA, Natl Marine Fisheries Serv, Natl Marine Mammal Lab, Seattle, WA 98115 USA. Alaska Dept Fish & Game, Fairbanks, AK 99701 USA. RP DeMaster, DP (reprint author), NOAA, Natl Marine Fisheries Serv, Natl Marine Mammal Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 14 TC 5 Z9 6 U1 0 U2 7 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JAN PY 2001 VL 99 IS 1 BP 197 EP 201 PG 5 WC Fisheries SC Fisheries GA 403VN UT WOS:000167063300017 ER PT S AU Roberts, JW Kelley, EF AF Roberts, JW Kelley, EF BE Kelley, EF Voutsas, T TI Measurements of static noise in display images SO FLAT PANEL DISPLAY TECHNOLOGY AND DISPLAY METROLOGY II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Thin Film Transistor Flat Panel Display Technology and Applications/Display Metrology II Conference CY JAN 22-23, 2001 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE DE array-device measurements; CCD measurements; display measurements; display metrology; narrow-frustum probe; image noise measurements; stray light control; stray-light-elimination tubes; frustums; veiling glare AB The appearance of noise on a display is an important usability issue. Sources of noise include electrical interference, display driver artifacts, resampling artifacts, transmission artifacts, compression artifacts, and any intrinsic noise artifacts produced within a display device. Issues for the severity of the noise problem include total magnitude of noise, noise spatial frequencies, proximity of the noise spatial frequencies to the spatial frequencies of the desired information content and the human-eye response to that information content, uniformity of the distribution of noise, and appearance of any visible or regular patterns in the noise. Whatever the source, an accurate method to measure noise may be required to properly assess the influence of the noise. We investigate the intricacies of using a digital camera to accurately measure noise in a static image on a flat panel display (FPD). The electro-optical transfer function of the FPD is measured. A known noise pattern is displayed and measured using the digital camera whereby the predicted noise is compared to the measured noise. Complications and limitations in the metrology will be discussed. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Roberts, JW (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3973-8 J9 P SOC PHOTO-OPT INS PY 2001 VL 4295 BP 211 EP 218 DI 10.1117/12.424874 PG 8 WC Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Engineering; Optics; Imaging Science & Photographic Technology GA BS55P UT WOS:000170315200025 ER PT S AU Boynton, PA Kelley, EF AF Boynton, PA Kelley, EF BE Kelley, EF Voutsas, T TI Light measuring device diagnostics for the photometric and colorimetric measurement of flying-spot displays SO FLAT PANEL DISPLAY TECHNOLOGY AND DISPLAY METROLOGY II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Thin Film Transistor Flat Panel Display Technology and Applications/Display Metrology II Conference CY JAN 22-23, 2001 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE DE display measurement; measurement diagnostic; flying-spot displays; laser displays; light-measuring devices; color measurement AB Flying-spot displays use narrow-spectrum high-power sources that scan the image across the display screen. They can provide a bright display with a large color gamut. When such displays are measured with conventional light-measuring devices (LMDs) such as luminance or illuminance meters, there is concern that the LMD may not accurately measure the display's photometric and colorimetric output. The unique characteristics of the source may exceed the limitations of the instrumentation. A series of diagnostics has been developed that allows for an evaluation of LMDs for use in measuring flying-spot displays. Limitations resulting from LMD saturation, timing, and tristimulus or photopic filters can be revealed, and in some cases, specific causes can be identified. Each diagnostic will be demonstrated using several instruments, including luminance meters, illuminance meters, colorimeters and spectroradiometers. Using a simple comparison box, flying-spot displays can be viewed side-by-side with steady-state sources in a bipartite image. After the sources have been visually matched in color and luminance, the two images can be measured (light output and color) with a particular LMD, and results compared. Any significant difference between results would indicate a limitation of the LMD. Further diagnostics, using integrating spheres, neutral density filters and interference filters, are used to aid in identifying the nature of the limitation, and in some cases, point to solutions. C1 Natl Inst Stand & Technol, Div Elect, Elect & Elect Engn Lab, US Dept Commerce, Gaithersburg, MD 20899 USA. RP Boynton, PA (reprint author), Natl Inst Stand & Technol, Div Elect, Elect & Elect Engn Lab, US Dept Commerce, Gaithersburg, MD 20899 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3973-8 J9 P SOC PHOTO-OPT INS PY 2001 VL 4295 BP 235 EP 247 DI 10.1117/12.424877 PG 13 WC Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Engineering; Optics; Imaging Science & Photographic Technology GA BS55P UT WOS:000170315200028 ER PT S AU Libert, JM Boynton, PA Kelley, EF AF Libert, JM Boynton, PA Kelley, EF BE Kelley, EF Voutsas, T TI A standard illumination source for the evaluation of display measurement methods and instruments SO FLAT PANEL DISPLAY TECHNOLOGY AND DISPLAY METROLOGY II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Thin Film Transistor Flat Panel Display Technology and Applications/Display Metrology II Conference CY JAN 22-23, 2001 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE DE display measurement; color measurement; standards AB A prototype display measurement assessment transfer standard (DMATS) is being developed by the National Institute of Standards and Technology (NIST) to assist the display industry in standardizing measurement methods used to quantify and specify the performance of electronic displays. Designed as an idealized electronic display, the DMATS illumination source emulates photometric and colorimetric measurement problems commonly encountered in measuring electronic displays. NIST will calibrate DMATS units and distribute them to participating laboratories for measurement. Analysis of initial interlaboratory comparison results will provide a baseline assessment of display measurement uncertainties. Also, diagnostic indicators expected to emerge from the data will be used to assist laboratories in correcting deficiencies or in identifying metrology problem areas for further research, such as measurement techniques tailored to new display technologies. This paper describes the design and construction of a prototype DMATS source and preliminary photometric and colorimetric characterization. Also, this paper compares measurements obtained by several instruments under constant environmental conditions and examines the effects of veiling glare on chromaticity measurements. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Libert, JM (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 7 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3973-8 J9 P SOC PHOTO-OPT INS PY 2001 VL 4295 BP 279 EP 286 DI 10.1117/12.424882 PG 8 WC Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Engineering; Optics; Imaging Science & Photographic Technology GA BS55P UT WOS:000170315200033 ER PT S AU Beyerlein, RA McVicker, GB AF Beyerlein, RA McVicker, GB BE Occelli, ML OConnor, P TI Defect structure and acid catalysis of high silica, FAU-framework zeolites: Effects of aluminum removal and of basic metal oxide addition SO FLUID CATALYTIC CRACKING V: MATERIALS AND TECHNOLOGICAL INNOVATIONS SE Studies in Surface Science and Catalysis LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; DEALUMINATED Y-ZEOLITES; RESOLUTION AL-27 NMR; IN-SITU NMR; SOLID ACIDS; H-Y; NONFRAMEWORK ALUMINUM; EXTRAFRAMEWORK ALUMINUM; CRACKING CATALYSTS; MESOPORE FORMATION C1 NIST, Gaithersburg, MD 20899 USA. ExxonMobil Res & Engn Co, Annandale, NJ 08801 USA. RP Beyerlein, RA (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 117 TC 8 Z9 8 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2991 BN 0-444-50475-3 J9 STUD SURF SCI CATAL PY 2001 VL 134 BP 3 EP 40 PG 38 WC Chemistry, Physical SC Chemistry GA BS70L UT WOS:000170910800001 ER PT J AU Hill, RJ Wilczak, JM AF Hill, RJ Wilczak, JM TI Fourth-order velocity statistics SO FLUID DYNAMICS RESEARCH LA English DT Article DE turbulence; higher-order correlations; structure functions ID LOCALLY ISOTROPIC TURBULENCE; SOUND GENERATION; BOUNDARY-LAYER; HYPOTHESIS; SPECTRA; FLOWS AB An investigation of several fourth-order velocity statistics is described. Whereas local isotropy and local scaling are applicable to structure functions expressible as averages of differences of velocity, local isotropy and local scaling are inapplicable to the structure functions that we study. Data from wind tunnel grid turbulence show the behavior of the fourth-order statistics for nearly isotropic turbulence. The scaling relations predicted by the joint Gaussian assumption (JGA) are considered, as are those from the statistical independence assumption (SIA). The basis of the JGA is that velocities at several points are joint Gaussian random variables, whereas the basis of the SIA is that locally averaged velocity is statistically independent of velocity difference. The JGA and SIA relate fourth-order statistics to the second-order velocity structure function, as well as to the velocity covariance. For various fourth-order statistics, the predictions of the JGA and SIA are compared with data. These comparisons quantify how accurately our fourth-order statistics follow the scaling dependence on second-order velocity structure functions and on velocity covariance as predicted by the JGA and SIA. Our measured structure functions are in agreement with the scaling predicted by the SIA with no exceptions and with that predicted by the JGA with two exceptions. As is known, one exception is the structure function that obeys local isotropy [e.g., [(u(i) - u(i)')(4)]] (which the SIA does not predict). The other exceptions are called anomalous components [e.g., [(u(i)(2) - u(i)'(2))(u(j)(2) - u(j)'(2))]]. These anomalous components are shown to be sensitive indicators of intermittency for locally isotropic turbulence, whereas they are indicators of anisotropy for the case of anisotropic turbulence. The anomalous components are in reasonable agreement with the scaling predicted by the SIA but not with the JGA. (C) 2001 The Japan society of Fluid Mechanics and Elsevier Science B.V. All rights reserved. C1 NOAA, Environm Res Labs, Environm Technol Lab, Boulder, CO 80303 USA. RP Hill, RJ (reprint author), NOAA, Environm Res Labs, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. NR 38 TC 10 Z9 10 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-5983 J9 FLUID DYN RES JI Fluid Dyn. Res. PD JAN PY 2001 VL 28 IS 1 BP 1 EP 22 DI 10.1016/S0169-5983(00)00017-4 PG 22 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 391CM UT WOS:000166336600001 ER PT S AU Nave, G AF Nave, G GP OSA OSA TI Fourier transform spectrometry of Rare Earth Elements for the lighting industry. SO FOURIER TRANSFORM SPECTROSCOPY, TECHNICAL DIGEST SE OSA TRENDS IN OPTICS AND PHOTONICS LA English DT Proceedings Paper CT Conference on Fourier Transform Spectroscopy CY FEB 05-08, 2001 CL COEUR DALENE, ID ID VACUUM-ULTRAVIOLET AB Branching fractions for neutral holmium have been measured with FT spectrometry. Hyperfine structure patterns have been analyzed using a modified Xgremlin program. (C) 2000 Optical Society of America. C1 NIST, Gaithersburg, MD 20899 USA. RP Nave, G (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-5695 BN 1-55752-665-6 J9 OSA TRENDS OPT PHOTO PY 2001 VL 51 BP 51 EP 52 PG 2 WC Optics; Spectroscopy SC Optics; Spectroscopy GA BU62Z UT WOS:000176557500018 ER PT S AU Bloom, HJ AF Bloom, HJ GP OSA OSA TI The cross-track infrared sounder (CrIS): a sensor for operational meteorological remote sensing SO FOURIER TRANSFORM SPECTROSCOPY, TECHNICAL DIGEST SE OSA TRENDS IN OPTICS AND PHOTONICS LA English DT Proceedings Paper CT Conference on Fourier Transform Spectroscopy CY FEB 05-08, 2001 CL COEUR DALENE, ID AB The Cross-track Infrared Sounder (CrIS) is one of the key instruments under development for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) program. CrIS is an interferometric sounding sensor which measures upwelling earth radiation at very high spectral resolution and uses this data combined with data from passive microwave instrumentation to construct vertical profiles of atmospheric temperature and moisture. This purpose of this paper is to focus on the instrument development status of the CrIS for a flight of opportunity on the NPOESS Preparatory Project (NPP) in early 2006. C1 NOAA, NESDIS, NPOESS Integrated Program Off, IPO, Washington, DC 20233 USA. RP Bloom, HJ (reprint author), NOAA, NESDIS, NPOESS Integrated Program Off, IPO, Washington, DC 20233 USA. NR 0 TC 0 Z9 0 U1 2 U2 2 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-5695 BN 1-55752-665-6 J9 OSA TRENDS OPT PHOTO PY 2001 VL 51 BP 76 EP 78 PG 3 WC Optics; Spectroscopy SC Optics; Spectroscopy GA BU62Z UT WOS:000176557500027 ER PT S AU Shaw, JA Bates, JJ Eberhard, WL Alvarez, RJ Sandberg, SP Strow, LL AF Shaw, JA Bates, JJ Eberhard, WL Alvarez, RJ Sandberg, SP Strow, LL GP OSA OSA TI Atmospheric measurements with unattended FTIR and lidar SO FOURIER TRANSFORM SPECTROSCOPY, TECHNICAL DIGEST SE OSA TRENDS IN OPTICS AND PHOTONICS LA English DT Proceedings Paper CT Conference on Fourier Transform Spectroscopy CY FEB 05-08, 2001 CL COEUR DALENE, ID ID INFRARED SPECTRAL RADIANCE; CLOUDS AB A combined FTIR-lidar system allows unattended, remote measurements of infrared atmospheric emission, aerosols, and clouds with depolarization discrimination of ice and liquid. C1 NOAA, Environm Technol Lab, Boulder, CO 80305 USA. RP Shaw, JA (reprint author), NOAA, Environm Technol Lab, 325 Broadway, Boulder, CO 80305 USA. RI Eberhard, Wynn/B-5402-2015; Alvarez, Raul/I-4879-2013 NR 10 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-5695 BN 1-55752-665-6 J9 OSA TRENDS OPT PHOTO PY 2001 VL 51 BP 79 EP 81 PG 3 WC Optics; Spectroscopy SC Optics; Spectroscopy GA BU62Z UT WOS:000176557500028 ER PT S AU Sansonetti, CJ Blackwell, MM Saloman, EB AF Sansonetti, CJ Blackwell, MM Saloman, EB GP OSA OSA TI Infrared spectra of Ne, Kr, and Xe SO FOURIER TRANSFORM SPECTROSCOPY, TECHNICAL DIGEST SE OSA TRENDS IN OPTICS AND PHOTONICS LA English DT Proceedings Paper CT Conference on Fourier Transform Spectroscopy CY FEB 05-08, 2001 CL COEUR DALENE, ID ID ENERGY-LEVELS AB New observations of the spectra of neutral Ne, Kr, and Xe in the region 0.7 to 5.0 mum with the 2-m NIST FTS provide precise new wavelengths and resolve questions concerning lines that were previously multiply classified. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Sansonetti, CJ (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-5695 BN 1-55752-665-6 J9 OSA TRENDS OPT PHOTO PY 2001 VL 51 BP 117 EP 119 PG 3 WC Optics; Spectroscopy SC Optics; Spectroscopy GA BU62Z UT WOS:000176557500041 ER PT S AU Griesmann, U AF Griesmann, U GP OSA OSA TI Just how far into the vacuum ultraviolet can we go? SO FOURIER TRANSFORM SPECTROSCOPY, TECHNICAL DIGEST SE OSA TRENDS IN OPTICS AND PHOTONICS LA English DT Proceedings Paper CT Conference on Fourier Transform Spectroscopy CY FEB 05-08, 2001 CL COEUR DALENE, ID AB The drive by the semiconductor industry to reduce feature sizes in integrated circuits has led to a renewed research effort to improve optical materials for the vacuum ultraviolet. Ultraviolet optical materials research at NIST and its implications for Fourier transform spectrometry in the vacuum ultraviolet will be discussed. (C) 2000 Optical Society of America. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Griesmann, U (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-5695 BN 1-55752-665-6 J9 OSA TRENDS OPT PHOTO PY 2001 VL 51 BP 128 EP 128 PG 1 WC Optics; Spectroscopy SC Optics; Spectroscopy GA BU62Z UT WOS:000176557500044 ER PT B AU Maslar, JE Hurst, WS Kremer, DM Ehrman, SH AF Maslar, JE Hurst, WS Kremer, DM Ehrman, SH BE Swihart, MT Allendorf, MD Meyyappan, M TI In situ gas-phase optical measurements of silane decomposition in a thermal chemical vapor deposition reactor SO FUNDAMENTAL GAS-PHASE AND SURFACE CHEMISTRY OF VAPOR-PHASE DEPOSITION II AND PROCESS CONTROL, DIAGNOSTICS, AND MODELING IN SEMICONDUCTOR MANFACTURING IV SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 2nd International Symposium on Fundamental Gas-Phase and Surface Chem of Vapor-Phase Deposition/4th Symp on Process Control, Diagnost and Modeling in Semiconductor Mfg CY MAR 26, 2001 CL WASHINGTON, D.C. SP Electrochem Soc, High Temp Mat & Dielect Sci & Technol Div ID DISK OMVPE REACTORS; CALIBRATION AB Gas phase processes occurring during silicon chemical vapor deposition via silane thermal decomposition were investigated. Raman spectroscopy was utilized to measure gas-phase temperatures and species concentrations while elastic light scattering was utilized to probe gas-phase particle nucleation and transport. The process parameters investigated were a substrate temperature of I 100 K, a chamber pressure of 26.7 kPa (200 torr), a gas flow rate of 19 L/min, and substrate rotation rates of 500 rpm and 1000 rpm. A strong correlation was observed between the gas-phase temperature and both silane concentration and particle light scattering intensity. C1 Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Maslar, JE (reprint author), Natl Inst Stand & Technol, Chem Sci & Technol Lab, 100 Bur Dr,Stop 8360, Gaithersburg, MD 20899 USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-319-9 J9 ELEC SOC S PY 2001 VL 2001 IS 13 BP 168 EP 175 PG 8 WC Chemistry, Physical; Electrochemistry SC Chemistry; Electrochemistry GA BW17X UT WOS:000181082600022 ER PT S AU Burton, BP Cockayne, E AF Burton, BP Cockayne, E BE Krakauer, H TI Prediction of the [Na1/2Bi1/2]TiO3 ground state SO FUNDAMENTAL PHYSICS OF FERROELECTRICS 2001 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Williamsburg Workshop on Fundamental Physics of Ferroelectrics CY FEB 04-07, 2001 CL WILLIAMSBURG, VA SP USN, Off Naval Res, Coll William & Mary ID TOTAL-ENERGY CALCULATIONS; SODIUM BISMUTH TITANATE; WAVE BASIS-SET; MOLECULAR-DYNAMICS; PHASE-TRANSITION; (NA1/2BI1/2)TIO3; NA0.5BI0.5TIO3; TEMPERATURE; CRYSTALS; METALS AB The Vienna Ab-initio Simulation Package (VASP) was used to perform fully relaxed, planewave pseudopotential calculations of formation energies (DeltaE(VASP)) for a large number of ordered supercells in the perovskite based system NaTiO3 - BiTiO3, including 38 supercells with the [Na1/2Bi1/2]TiO3 (NBT) composition. The DeltaE(VASP) were used to fit a cluster expansion Hamiltonian to verify that the no other superstructure is predicted to have lower energy than the lowest DeltaE(VASP), which is a 40 atom supercell with space group symmetry P11m. Its chemical ordering is characterized by pseudocubic doubling of the cell constants, with alternating [100] rows of Na and Bi atoms in (hk0) planes plus alternating [010] rows in (hk1/2) planes. Chemical ordering alone reduces space group symmetry from cubic, Pm3m, to tetragonal, P4(2)/mmc, and octahedral tilting (a(-)a(-)c(+) system) further reduces it to monoclinic, P11m. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Burton, BP (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 24 TC 8 Z9 8 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0021-0 J9 AIP CONF PROC PY 2001 VL 582 BP 82 EP 90 PG 9 WC Physics, Condensed Matter SC Physics GA BT20H UT WOS:000172263800009 ER PT S AU Cockayne, E Burton, BP Bellaiche, L AF Cockayne, E Burton, BP Bellaiche, L BE Krakauer, H TI Temperature-dependent behavior of PbSc1/2Nb1/2O3 from first Principles SO FUNDAMENTAL PHYSICS OF FERROELECTRICS 2001 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Williamsburg Workshop on Fundamental Physics of Ferroelectrics CY FEB 04-07, 2001 CL WILLIAMSBURG, VA SP USN, Off Naval Res, Coll William & Mary ID FERROELECTRIC-PHASE-TRANSITION; TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; DISORDERED PB(SC1/2NB1/2)O-3; DIELECTRIC-CONSTANT; POLARIZATION; PEROVSKITES; ALLOYS; PSEUDOPOTENTIALS; METALS AB We study the ferroelectric phase transition in PbSc1/2Nb1/2O3 (PSN) using a first-principles effective Hamiltonian approach. Results for PSN with NaCl-type ordering of Sc and Nb on the B sites shows that a Pb-centered effective Hamiltonian is appropriate for the ordered cell. We obtain a complete effective Hamiltonian for ordered PSN that has the form of effective Hamiltonians for simple perovskites. We modify the effective Hamiltonian to include the effects of Sc-Nb disorder by adding one additional term giving the effective force on the Pb site due to the nearest neighbor B-site cations. Monte Carlo simulations of our model shows that disordered PSN has a lower Curie temperature than ordered PSN, in agreement with a previous first-principles study based on a virtual crystal approach. No evidence for relaxor behavior is seen in our model. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. RP Cockayne, E (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Div Ceram, Gaithersburg, MD 20899 USA. NR 25 TC 10 Z9 10 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0021-0 J9 AIP CONF PROC PY 2001 VL 582 BP 191 EP 200 PG 10 WC Physics, Condensed Matter SC Physics GA BT20H UT WOS:000172263800021 ER PT S AU Hsu, SM McGuiggan, PM Zhang, J Wang, Y Yin, F Yeh, YP Gates, RS AF Hsu, SM McGuiggan, PM Zhang, J Wang, Y Yin, F Yeh, YP Gates, RS BE Bhushan, B TI Scaling issues in the measurement of monolayer films SO FUNDAMENTALS OF TRIBOLOGY AND BRIDGING THE GAP BETWEEN THE MACRO-AND MICRO/NANOSCALES SE NATO Science Series II-Mathematics Physics and Chemistry LA English DT Proceedings Paper CT Conference of the NATO Advanced Study Institute on Fundamentals of Tribology and Bridging the Gap Between the Macro-and Micro/Nanoscales CY AUG 13-25, 2000 CL KESZTHELY, HUNGARY SP NATO, Sci & Environm Affairs Div ID ATOMIC-FORCE-MICROSCOPE; SHEAR AB An atomic force microscope (AFM), a surface forces apparatus (SFA), and a ball-on-inclined plane (BOIP) apparatus were used to measure the mechanical properties of thin lubricant films. The frictional force of a set of Four samples with different lubricant chemistries was measured by an AFM using a conventional sharp silicon nitride tip. Very little difference was observed among the different chemistries. A careful study using different tip sizes on two model compounds on mica was compared to results obtained with the SFA and suggested a tip size effect (scaling issue). A systematic test protocol was then developed to measure the adhesive strength and durability of films on nanometer and larger scales. A one pass ball-on-inclined plane test was used to measure the adhesive strength of various chemical films. A high speed version of the ball-on-inclined plane was then used to measure the durability of these films. Successful measurements depend on controlling the relative surface roughness down to the nanometer scale even though the test itself is at the mm scale. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Hsu, SM (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM stephen.hsu@nist.gov RI McGuiggan, Patricia/A-3379-2010 NR 11 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1568-2609 BN 0-7923-6837-1 J9 NATO SCI SER II-MATH PY 2001 VL 10 BP 691 EP 710 PG 20 WC Engineering, Mechanical; Mechanics; Physics, Applied SC Engineering; Mechanics; Physics GA BS17A UT WOS:000168949100051 ER PT S AU Bennett, HS AF Bennett, HS GP IEEE IEEE TI Why you should be interested in technology roadmaps for compound semiconductors SO GAAS IC SYMPOSIUM, TECHNICAL DIGEST 2001 SE TECHNICAL DIGEST - IEEE GALLIUM ARSENIDE INTEGRATED CIRCUIT SYMPOSIUM LA English DT Proceedings Paper CT 23rd Annual IEEE GaAs IC Symposium CY OCT 21-24, 2001 CL BALTIMORE, MD SP IEEE Electron Devices Soc, IEEE Microwave Theory & Tech Soc, IEEE Solid State Circuits Soc AB Unlike the silicon semiconductor industry, the compound semiconductor industry does not have an international consensus for a few selected applications and markets to set priorities for investments. The main purpose of this paper is to increase the awareness among industrial decision-makers about the need for an international consensus or technology roadmap concerning selected compound semiconductors. Reasons are given for why there needs to be more wide-spread involvement in technology roadmaps for compound semiconductors. The technical challenges presented by predictive computer simulations, high performance analog-to-digital converters, and RF power devices are three areas from among many for which technology roadmaps would be appropriate. C1 Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Bennett, HS (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, 100 Bur Dr,MS 8120, Gaithersburg, MD 20899 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1064-7775 BN 0-7803-6663-8 J9 TG IEEE GAL ARS PY 2001 BP 19 EP 22 DI 10.1109/GAAS.2001.964337 PG 4 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BT68H UT WOS:000173723800005 ER PT B AU Goyette, AN de Urquijo, J Wang, YC Christophorou, LG Olthoff, JK AF Goyette, AN de Urquijo, J Wang, YC Christophorou, LG Olthoff, JK BE Christophorou, LG Olthoff, JK TI Electron transport, ionization, and attachment coefficients in C2F4 and C2F4/Ar mixtures SO GASEOUS DIELECTRICS IX LA English DT Proceedings Paper CT 9th International Symposium on Gaseous Dielectrics CY MAY 21-25, 2001 CL ELLICOTT CITY, MD SP Natl Inst Stand & Technol, ABB, USAF Res Lab, Hitachi Ltd, Kansai Elect Power Co, Toshiba Corp, IEEE Dielect & Elect Insulat Soc ID DRIFT; CHF3; ION C1 Natl Inst Stand & Technol, Div Elect, Gaithersburg, MD 20899 USA. RP Goyette, AN (reprint author), Natl Inst Stand & Technol, Div Elect, 100 Bureau Dr,Mail Stop 8113, Gaithersburg, MD 20899 USA. NR 10 TC 0 Z9 0 U1 1 U2 1 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA BN 0-306-46705-4 PY 2001 BP 43 EP 48 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Atomic, Molecular & Chemical SC Engineering; Physics GA BT88X UT WOS:000174363400005 ER PT B AU Wang, YC Champion, RL Dyakov, IV Peko, BL AF Wang, YC Champion, RL Dyakov, IV Peko, BL BE Christophorou, LG Olthoff, JK TI Rate constants for unimolecular decomposition of SF6- SO GASEOUS DIELECTRICS IX LA English DT Proceedings Paper CT 9th International Symposium on Gaseous Dielectrics CY MAY 21-25, 2001 CL ELLICOTT CITY, MD SP Natl Inst Stand & Technol, ABB, USAF Res Lab, Hitachi Ltd, Kansai Elect Power Co, Toshiba Corp, IEEE Dielect & Elect Insulat Soc ID MIXTURES C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Wang, YC (reprint author), Natl Inst Stand & Technol, 100 Bureau Dr,Mail Stop 8113, Gaithersburg, MD 20899 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA BN 0-306-46705-4 PY 2001 BP 49 EP 54 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Atomic, Molecular & Chemical SC Engineering; Physics GA BT88X UT WOS:000174363400006 ER PT B AU Christophorou, LG Olthoff, JK AF Christophorou, LG Olthoff, JK BE Christophorou, LG Olthoff, JK TI Electron interactions with c-C4F8 SO GASEOUS DIELECTRICS IX LA English DT Proceedings Paper CT 9th International Symposium on Gaseous Dielectrics CY MAY 21-25, 2001 CL ELLICOTT CITY, MD SP Natl Inst Stand & Technol, ABB, USAF Res Lab, Hitachi Ltd, Kansai Elect Power Co, Toshiba Corp, IEEE Dielect & Elect Insulat Soc ID ATTACHMENT C1 Natl Inst Stand & Technol, Div Elect, Elect & Elect Engn Lab, Gaithersburg, MD 20899 USA. RP Christophorou, LG (reprint author), Natl Inst Stand & Technol, Div Elect, Elect & Elect Engn Lab, 100 Bureau Dr,Mail Stop 8113, Gaithersburg, MD 20899 USA. NR 26 TC 0 Z9 0 U1 0 U2 1 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA BN 0-306-46705-4 PY 2001 BP 63 EP 74 PG 12 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Atomic, Molecular & Chemical SC Engineering; Physics GA BT88X UT WOS:000174363400008 ER PT J AU Gharrett, AJ Lane, S McGregor, AJ Taylor, SG AF Gharrett, AJ Lane, S McGregor, AJ Taylor, SG TI Use of a genetic marker to examine genetic interaction among subpopulations of pink salmon (Oncorhynchus gorbuscha) SO GENETICA LA English DT Article DE allozyme; gene flow; genetic marking; hatchery; introgression; pink salmon; salmonid; straying ID OUTBREEDING DEPRESSION; GREAT-LAKES; FISH; POPULATIONS; SURVIVAL; HYBRIDS; ALASKA AB In 1979 and 1981, a genetic marker was bred into one of the five identifiable subpopulations of pink salmon [Oncorhynchus gorbuscha (Walbaum)] in the Auke Lake drainage in Southeast Alaska. As a result of the marking effort, the frequencies of two malate dehydrogenase (MDH-B1, 2*) alleles were changed in the marked subpopulation, but not in other subpopulations that spawn at different times or places. Between 1983 and 1989, the marker allele frequencies were monitored in many of these subpopulations and in early- and late-run pink salmon spawning in nearby Waydelich Creek, located approximately 1 km away. Changes in allele frequencies at MDH-B1, 2*, used to obtain direct estimates of average migration rates (m) from the marked to the unmarked subpopulations, revealed little or no introgression into early subpopulations or into nearby Waydelich Creek. Moreover, spatially distinct late-run Auke Creek subpopulations were not immediately overrun by the more abundant marked subpopulation. These observations suggest that genetic isolation exists between temporally distinct spawning runs and that small temporal and spatial (or ecological) differences contribute to population structure. These observations should be considered in taking actions that affect conservation and harvest management or extensive culture of salmonids. C1 Univ Alaska, Sch Fisheries & Ocean Sci, Div Fisheries, Juneau, AK 99801 USA. US Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. Taku Smokeries, Juneau, AK 99801 USA. Alaska Dept Fish & Game, Commercial Fisheries Div, Douglas, AK 99824 USA. RP Gharrett, AJ (reprint author), Univ Alaska, Sch Fisheries & Ocean Sci, Div Fisheries, 11120 Glacier Highway, Juneau, AK 99801 USA. EM ffajg@uaf.edu NR 35 TC 10 Z9 12 U1 0 U2 8 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0016-6707 J9 GENETICA JI Genetica PY 2001 VL 111 IS 1-3 BP 259 EP 267 DI 10.1023/A:1013791314900 PG 9 WC Genetics & Heredity SC Genetics & Heredity GA 511NJ UT WOS:000173270000021 PM 11841171 ER PT J AU Hotinski, RM Bice, KL Kump, LR Najjar, RG Arthur, MA AF Hotinski, RM Bice, KL Kump, LR Najjar, RG Arthur, MA TI Ocean stagnation and end-Permian anoxia SO GEOLOGY LA English DT Article DE Permian; anoxia; ocean circulation; phosphate cycle; oxygen cycle ID TRIASSIC MASS EXTINCTION; EARLY DIAGENESIS; BOUNDARY; WATER; MODEL; CIRCULATION; PHOSPHORUS; SEDIMENTS; EVOLUTION; NUTRIENT AB Ocean stagnation has been invoked to explain the widespread occurrence of organic-carbon-rich, laminated sediments interpreted to have been deposited under anoxic bottom waters at the time of the end-Permian mass extinction. However, to a first approximation, stagnation would severely reduce the upwelling supply of nutrients to the photic zone, reducing productivity. Moreover, it is not obvious that ocean stagnation can be achieved. Numerical experiments performed with st three-dimensional global ocean model linked to a biogeochemical model of phosphate and oxygen cycling indicate that a low equator to pole temperature gradient could have produced weak oceanic circulation and widespread anoxia in the Late Permian ocean. We find that polar warming and tropical cooling of sea-surface temperatures cause anoxia throughout the deep ocean as a result of both lower dissolved oxygen in bottom source waters and increased nutrient utilization. Buildup of quantities of H2S and CO2 in the Late Permian ocean sufficient to directly cause a mass extinction, however, would have required large increases in the oceanic nutrient inventory. C1 Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. RP Hotinski, RM (reprint author), Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. RI Kump, Lee/H-8287-2012; Arthur, Michael/E-2872-2014 OI Arthur, Michael/0000-0002-3028-6279 NR 31 TC 131 Z9 137 U1 3 U2 40 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD JAN PY 2001 VL 29 IS 1 BP 7 EP 10 DI 10.1130/0091-7613(2001)029<0007:OSAEPA>2.0.CO;2 PG 4 WC Geology SC Geology GA 392ZA UT WOS:000166441700002 ER PT B AU Beechie, TJ Collins, BD Pess, GR AF Beechie, TJ Collins, BD Pess, GR BE Dorava, JM Montgomery, DR Palcsak, BB Fitzpatrick, FA TI Holocene and recent geomorphic processes, land use, and salmonid habitat in two North Puget Sound river basins SO GEOMORPHIC PROCESSES AND RIVERINE HABITAT SE WATER SCIENCE AND APPLICATION LA English DT Proceedings Paper CT Fall Meeting of the American-Geophysical-Union CY DEC 06-10, 1998 CL SAN FRANCISCO, CA SP Amer Geophys Union ID MOUNT ST-HELENS; LARGE WOODY DEBRIS; CHANNEL HYDRAULICS; PACIFIC-NORTHWEST; 1980 ERUPTION; ICE-SHEET; WASHINGTON; STREAMS; MORPHOLOGY; CALIFORNIA AB The quantity, quality, and distribution of salmonid habitats in the Skagit and Stillaguamish River basins have changed dramatically in response to post-glacial landscape evolution and volcanism over the last 16,000 years, and the more recent history of land use (approximately 150 years). After retreat of the Cordilleran ice sheet about 16,000 years ago, streams incised rapidly into valley-filling glacial sediments, lowering valley floors and creating terraces. Mainstems and floodplain sloughs on valley floors provided the majority of habitat, but moderate-gradient tributaries on terraces provided additional habitat for some salmonids. Channels in bedrock terrain were too steep to support anadromous salmonids and remain so today. Voluminous lahars from Glacier Peak approximately 5,500 years before present created an extensive low-gradient delta on the Skagit River, which then developed abundant habitats in wetlands and distributary channels. Since non-Native American settlers arrived in the mid-1800s, removal of beaver ponds, diking, ditching, and dredging of streams on the floodplains and deltas has isolated or obliterated approximately 50% of the coho salmon winter rearing habitat in both basins. These losses are associated mainly with agricultural practices, which occupy the same landforms as the majority of historical coho salmon habitat. Forestry activities are concentrated on the steeper slopes of the glacial sediments and bedrock terrain, and contribute to habitat losses by increasing sediment supplies and reducing wood abundance. Understanding the interplay of Holocene landscape evolution, geomorphic processes, land use, and salmonid habitat provides a context for developing habitat restoration programs. C1 NW Fisheries Sci Ctr, Watershed Program, Seattle, WA 98112 USA. RP Beechie, TJ (reprint author), NW Fisheries Sci Ctr, Watershed Program, Seattle, WA 98112 USA. NR 57 TC 38 Z9 38 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA BN 0-87590-353-3 J9 WATER SCI APPL PY 2001 VL 4 BP 37 EP 54 PG 18 WC Ecology; Geography, Physical; Geology; Water Resources SC Environmental Sciences & Ecology; Physical Geography; Geology; Water Resources GA BV90G UT WOS:000180348500005 ER PT J AU Goni, GJ Johns, WE AF Goni, GJ Johns, WE TI A census of North Brazil Current rings observed from TOPEX/POSEIDON altimetry: 1992-1998 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CURRENT RETROFLECTION; GEOSAT ALTIMETRY; ATLANTIC; VARIABILITY; OCEAN AB Six years of TOPEX/POSEIDON altimeter data are used to investigate the formation of rings and eddies shed by the North Brazil Current. Upper layer thickness maps were used to identify 34 of these features formed in the North Brazil Current retroflection region, an average of more than 5 rings and eddies per year. The ensemble of ring trajectories closely parallels the 500 m isobath, and one out of six rings penetrate into the Caribbean Sea through the southern Lesser Antilles. The rest of the rings and eddies follow a northern trajectory past Barbados once they reach 58W. Their estimated mean translation speed is 14 km/day and their mean length scale is approximately 100 km. Our results suggest that the formation rate of NBC rings and eddies is nearly twice that previously thought, and that they may account for more than 1/3 of the interhemispheric transport within the Atlantic meridional overturning cell. C1 US Dept Commerce, NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. RP Goni, GJ (reprint author), US Dept Commerce, NOAA, Atlantic Oceanog & Meteorol Lab, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Goni, Gustavo/D-2017-2012 OI Goni, Gustavo/0000-0001-7093-3170 NR 12 TC 67 Z9 67 U1 2 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 JAN 1 PY 2001 VL 28 IS 1 BP 1 EP 4 DI 10.1029/2000GL011717 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 390JD UT WOS:000166291200002 ER PT J AU Gao, Y Kaufman, YJ Tanre, D Kolber, D Falkowski, PG AF Gao, Y Kaufman, YJ Tanre, D Kolber, D Falkowski, PG TI Seasonal distributions of aeolian iron fluxes to the global ocean SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EQUATORIAL PACIFIC-OCEAN; ATMOSPHERIC TRANSPORT; NORTH PACIFIC; SEA-SALT; AEROSOL; DUST; DEPOSITION; CLIMATE; EVENTS; CO2 AB Among the factors affecting the photosynthetic rate of marine phytoplankton, aeolian iron (Fe) fluxes appear to be critical in several large regions of the global ocean. Here we present an analysis of in situ aerosol iron data obtained from a wide variety of marine locations to quantify the seasonal Fe inputs to the global ocean. When extrapolated to the global ocean, our results indicate strong seasonal variations in aeolian Fe fluxes in different oceanic basins. The predominant fraction of the Fe inputs enters the oceans in the Northern Hemisphere, with the summer flux rates ca. twice those of winter. The high Fe fluxes in the Northern Hemisphere are concentrated in low and mid-latitudes. With the promising new data from MODIS aboard the Terra satellite, the linkage between Fe fluxes and phytoplankton biomass and productivity may be soon further quantified. C1 Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08901 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Lille 1, Opt Atmospher Lab, F-59655 Villeneuve Dascq, France. Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Gao, Y (reprint author), Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08901 USA. NR 25 TC 119 Z9 124 U1 1 U2 20 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 JAN 1 PY 2001 VL 28 IS 1 BP 29 EP 32 DI 10.1029/2000GL011926 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 390JD UT WOS:000166291200009 ER PT J AU Toivanen, PK Baker, DN Peterson, WK Singer, HJ Turner, NE Li, X Kauristie, K Syrjasuo, M Viljanen, A Pulkkinen, TI Keiling, A Wygant, JR Kletzing, CA AF Toivanen, PK Baker, DN Peterson, WK Singer, HJ Turner, NE Li, X Kauristie, K Syrjasuo, M Viljanen, A Pulkkinen, TI Keiling, A Wygant, JR Kletzing, CA TI Reconciliation of the substorm onset determined on the ground and at the Polar spacecraft SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INSTRUMENT; PARTICLE; MISSION; MODEL AB An isolated substorm on Oct. 17, 1997 during a close conjunction of the Polar spacecraft and the ground-based MIRACLE network is studied in detail. We identify signatures of substorm onset in the plasma sheet midway between the ionosphere and the equatorial plasma sheet, determine their timing relative to the ground signatures, and discuss their counterparts on the ground and in the equatorial plasma sheet. The substorm onset is determined as the negative bay onset at 2040:42(+/- 5 sec) UT coinciding with the onset of auroral precipitation, energization of plasma sheet electrons at Polar, and strong magnetic field variations perpendicular to the ambient field. Such accurate timing coincidence is consistent with the Alfven transit time between Polar and the ionosphere. Furthermore, the timing of other field and particle signatures at Polar showed clear deviations from the onset time (+/- 2 min). This suggests that the sequence of these signatures around the onset time can be used to validate the signatures predicted by various substorm onset models. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Lockheed Martin Space Sci Lab, Palo Alto, CA USA. NOAA, Space Environm Ctr, Boulder, CO USA. Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. RP Toivanen, PK (reprint author), Univ Colorado, Atmospher & Space Phys Lab, 1234 Innovat Dr, Boulder, CO 80309 USA. RI Syrjasuo, Mikko/E-5088-2012; Peterson, WK/A-8706-2009; Pulkkinen, Tuija/D-8403-2012; OI Peterson, WK/0000-0002-1513-6096; Pulkkinen, Tuija/0000-0002-6317-381X; Kletzing, Craig/0000-0002-4136-3348; Turner, Niescja/0000-0002-3280-4260 NR 16 TC 4 Z9 4 U1 0 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 JAN 1 PY 2001 VL 28 IS 1 BP 107 EP 110 DI 10.1029/2000GL000099 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 390JD UT WOS:000166291200029 ER PT J AU Dyar, MD Wiedenbeck, M Robertson, D Cross, LR Delaney, JS Ferguson, K Francis, CA Grew, ES Guidotti, CV Hervig, RL Hughes, JM Husler, J Leeman, W McGuire, AV Rhede, D Rothe, H Paul, RL Richards, I Yates, M AF Dyar, MD Wiedenbeck, M Robertson, D Cross, LR Delaney, JS Ferguson, K Francis, CA Grew, ES Guidotti, CV Hervig, RL Hughes, JM Husler, J Leeman, W McGuire, AV Rhede, D Rothe, H Paul, RL Richards, I Yates, M TI Reference minerals for the Microanalysis of light elements SO GEOSTANDARDS NEWSLETTER-THE JOURNAL OF GEOSTANDARDS AND GEOANALYSIS LA English DT Article DE light elements; tourmaline; danburite; spodumene; muscovite; isotopes ID QUADRUPOLE SPLITTING DISTRIBUTIONS; GAMMA NEUTRON-ACTIVATION; BORON ISOTOPIC ANALYSIS; ION MASS-SPECTROMETRY; MOSSBAUER-SPECTROSCOPY; RAY SPECTROMETRY; X-RAY; MICROPROBE; EXTRACTION; TOURMALINE AB The quantitative determination of light element concentrations in geological specimens represents a major analytical challenge as the electron probe is generally not suited to this tasks With the development of new in situ analytical techniques, and in particular the increasing use of secondary ion mass spectrometry, the routine determination of Li, Be and B contents has become a realistic goal. However, a major obstacle to the development of this research field is the critical dependence of SIMS on the availability of well characterized, homogeneous reference materials that are closely matched in matrix (composition and structure) to the sample being studied. Here we report the first results from a suite of large, gem crystals which cover a broad spectrum of minerals in which light elements are major constituents. We have characterized these materials using both in situ and wet chemical techniques. The samples described here are intended for distribution to geochemical laboratories active in the study of light elements. Further work is needed before reference values for these materials can be finalized, but the availability of this suite of materials represents a major step toward the routine analysis of the light element contents of geological specimens. C1 Mt Holyoke Coll, Dept Earth & Environm, S Hadley, MA 01075 USA. Geoforschungszentrum Potsdam, D-14473 Potsdam, Germany. Univ Missouri, Dept Chem, Columbia, MO 65211 USA. Univ Kentucky, Dept Chem, Lexington, KY 40506 USA. Rutgers State Univ, Dept Geol Sci, Piscataway, NJ 08855 USA. So Methodist Univ, Dept Geol Sci, Dallas, TX 75275 USA. Harvard Univ, Mineral Museum, Cambridge, MA 02138 USA. Univ Maine, Dept Geol Sci, Orono, ME 04469 USA. Arizona State Univ, Ctr Solid State Sci, Tempe, AZ 85287 USA. Miami Univ, Dept Geol, Oxford, OH 45056 USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. Rice Univ, Dept Geol & Geophys, Houston, TX 77005 USA. Univ Houston, Dept Geosci, Houston, TX 77204 USA. NIST, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Dyar, MD (reprint author), Mt Holyoke Coll, Dept Earth & Environm, S Hadley, MA 01075 USA. EM mdyar@mtholyoke.edu NR 77 TC 87 Z9 88 U1 1 U2 13 PU GEOSTANDARDS PI VANDOEUVRE NANCY PA 15 RUE NOTRE-DAME-DES-PAUVRES BP 20, 54501 VANDOEUVRE NANCY, FRANCE SN 0150-5505 J9 GEOSTANDARD NEWSLETT JI Geostand. Newsl. PY 2001 VL 25 IS 2-3 BP 441 EP 463 DI 10.1111/j.1751-908X.2001.tb00616.x PG 23 WC Geosciences, Multidisciplinary SC Geology GA 525GD UT WOS:000174059800026 ER PT S AU Flater, D AF Flater, D BE Mo, JPT Nemes, L TI Specifying interactions in integrated manufacturing systems SO GLOBAL ENGINEERING, MANUFACTURING AND ENTERPRISE NETWORKS SE INTERNATIONAL FEDERATION FOR INFORMATION PROCESSING LA English DT Proceedings Paper CT 4th International Working Conference on the Design of Information Infrastructure Systems for Manufacturing (DIISM 2000) CY NOV 15-17, 2000 CL MELBOURNE, AUSTRALIA SP Int Federation Informat Processing, TC5, WG5 3, 5 7, 5 12 DE component; integration; modelling; specification AB Systems of manufacturing software are often constructed by integrating preexisting software components. Accurate specification of the component interactions in these systems is needed to ensure testability and maintainability. Moreover, standards for manufacturing systems must specify the interactions to achieve interoperability and substitutability of components. In this report we discuss approaches for specifying component interactions and examine a number of potentially useful specification techniques. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Flater, D (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBLISHERS PI NORWELL PA 101 PHILIP DRIVE, ASSINIPPI PARK, NORWELL, MA 02061 USA SN 1571-5736 BN 0-7923-7358-8 J9 INT FED INFO PROC PY 2001 VL 63 BP 103 EP 110 PG 8 WC Engineering, Industrial; Engineering, Manufacturing; Management SC Engineering; Business & Economics GA BS37R UT WOS:000169679700012 ER PT S AU Denno, P AF Denno, P BE Mo, JPT Nemes, L TI Modelling requirements for self-integrating manufacturing systems SO GLOBAL ENGINEERING, MANUFACTURING AND ENTERPRISE NETWORKS SE INTERNATIONAL FEDERATION FOR INFORMATION PROCESSING LA English DT Proceedings Paper CT 4th International Working Conference on the Design of Information Infrastructure Systems for Manufacturing (DIISM 2000) CY NOV 15-17, 2000 CL MELBOURNE, AUSTRALIA SP Int Federation Informat Processing, TC5, WG5 3, 5 7, 5 12 DE self-integrating systems; information infrastructure; self-describing systems AB This paper discusses modelling requirements to support self-integrating manufacturing systems. Integration requires reconciliation of mismatch in various forms of context. Four forms of mismatch involving software components and aspect of the enterprise are identified. Although the paper stops short of describing a complete solution, aspects of the solution, as they relate to the four forms of mismatch, are discussed. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Denno, P (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBLISHERS PI NORWELL PA 101 PHILIP DRIVE, ASSINIPPI PARK, NORWELL, MA 02061 USA SN 1571-5736 BN 0-7923-7358-8 J9 INT FED INFO PROC PY 2001 VL 63 BP 137 EP 144 PG 8 WC Engineering, Industrial; Engineering, Manufacturing; Management SC Engineering; Business & Economics GA BS37R UT WOS:000169679700016 ER PT S AU Lee, S Griffith, D Coussot, V Su, D AF Lee, S Griffith, D Coussot, V Su, D GP IEEE IEEE TI ER-LSP setup for multi-service in lambda labeling network SO GLOBECOM '01: IEEE GLOBAL TELECOMMUNICATIONS CONFERENCE, VOLS 1-6 SE IEEE Global Telecommunications Conference (Globecom) LA English DT Proceedings Paper CT IEEE Global Telecommunications Conference (GLOBECOM 01) CY NOV 25-29, 2001 CL SAN ANTONIO, TX SP IEEE, Fujitsu Network Commun, SBC Commun Inc, Siemens, CIENA Corp, Corning Cable Syst, Nortel Networks, Tellabs AB Generalized Multiprotocol Label Switching (GMPLS) is being applied to optical networks as a means of moving control functionality from the management plane to the control plane, and automating lightpath provisioning and maintenance. GMPLS enables IP networks with Quality of Service (QoS) to be traffic engineered efficiently. However, computation of explicitly-defined paths optimizing network performance is a difficult task. Previous versions of these optimization routines have not taken path delay, including queueing delay at layer 3, into account. In this paper we present a technique for traffic engineering in optical networks that support QoS considering the traffic flows with delay QoS constraint across lambda labeling networks. The proposed mechanism would facilitate lam a label path setup with specific dealy QoS requirements. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Lee, S (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8920, Gaithersburg, MD 20899 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1930-529X BN 0-7803-7206-9 J9 GLOB TELECOMM CONF PY 2001 BP 81 EP 85 DI 10.1109/GLOCOM.2001.965084 PG 5 WC Optics; Telecommunications SC Optics; Telecommunications GA BV36Z UT WOS:000178714800016 ER PT S AU Golmie, N Chevrollier, N ElBakkouri, I AF Golmie, N Chevrollier, N ElBakkouri, I GP IEEE IEEE TI Interference aware bluetooth packet scheduling SO GLOBECOM '01: IEEE GLOBAL TELECOMMUNICATIONS CONFERENCE, VOLS 1-6 SE IEEE Global Telecommunications Conference (Globecom) LA English DT Proceedings Paper CT IEEE Global Telecommunications Conference (GLOBECOM 01) CY NOV 25-29, 2001 CL SAN ANTONIO, TX SP IEEE, Fujitsu Network Commun, SBC Commun Inc, Siemens, CIENA Corp, Corning Cable Syst, Nortel Networks, Tellabs DE WPANs; bluetooth; interference; max-min fairness; scheduling AB Bluetooth is a radio technology for Wireless Personal Area Networks operating in the 2.4 GHz: ISM band. Since both Bluetooth and IEEE 802.11 devices use the same frequency band and may likely come together in a laptop or may be close together at a desktop, interference may lead to significant performance degradation. The main goal of this paper is to propose a scheduling algorithm aimed at reducing the impact of interference. This algorithm takes advantage of the fact that devices in the same piconet will not be subject to the same levels of interference on all channels of the band. The basic idea is to utilize the Bluetooth frequency hopping pattern and distribute channels to devices such that to maximize their throughput while ensuring fairness of access among users. Simulation results are given for selected scenarios and configurations of interest. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1930-529X BN 0-7803-7206-9 J9 GLOB TELECOMM CONF PY 2001 BP 2857 EP 2863 PG 7 WC Optics; Telecommunications SC Optics; Telecommunications GA BV36Z UT WOS:000178714800550 ER PT S AU Soltanian, A Van Dyck, RE AF Soltanian, A Van Dyck, RE GP IEEE IEEE TI Performance of the bluetooth system in fading dispersive channels and interference SO GLOBECOM '01: IEEE GLOBAL TELECOMMUNICATIONS CONFERENCE, VOLS 1-6 SE IEEE Global Telecommunications Conference (Globecom) LA English DT Proceedings Paper CT IEEE Global Telecommunications Conference (GLOBECOM 01) CY NOV 25-29, 2001 CL SAN ANTONIO, TX SP IEEE, Fujitsu Network Commun, SBC Commun Inc, Siemens, CIENA Corp, Corning Cable Syst, Nortel Networks, Tellabs ID GHZ AB A noncoherent limiter-discriminator receiver is often considered for the Bluetooth system because of its simplicity and low cost While its performance is more than adequate for some channels, the results are significantly degraded in either an interference-limited environment or a frequency selective channel. In this paper, we compare the performance of the traditional limiter-discriminator with integrate and dump filter to a more sophisticated Viterbi receiver. We find that the Bluetooth access code is sufficient to be used for channel estimation in the Viterbi receiver. A comparison is carried out in a Rayleigh fading channel and in the presence of interference either from another Bluetooth piconet or an IEEE 802.11b wireless local area network. Performance metrics include bit error rate and packet loss rate. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 12 TC 6 Z9 6 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1930-529X BN 0-7803-7206-9 J9 GLOB TELECOMM CONF PY 2001 BP 3499 EP 3503 PG 5 WC Optics; Telecommunications SC Optics; Telecommunications GA BV36Z UT WOS:000178714800671 ER PT S AU Ott, WR AF Ott, WR BE Londono, C TI 100 years of optical science and metrology at NIST SO HARNESSING LIGHT: OPTICAL SCIENCE AND METROLOGY AT NIST SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Harnessing Light: Optical Science and Metrology at NIST CY AUG 01, 2001 CL SAN DIEGO, CA SP SPIE DE history; lasers; metrology; optical science; NBS; NIST; photometry; radiometry; spectroscopy; standards ID VACUUM ULTRAVIOLET RADIOMETRY; SPECTRAL RADIANCE; LASER WAVELENGTH; HYDROGEN ARCS; CALIBRATIONS; FREQUENCY; STANDARD; DETECTOR; ACCURACY; COMB AB The National Bureau of Standards (NBS) was formed by Congress 100 years ago. The early "Bureau" was a small organization, founded at the beginning of the age of electricity to promote industrial productivity, commerce, technological progress, and the quality of life. It provided a basis for standardizing the measurements and products that are so important to a nation's infrastructure. The original staff numbered 12. There were 15 offices and laboratories. Five areas of optics have been important elements of the Bureau's research for almost its entire history: atomic and molecular spectroscopy; radiometry; colorimetry; optical properties of materials; and, for the last 40 years, laser science and applications. Research and measurement services have supported national programs ranging from the manufacture of high quality optical glass during two World Wars to the calibration of spectrometers on the Hubble Space Telescope. Pioneers in optical science and metrology at NBS/NIST include many well known scientists, ranging from William Coblentz, who established the field of optical radiometry during his 40 year career from 1905-1945, to William Phillips, who received the Nobel Prize in Physics in 1997 for his research on the laser cooling and trapping of atoms. C1 Natl Inst Stand & Technol, Technol Adm, US Dept Commerce, Phys Lab, Gaithersburg, MD 20899 USA. RP Ott, WR (reprint author), Natl Inst Stand & Technol, Technol Adm, US Dept Commerce, Phys Lab, Gaithersburg, MD 20899 USA. NR 52 TC 0 Z9 0 U1 1 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4164-3 J9 P SOC PHOTO-OPT INS PY 2001 VL 4450 BP 1 EP 14 DI 10.1117/12.431243 PG 14 WC Optics SC Optics GA BT36X UT WOS:000172808800001 ER PT S AU Hardis, JE AF Hardis, JE BE Londono, C TI 100 years of photometry and radiometry SO HARNESSING LIGHT: OPTICAL SCIENCE AND METROLOGY AT NIST SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Harnessing Light: Optical Science and Metrology at NIST CY AUG 01, 2001 CL SAN DIEGO, CA SP SPIE DE photometry; radiometry; blackbody radiation; candela; NIST history ID FUNDAMENTAL PHYSICAL CONSTANTS; CODATA RECOMMENDED VALUES; CRYOGENIC RADIOMETER; SPECTRAL-IRRADIANCE; SCALE AB Measurement of light is an old subject, though the past 100 years have seen significant advances. 100 years ago, photometry-the art and science of measuring light as it is perceived by people-had the greater technological importance. Even today, SI (the metric system) retains a base unit for photometry, the candela. However, early work at NBS included pivotal projects in the field of radiometry-the measurement of the physical characteristics of light. These included the validation of Planck's newly-minted theory of blackbody radiation, determining the radiation constants with good accuracy, and the definitive analysis of the spectral responsivity of human vision, so as to relate photometry to radiometry. This latter work has only increased in importance over the past 75 years as the definition of the candela has changed and improved. Today, NIST makes radiometric, and hence photometric measurements, with unprecedented precision. Cryogenic radiometers based on the principle of electrical substitution measure optical flux with uncertainties of 0.02 %. Additional facilities enable measurement of spectral responsivity, spectral radiance, and spectral irradiance. Novel detectors, such as light-traps, allow the best accuracy to be transferred from the primary standards to routinely-used instruments and to calibration customers. Filtered detectors are used to realize photometric scales, radiation temperature scales, and other, specialized measurements. Indeed, the story of the metrology of light is the story of continuous improvement, both driven by and enabled by advances in technology. We touch upon some of these as a prelude to the other talks in this Conference. C1 Natl Inst Stand & Technol, Technol Adm, US Dept Commerce, Phys Lab, Gaithersburg, MD 20899 USA. RP Hardis, JE (reprint author), Natl Inst Stand & Technol, Technol Adm, US Dept Commerce, Phys Lab, Gaithersburg, MD 20899 USA. NR 44 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4164-3 J9 P SOC PHOTO-OPT INS PY 2001 VL 4450 BP 15 EP 32 DI 10.1117/12.431250 PG 18 WC Optics SC Optics GA BT36X UT WOS:000172808800002 ER PT S AU Day, GW AF Day, GW BE Londono, C TI Metrology for the optoelectronics industry SO HARNESSING LIGHT: OPTICAL SCIENCE AND METROLOGY AT NIST SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Harnessing Light: Optical Science and Metrology at NIST CY AUG 01, 2001 CL SAN DIEGO, CA SP SPIE DE lasers; metrology; optical communications; optoelectronics ID WAVELENGTH; DETECTOR; DESIGN AB The National Institute of Standards and Technology (NIST) provides measurement technology, standards, and traceability for much of the optoelectronics industry. This paper covers its support for two major industry segments, the laser industry and the optical communications industry. C1 Natl Inst Stand & Technol, Div Optoelect, Boulder, CO 80305 USA. RP Day, GW (reprint author), Natl Inst Stand & Technol, Div Optoelect, 325 Broadway, Boulder, CO 80305 USA. NR 62 TC 1 Z9 1 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4164-3 J9 P SOC PHOTO-OPT INS PY 2001 VL 4450 BP 33 EP 43 DI 10.1117/12.431251 PG 11 WC Optics SC Optics GA BT36X UT WOS:000172808800003 ER PT S AU Kelley, EF AF Kelley, EF BE Londono, C TI Electronic display metrology - Not a simple matter SO HARNESSING LIGHT: OPTICAL SCIENCE AND METROLOGY AT NIST SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Harnessing Light: Optical Science and Metrology at NIST CY AUG 01, 2001 CL SAN DIEGO, CA SP SPIE DE display metrology; haze; NIST; reflection measurements; stray light; veiling glare AB Most would assume that the characterization of electronic display quality would be a straightforward process offering few complications. However, what the eye sees can be very difficult to capture accurately and quickly in a meaningful way. With the advent of many new display technologies, there is a need for a level playing field so that different technologies can be compared on an equivalent basis. Orchestrating display metrology to accomplish this is wrought with several difficulties that will be reviewed especially in the areas of stray light management/measurement and meaningful reflection characterization. C1 NIST, Gaithersburg, MD 20899 USA. RP Kelley, EF (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4164-3 J9 P SOC PHOTO-OPT INS PY 2001 VL 4450 BP 44 EP 53 DI 10.1117/12.431252 PG 10 WC Optics SC Optics GA BT36X UT WOS:000172808800004 ER PT S AU Hollberg, L Diddams, SA Curtis, EA Oates, CW Fox, RW AF Hollberg, L Diddams, SA Curtis, EA Oates, CW Fox, RW BE Londono, C TI Optical frequency standards for clocks of the future SO HARNESSING LIGHT: OPTICAL SCIENCE AND METROLOGY AT NIST SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Harnessing Light: Optical Science and Metrology at NIST CY AUG 01, 2001 CL SAN DIEGO, CA SP SPIE DE atomic clocks; optical frequency standards; stable lasers; cold atoms ID MONO-ION OSCILLATOR; RAMSEY FRINGES; SATURATED ABSORPTION; LASER; SPECTROSCOPY; STABILIZATION; RESOLUTION; PHASE AB Now scientific insight and technological developments of the past few years have stimulated renewed enthusiasm for the development of optical frequency standards. Long-standing problems have now been eliminated, and it appears that frequency standards using stable lasers and optical transitions may someday replace modem atomic clocks that are based on microwave transitions. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Hollberg, L (reprint author), Natl Inst Stand & Technol, Boulder, CO 80305 USA. RI Diddams, Scott/L-2819-2013 NR 26 TC 0 Z9 0 U1 0 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4164-3 J9 P SOC PHOTO-OPT INS PY 2001 VL 4450 BP 54 EP 59 DI 10.1117/12.431253 PG 6 WC Optics SC Optics GA BT36X UT WOS:000172808800005 ER PT S AU Cornell, EA Haljan, PC AF Cornell, EA Haljan, PC BE Londono, C TI The ultra-low temperature magnifying glass: How Bose-Einstein condensation makes quantum mechanics visible SO HARNESSING LIGHT: OPTICAL SCIENCE AND METROLOGY AT NIST SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Harnessing Light: Optical Science and Metrology at NIST CY AUG 01, 2001 CL SAN DIEGO, CA SP SPIE DE Bose-Einstein condensation; vortex AB Experiments in Bose-Einstein condensation provide an unusually direct view of the working of quantum wave mechanics. We make use of two internal states of Rb-87 to engineer desired wavefunction patterns, and with the use of simple optical imaging, we characterize the results of these efforts. C1 Natl Inst Stand & Technol, Quantum Phys Div, Boulder, CO 80309 USA. RP Cornell, EA (reprint author), Natl Inst Stand & Technol, Quantum Phys Div, 325 Broadway, Boulder, CO 80309 USA. NR 14 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4164-3 J9 P SOC PHOTO-OPT INS PY 2001 VL 4450 BP 60 EP 69 DI 10.1117/12.431254 PG 10 WC Optics SC Optics GA BT36X UT WOS:000172808800006 ER PT S AU Goldner, LS Weston, KD Heinz, WF Hwang, JS DeJong, ES Marino, JP AF Goldner, LS Weston, KD Heinz, WF Hwang, JS DeJong, ES Marino, JP BE Londono, C TI Single molecule probes SO HARNESSING LIGHT: OPTICAL SCIENCE AND METROLOGY AT NIST SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Harnessing Light: Optical Science and Metrology at NIST CY AUG 01, 2001 CL SAN DIEGO, CA SP SPIE DE confocal microscopy; single molecule; fluorescence; RNA; polymers ID FLUORESCENCE CORRELATION SPECTROSCOPY; SCANNING OPTICAL MICROSCOPY; RESONANCE ENERGY-TRANSFER; ROOM-TEMPERATURE; POLYMER-FILMS; POLARIZATION-MODULATION; LIVING CELLS; DYNAMICS; SURFACE; POLYSTYRENE AB The technology to rapidly manipulate and screen individual molecules lies at the frontier of measurement science, with impacts in bio- and nano-technology. Fundamental biological and chemical processes can now be probed with unprecedented detail, one molecule at a time. These "single molecule probes" are most often fluorescent dye molecules embedded in a material or attached to a target molecule, such as a protein or nucleic acid, whose behavior is under study. The fluorescence from a single dye molecule can be detected, its spectrum and lifetime measured and its absorption or emission dipole calculated. From this information, the rotational and translational dynamics of the fluorophore can be calculated, as can details of its photophysics. To the extent that these properties reflect the properties of the target molecule, we can use these fluorescent tags to probe the dynamics and structure of the target. In this work we discuss the dependence of the physical and photophysical dynamics of fluorescent molecules on their local environment, and we use confocal microscopy to study single molecules in thin films, on surfaces, and in various liquid and gaseous environments. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Goldner, LS (reprint author), NIST Stop 8441, Gaithersburg, MD 20899 USA. NR 52 TC 1 Z9 1 U1 1 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4164-3 J9 P SOC PHOTO-OPT INS PY 2001 VL 4450 BP 70 EP 80 DI 10.1117/12.431255 PG 11 WC Optics SC Optics GA BT36X UT WOS:000172808800007 ER PT S AU Evans, CJ Davies, A Schmitz, T Parks, RE AF Evans, CJ Davies, A Schmitz, T Parks, RE BE Londono, C TI Interferometric figure metrology; enabling in-house traceability SO HARNESSING LIGHT: OPTICAL SCIENCE AND METROLOGY AT NIST SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Harnessing Light: Optical Science and Metrology at NIST CY AUG 01, 2001 CL SAN DIEGO, CA SP SPIE DE traceability; uncertainty; interferometer; wavefront; figure ID FIZEAU INTERFEROMETER AB The basic goal of the Advanced Optics Metrology program in NIST's Manufacturing Engineering Laboratory is to help industry ensure that their measurement results of optical figure and wavefront are traceable. This paper underscores the importance of traceability and reviews the facilities and projects dedicated to achieving that objective. C1 Natl Inst Stand & Technol, Mfg Metrol Div, Gaithersburg, MD 20899 USA. RP Evans, CJ (reprint author), Natl Inst Stand & Technol, Mfg Metrol Div, Stop 8220, Gaithersburg, MD 20899 USA. NR 17 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4164-3 J9 P SOC PHOTO-OPT INS PY 2001 VL 4450 BP 81 EP 93 DI 10.1117/12.431256 PG 13 WC Optics SC Optics GA BT36X UT WOS:000172808800008 ER PT S AU Tarrio, C Vest, RE Grantham, S AF Tarrio, C Vest, RE Grantham, S BE Londono, C TI Absolute extreme-ultraviolet metrology SO HARNESSING LIGHT: OPTICAL SCIENCE AND METROLOGY AT NIST SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Harnessing Light: Optical Science and Metrology at NIST CY AUG 01, 2001 CL SAN DIEGO, CA SP SPIE DE extreme ultraviolet; metrology; reflectometry; radiometry; synchrotron radiation; lithography ID SILICON PHOTODIODES; CALIBRATION FACILITY; OPTICAL-CONSTANTS; SURF-II; REGION; REFLECTION; COATINGS AB NIST has a long-standing program for the calibration of extreme ultraviolet optical components. Early activities, which began with the advent of the Synchrotron Ultraviolet Radiation Facility (SURF) almost 40 years ago, centered on the development and characterization of detectors for extreme ultraviolet (EUV) radiation. About a decade ago the program was expanded to include reflectometry of normal-incidence EUV multilayer optics. Both calibrated detectors and EUV optics are used by researchers in private industry, academia, and government, in such diverse fields as EUV lithography, astronomy, and plasma physics. Since the inception of SURF, nearly 800 transfer standard photodiodes have been issued to customers, and over 500 measurements of other EUV optical components have been made. NIST researchers, in collaboration with U.S. companies, have developed new, high-quality radiometric detectors for use throughout the EUV spectral range. We will discuss the history of NIST's involvement in EUV metrology and offer examples of our recent work. C1 Natl Inst Stand & Technol, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. RP Tarrio, C (reprint author), Natl Inst Stand & Technol, Div Electron & Opt Phys, Gaithersburg, MD 20899 USA. NR 33 TC 5 Z9 5 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4164-3 J9 P SOC PHOTO-OPT INS PY 2001 VL 4450 BP 94 EP 107 DI 10.1117/12.431244 PG 14 WC Optics SC Optics GA BT36X UT WOS:000172808800009 ER PT S AU Rice, JP Johnson, BC AF Rice, JP Johnson, BC BE Londono, C TI NIST activities in support of space-based radiometric remote sensing SO HARNESSING LIGHT: OPTICAL SCIENCE AND METROLOGY AT NIST SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Harnessing Light: Optical Science and Metrology at NIST CY AUG 01, 2001 CL SAN DIEGO, CA SP SPIE DE remote sensing; environment; defense; radiometry; aerospace; calibration ID STANDARDS-AND-TECHNOLOGY; INFRARED INTEGRATING SPHERE; SEAWIFS QUALITY MONITOR; LIGHT-SOURCE; CALIBRATION; RADIANCE; FACILITY; SENSORS AB We provide an historical overview of NIST research and development in radiometry for space-based remote sensing. The applications in this field can be generally divided into two areas: environmental and defense. In the environmental remote sensing area, NIST has had programs with agencies such as the National Aeronautical and Space Administration. (NASA) and the National Oceanic and Atmospheric Administration (NOAA) to verify and improve traceability of the radiometric calibration of sensors that fly on board Earth-observing satellites. These produce data used in climate models and weather prediction. Over the years, the scope of activities has expanded from existing routine calibration services for artifacts such as lamps, diffusers, and filters, to development and off-site deployment of portable radiometers for radiance- and irradiance-scale intercomparisons. In the defense remote sensing area, NIST has had programs with agencies such as the Department of Defense (DOD) for support of calibration of small, low-level infrared sources in a low infrared background. These are used by the aerospace industry to simulate ballistic missiles in a cold space background. Activities have evolved from calibration of point-source cryogenic blackbodies at NIST to measurement of irradiance in off-site calibration chambers by a portable vacuum/cryogenic radiometer. Both areas of application required measurements on the cutting edge of what was technically feasible, thus compelling NIST to develop a state-of-the-art radiometric measurement infrastructure to meet the needs. This infrastructure has led to improved dissemination of the NIST spectroradiometric quantities. C1 Natl Inst Stand & Technol, Technol Adm, US Dept Commerce, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Rice, JP (reprint author), Natl Inst Stand & Technol, Technol Adm, US Dept Commerce, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 58 TC 17 Z9 17 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4164-3 J9 P SOC PHOTO-OPT INS PY 2001 VL 4450 BP 108 EP 126 DI 10.1117/12.431245 PG 19 WC Optics SC Optics GA BT36X UT WOS:000172808800010 ER PT S AU Reader, J AF Reader, J BE Londono, C TI Atomic spectroscopy at NIST - 2001 SO HARNESSING LIGHT: OPTICAL SCIENCE AND METROLOGY AT NIST SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Harnessing Light: Optical Science and Metrology at NIST CY AUG 01, 2001 CL SAN DIEGO, CA SP SPIE DE wavelengths; energy levels; high-resolution spectrometers; laser spectroscopy; databases ID LASER AB The program in atomic spectroscopy at NIST continues to provide accurate reference data on spectral lines and energy levels for a wide variety of important applications. With spectrometers that can record spectra from the extreme ultraviolet (1 nm) to the infrared (18 000 nm), we can measure spectra over a large spectral range. Most of these spectrometers are the most powerful of their type in the world. We recently used our 10.7-m normal-incidence vacuum spectrograph to make precision measurements of the wavelengths of lasing lines in a commercial molecular fluorine laser at 157 nm. These results establish standard values to be applied in the design of optics for microlithography at this wavelength. Our high resolution Fourier transform spectrometer is being used to measure wavelengths and transition probabilities for rare-earth atoms and ions that are used as additives in the production of high intensity discharge lamps. The data allow lamp designers to model the processes occurring in the discharge. Our 10.7-m grazing incidence spectrograph is being used to obtain data for diagnostics of magnetic fusion research plasmas as well as for astronomical applications such as the Chandra X-ray Observatory. Precision laser spectroscopy on neutral Li is being carried out to test the validity of quantum electrodynamics (QED) calculations. Finally, we are continuing to carry out critical compilations of wavelengths, energy levels, and transition probabilities and to improve our Atomic Spectra Database on the World Wide Web. These data activities support many applications throughout industry and the scientific community. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Reader, J (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 22 TC 0 Z9 0 U1 2 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4164-3 J9 P SOC PHOTO-OPT INS PY 2001 VL 4450 BP 127 EP 139 DI 10.1117/12.431246 PG 13 WC Optics SC Optics GA BT36X UT WOS:000172808800011 ER PT J AU Romanyukha, AA Nagy, V Sleptchonok, O Desrosiers, MF Jiang, JJ Heiss, A AF Romanyukha, AA Nagy, V Sleptchonok, O Desrosiers, MF Jiang, JJ Heiss, A TI Individual biodosimetry at the natural radiation background level SO HEALTH PHYSICS LA English DT Article DE dose assessment; detection limits; radiation, background; exposure, radiation AB The present note describes new advancements to a valued tool in retrospective biodosimetry that lower the threshold of detection of radiation dose to 29 mGy. The advanced method is based on the electron paramagnetic resonance measurements of stable radiation-induced radicals in tooth enamel. Earlier this method had been used only for reconstruction of high radiation doses obtained accidentally. New opportunity of reconstruction of doses lower than 100 mGy opens a new realm of possibilities for assessing the health effects of ionizing radiation at the natural radiation background level. C1 Natl Inst Stand & Technol, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. Bruker Instruments Inc, EPR Div, Billerica, MA 01821 USA. NR 11 TC 20 Z9 22 U1 0 U2 3 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD JAN PY 2001 VL 80 IS 1 BP 71 EP 73 DI 10.1097/00004032-200101000-00013 PG 3 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 383ZB UT WOS:000165913600013 PM 11204121 ER PT J AU Yashar, DA Wilson, MJ Kopke, HR Graham, DM Chato, JC Newell, TA AF Yashar, DA Wilson, MJ Kopke, HR Graham, DM Chato, JC Newell, TA TI An investigation of refrigerant void fraction in horizontal, microfin tubes SO HVAC&R RESEARCH LA English DT Article ID PRESSURE-DROP; HEAT-TRANSFER; CONDENSATION; FLOW AB A series of experiments to determine void fraction in both condensation and evaporation have been performed in horizontal microfin tubes with refrigerants R134a and R410A. Mass flux varied from 75 kg/m(2).s to 700 kg/m(2).s and average rest section quality varied from 5% to 80%. Zero degree (axial grooving) and 18 degree helix microfin tube configurations have been examined in both condensation and evaporation. Four tubes were examined (7.3 mm and 8.9 mm diameters with axial and 18 degree helix angle microfins). Evaporation and adiabatic conditions in microfin tubes generally show similar void fraction trends found in smooth tubes. Condensation results for microfin tubes show a lower void fraction than smooth tubes. C1 Natl Inst Stand & Technol, US Dept Commerce, Gaithersburg, MD 20899 USA. Univ Illinois, Dept Mech & Ind Engn, Urbana, IL 61801 USA. RP Yashar, DA (reprint author), Natl Inst Stand & Technol, US Dept Commerce, Gaithersburg, MD 20899 USA. NR 33 TC 23 Z9 24 U1 3 U2 6 PU AMER SOC HEATING REFRIGERATING AIR-CONDITIONING ENG, INC, PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 USA SN 1078-9669 J9 HVAC&R RES JI HVAC&R Res. PD JAN PY 2001 VL 7 IS 1 BP 67 EP 82 DI 10.1080/10789669.2001.10391430 PG 16 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA 407KW UT WOS:000167271600006 ER PT J AU Peterson, WT AF Peterson, WT TI Patterns in stage duration and development among marine and freshwater calanoid and cyclopoid copepods: a review of rules, physiological constraints, and evolutionary significance SO HYDROBIOLOGIA LA English DT Review DE copepod development; isochronal development; developmental constraints ID LONG-ISLAND SOUND; PLANKTONIC COPEPODS; EGG-PRODUCTION; POPULATION-DYNAMICS; EQUIPROPORTIONAL DEVELOPMENT; PSEUDOCALANUS-ELONGATUS; CRUSTACEAN ZOOPLANKTON; TEMORA-LONGICORNIS; EUTROPHIC INLET; ACARTIA-TONSA AB Studies of development time of marine and freshwater copepods have taken separate tracks. Most studies on marine copepods report development time of each individual development stage, whereas studies on freshwater copepods report only development time, from egg to nauplius and nauplius to adult. This bias allows comparison of total development time but prevents detailed comparisons of patterns in stage-specific developmental schedules. With respect to egg to adult development time, three general relationships are known: developmental rates are dependent upon temperature and food concentration but independent of terminal body size; freshwater calanoids develop significantly slower than marine calanoids; freshwater cyclopoids develop at the same rate as marine calanoids. Two rules describe stage-specific developmental rates: the equiproportional rule and the isochronal rule. The first rule states that the duration of a given life history stage is a constant proportion of the embryonic development time; the second rule states that the time spent in each stage is the same for all stages. This review focuses on the second rule. From the 80+ published studies of copepod stage-specific developmental times, no species follows the isochronal rule strictly: Acartia spp. come closest with isochronal development from third nauplius (N3) to fourth copepodite (C4). The only pattern followed by all species is rapid development of the first and/or second naupliar stages, slow development of the second and/or third nauplius and prolonged development of the final copepodite stage. Once adulthood is reached, males are usually short-lived, but females can live for weeks to months in the laboratory. Adult longevity in the sea is, however, on the order of only a few days. The evolution of developmental patterns is discussed in the context of physiological constraints, along with consideration of possible relationships between stage-specific mortality rates and life history strategies. Physiological constraints may operate at critical bottlenecks in development (e.g. at the first feeding nauplius, N6, and the fifth copepodite stage). High mortality of eggs may explain why broadcast eggs hatch 2-3 times faster than eggs carried by females in a sac; high mortality of adults may explain why adults do not grow rather they maximize their reproductive effort by partitioning all energy for growth into egg production. C1 Natl Marine Fisheries Serv, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. RP Peterson, WT (reprint author), Natl Marine Fisheries Serv, Hatfield Marine Sci Ctr, 2030 S Marine Sci Dr, Newport, OR 97365 USA. EM bill.peterson@noaa.gov NR 69 TC 55 Z9 60 U1 1 U2 26 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PY 2001 VL 453 IS 1-3 BP 91 EP 105 DI 10.1023/A:1013111832700 PG 15 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 499ZD UT WOS:000172600200008 ER PT J AU Jentschura, UD Mohr, PJ Soff, G AF Jentschura, UD Mohr, PJ Soff, G TI Calculation of QED effects in hydrogen SO HYPERFINE INTERACTIONS LA English DT Article; Proceedings Paper CT Conference on Atomic Physics at Accelerators: Mass Spectrometry (APAC 2000) CY SEP 19-23, 2000 CL CARGESE, FRANCE DE quantum electrodynamics; specific calculations ID FREQUENCY AB Atomic mass differences are influenced by QED corrections, and a reliable understanding of these corrections is therefore of importance for the current and next generation of high-precision mass determinations based on Penning traps. We present a numerical evaluation of the self-energy correction, which is the dominant contribution to the Lamb shift, in the region of low nuclear charge. Our calculation is nonperturbative in the binding field and has a numerical uncertainty of 0.8 Hz in atomic hydrogen for the ground state and of 1.0 Hz for L-shell states (2S(1/2), 2P(1/2), and 2P(3/2)). C1 Tech Univ Dresden, Inst Theoret Phys, D-01062 Dresden, Germany. Lab Kastler Brossel, F-75252 Paris 05, France. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Jentschura, UD (reprint author), Tech Univ Dresden, Inst Theoret Phys, D-01062 Dresden, Germany. NR 5 TC 1 Z9 1 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0304-3843 J9 HYPERFINE INTERACT JI Hyperfine Interact. PY 2001 VL 132 IS 1-4 BP 375 EP 377 PG 3 WC Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Physics, Nuclear SC Physics GA 492CC UT WOS:000172148900037 ER PT B AU Ball, A AF Ball, A BE Markham, JW Duda, AL TI IAMSLIC Linking Libraries Project SO IAMSLIC 2000: TIDES OF TECHNOLOGY SE INTERNATIONAL ASSOCIATION OF MARINE SCIENCE LIBRARIES AND INFORMATION CENTERS CONFERENCE SERIES LA English DT Meeting Abstract CT 26th Annual Conference of the International-Association-of-Aquatic-and-Marine-Science-Libraries-and-In formation-Centers CY SEP 30-OCT 05, 2000 CL VICTORIA, CANADA SP Int Assoc Aquat & Marine Sci Lib & Informat Ctr C1 NOAA, Coastal Serv Ctr, Informat Resources, Charleston, SC 29405 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT ASSOC MARINE SCIENCE LIBRARIES & INFORMATION CENTER PI FORT PIERCE PA C/O HBOI LIBRARY, 5600 OLD DIXIE HWY, FORT PIERCE, FL 34946 USA J9 IAMSLIC CON PY 2001 BP 63 EP 65 PG 3 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA BS21F UT WOS:000169088200011 ER PT B AU Pikula, L Cantillo, A Hale, K AF Pikula, L Cantillo, A Hale, K BE Markham, JW Duda, AL TI CEDAR: Data and document rescue - Coastal and Estuarine Data/Document Archeology and Rescue SO IAMSLIC 2000: TIDES OF TECHNOLOGY SE INTERNATIONAL ASSOCIATION OF MARINE SCIENCE LIBRARIES AND INFORMATION CENTERS CONFERENCE SERIES LA English DT Meeting Abstract CT 26th Annual Conference of the International-Association-of-Aquatic-and-Marine-Science-Libraries-and-In formation-Centers CY SEP 30-OCT 05, 2000 CL VICTORIA, CANADA SP Int Assoc Aquat & Marine Sci Lib & Informat Ctr C1 NOAA, NODC, LISD, Miami, FL 33149 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT ASSOC MARINE SCIENCE LIBRARIES & INFORMATION CENTER PI FORT PIERCE PA C/O HBOI LIBRARY, 5600 OLD DIXIE HWY, FORT PIERCE, FL 34946 USA J9 IAMSLIC CON PY 2001 BP 146 EP 147 PG 2 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA BS21F UT WOS:000169088200033 ER PT B AU Poole-Kober, EM AF Poole-Kober, EM BE Markham, JW Duda, AL TI Atmospheric Science Librarians International (ASLI) - Professional organization for atmospheric science librarians SO IAMSLIC 2000: TIDES OF TECHNOLOGY SE INTERNATIONAL ASSOCIATION OF MARINE SCIENCE LIBRARIES AND INFORMATION CENTERS CONFERENCE SERIES LA English DT Meeting Abstract CT 26th Annual Conference of the International-Association-of-Aquatic-and-Marine-Science-Libraries-and-In formation-Centers CY SEP 30-OCT 05, 2000 CL VICTORIA, CANADA SP Int Assoc Aquat & Marine Sci Lib & Informat Ctr C1 NOAA, Air Resources Lab, Atmospher Sci Modeling Div, Res Triangle Pk, NC 27711 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT ASSOC MARINE SCIENCE LIBRARIES & INFORMATION CENTER PI FORT PIERCE PA C/O HBOI LIBRARY, 5600 OLD DIXIE HWY, FORT PIERCE, FL 34946 USA J9 IAMSLIC CON PY 2001 BP 148 EP 148 PG 1 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA BS21F UT WOS:000169088200034 ER PT B AU Guillaume, N Kiihamaki, J Karttunen, J Kattelus, H AF Guillaume, N Kiihamaki, J Karttunen, J Kattelus, H GP IEEE IEEE TI Use of electrical test structures to characterize trench profiles etched on SOI wafers SO ICMTS 2001: PROCEEDINGS OF THE 2001 INTERNATIONAL CONFERENCE ON MICROELECTRONIC TEST STRUCTURES LA English DT Proceedings Paper CT 14th International Conference on Microelectronic Test Structures (ICMTS 2001) CY MAR 19-22, 2001 CL KOBE, JAPAN SP IEEE Electron Divices Soc AB This paper demonstrates the use of electrical test structures patterned on Silicon-On-Insulator (SOI) material to evaluate the performance of the plasma etching process. Electrical characterization is performed by capacitance and resistance measurements. The measurements are used to compare the etch results of slightly varied plasma etch processes. Subtle differences in submicron trench profiles are very difficult to distinguish and quantify when using scanning electron microscopy (SEM). The electrical measurements can reveal these differences which facilitates the etch process development. Experimental results are presented and compared to cross-sectional SEM analysis. The goal of the development of test structures presented here is to establish a fast, low cost, and non-destructive method to characterize and optimize deep trench etching process cycles needed in the fabrication of micromachined devices. C1 George Washington Univ, NIST, Washington, DC 20037 USA. RP Guillaume, N (reprint author), George Washington Univ, NIST, Washington, DC 20037 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6511-9 PY 2001 BP 159 EP 164 DI 10.1109/ICMTS.2001.928655 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BS56J UT WOS:000170336100029 ER PT B AU Cresswell, MW Arora, N Allen, RA Murabito, CE Richter, CA Gupta, A Linholm, LW Pachura, D Bendix, P AF Cresswell, MW Arora, N Allen, RA Murabito, CE Richter, CA Gupta, A Linholm, LW Pachura, D Bendix, P GP IEEE IEEE TI Test chip for electrical linewidth of copper-interconnect features and related parameters SO ICMTS 2001: PROCEEDINGS OF THE 2001 INTERNATIONAL CONFERENCE ON MICROELECTRONIC TEST STRUCTURES LA English DT Proceedings Paper CT 14th International Conference on Microelectronic Test Structures (ICMTS 2001) CY MAR 19-22, 2001 CL KOBE, JAPAN SP IEEE Electron Divices Soc C1 Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Cresswell, MW (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6511-9 PY 2001 BP 183 EP 188 DI 10.1109/ICMTS.2001.928659 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BS56J UT WOS:000170336100033 ER PT J AU Richter, CA Hefner, AR Vogel, EM AF Richter, CA Hefner, AR Vogel, EM TI A comparison of quantum-mechanical capacitance-voltage simulators SO IEEE ELECTRON DEVICE LETTERS LA English DT Article DE capacitance; effective oxide thickness; gate dielectric; inversion quantization; MOS devices; polysilicon depletion ID OXIDE THICKNESS; DEVICES AB We have systematically compared the results of an extensive ensemble of the most advanced available quantum-mechanical capacitance-voltage (C-V) simulation and analysis packages for a range of metal-oxide-semiconductor device parameters. While all have similar trends accounting for polysilicon depletion and quantum-mechanical confinement, quantitatively, there is a difference of up to 20 % in the calculated accumulation capacitance for devices with ultrathin gate dielectrics. This discrepancy leads to large inaccuracies in the values of dielectric thickness extracted from capacitance measurements and illustrates the importance of consistency during C-V analysis and the need to fully report how such analysis is done. C1 Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Richter, CA (reprint author), Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. EM Curt.Richter@NIST.Gov RI Vogel, Eric/A-7731-2008 OI Vogel, Eric/0000-0002-6110-1361 NR 10 TC 61 Z9 64 U1 0 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0741-3106 J9 IEEE ELECTR DEVICE L JI IEEE Electron Device Lett. PD JAN PY 2001 VL 22 IS 1 BP 35 EP 37 DI 10.1109/55.892436 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 387TE UT WOS:000166137300012 ER PT B AU Lipe, TE AF Lipe, TE GP IEEE IEEE TI Recent developments in the NIST AC-DC difference calibration service for thermal transfer standards SO IEEE SYSTEMS READINESS TECHNOLOGY CONFERENCE: 2001 IEEE AUTOTESTCON PROCEEDINGS LA English DT Proceedings Paper CT 37th Annual AUTOTESTCON Conference CY AUG 20-23, 2001 CL VALLEY FORGE, PA SP IEEE, Aerosp & Electr Syst Soc, Instrumentat & Measurement Soc, IEEE Philadelphia Sect DE ac-dc difference; binary divider; current shunt; thermal converter; thermal transfer; transition edge sensor AB This paper presents a brief summary of the ac-dc difference calibration service for thermal transfer standards at the National Institute of Standards and Technology in Gaithersburg, MD. Related topics discussed include automated calibration systems, research into a new cryogenic thermal transfer standard, fabrication of thermal converters using semiconductor processing techniques, and a high-voltage comparator system based on a binary inductive voltage divider. C1 Natl Inst Stand & Technol, Div Elect, Gaithersburg, MD 20899 USA. RP Lipe, TE (reprint author), Natl Inst Stand & Technol, Div Elect, 100 Bur Dr,Mail Stop 8111, Gaithersburg, MD 20899 USA. EM thomas.lipe@nist.gov NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7094-5 PY 2001 BP 105 EP 114 DI 10.1109/AUTEST.2001.948924 PG 10 WC Engineering, Aerospace; Computer Science, Interdisciplinary Applications; Engineering, Industrial; Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Computer Science; Instruments & Instrumentation GA BT20K UT WOS:000172264000010 ER PT J AU Corbella, I Gasiewski, AJ Klein, M Piepmeier, JR AF Corbella, I Gasiewski, AJ Klein, M Piepmeier, JR TI Compensation of elevation angle variations in polarimetric brightness temperature measurements from airborne microwave radiometers SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE calibration; radiometry ID MODEL AB This paper presents a method for compensating the elevation angle fluctuations occurring in airborne radiometry due to aircraft roll and pitch. The correction is based on a radiative transfer model, and is demonstrated by real data from conical scans over the ocean, showing good results. C1 Univ Politecn Catalunya, ES-08034 Barcelona, Spain. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Georgia Inst Technol, Sch Elect Engn & Comp Engn, Atlanta, GA 30332 USA. RP Corbella, I (reprint author), Univ Politecn Catalunya, ES-08034 Barcelona, Spain. RI Corbella, Ignasi/E-9578-2013 OI Corbella, Ignasi/0000-0001-5598-7955 NR 7 TC 7 Z9 7 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2001 VL 39 IS 1 BP 193 EP 195 DI 10.1109/36.898683 PG 3 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 398CJ UT WOS:000166738100022 ER PT J AU Bayne, SB Portnoy, WM Hefner, AR AF Bayne, SB Portnoy, WM Hefner, AR TI MOS-gated thyristors (MCTs) for repetitive high power switching SO IEEE TRANSACTIONS ON POWER ELECTRONICS LA English DT Article DE high power; power semiconductor switching; reliability; repetitive pulsing AB Certain applications for pulse power require narrow, high current pulses for their implementation. This work was performed to determine if MOS controlled thyristors (MCTs) could be used for these applications. The MCTs were tested as discharge switches in a low inductance circuit delivering 1 mus pulses at currents between roughly 3 kA and 11kA, single shot and repetitively at 1, 10, and 50 Hz, Although up to 9000 switching events could be obtained, all the devices failed at some combination of current and repetition rate, Failure was attributed to termperature increases caused by average power dissipated in the thyristor during the switching sequence, A simulation was performed to confirm that the temperature rise was sufficient to account for failure. Considerable heat sinking, and perhaps a better thermal package, would be required before the MCT could be considered for pulse power applications. C1 Texas Tech Univ, Dept Elect Engn, Lubbock, TX 79409 USA. Natl Inst Stand & Technol, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Bayne, SB (reprint author), USA, Res Lab, Adelphi, MD 20783 USA. NR 11 TC 2 Z9 2 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-8993 J9 IEEE T POWER ELECTR JI IEEE Trans. Power Electron. PD JAN PY 2001 VL 16 IS 1 BP 125 EP 131 DI 10.1109/63.903997 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA 403ZZ UT WOS:000167074100015 ER PT J AU Remley, KA Anderson, HR Weisshaar, A AF Remley, KA Anderson, HR Weisshaar, A TI Improving the accuracy of ray-tracing techniques for indoor propagation modeling (vol 49, p 2350, 2000) SO IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY LA English DT Correction C1 Natl Inst Stand & Technol, RF Technol Div, Boulder, CO 80303 USA. EDX Engn Inc, Eugene, OR 97440 USA. Oregon State Univ, Corvallis, OR 97331 USA. RP Remley, KA (reprint author), Natl Inst Stand & Technol, RF Technol Div, 325 Broadway, Boulder, CO 80303 USA. NR 1 TC 0 Z9 0 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9545 J9 IEEE T VEH TECHNOL JI IEEE Trans. Veh. Technol. PD JAN PY 2001 VL 50 IS 1 BP 335 EP 335 DI 10.1109/TVT.2001.917962 PG 1 WC Engineering, Electrical & Electronic; Telecommunications; Transportation Science & Technology SC Engineering; Telecommunications; Transportation GA 423KM UT WOS:000168175500034 ER PT B AU Wood, HM AF Wood, HM GP IEEE IEEE TI The use of earth observing satellites for hazard support SO IGARSS 2001: SCANNING THE PRESENT AND RESOLVING THE FUTURE, VOLS 1-7, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 09-13, 2001 CL UNIV NEW S WALES, SYDNEY, AUSTRALIA SP IEEE, IEEE, Geosci & Remote Sensing Soc, NASA, US Dept Commerce, Natl Ocean & Atmosphere Adm, CSA ASC, Off Naval Res, RSPAA, URSI HO UNIV NEW S WALES AB Weather satellites have long been used to support forecasting of intensive weather hazards such as tropical cyclones, severe storms and flash flooding. Although there have been numerous research and operational demonstrations that illustrate the potential usefulness of EO satellite data for a broader range of hazards, the operational application of these data to other hazards is rare. Recognizing the benefits that could be gained from better application of EO satellite data to natural and technological hazards, the Committee of Earth Observation Satellites (CEOs) initiated a project for disaster management support. The project has published two annual reports. Since the last report was published, the project has become an ad hoc working group. This paper summarizes the work of the ad hoc working group. A full report of the work of the group is in the group's first annual report which is available from the author of this paper. C1 NOAA, Suitland, MD 20746 USA. RP Wood, HM (reprint author), NOAA, Code E-SP,Room 1069,FB-4,5200 Auth Rd, Suitland, MD 20746 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7031-7 J9 INT GEOSCI REMOTE SE PY 2001 BP 135 EP 137 PG 3 WC Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Remote Sensing SC Engineering; Geology; Remote Sensing GA BU88J UT WOS:000177297200043 ER PT B AU Pichel, WG McGuire, J Taube, D AF Pichel, WG McGuire, J Taube, D GP IEEE IEEE TI User requirements for an ocean observation satellite system SO IGARSS 2001: SCANNING THE PRESENT AND RESOLVING THE FUTURE, VOLS 1-7, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 09-13, 2001 CL UNIV NEW S WALES, SYDNEY, AUSTRALIA SP IEEE, IEEE, Geosci & Remote Sensing Soc, NASA, US Dept Commerce, Natl Ocean & Atmosphere Adm, CSA ASC, Off Naval Res, RSPAA, URSI HO UNIV NEW S WALES AB A summary of an on-going study of a U.S. Ocean Observer Satellite System is presented. Included are the genesis and scope of the study, details of how the measurement requirements were developed, a summary of the Ocean Observer User Requirements Document, and a sketch of the notional instruments that have been proposed to meet the observational requirements. C1 NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD 20746 USA. RP Pichel, WG (reprint author), NOAA, NESDIS, Off Res & Applicat, ERA3,Room 102 WWBG,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Pichel, William/F-5619-2010 OI Pichel, William/0000-0001-6332-0149 NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7031-7 J9 INT GEOSCI REMOTE SE PY 2001 BP 239 EP 242 PG 4 WC Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Remote Sensing SC Engineering; Geology; Remote Sensing GA BU88J UT WOS:000177297200076 ER PT B AU Hardesty, RM Senff, CJ Banta, RM Brewer, WA Alvarez, RJ Darby, LS Marchbanks, RD AF Hardesty, RM Senff, CJ Banta, RM Brewer, WA Alvarez, RJ Darby, LS Marchbanks, RD GP IEEE IEEE TI Lidar applications in regional air quality studies SO IGARSS 2001: SCANNING THE PRESENT AND RESOLVING THE FUTURE, VOLS 1-7, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 09-13, 2001 CL UNIV NEW S WALES, SYDNEY, AUSTRALIA SP IEEE, IEEE, Geosci & Remote Sensing Soc, NASA, US Dept Commerce, Natl Ocean & Atmosphere Adm, CSA ASC, Off Naval Res, RSPAA, URSI HO UNIV NEW S WALES ID OZONE AB During recent air quality studies in the United States, NOAA's Environmental Technology Laboratory (ETL) deployed three lidars to improve characterization of the regional environment. An airborne ozone DIAL system mapped out 3-dimensional profiles of ozone and aerosol, enabling tracking of urban plumes, identification of the residual layer, and specification of ozone production efficiency and dispersion associated with power plant plumes. At surface sites, Doppler and ozone DIAL systems characterized the time evolution of wind profiles, turbulence, vertical mixing, horizontal transport from low level flows, and effects of transient events such as gust front passages. The lidar information greatly complemented observations from airborne and surface in situ sensors, and will be critical for improving understanding and modeling of regional air quality events. C1 NOAA, Environm Technol Lab, Boulder, CO 80305 USA. RP Hardesty, RM (reprint author), NOAA, Environm Technol Lab, R-E-ET2,325 Broadway, Boulder, CO 80305 USA. RI Darby, Lisa/A-8037-2009; Hardesty, Robert/H-9844-2013; Brewer, Wm Alan/I-3920-2013; Alvarez, Raul/I-4879-2013; Senff, Christoph/I-2592-2013; Marchbanks, Richard/I-4410-2013 OI Darby, Lisa/0000-0003-1271-0643; NR 3 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7031-7 J9 INT GEOSCI REMOTE SE PY 2001 BP 1029 EP 1031 PG 3 WC Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Remote Sensing SC Engineering; Geology; Remote Sensing GA BU88J UT WOS:000177297200323 ER PT B AU Li, XF He, MX Pichel, WG Zeng, K Friedman, KS Colon, PC Wang, LB Zhao, CF AF Li, XF He, MX Pichel, WG Zeng, K Friedman, KS Colon, PC Wang, LB Zhao, CF GP IEEE IEEE TI Analysis of oceanic long wave refraction at the Gulf Stream boundary using RADARSAT Synthetic Aperture Radar during Hurricane Bonnie SO IGARSS 2001: SCANNING THE PRESENT AND RESOLVING THE FUTURE, VOLS 1-7, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 09-13, 2001 CL UNIV NEW S WALES, SYDNEY, AUSTRALIA SP IEEE, IEEE, Geosci & Remote Sensing Soc, NASA, US Dept Commerce, Natl Ocean & Atmosphere Adm, CSA ASC, Off Naval Res, RSPAA, URSI HO UNIV NEW S WALES AB In this study, we analyze the Gulf Stream's effect on the refraction of ocean waves observed in data obtained from the RADARSAT Synthetic Aperture Radar (SAR). The ocean waves observed on this SAR image have very long wavelengths and are mainly generated by Hurricane Bonnie which was located to the east of the Gulf Stream when the SAR image was taken. 256 by 256 pixel sub-images are extracted from the SAR image, and the SAR image spectrum is calculated from these sub-images. The SAR image spectrum should represent the directional ocean wave spectrum in this case, because the dominant wavelength is very long at about 400 m. A wave-current interaction model is used to simulate the wave refraction and reflection at the Gulf Stream boundary. We rind that wave refraction is the dominant mechanism at the Gulf Stream boundary for these very long oceanic waves, while wave reflection is not a dominant factor. The waves turn about 15 degrees from their original direction. C1 NOAA, NESDIS, ERA3, WWBG, Camp Springs, MD 20746 USA. RP Li, XF (reprint author), NOAA, NESDIS, ERA3, WWBG, Room 102,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Pichel, William/F-5619-2010; Li, Xiaofeng/B-6524-2008 OI Pichel, William/0000-0001-6332-0149; Li, Xiaofeng/0000-0001-7038-5119 NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7031-7 J9 INT GEOSCI REMOTE SE PY 2001 BP 1225 EP 1227 PG 3 WC Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Remote Sensing SC Engineering; Geology; Remote Sensing GA BU88J UT WOS:000177297200387 ER PT B AU Raizer, VY AF Raizer, VY GP IEEE IEEE TI Passive microwave radiometry, fractals, and ocean dynamics SO IGARSS 2001: SCANNING THE PRESENT AND RESOLVING THE FUTURE, VOLS 1-7, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing IGARSS LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 09-13, 2001 CL UNIV NEW S WALES, SYDNEY, AUSTRALIA SP IEEE, IEEE, Geosci & Remote Sensing Soc, NASA, US Dept Commerce, Natl Ocean & Atmosphere Adm, CSA ASC, Off Naval Res, RSPAA, URSI HO UNIV NEW S WALES ID SURFACE AB An idea to explore fractal structures in the field of the ocean microwave radiance is suggested. To solve this problem we must be able to relate natural ocean surface features to their thermal microwave emission signatures. This task has two problems: 1) the study of hydrodynamic fractal structures in the ocean, and 2) the creation of an adequate microwave imaging model. One possibility is to consider a fractal model of the ocean surface with scaling (power law) wave number spectra. Microwave emission effects from a rough water surface are calculated quite using a small-perturbation approach well known in the ocean passive microwave radiometry. Combined computer simulations allow us to generate microwave fractal images and local patterns. Some related experimental data have been found recently during the polarimetric scanning radiometer measurements. C1 NOAA, Environm Technol Lab, Sci & Technol Corp, Fairfax, VA 22032 USA. RP Raizer, VY (reprint author), NOAA, Environm Technol Lab, Sci & Technol Corp, 10281 Friendship Court, Fairfax, VA 22032 USA. EM vraizer@aol.com NR 11 TC 1 Z9 1 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7031-7 J9 INT GEOSCI REMOTE SE PY 2001 BP 1240 EP 1242 PG 3 WC Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Remote Sensing SC Engineering; Geology; Remote Sensing GA BU88J UT WOS:000177297200392 ER PT B AU Raizer, VY AF Raizer, VY GP IEEE IEEE TI Modeling of sea-roughness radiometric effects for the retrieval of surface salinity at 14.3 GHz SO IGARSS 2001: SCANNING THE PRESENT AND RESOLVING THE FUTURE, VOLS 1-7, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 09-13, 2001 CL UNIV NEW S WALES, SYDNEY, AUSTRALIA SP IEEE, IEEE, Geosci & Remote Sensing Soc, NASA, US Dept Commerce, Natl Ocean & Atmosphere Adm, CSA ASC, Off Naval Res, RSPAA, URSI HO UNIV NEW S WALES ID MICROWAVE AB In this study, we consider an advanced variant of electromagnetic model of a rough surface with the goal to provide numerical modeling of the salinity-temperature radiometric contrasts. These calculations are made especially at the wavelength 21 cm (14.3 GHz) and the nadir incidence angle for low-wind (< 7 m/s) and foam-free sea conditions. In these cases, passive microwave radiometric measurements perhaps are the best suited for the sea salinity mapping and the retrieval with quite accuracy. Some numerical examples of salinity radiometric effects are presented. C1 NOAA, Environm Technol Lab, Sci & Technol Corp, Fairfax, VA 22032 USA. RP Raizer, VY (reprint author), NOAA, Environm Technol Lab, Sci & Technol Corp, 10281 Friendship Court, Fairfax, VA 22032 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7031-7 J9 INT GEOSCI REMOTE SE PY 2001 BP 1761 EP 1763 PG 3 WC Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Remote Sensing SC Engineering; Geology; Remote Sensing GA BU88J UT WOS:000177297200562 ER PT B AU Friedman, KS Wackerman, C Funk, F Pichel, WG Clemente-Colon, P Li, XF AF Friedman, KS Wackerman, C Funk, F Pichel, WG Clemente-Colon, P Li, XF GP IEEE IEEE TI Validation of a CFAR vessel detection algorithm using known vessel locations SO IGARSS 2001: SCANNING THE PRESENT AND RESOLVING THE FUTURE, VOLS 1-7, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 09-13, 2001 CL UNIV NEW S WALES, SYDNEY, AUSTRALIA SP IEEE, IEEE, Geosci & Remote Sensing Soc, NASA, US Dept Commerce, Natl Ocean & Atmosphere Adm, CSA ASC, Off Naval Res, RSPAA, URSI HO UNIV NEW S WALES AB The National Oceanic and Atmospheric Administration (NOAA)/National Environmental Satellite, Data, and Information Service (NESDIS) is in the second year of a two-year demonstration of Synthetic Aperture Radar (SAR) derived products called the Alaska SAR Demonstration (AKDEMO). This demonstration provides near real-time SAR data and derived products, including wind images and vectors, hard target locations, along with ancillary data, to specific users in the government community. One of the derived products are vessel positions obtained from a constant false alarm rate (CFAR) vessel detection algorithm developed by Veridian E RI NI. This algorithm has been tested and validated to maximize the number of ships found while minimizing the number or false alarms on one SAR image of the Red King Crab fishery in Bristol Bay on October 18, 1999. This resulted in using a detection statistic threshold of about 5.5, depending on image resolution used. Until now, this validation has been done with only general knowledge of fishing fleet size and location, but no in situ vessel information. During the Red King Crab Fishery in Bristol Bay in October 2000, twenty-one Alaska Department of Fish and Game fishery observers recorded the position of the vessels they occupied (and sometimes the wind speed), during two ScanSAR overpasses on October 18 and 19, 2000. These ScanSAR passes, with a width of 480 km, cover the region of the fishery and many of the vessels with recorded positions. This paper presents the results of a validation of the SAR vessel detection algorithm using these observer reported vessel positions along with information on vessel size and local wind speed. C1 NOAA, Caelum Res Corp, WWBG, Camp Springs, MD 20746 USA. RP Friedman, KS (reprint author), NOAA, Caelum Res Corp, WWBG, E-RA3,Room 102, Camp Springs, MD 20746 USA. RI Clemente-Colon, Pablo/F-5581-2010; Pichel, William/F-5619-2010; Li, Xiaofeng/B-6524-2008 OI Pichel, William/0000-0001-6332-0149; Li, Xiaofeng/0000-0001-7038-5119 NR 3 TC 6 Z9 8 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7031-7 J9 INT GEOSCI REMOTE SE PY 2001 BP 1804 EP 1806 PG 3 WC Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Remote Sensing SC Engineering; Geology; Remote Sensing GA BU88J UT WOS:000177297200576 ER PT B AU Clemente-Colon, P AF Clemente-Colon, P GP IEEE IEEE TI Evolution of upwelling-associated biological features in the Middle Atlantic sight as captured by SAR, SST, and ocean color sensors SO IGARSS 2001: SCANNING THE PRESENT AND RESOLVING THE FUTURE, VOLS 1-7, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 09-13, 2001 CL UNIV NEW S WALES, SYDNEY, AUSTRALIA SP IEEE, IEEE, Geosci & Remote Sensing Soc, NASA, US Dept Commerce, Natl Ocean & Atmosphere Adm, CSA ASC, Off Naval Res, RSPAA, URSI HO UNIV NEW S WALES AB Seasonal upwelling in the Middle Atlantic Bight (MAB) occurs during the summer months as a result of episodic wind forcing generally from the south. A wind-generated Ekman divergent surface flow is compensated by an onshore deeper flow that brings nutrient-rich colder waters to the surface. Colder upwelled waters are readily detectable using spaceborne sea surface temperature (SST) observations while increased productivity associated with the enhanced nutrient availability can be imaged by ocean color observations. Low backscatter patterns imaged by synthetic aperture radar (SAR) match closely upwelling patterns observed in the SST data. An abundance of slick filaments also indicated by SAR is consistent with enhanced biological activity associated with the upwelling regime NOAA AVHRR SST, SeaWiFS ocean color (i.e., Chl-a), and RADARSAT-1 SAR imagery of upwelling conditions in the MAB during 1998 were reviewed. The data indicate the development of upwelling centers along the MAB coast. The offshore extension of upwelling-associated filaments as well as offshore blooms is observed in the data. The ability and limitations of these diverse datasets to complement each other in the detection, interpretation, and monitoring of upwelling-associated biological features are explored. C1 NOAA, ORA, NESDIS, Camp Springs, MD 20746 USA. RP Clemente-Colon, P (reprint author), NOAA, ORA, NESDIS, 5200 Auth Rd,Room 102, Camp Springs, MD 20746 USA. RI Clemente-Colon, Pablo/F-5581-2010 NR 2 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7031-7 J9 INT GEOSCI REMOTE SE PY 2001 BP 2616 EP 2618 PG 3 WC Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Remote Sensing SC Engineering; Geology; Remote Sensing GA BU88J UT WOS:000177297200842 ER PT B AU Klein, M Gasiewski, AJ Corbella, I Yevgrafov, A Leuskiy, V AF Klein, M Gasiewski, AJ Corbella, I Yevgrafov, A Leuskiy, V GP IEEE IEEE TI Hydrometeor parameters observed using high-resolution passive microwave imagery during CAMEX-3 SO IGARSS 2001: SCANNING THE PRESENT AND RESOLVING THE FUTURE, VOLS 1-7, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 09-13, 2001 CL UNIV NEW S WALES, SYDNEY, AUSTRALIA SP IEEE, IEEE, Geosci & Remote Sensing Soc, NASA, US Dept Commerce, Natl Ocean & Atmosphere Adm, CSA ASC, Off Naval Res, RSPAA, URSI HO UNIV NEW S WALES ID PRECIPITATION AB Microwave brightness imagery obtained using the NOAA Polarimetric Scanning Radiometer (PSR/A) during the NASA CAMEX-3 experiment offers a unique high-resolution perspective of clouds, rain, water vapor fields, and sea state during hurricane conditions. The uniqueness of this data lies in the broadness spectral range of the observed bands, the full (fore and aft) conical scanning mode (providing two looks at the same scene), the high spatial resolution (1-2.5 km), and polarimetric sensitivity. The PSR/A radiometers operate at the atmospheric window frequencies of 10.7, 18.7, 37 and 89 GHz, with one channel at 21.5 GHz on the wing of the 22.235 GHz water absorption line. All channels are sensitive to both vertical and horizontal polarization. CAMEX-3 flights occurred under different atmospheric conditions ranging from clear sky to severe tropical convection, and included hurricane rainband and eyewall overpasses. The data cover variety of conditions for which the first rain rate retrievals from an airborne conical imaging radiometer are presented. C1 Univ Colorado, NOAA, CIRES, Environm Technol Lab, Boulder, CO 80305 USA. RP Klein, M (reprint author), Univ Colorado, NOAA, CIRES, Environm Technol Lab, R E ETI 325 Broadway, Boulder, CO 80305 USA. RI Corbella, Ignasi/E-9578-2013 OI Corbella, Ignasi/0000-0001-5598-7955 NR 6 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7031-7 J9 INT GEOSCI REMOTE SE PY 2001 BP 2850 EP 2852 PG 3 WC Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Remote Sensing SC Engineering; Geology; Remote Sensing GA BU88J UT WOS:000177297200917 ER PT B AU Klein, M Gasiewski, AJ Schuler, K Cavalieri, D Markus, T Yevgrafov, A AF Klein, M Gasiewski, AJ Schuler, K Cavalieri, D Markus, T Yevgrafov, A GP IEEE IEEE TI Sea ice brightness imagery observed during the meltpond 2000 experiment SO IGARSS 2001: SCANNING THE PRESENT AND RESOLVING THE FUTURE, VOLS 1-7, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 09-13, 2001 CL UNIV NEW S WALES, SYDNEY, AUSTRALIA SP IEEE, IEEE, Geosci & Remote Sensing Soc, NASA, US Dept Commerce, Natl Ocean & Atmosphere Adm, CSA ASC, Off Naval Res, RSPAA, URSI HO UNIV NEW S WALES ID MICROWAVE AB As a part of the NASA Aqua satellite validation program the NOAA Environmental Research Laboratory's Polarimetric Scanning Radiometer (PSR) was flown on a Navy P-3 aircraft in June-July of 2000. Several flights over melting ice floes in Baffin Bay and Melville Sound were performed with the aim of imaging microwave brightness temperatures at high spatial resolution and under a variety of ice melt states. Conditions observed range from open water to completely frozen ice pack, including melting ponds. Two PSR scanheads were used during the experiment: (1) the PSR/C scanhead provided a C-band microwave radiometer with vertically and horizontally polarized channels at 6.00, 6.50, and 7.325 GHz and a fully polarimetric channel at the AMSR band of 6.92 GHz, (2) the PSR/A scanhead provided fully polarimetric channels at 10.7 and 18.7 GHz, tri-polarimetric channels at 37 and 89 GHz, and a dual-polarimetric channel at 21.5 GHz. Both scanheads provided an infrared radiometer operating from 9.5-11 mum. Using the two scanheads all AMSR-E frequencies were covered. In addition, L-band data was obtained using the Scanning Low-Frequency Microwave Radiometer (SLFMR). Results from the calibration of the PSR brightness imagery are presented for both ice and water. These results from PSR and SLFMR show an excellent ability of high-resolution microwave imagery to distinguish melting ice from water, and provide a means of determining the fractal structure of sea ice coverage. C1 Univ Colorado, CIRES, NOAA, Environm Technol Lab,R E ETI, Boulder, CO 80305 USA. RP Klein, M (reprint author), Univ Colorado, CIRES, NOAA, Environm Technol Lab,R E ETI, 325 Broadway, Boulder, CO 80305 USA. RI Markus, Thorsten/D-5365-2012 NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7031-7 J9 INT GEOSCI REMOTE SE PY 2001 BP 2853 EP 2855 PG 3 WC Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Remote Sensing SC Engineering; Geology; Remote Sensing GA BU88J UT WOS:000177297200918 ER PT S AU Krasnopolsky, VM AF Krasnopolsky, VM GP IEEE IEEE IEEE IEEE TI Artificial neural networks in environmental sciences. Part I: NNs in satellite remote sensing and satellite meteorology SO IJCNN'01: INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS, VOLS 1-4, PROCEEDINGS SE IEEE International Joint Conference on Neural Networks (IJCNN) LA English DT Proceedings Paper CT International Joint Conference on Neural Networks (IJCNN 01) CY JUL 15-19, 2001 CL WASHINGTON, D.C. SP Int Neural Network Soc, IEEE, Neural Networks Council ID NUMERICAL WEATHER PREDICTION; MULTIPLE-SCATTERING MODEL; INVERSION; SSM/I; ALGORITHM AB Two generic satellite remote sensing NN applications are described: NN solutions for forward and in verse (or retrieval) problems in satellite remote sensing. These two solutions correspond to two different approaches in satellite retrievals: variational retrievals (retrievals through the direct assimilation of sensor measurements) and standard retrievals. It is shown that both the forward model and the retrieval problem can be considered as nonlinear continuous mappings. The NN technique is a generic technique to perform continuous mappings. It is compared with regression approaches. Examples of a NN SSM/I forward model and a NN SSM/I retrieval algorithm are used to illustrate advantages of using neural networks for developing both retrieval algorithms and forward models, and for minimizing the retrieval errors. C1 NOAA, NWS, Natl Ctr Environm Predict, Sci Applicat Int Corp, Camp Springs, MD 20746 USA. RP Krasnopolsky, VM (reprint author), NOAA, NWS, Natl Ctr Environm Predict, Sci Applicat Int Corp, 5200 Auth Rd, Camp Springs, MD 20746 USA. NR 21 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1098-7576 BN 0-7803-7044-9 J9 IEEE IJCNN PY 2001 BP 1392 EP 1397 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BT36Q UT WOS:000172784800247 ER PT S AU Krasnopolsky, VM AF Krasnopolsky, VM GP IEEE IEEE IEEE IEEE TI Artificial neural networks in environmental sciences. Part II: NNs for fast parameterization of physics in numerical models SO IJCNN'01: INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS, VOLS 1-4, PROCEEDINGS SE IEEE International Joint Conference on Neural Networks (IJCNN) LA English DT Proceedings Paper CT International Joint Conference on Neural Networks (IJCNN 01) CY JUL 15-19, 2001 CL WASHINGTON, D.C. SP Int Neural Network Soc, IEEE, Neural Networks Council AB A new generic approach, based on the neural networks (NN) technique, to improve computational efficiency of parameterizations in numerical environmental models is formulated. Such parameterizations generally require computations involving complex mathematical expressions, including differential and integral equations, rules, restrictions and highly nonlinear empirical relations based on physical or statistical models. From a mathematical point of view, such parameterizations can usually, be considered as continuous mappings (continuous dependencies between two vectors). NNs are a generic tool for fast and accurate approximation of continuous mappings and, therefore, they can be used to replace primary parameterization algorithms. In addition to fast and accurate approximation to the primary parameterization, NN also provides the entire Jacobian for very little computation cost. C1 NOAA, NWS, Natl Ctr Environm Predict, Sci Applicat Int Corp, Camp Springs, MD 20746 USA. RP Krasnopolsky, VM (reprint author), NOAA, NWS, Natl Ctr Environm Predict, Sci Applicat Int Corp, 5200 Auth Rd, Camp Springs, MD 20746 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1098-7576 BN 0-7803-7044-9 J9 IEEE IJCNN PY 2001 BP 1398 EP 1403 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BT36Q UT WOS:000172784800248 ER PT S AU Krasnopolsky, V Chalikov, DV Tolman, HL AF Krasnopolsky, V Chalikov, DV Tolman, HL GP IEEE IEEE IEEE IEEE TI Using neural network for parameterization of nonlinear interactions in wind wave models SO IJCNN'01: INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS, VOLS 1-4, PROCEEDINGS SE IEEE International Joint Conference on Neural Networks (IJCNN) LA English DT Proceedings Paper CT International Joint Conference on Neural Networks (IJCNN 01) CY JUL 15-19, 2001 CL WASHINGTON, D.C. SP Int Neural Network Soc, IEEE, Neural Networks Council ID ENERGY-TRANSFER; APPROXIMATION; COMPUTATIONS; OPERATORS; SPECTRUM AB A new NN application, a cheap yet accurate approximation for the nonlinear wave-wave interaction term in wind-wave numerical models has been developed. This NN approximation is 5 orders of magnitude faster than exact calculations. It provides twice better accuracy and is only roughly, 3 times slower than approximation used before for calculations of this term in wind-wave models. C1 NOAA, NCEP, Environm Modeling Ctr, Ocean Modeling Branch, Camp Springs, MD 20746 USA. RP Krasnopolsky, V (reprint author), NOAA, NCEP, Environm Modeling Ctr, Ocean Modeling Branch, 5200 Auth Rd, Camp Springs, MD 20746 USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1098-7576 BN 0-7803-7044-9 J9 IEEE IJCNN PY 2001 BP 1421 EP 1425 PG 5 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BT36Q UT WOS:000172784800252 ER PT S AU Lee, K AF Lee, K GP IEEE IEEE TI Sensor networking and interface standardization SO IMTC/2001: PROCEEDINGS OF THE 18TH IEEE INSTRUMENTATION AND MEASUREMENT TECHNOLOGY CONFERENCE, VOLS 1-3: REDISCOVERING MEASUREMENT IN THE AGE OF INFORMATICS SE IEEE INSTRUMENTATION & MEASUREMENT TECHNOLOGY CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 18th IEEE Instrumentation and Measurement Technology Conference (IMTC/2001) CY MAY 21-23, 2001 CL BUDAPEST, HUNGARY SP IEEE Instrument & Measurement Soc, Budapest Univ Technol & Econ, Int Measurement Confederat (IMEKO) DE communication protocol; control network; electronic data sheet; field network; IEEE 1451; interface standard; NCAP; networking; sensor; sensor bus; sensor network; smart sensor; TEDS; transducer electronic data sheet AB Sensors are used in various industries, ranging from aerospace, automotive, biomedicine, building, industrial automation, manufacturing, and process control to environmental monitoring. Traditionally, sensor outputs are analog signals, which are then fed to an instrumentation system for processing and display. The incorporating of microelectronics and microprocessor technologies into sensors has enabled greater functionality such as smart and digital communication capabilities to be built into the sensors. This enables the transitioning of sensors into the digital sensor domain. Sensor networking, a technology adopted from the networking of personal computers, is becoming pervasive in all areas of the industrial world and is causing a major shift in the measurement arena. The rapid development and emergence of smart sensor and networking technologies have made the networking of smart transducers (sensors or actuators) a very economical and attractive solution for measurement and control applications, but have created some standardization issues in industry. In this talk, the evolution and state of the sensor networking technologies will be discussed and the effort to bring about a set of standard interfaces to address this issue will be described. C1 NIST, Gaithersburg, MD 20899 USA. RP Lee, K (reprint author), NIST, 100 Bureau Dr Stop 8220, Gaithersburg, MD 20899 USA. NR 11 TC 9 Z9 9 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1091-5281 BN 0-7803-6646-8 J9 IEEE IMTC P PY 2001 BP 147 EP 152 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic; Instruments & Instrumentation SC Computer Science; Engineering; Instruments & Instrumentation GA BT30J UT WOS:000172550900026 ER PT S AU Obrzut, J Nozaki, R AF Obrzut, J Nozaki, R GP IEEE IEEE TI Broadband characterization of dielectric films for power-ground decoupling SO IMTC/2001: PROCEEDINGS OF THE 18TH IEEE INSTRUMENTATION AND MEASUREMENT TECHNOLOGY CONFERENCE, VOLS 1-3: REDISCOVERING MEASUREMENT IN THE AGE OF INFORMATICS SE IEEE INSTRUMENTATION & MEASUREMENT TECHNOLOGY CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 18th IEEE Instrumentation and Measurement Technology Conference (IMTC/2001) CY MAY 21-23, 2001 CL BUDAPEST, HUNGARY SP IEEE Instrument & Measurement Soc, Budapest Univ Technol & Econ, Int Measurement Confederat (IMEKO) DE dielectric permittivity; decoupling capacitance; broadband measurements; coaxial discontinuity; microwave characterization; TDR AB We evaluated the dielectric permittivity and impedance characteristics of high dielectric constant polymer composite films. Such materials are being investigated by the electronic industry in response to the growing need for efficient integrated power-ground de-coupling capacitance in microwave circuits and fast switching devices. In order to extend the dielectric measurements to the microwave range, we developed an appropriate expression for the input admittance of a thin film capacitance terminating a coaxial line. The theoretical model treats the capacitance as a distributed network and takes into consideration the wave propagation in the specimen section. The dielectric permittivity of several high dielectric constant materials for de-coupling capacitance applications was evaluated at frequencies of 100 MHz to 10 GHz. and the corresponding impedance characteristics were determined directly in time domain. Polymer resins filled with ferroelectric ceramics showed low impedance values and flat impedance characteristics over a broad frequency range, which makes these materials attractive for power-ground decoupling applications in high-speed electronic circuits. C1 NIST, Div Polymers, Gaithersburg, MD 20899 USA. RP Obrzut, J (reprint author), NIST, Div Polymers, Gaithersburg, MD 20899 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1091-5281 BN 0-7803-6646-8 J9 IEEE IMTC P PY 2001 BP 1000 EP 1004 PG 3 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic; Instruments & Instrumentation SC Computer Science; Engineering; Instruments & Instrumentation GA BT30J UT WOS:000172550900191 ER PT S AU Yeh, TT Espina, PI Osella, SA AF Yeh, TT Espina, PI Osella, SA GP IEEE IEEE TI An intelligent ultrasonic flow meter for improved flow measurement and flow calibration facility SO IMTC/2001: PROCEEDINGS OF THE 18TH IEEE INSTRUMENTATION AND MEASUREMENT TECHNOLOGY CONFERENCE, VOLS 1-3: REDISCOVERING MEASUREMENT IN THE AGE OF INFORMATICS SE IEEE INSTRUMENTATION & MEASUREMENT TECHNOLOGY CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 18th IEEE Instrumentation and Measurement Technology Conference (IMTC/2001) CY MAY 21-23, 2001 CL BUDAPEST, HUNGARY SP IEEE Instrument & Measurement Soc, Budapest Univ Technol & Econ, Int Measurement Confederat (IMEKO) DE ultrasonic flowmeter; artificial intelligence; flow measurement AB An increasing need for reduced uncertainty has forced metrologists to look for novel ways to improve the calibration standards for flow. The NIST Fluid Flow Group is experimenting with the use of an advanced ultrasonic flow meter (AUFM) to improve flow measurement and to detect the dynamic properties of calibration facilities. Ultrasonic technology is evolving rapidly and technical advances have significantly improved flow measurement in continuous industrial process. The AUFM couples multi-path ultrasonic sensing capabilities with pattern recognition software to predict likely flow fields and their probability of existence. The knowledge encoded in the AUFM is derived from training exercises that use computational fluid dynamics and experimental results to teach a flow field recognizer (FFR) via a learning algorithm. A four-path ultrasonic flowmeter prototype has been used to demonstrate the AUFM operational principle. Results showed that the four-path meter can successfully identified flow patterns among several selected flow fields. The results also indicated that the ability of the FFR to identify flow patterns increases as the accuracy of the sensor increases, while decreases as the number of flow patterns considered increases. In addition to being used as a flow diagnostic tool, the AUFM could prove beneficial in field applications where installation effects can lead to gross errors when ultrasonic signals are evaluated using conventional integration techniques. C1 Natl Inst Stand & Technol, Bethesda, MD 20889 USA. RP Yeh, TT (reprint author), Natl Inst Stand & Technol, Bethesda, MD 20889 USA. NR 11 TC 5 Z9 7 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1091-5281 BN 0-7803-6646-8 J9 IEEE IMTC P PY 2001 BP 1741 EP 1746 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic; Instruments & Instrumentation SC Computer Science; Engineering; Instruments & Instrumentation GA BT30J UT WOS:000172550900323 ER PT S AU Kinard, JR Lipe, TE Avramov-Zamurovic, S AF Kinard, JR Lipe, TE Avramov-Zamurovic, S GP IEEE IEEE TI A new binary inductive divider comparator system for measuring high-voltage thermal converters SO IMTC/2001: PROCEEDINGS OF THE 18TH IEEE INSTRUMENTATION AND MEASUREMENT TECHNOLOGY CONFERENCE, VOLS 1-3: REDISCOVERING MEASUREMENT IN THE AGE OF INFORMATICS SE IEEE INSTRUMENTATION & MEASUREMENT TECHNOLOGY CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 18th IEEE Instrumentation and Measurement Technology Conference (IMTC/2001) CY MAY 21-23, 2001 CL BUDAPEST, HUNGARY SP IEEE Instrument & Measurement Soc, Budapest Univ Technol & Econ, Int Measurement Confederat (IMEKO) DE ac-dc difference; high-voltage TVC; inductive divider; thermal voltage converter; thermal converter ID DC; DEPENDENCE AB National Measurement Institutes have traditionally used bootstrapping or build-up techniques to determine the ac-dc difference of high-voltage thermal converters (HVTCs) in terms of the ac-dc difference of lower-voltage converters. We describe a method of determining the ac-de difference of HVTCs that is independent of the build-up process. A description of the system and technique is given, and preliminary data are presented. C1 Natl Inst Stand & Technol, Div Elect, Gaithersburg, MD 20899 USA. RP Kinard, JR (reprint author), Natl Inst Stand & Technol, Div Elect, Gaithersburg, MD 20899 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1091-5281 BN 0-7803-6646-8 J9 IEEE IMTC P PY 2001 BP 2145 EP 2148 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic; Instruments & Instrumentation SC Computer Science; Engineering; Instruments & Instrumentation GA BT30J UT WOS:000172550900396 ER PT B AU Stoudt, MR Ricker, RE AF Stoudt, MR Ricker, RE BE Demeri, MY TI The influence of grain size on the roughening behavior of Al-Mg alloys SO INNOVATIONS IN PROCESSING AND MANUFACTURING OF SHEET MATERIALS LA English DT Proceedings Paper CT 2nd Global Symposium on Innovations in Materials Processing and Manufacturing - Sheet Materials held at the 2001 TMS Annual Meeting CY FEB 11-15, 2001 CL NEW ORLEANS, LA SP TMS Mat Processing & Mfg Div ID SURFACE; DEFORMATION; SHEET AB The discontinuous plastic flow exhibited by numerous aluminum alloys presents significant challenges to the use of aluminum alloys in automotive applications. The inhomogeneous morphology of the surface asperities generated during metal forming causes strain localization resulting in tearing during metal forming, and increasing friction between mating die surfaces that results in accelerated die wear and in progressively reduced shape accuracy in metal stampings. Before forming models that account for changes in friction can be developed, the relationships between plastic strain, grain size, and surface roughness need to be better understood. To accomplish this objective, the roughening behavior of a commercial Al alloy was examined with different heat treatments and grain sizes. The results of this evaluation indicate that the standard roughness measures increase with strain in a manner that can be represented by a simple linear model with the slope a function of heat treatment and grain size. However, optical microscopy indicates that the roughening process may be more complex than suggested by this simple model. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Stoudt, MR (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Ricker, Richard/H-4880-2011 OI Ricker, Richard/0000-0002-2871-4908 NR 21 TC 1 Z9 1 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-490-9 PY 2001 BP 237 EP 244 PG 8 WC Engineering, Manufacturing; Materials Science, Coatings & Films; Materials Science, Composites SC Engineering; Materials Science GA BS15D UT WOS:000168851900019 ER PT J AU White, GS Blendell, JE Fuller, ER AF White, GS Blendell, JE Fuller, ER TI Domain stability in PZT thin films SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT 13th International Symposium on Integrated Ferroelectrics CY MAR 11-14, 2001 CL COLORADO SPRINGS, COLORADO SP aixACCT, Aixtron, Panasonic, Ramtron, Symetrix, Int Journal Integraded Ferroelect DE AFM; domain; ferroelectric; grain boundary; pinning; PZT ID SCANNING FORCE MICROSCOPY; FATIGUE; PB(ZR,TI)O-3; INTERFACE AB AFM measurements were made on 111 textured lead zirconate titanate thin films excited by a 1 V-rms in the presence of various DC biasing voltages. Domain pinning sites were found in the film. All sites were located at grain boundaries and were coincident with abnormally large piezoelectric displacements in the film. Different sites were associated with domain polarization aligned toward the free surface of the film than with polarization aligned toward the substrate. Finite element calculations used to determine residual stress as a function of grain misorientation showed that large residual stresses and strains normal to the film plane would be generated at grain boundaries for certain grain misorientations. Domain pinning sites in PZT thin films are interpreted in terms of residual stresses at grain boundaries due to grain misorientation. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP White, GS (reprint author), Natl Inst Stand & Technol, 100 Bur Dr Stop 8522, Gaithersburg, MD 20899 USA. NR 15 TC 0 Z9 0 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK,, ABINGDON OX14 4RN, OXON, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2001 VL 38 IS 1-4 BP 713 EP 722 PG 10 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 508BD UT WOS:000173066600009 ER PT S AU Fahnenstiel, GL Lohrenz, SE Kelly, K Millie, DF Schofield, OME AF Fahnenstiel, Gary L. Lohrenz, Steven E. Kelly, Kimberly Millie, David F. Schofield, Oscar M. E. BE Williams, WD TI Light absorption characteristics of individual phytoplankton cells from a natural community: examples from Lake Michigan during the winter period SO INTERNATIONAL ASSOCIATION OF THEORETICAL AND APPLIED LIMNOLOGY, PROCEEDINGS, VOL 27, PT 4 SE International Association of Theoretical and Applied Limnology Proceedings LA English DT Proceedings Paper CT 27th Congress of the International-Association-of-Theoretical-and-Applied-Limnology CY 1998 CL Dublin, IRELAND SP Int Assoc Theoret & Appl Limnol ID SPECTRAL ABSORPTION; EFFICIENCY; DYNAMICS; GROWTH; SEA C1 [Fahnenstiel, Gary L.] GLERL NOAA, Lake Michigan Field Stn, Muskegon, MI 49441 USA. RP Fahnenstiel, GL (reprint author), GLERL NOAA, Lake Michigan Field Stn, 1431 Beach St, Muskegon, MI 49441 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU E SCHWEIZERBART'SCHE VERLAGSBUCHHANDLUNG PI STUTTGART PA JOHANNESTRASSE 3, W-7000 STUTTGART, GERMANY SN 0368-0770 BN 978-3-510-54055-6 J9 INT VER THEOR ANGEW PY 2001 VL 27 BP 1836 EP 1840 PN 4 PG 5 WC Limnology SC Marine & Freshwater Biology GA BTL81 UT WOS:000287228100025 ER PT S AU Nalepa, TF Lang, GA Fanslow, DL AF Nalepa, TF Lang, GA Fanslow, DL BE Williams, WD TI Trends in benthic macroinvertebrate populations in southern Lake Michigan SO INTERNATIONAL ASSOCIATION OF THEORETICAL AND APPLIED LIMNOLOGY, VOL 27, PT 5, PROCEEDINGS SE INTERNATIONAL ASSOCIATION OF THEORETICAL AND APPLIED LIMNOLOGY - PROCEEDINGS LA English DT Proceedings Paper CT 27th Congress of the International-Association-of-Theoretical-and-Applied-Limnology CY 1998 CL DUBLIN, IRELAND SP Int Assoc Theoret & Appl Limnol ID DREISSENA; COMMUNITY; ERIE; INVASION; ONTARIO C1 Natl Ocean & Atmospher Adm, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Nalepa, TF (reprint author), Natl Ocean & Atmospher Adm, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 25 TC 0 Z9 0 U1 0 U2 0 PU E SCHWEIZERBART'SCHE VERLAGSBUCHHANDLUNG PI STUTTGART PA JOHANNESTRASSE 3, W-7000 STUTTGART, GERMANY SN 0368-0770 BN 3-510-54056-5 J9 INT VER THEOR ANGEW PY 2001 VL 27 BP 2540 EP 2545 PN 5 PG 4 WC Limnology SC Marine & Freshwater Biology GA BU06W UT WOS:000174899600009 ER PT S AU Assel, R Herche, L AF Assel, R Herche, L BE Williams, WD TI Coherence of long-term lake ice records SO INTERNATIONAL ASSOCIATION OF THEORETICAL AND APPLIED LIMNOLOGY, VOL 27, PT 5, PROCEEDINGS SE INTERNATIONAL ASSOCIATION OF THEORETICAL AND APPLIED LIMNOLOGY - PROCEEDINGS LA English DT Proceedings Paper CT 27th Congress of the International-Association-of-Theoretical-and-Applied-Limnology CY 1998 CL DUBLIN, IRELAND SP Int Assoc Theoret & Appl Limnol C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Assel, R (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 8 TC 0 Z9 0 U1 1 U2 4 PU E SCHWEIZERBART'SCHE VERLAGSBUCHHANDLUNG PI STUTTGART PA JOHANNESTRASSE 3, W-7000 STUTTGART, GERMANY SN 0368-0770 BN 3-510-54056-5 J9 INT VER THEOR ANGEW PY 2001 VL 27 BP 2789 EP 2792 PN 5 PG 4 WC Limnology SC Marine & Freshwater Biology GA BU06W UT WOS:000174899600059 ER PT J AU Lin, YJ Damodharan, K Shakarji, C AF Lin, YJ Damodharan, K Shakarji, C TI Standardised reference data sets generation for coordinate measuring machine (CMM) software assessment SO INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY LA English DT Article DE CMM measurement data; CMM software assessment; form errors and noise; reference data generation ID INSPECTION; PATH; ALGORITHM; SURFACES AB Rapid and accurate in-process measurement has recently become more common in product cycles, especially, for producing parts having 3D contoured shapes. As a result, the ability to analyse large quantities of dimensional data requires today's coordinate measuring machines (CMM) to employ, their extreme functionality. With the increasing demand for performance of the software supplied for a CMM, the testing methods for these software packages must be rigorous, stable, and efficient. Motivated by the aforementioned demand, this work is intended to design and develop an algorithm and computer code to generate the reference data sets representing the coordinates of Gaussian associated features for CMM measured parts. These reference data sets can be used to test the CMM software submitted for approval to the National Institute of Standards and Technology (NIST). A generic algorithm for the development of the data sets is proposed and the program code is designed and developed by employing object oriented concepts. Dynamic errors during measurement are also accounted for, using Fourier harmonics representing the form errors and noise in the measured data. The data sets, being an integral part of the proposed International Standard - ISO 10360, will become a significant step towards the standardisation of software testing procedures for coordinate measuring machines. C1 Univ Akron, Dept Mech Engn, Akron, OH 44325 USA. NIST, Gaithersburg, MD 20899 USA. RP Lin, YJ (reprint author), Univ Akron, Dept Mech Engn, Akron, OH 44325 USA. NR 27 TC 2 Z9 2 U1 0 U2 2 PU SPRINGER-VERLAG LONDON LTD PI GODALMING PA SWEETAPPLE HOUSE CATTESHALL ROAD, GODALMING GU7 3DJ, SURREY, ENGLAND SN 0268-3768 J9 INT J ADV MANUF TECH JI Int. J. Adv. Manuf. Technol. PY 2001 VL 18 IS 11 BP 819 EP 830 DI 10.1007/s001700170007 PG 12 WC Automation & Control Systems; Engineering, Manufacturing SC Automation & Control Systems; Engineering GA 504FH UT WOS:000172846300007 ER PT J AU Nidamarthi, S Allen, RH Sriram, RD AF Nidamarthi, S Allen, RH Sriram, RD TI Observations from supplementing the traditional design process via Internet-based collaboration tools SO INTERNATIONAL JOURNAL OF COMPUTER INTEGRATED MANUFACTURING LA English DT Article AB We report on our observations about supporting, via the Internet, the design and manufacture of an atomic artefact transport system (ATS) by a team of geographically separated physicists, designers and fabricators. To supplement the design process, we have deployed two Internet-based approaches. In our first approach, we have used a client- and server-based suite of tools with facilities for design activities and design rationale capture. In the second method, we implemented virtual reality modelling language (VRML) as a communication and visualization medium for evaluation of detailed designs and assembly sequences. In each approach, we observed changes in the design process as a result of incorporating collaborative technology. These changes include being able to capture design rationale and exchange ideas analogously to traditional methods, and being able to simulate the assembly sequence in the iterative design phase. Our data support the view that collaborative technologies will supplement, rather than supplant, traditional design processes. We conclude that collaborative environments can be effective in helping teams overcome the problems associated with conflicting schedules, heterogeneous computing environments and data, and can be effective in facilitating consensus-based decision-making necessary for collaborative design. C1 Univ Cambridge, Cambridge CB2 1TN, England. Univ Maryland, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Nidamarthi, S (reprint author), Univ Cambridge, Cambridge CB2 1TN, England. RI Allen, Robert/A-3731-2010 NR 31 TC 19 Z9 26 U1 0 U2 6 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0951-192X J9 INT J COMP INTEG M JI Int. J. Comput. Integr. Manuf. PD JAN-FEB PY 2001 VL 14 IS 1 BP 95 EP 107 DI 10.1080/09511920150214938 PG 13 WC Computer Science, Interdisciplinary Applications; Engineering, Manufacturing; Operations Research & Management Science SC Computer Science; Engineering; Operations Research & Management Science GA 395ZZ UT WOS:000166613000009 ER PT J AU Irwin, JS AF Irwin, JS TI Effects of concentration fluctuations on statistical evaluations of centreline concentration estimates by atmospheric dispersion models SO INTERNATIONAL JOURNAL OF ENVIRONMENT AND POLLUTION LA English DT Article; Proceedings Paper CT 6th International Conference on Harmonization within Atmospherica Dispersion Modelling for Regulatory Purposes CY OCT 11-14, 1999 CL ROUEN, FRANCE DE air dispersion modelling; model performance; statistical evaluation ID QUALITY AB An investigation is undertaken of a concept expressed in a draft Guide under construction, which recommends that evaluation data having similar meteorological and physical conditions be grouped together, the modelling results and observations be separately averaged and that the evaluation shall consist of a comparison of the respective averages. It is determined that, even though large uncertainties are associated with this process, the summary conclusions reached regarding relative model performance in estimating the average centreline concentration values are preserved. It is recommended that the Guide be finalized for routine use and the concepts further tested using other testable features in the concentration pattern. C1 Natl Ocean & Atmospher Adm, Air Resources Lab, Atmospher Sci Modelling Div, Res Triangle Pk, NC 27711 USA. RP Irwin, JS (reprint author), Natl Ocean & Atmospher Adm, Air Resources Lab, Atmospher Sci Modelling Div, MD-14, Res Triangle Pk, NC 27711 USA. NR 11 TC 2 Z9 2 U1 0 U2 1 PU INDERSCIENCE ENTERPRISES LTD PI GENEVA AEROPORT PA WORLD TRADE CENTER BLDG 110 AVE LOUSIS CASAI CP 306, CH-1215 GENEVA AEROPORT, SWITZERLAND SN 0957-4352 J9 INT J ENVIRON POLLUT JI Int. J. Environ. Pollut. PY 2001 VL 16 IS 1-6 SI SI BP 36 EP 48 PG 13 WC Environmental Sciences SC Environmental Sciences & Ecology GA 549QV UT WOS:000175457600006 ER PT J AU Zhang, JZ Fischer, CJ Ortner, PB AF Zhang, JZ Fischer, CJ Ortner, PB TI Continuous flow analysis of phosphate in natural waters using hydrazine as a reductant SO INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY LA English DT Article DE phosphate determination; hydrazine; silicate interference; coating; continuous flow analysis ID PHOSPHOANTIMONYLMOLYBDENUM BLUE COMPLEX; PHOSPHORUS LIMITATION; MARINE-ENVIRONMENT; MOLYBDENUM BLUE; SILICATE; INTERFERENCE AB The use of hydrazine to reduce 12-molybdophosphoric acid to phosphomolybdenum blue in continuous flow analysis of phosphate in natural water samples is characterized. Using hydrazine in gas-segmented continuous flow phosphate analysis minimizes coating and silicate interference in comparison with using ascorbic acid. The addition of Sb to the molybdate reagent increases sensitivity at temperatures greater than 50 degreesC but causes severe additional coating. The degree of coating was found to be a function of pH. Minimal coatings were achieved at a final solution pH of 0.5. Silicate interference was found to increase dramatically with color development temperature. At room temperature no detectable silicate interference was found. We recommend hydrazine in preference to ascorbic acid for gas-segmented continuous flow phosphate analysis with optimal reaction conditions of room temperature color development and a final solution pH of 0.5. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Cooperat Inst Marine & Atmospher Studies, Miami, FL 33149 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Ocean Chem Div, Miami, FL 33149 USA. RP Zhang, JZ (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Cooperat Inst Marine & Atmospher Studies, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. RI Zhang, Jia-Zhong/B-7708-2008; Fischer, Charles/A-3843-2017 OI Zhang, Jia-Zhong/0000-0002-1138-2556; NR 38 TC 19 Z9 19 U1 0 U2 5 PU GORDON BREACH PUBLISHING, TAYLOR & FRANCIS GROUP PI PHILADELPHIA PA 325 CHESTNUT ST, 8TH FL, PHILADELPHIA, PA 19106 USA SN 0306-7319 J9 INT J ENVIRON AN CH JI Int. J. Environ. Anal. Chem. PY 2001 VL 80 IS 1 BP 61 EP 73 DI 10.1080/03067310108044386 PG 13 WC Chemistry, Analytical; Environmental Sciences SC Chemistry; Environmental Sciences & Ecology GA 480ZT UT WOS:000171494100006 ER PT J AU Stoudt, MR Ricker, RE Cammarata, RC AF Stoudt, MR Ricker, RE Cammarata, RC TI The influence of a multilayered metallic coating on fatigue crack nucleation SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article; Proceedings Paper CT 3rd International Conference on Fatigue Damage of Structural Materials CY SEP 17-22, 2000 CL HYANNIS, MASSACHUSETTS DE fatigue; multilayers; nanomaterials; electroplating; surfaces; crack initiation ID COPPER SINGLE-CRYSTALS; LOW AMPLITUDE FATIGUE; THIN-FILMS; ELASTIC PROPERTIES; POLYCRYSTALLINE COPPER; MECHANICAL-PROPERTIES; DAMAGE ACCUMULATION; SURFACE; INITIATION; DEFORMATION AB A thorough review of the literature on fatigue crack initiation indicates that for optimum resistance to fatigue crack initiation, a surface coating needs more than just a high hardness and that a combination of properties including toughness, cyclic work hardenability, residual compressive stresses, and adherence, in addition to a hardness higher than that of the substrate are required. Based on this assumption, it was hypothesized that nanometer-scale, multilayer coatings will posses a combination of these required properties enabling significant increases in fatigue crack initiation resistance. To test this hypothesis, fatigue experiments were conducted on Cu samples with different surface treatments including a nanoscale Cu-Ni multilayer. The fatigue lives of the multilayer coated samples were significantly greater than those of uncoated samples or samples coated with a monolithic coating of Cu or Ni indicating that the nanodimensional layering of the multilayer coating is responsible for retarding fatigue crack initiation and failure. The samples were examined with various analytical techniques including scanning and transmission electron microscopy and atomic force microscopy. Published by Elsevier Science Ltd. C1 NIST, Div Met, Technol Adm, US Dept Commerce, Gaithersburg, MD 20899 USA. Johns Hopkins Univ, Dept Mat Sci & Engn, Baltimore, MD 21218 USA. RP Stoudt, MR (reprint author), NIST, Div Met, Technol Adm, US Dept Commerce, Gaithersburg, MD 20899 USA. RI Cammarata, Robert /A-3307-2010; Ricker, Richard/H-4880-2011 OI Ricker, Richard/0000-0002-2871-4908 NR 57 TC 11 Z9 12 U1 1 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PY 2001 VL 23 SU S BP S215 EP S223 PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 508DB UT WOS:000173071800027 ER PT J AU Lippiatt, BC Boyles, AS AF Lippiatt, BC Boyles, AS TI Using BEES to select cost-effective green products SO INTERNATIONAL JOURNAL OF LIFE CYCLE ASSESSMENT LA English DT Article DE BEES; building for environmental and economic; sustainability (BEES); building product performance; environmentally preferable purchasing; environmental decision support software; green buildings; InLCA; LCA; Life Cycle Assessment (LCA); life-cycle costing; measuring economic performance; measuring environmental performance; multiattribute decision analysis; software products; sustainable development AB The BEES (Building for Environmental and Economic Sustainability) software brings to your fingertips a powerful technique for balancing the environmental and economic performance of building products. The tool is based on consensus standards and designed to be practical, flexible, and transparent. Version 2.0 of the Windows(TM)-based decision support software, aimed at designers, builders, and product manufacturers, includes actual environmental and economic performance data for 65 building products. The purpose is to support purchasing decisions by providing key science-based information often lacking in 'green' product selection. The intended result is a cost-effective reduction in building-related contributions to environmental problems. C1 NIST, Gaithersburg, MD 20899 USA. RP Lippiatt, BC (reprint author), NIST, 100 Bur Dr,Stop 8603, Gaithersburg, MD 20899 USA. NR 8 TC 20 Z9 21 U1 0 U2 5 PU ECOMED PUBLISHERS PI LANDSBERG PA RUDOLF-DIESEL-STR 3, D-86899 LANDSBERG, GERMANY SN 0948-3349 J9 INT J LIFE CYCLE ASS JI Int. J. Life Cycle Assess. PY 2001 VL 6 IS 2 BP 76 EP 80 PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 475HM UT WOS:000171157300003 ER PT J AU Kedzierski, MA AF Kedzierski, MA TI The effect of lubricant concentration, miscibility, and viscosity on R134a pool boiling SO INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID LA English DT Article DE refrigerant; R134a; pool boiling; heat transfer; lubricant; concentration; miscibility; viscosity ID REFRIGERANT-OIL MIXTURES; ENHANCEMENT AB This paper presents pool boiling heat transfer data for 12 different R134a/lubricant mixtures and pure R134a on a Turbo-BII (TM) -HP surface. The mixtures were designed to examine the effects of lubricant mass fraction, viscosity, and miscibility on the heat transfer performance of R134a. The magnitude of the effect of each parameter on the heat transfer was quantified with a regression analysis. The mechanistic cause of each effect was given based on new theoretical interpretation and/or one from the literature. The model illustrates that large improvements over pure R134a heat transfer can be obtained for R134a/lubricant mixtures with small lubricant mass fraction, high lubricant viscosity, and a large critical solution temperature (CST), The ratio of the heat flux of the R134a/lubricant mixture to that of the pure R134a for fixed wall superheat was given as a function of pure R134a heat flux for all 12 mixtures. The lubricant that had the largest CST with R134a exhibited the greatest heat transfer: 100%+/- 20% greater than that of pure R134a. By contrast, the heat transfer of the mixture with the lubricant that had the smallest viscosity and the smallest CST with R134a was 55%+/-9% less than that of pure R134a. High-speed films of the pure and mixture pool boiling were taken to observe the effect of the lubricant on the nucleate boiling. (C) 2001 Published by Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kedzierski, MA (reprint author), Natl Inst Stand & Technol, Bldg 226,Rm B114, Gaithersburg, MD 20899 USA. NR 36 TC 25 Z9 31 U1 1 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0140-7007 J9 INT J REFRIG JI Int. J. Refrig.-Rev. Int. Froid PY 2001 VL 24 IS 4 BP 348 EP 366 DI 10.1016/S0140-7007(00)00030-X PG 19 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 431PJ UT WOS:000168639500006 ER PT J AU Jargon, JA Gupta, KC AF Jargon, JA Gupta, KC TI Artificial neural network modeling for improved coaxial line-reflect-match calibrations SO INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING LA English DT Article DE artificial neural network; network analyzer; calibration; model; standards; measurement AB We model a coaxial load using an artificial neural network (ANN) to improve a coaxial line-reflect-match (LRM) calibration of an automatic network analyzer. The ANN is trained with measurement data obtained from a thru-reflect-line (TRL) calibration. The accuracy of the LRM calibration using the ANN-modeled load compares favorably to a benchmark multiline TRI, calibration, with an average worst-case scattering-parameter error bound of 0.024 over an 18-GHz bandwidth. (C) 2001 John Wiley & Sons, Inc. C1 Natl Inst Stand & Technol, RF Elect Grp, Boulder, CO 80303 USA. Univ Colorado, CAMPmode, Boulder, CO 80309 USA. RP Jargon, JA (reprint author), Natl Inst Stand & Technol, RF Elect Grp, 325 Broadway, Boulder, CO 80303 USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1096-4290 J9 INT J RF MICROW C E JI Int. J. RF Microw. Comput-Aid. Eng. PD JAN PY 2001 VL 11 IS 1 BP 33 EP 37 DI 10.1002/1099-047X(200101)11:1<33::AID-MMCE4>3.0.CO;2-C PG 5 WC Computer Science, Interdisciplinary Applications; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 385HJ UT WOS:000165997800003 ER PT J AU Sengers, JMHL AF Sengers, JMHL TI The laboratory founded by Van der Waals' SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Amer Soc Mech Engineers, Comm Thermophys Properties Heat Transfer Div, Phys & Chem Properties Div, Chem Sci & Technol Lab HO UNIV COLORADO DE high pressure; history; molecular physics; NMR; phase equilibria; PVT data; thermal conductivity; Van der Waals Laboratory; viscosity ID METHANE AB During the past century the Van der Waals Laboratory at the University of Amsterdam has been the principal provider of reliable fluid property data over large ranges of pressure and temperature. This paper describes the history of the laboratory, starting in 1898 when funding for it was obtained. In the early period; under Van der Waals and Kohnstamm. the high-pressure direction was chosen, and the first PVT and phase equilibria data were published. The main focus of this paper is the Michels period, from 1921 to 1960. In this period, the laboratory acquired its own building and assumed a unique position in the world because of its highly accurate thermodynamic, transport, and other property measurements in fluids at high pressures. In the 1950s. a second laboratory was built by Michels at the University of Maryland, per request of the U.S. Navy. Under Trappeniers, 1961-1987, the laboratory incorporated new techniques, such as NMR, undertook a major expansion of the pressure range, and extended its interest to phase transitions in molecular solids. The position of the Van det Waals Laboratory: in the world of high-pressure science is highlighted. C1 NIST, Chem Sci & Technol Lab, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Sengers, JMHL (reprint author), NIST, Chem Sci & Technol Lab, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. NR 26 TC 0 Z9 0 U1 0 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JAN PY 2001 VL 22 IS 1 BP 3 EP 22 DI 10.1023/A:1006761818526 PG 20 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 432WU UT WOS:000168719400002 ER PT J AU Mountain, RD AF Mountain, RD TI Ion solvation in water-acetonitrile mixtures SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Amer Soc Mech Engineers, Comm Thermophys Properties Heat Transfer Div, Phys & Chem Properties Div, Chem Sci & Technol Lab HO UNIV COLORADO DE acetonitrile; aqueous acetonitrile; ion association; ion solvation; molecular dynamics; water ID COMPUTER-SIMULATION; MOLECULAR-DYNAMICS; ALKALI-HALIDES; POTENTIALS AB The results of a preliminary molecular dynamics study of ion (Na+ and Cl- salvation and association ill water, acetonitrile, and aqueous acetonitrile are discussed. There mixtures are compositionally heterogeneous on the scale of a few molecular sizes, and this heterogeneity is expected to be an important factor governing ion salvation and association. Results for ions in pure water and pure acetonitrile are presented for ambient conditions. The degree of association is law in water, a high-density fluid, and high in acetonitrile, a low-density: fluid. A separate set of simulations for water at supercritical temperatures demonstrates that the fluid density is more important than the temperature in deter mining the degree of ion association. Preliminary results for the mixtures are inconclusive except that they indicate the existence of an important sampling issue related to the compositional heterogeneity of the mixtures. Sin approach to resolving the sampling issue is suggested. C1 Natl Inst Stand & Technol, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RP Mountain, RD (reprint author), Natl Inst Stand & Technol, Phys & Chem Properties Div, 100 Bur Dr,Stop 8380, Gaithersburg, MD 20899 USA. NR 24 TC 6 Z9 6 U1 1 U2 10 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JAN PY 2001 VL 22 IS 1 BP 101 EP 110 DI 10.1023/A:1006707619435 PG 10 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 432WU UT WOS:000168719400008 ER PT J AU Meier, K Laesecke, A Kabelac, S AF Meier, K Laesecke, A Kabelac, S TI A molecular dynamics simulation study of the self-diffusion coefficient and viscosity of the Lennard-Jones fluid SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Amer Soc Mech Engineers, Comm Thermophys Properties Heat Transfer Div, Phys & Chem Properties Div, Chem Sci & Technol Lab HO UNIV COLORADO DE Einstein relation; equilibrium molecular dynamics; Lennard-Jones fluid; self-diffusion coefficient; transport properties; viscosity; viscosity contributions ID TRANSPORT-COEFFICIENTS; STATE AB Self-diffusion coefficients and viscosities for the Lennard-Jones fluid were obtained from extensive equilibrium molecular dynamics simulations using the Einstein plot method. Over 300 simulated state points cover the entire fluid region from the low-density gas to the compressed liquid close to the melting line in thr temperature range T* = Tk/epsilon = 0.7 to 6.0. The translation al-translational, translational-configurational. and configurational-configurational contributions to the viscosity are resolved over this broad range of liquid states, thus providing coherent insight into the nature of this transport property. The uncertainties of the simulation data are conservatively estimated to be 0.5% for self diffusion coefficients and 2% for viscosities in the liquid region, increasing to 15% at low-density gaseous states. C1 Univ Hannover, Inst Thermodynam, D-30167 Hannover, Germany. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80303 USA. RP Kabelac, S (reprint author), Univ Hannover, Inst Thermodynam, Callinstr 36, D-30167 Hannover, Germany. NR 16 TC 33 Z9 35 U1 4 U2 15 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JAN PY 2001 VL 22 IS 1 BP 161 EP 173 DI 10.1023/A:1006715921252 PG 13 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 432WU UT WOS:000168719400013 ER PT J AU Polikhronidi, NG Abdulagatov, IM Magee, JW Stepanov, GV AF Polikhronidi, NG Abdulagatov, IM Magee, JW Stepanov, GV TI Isochoric heat capacity measurements for light and heavy water near the critical point SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Amer Soc Mech Engineers, Comm Thermophys Properties Heat Transfer Div, Phys & Chem Properties Div, Chem Sci & Technol Lab HO UNIV COLORADO DE adiabatic calorimeter; critical point; coexistence curve; crossover equation of state; density; heavy water; isochoric heat capacity; light water; quasi-static thermogram method ID THERMODYNAMIC PROPERTIES; CRITICAL REGION; CARBON-DIOXIDE; EQUATION; STATE; D2O AB The isochoric heat capacity was measured for D2O at a fixed density of 356.075 kg.m(-3) and for H2O at 309.905 kg.m(-3). The measurements cover the range of temperatures from 623 to 661 K. The measurements were made with a high-temperature. high-pressure, adiabatic calorimeter with a nearly; constant inner volume. The uncertainty of the temperature is 10 mK, while the uncertainty of the heat capacity is estimated to be 2 to 3%. Measurements were made in both the two-phase and the one-phase regions. The calorimeter instrumentation also enables measurements of PVT and the temperature derivative (partial derivativeP/partial derivativeT)(V) along Each measured isochore. A detailed discussion is presented on the experimental temperature behavior of C-V in the one and two-phase regions including the coexistence curve near the critical point. A quasi-static thermogram method was applied to determine values of temperature at saturation T-S(rho) on measured isochores. The uncertainty of the phase-transition temperature measurements is about +/-0.02 K. The measured C-V data for D2O and H2O are compared with values predicted from a recent developed parametric crossover equation of state and IAPWS-95 formulation. C1 Russian Acad Sci, Inst Phys, Dagestan Sci Ctr, Makhachkala 367005, Dagestan, Russia. Natl Inst Stand & Technol, Phys & Chem Properties Div, Boulder, CO 80305 USA. RP Abdulagatov, IM (reprint author), Russian Acad Sci, Inst Phys, Dagestan Sci Ctr, M Yaragskogo Str 94, Makhachkala 367005, Dagestan, Russia. RI Magee, Joseph/A-8496-2009 OI Magee, Joseph/0000-0002-9312-8593 NR 27 TC 30 Z9 30 U1 0 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JAN PY 2001 VL 22 IS 1 BP 189 EP 200 DI 10.1023/A:1006767905322 PG 12 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 432WU UT WOS:000168719400015 ER PT J AU Frenkel, M Dong, Q Wilhoit, RC Hall, KR AF Frenkel, M Dong, Q Wilhoit, RC Hall, KR TI TRC SOURCE database: A unique tool for automatic production of data compilations SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Amer Soc Mech Engineers, Comm Thermophys Properties Heat Transfer Div, Phys & Chem Properties Div, Chem Sci & Technol Lab HO UNIV COLORADO DE automatic data productions; database applications; data compilation; data correlation; experimental values; relational database; thermophysical properties AB Thermochemical and thermophysical properties of chemicals are the basis of most simulations of commercial processes. The TRC SOURCE database is an extensive archive of commercial experimental values of thermophysical properties extracted from the world's scientific literature. A suite of input/output routines that utilize current database technology has been developed. The database in combination with suitable software enables the automatic retrieval, interpretation, selection, and formatting of a wide range of thermophysical properties. Their output supports the automatic production of user specified compilations and the direct intel action with user-written application programs. C1 Natl Inst Stand & Technol, Thermodynam Res Ctr, Phys & Chem Properties Div, Boulder, CO 80303 USA. Texas A&M Univ Syst, College Stn, TX 77843 USA. Texas A&M Univ, Dept Chem Engn, College Stn, TX 77843 USA. RP Frenkel, M (reprint author), Natl Inst Stand & Technol, Thermodynam Res Ctr, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 11 TC 52 Z9 52 U1 0 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JAN PY 2001 VL 22 IS 1 BP 215 EP 226 DI 10.1023/A:1006720022161 PG 12 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 432WU UT WOS:000168719400017 ER PT J AU Yan, X Dong, Q Frenkel, M Hall, KR AF Yan, X Dong, Q Frenkel, M Hall, KR TI Window-based applications of TRC databases: Structure and Internet distribution SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Amer Soc Mech Engineers, Comm Thermophys Properties Heat Transfer Div, Phys & Chem Properties Div, Chem Sci & Technol Lab HO UNIV COLORADO DE database evaluation; experimental data; recommended data; thermophysical property; windows AB Thermophysical and thermochemical property data on organic compounds provide vital background information for scientific and engineering communities in both academic and industrial environments. The Thermodynamics Reseal ch Center (TRC) has collected an enormous amount of property data over the past 55 years. New advances in computer technology enable relatively large databases to have friendly "communications'' based upon a PC Windows platform. Here we discuss the structure, upgrade procedures, and mechanisms for distribution over local PC networks and the Internet, with emphasis on three databases. TRC COMPOUNDS (Wincmp) SOURCE (WinSource), the archive of raw: experimental data, and FRC TABLE (WinTable), the TRC collection of recommended data. C1 Natl Inst Stand & Technol, Thermodynam Res Ctr, Phys & Chem Properties Div, Boulder, CO 80303 USA. Texas A&M Univ, Dept Chem Engn, College Stn, TX 77843 USA. RP Dong, Q (reprint author), Natl Inst Stand & Technol, Thermodynam Res Ctr, Phys & Chem Properties Div, 325 Broadway, Boulder, CO 80303 USA. NR 18 TC 9 Z9 9 U1 2 U2 4 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JAN PY 2001 VL 22 IS 1 BP 227 EP 241 DI 10.1023/A:1006772006231 PG 15 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 432WU UT WOS:000168719400018 ER PT J AU Khan, RN Tall, EG Rebecchi, M Ramsdell, JS Pentyala, S AF Khan, RN Tall, EG Rebecchi, M Ramsdell, JS Pentyala, S TI Effect of maitotoxin on guanine nucleotide interaction with G-protein alpha subunits SO INTERNATIONAL JOURNAL OF TOXICOLOGY LA English DT Article DE G alpha subunit; G-proteins; maitotoxin; marine toxin ID PHOSPHOINOSITIDE BREAKDOWN; INTRACELLULAR CA2+; MARINE NEUROTOXINS; CALCIUM-CHANNEL; PITUITARY-CELLS; HIGH-AFFINITY; ION CHANNELS; MECHANISM; ACTIVATION; MEMBRANE AB Maitotoxin is a potent water-soluble polyether toxin produced by the marine dinoflagellate Gambierdiscus toxicus, Although associated with increased calcium uptake, mobilization of internal calcium stores, and enhanced phosphoinositide metabolism, the primary molecular mechanism underlying its actions remains unclear, In this study, we evaluated the effects of maitotoxin (MTX) on the interaction of guanine nucleotides with G-protein alpha subunits, Equilibrium binding of the nonhydrolyzable GTP analog, GTP gammaS, to a subunits (Go, Gs, Gil, Gi2, and Gi3) was decreased in the presence of MTX, Furthermore, reconstitution of G alpha with G beta gamma dimer showed a reversal of the inhibition elicited by MTX, GDP/GTP exchange rate for G alpha subunits was significantly inhibited in the presence of MTX, MTX had no effect on the rate of GDP or GTP dissociation from a subunits, Also, the mastoparan-induced component of nucleotide exchange is not effected by MTX, These results suggest that MTX acts on G alpha subunits to modulate their interaction with guanine nucleotides, perhaps by stabilizing an empty state of the alpha subunit, Accordingly, MTX may disrupt the normal signal transduction pathways by inhibiting GTP binding to G alpha subunits and interfering with the GDP/GTP exchange. C1 Armstrong Atlantic State Univ, Dept Biol, Savannah, GA 31419 USA. SUNY Stony Brook, Sch Med, Dept Anesthesiol & Physiol & Biophys, Stony Brook, NY 11794 USA. NOAA, Ctr Coastal Environm Hlth & Biomol Res, Marine Biotoxins Program, Charleston, SC USA. RP Khan, RN (reprint author), Armstrong Atlantic State Univ, Dept Biol, 11935 Abercorn St, Savannah, GA 31419 USA. NR 32 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 1091-5818 J9 INT J TOXICOL JI Int. J. Toxicol. PY 2001 VL 20 IS 1 BP 39 EP 44 PG 6 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA 406VB UT WOS:000167235800007 PM 11288932 ER PT J AU Hess, JC Scott, CA Hufford, GL Fleming, MD AF Hess, JC Scott, CA Hufford, GL Fleming, MD TI El Nino and its impact on fire weather conditions in Alaska SO INTERNATIONAL JOURNAL OF WILDLAND FIRE LA English DT Article DE El Nino; ENSO; Alaska; wildfires; weather patterns; burned area ID SOUTHERN OSCILLATION; ATMOSPHERIC CIRCULATION; UNITED-STATES; ANOMALIES AB Examining the relationship of El Nino to weather patterns in Alaska shows wide climate variances that depend on the teleconnection between the tropics and the northern latitudes. However, the weather patterns exhibited in Alaska during and just after moderate to strong El Nino episodes are generally consistent: above normal temperature and precipitation along the Alaskan coast, and above normal temperature and below normal precipitation in the interior, especially through the winter. The warm, dry conditions in the Alaskan interior increase summer wildfire potential. Statistics on the area burned since 1940 show that 15 out of 17 of the biggest fire years occurred during a moderate to strong El Nino episode. These 15 years account for nearly 63% of the total area burned over the last 58 years. Evidence points to increased dry thunderstorms and associated lightning activity during an El Nino episode; the percentage of total area burned by lightning caused fires during five episodes increased from a normal of less than 40% to a high of about 96%. C1 Anchorage Weather Serv, Forecast Off, Anchorage, AK 99502 USA. RP Hess, JC (reprint author), Natl Weather Serv, Alaska Reg, 222 W 7th Ave, Anchorage, AK 99513 USA. NR 18 TC 40 Z9 43 U1 0 U2 7 PU INT ASSOC WILDLAND FIRE PI CLANCY PA PO BOX 2156, CLANCY, MT 59634-2156 USA SN 1049-8001 J9 INT J WILDLAND FIRE JI Int. J. Wildland Fire PY 2001 VL 10 IS 1 BP 1 EP 13 DI 10.1071/WF01007 PG 13 WC Forestry SC Forestry GA 438EF UT WOS:000169040200001 ER PT J AU Schloesser, DW Nalepa, TF AF Schloesser, DW Nalepa, TF TI Changing abundance of Hexagenia mayfly nymphs in western Lake Erie of the Laurentian Great Lakes: Impediments to assessment of lake recovery? SO INTERNATIONAL REVIEW OF HYDROBIOLOGY LA English DT Article DE mayfly; lake recovery; recruitment; Laurentian Great Lakes ID BURROWING MAYFLIES; CONNECTING CHANNELS; LIMBATA; EPHEMEROPTERA; EPHEMERIDAE; SEDIMENTS AB After an absence of 40 years, mayfly nymphs of the genus Hexagenia were found in sediments of western Lake Erie of the Laurentian Great Lakes in 1993 and, by 1997, were abundant enough to meet a mayfly-density management goal (ca. 350 nymphs m(-2)) based on pollution-abatement programs. We sampled nymphs in western Lake Erie and Lake St. Clair, located upstream of western Lake Erie, to determine the importance of seasonal abundance and life-history characteristics of nymphs (e.g., emergence and recruitment) on density estimates relative to the mayfly-density management peal. Two types of density patterns were observed: (1) densities were relatively high in spring and gradually decreased through late summer (observed in Lake Erie and Lake St. Clair in 1997 and Lake St. Clair in 1999) and (2) densities were relatively high in spring, gradually decreased to mid summer, abruptly decreased in mid summer, and then increased between summer and late fall (Lake Erie and Lake St. Clair in 1998 and Lake Erie in 1999). Length-frequency distributions of nymphs and observations of adults indicate that the primary cause for the two density patterns was attributed to failed (first pattern) and successful (second pattern) reproduction and emergence of nymphs into adults in mid summer. Gradual declines in densities were attributed to mortality of nymphs. Our results indicate that caution should be used when evaluating progress of pollution-abatement programs based on mayfly densities because recruitment success is variable both between and within years. Additionally, the interpretation of progress toward management goals, relative to the restoration of Hexagenia populations in the Great Lakes and possibly other water bodies throughout the world, is influenced by the number of years in which consequtive collections are made. C1 US Geol Survey, Great Lakes Sci Ctr, Ann Arbor, MI 48105 USA. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Schloesser, DW (reprint author), US Geol Survey, Great Lakes Sci Ctr, Ann Arbor, MI 48105 USA. NR 45 TC 21 Z9 21 U1 0 U2 3 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 1434-2944 J9 INT REV HYDROBIOL JI Int. Rev. Hydrobiol. PY 2001 VL 86 IS 1 BP 87 EP 103 DI 10.1002/1522-2632(200101)86:1<87::AID-IROH87>3.3.CO;2-X PG 17 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 401FK UT WOS:000166917400005 ER PT J AU Dragnea, B Leone, SR AF Dragnea, B Leone, SR TI Advances in submicron infrared vibrational band chemical imaging SO INTERNATIONAL REVIEWS IN PHYSICAL CHEMISTRY LA English DT Review ID FIELD OPTICAL MICROSCOPY; SCANNING TUNNELING MICROSCOPE; ENHANCED RAMAN-SCATTERING; FREE-ELECTRON-LASER; ATOMIC-FORCE MICROSCOPE; ETCHED FIBER TIPS; NEAR-FIELD; SINGLE MOLECULES; SUBWAVELENGTH RESOLUTION; APERTURELESS MICROSCOPY AB The technique of infrared near-field microscopy with submicron resolution is an important addition to the chemical sciences arsenal in the last few years. Although related to highly successful scanning optical probe microscopies in the visible, infrared near-field microscopy had to overcome several obstacles, which slowed its development. This review illustrates the history as well as the state of the art of this new field, its limitations and perspectives. At present, two main experimental approaches have been successful: the apertureless metal tip approach and the fibre tip aperture approach. The two variants are compared from the point of view of resolution, ease of implementation in the laboratory and image formation mechanisms. The techniques using chemically specific vibrational absorption contrast are emphasized here, in the general context of chemical microscopy, which includes other methods such as chemical force,]Raman and fluorescence microscopies. The phenomenon of surface-enhanced infrared absorption is also mentioned in relation to near-field infrared microscopy, with regard to important aspects of image formation and possible improvements. The main advantages of spatial resolution, chemical sensitivity; non-intrusiveness, minute amounts of specimen and the possibility of quantitative analytical measurements make infrared near-field microscopy a powerful tool. We also examine here possible future applications that go beyond the limits of classical vibrational microspectroscopy, as well as directions for additional advances. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Dragnea, B (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 146 TC 20 Z9 20 U1 3 U2 10 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0144-235X J9 INT REV PHYS CHEM JI Int. Rev. Phys. Chem. PD JAN-MAR PY 2001 VL 20 IS 1 BP 59 EP 92 DI 10.1080/01442350010012557 PG 34 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 415BD UT WOS:000167699900003 ER PT B AU Nalli, NR Stowe, LL AF Nalli, NR Stowe, LL BE Smith, WL Timofeyev, YM TI Correcting AVHRR derived sea surface temperatures for the effects of atmospheric aerosols SO IRS 2000: CURRENT PROBLEMS IN ATMOSPHERIC RADIATION SE STUDIES IN GEOPHYSICAL OPTICS AND REMOTE SENSING LA English DT Proceedings Paper CT International Radiation Symposium CY JUL 24-29, 2000 CL ST PETERSBURG STATE UNIV, RES INST PHYS, ST PETERSBURG, RUSSIA SP Russian Fund Basic Res, NIERSC, NASA, EUMETSAT, NERSC HO ST PETERSBURG STATE UNIV, RES INST PHYS ID SATELLITE AB This paper describes the initial development of an aerosol correction algorithm for sea surface temperature from AVHRR. Our approach is to utilize the AVHRR Pathfinder Atmosphere (PATMOS) daily gridded radiance and aerosol optical depth data sets (1981-present) to provide an empirical correction for aerosol attenuation. Buoy measurements from the Pathfinder Oceans 1985-1998 matchup database are merged with the satellite gridded data. The merged data set will yield daytime equations applicable to operational and retrospective AVHRR data collected since its inception. Results from initial efforts to remove the effects of the 1991 Mt. Pinatubo aerosol bias are presented. C1 Colorado State Univ, CIRA, NOAA, NESDIS, Camp Springs, MD 20746 USA. RP Nalli, NR (reprint author), Colorado State Univ, CIRA, NOAA, NESDIS, Camp Springs, MD 20746 USA. RI Nalli, Nicholas/F-6731-2010 OI Nalli, Nicholas/0000-0002-6914-5537 NR 6 TC 0 Z9 0 U1 0 U2 0 PU A DEEPAK PUBLISHING PI HAMPTON PA 101 RESEARCH DRIVE, PO BOX 7390, HAMPTON, VA 23666 USA BN 0-937194-43-3 J9 STUD GEO OP PY 2001 BP 52 EP 55 PG 2 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Remote Sensing; Spectroscopy SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Remote Sensing; Spectroscopy GA BU75Q UT WOS:000176920100014 ER PT B AU Knapp, KR Stowe, LL AF Knapp, KR Stowe, LL BE Smith, WL Timofeyev, YM TI Deriving an aerosol optical depth climatology over land using AVHRR SO IRS 2000: CURRENT PROBLEMS IN ATMOSPHERIC RADIATION SE STUDIES IN GEOPHYSICAL OPTICS AND REMOTE SENSING LA English DT Proceedings Paper CT International Radiation Symposium CY JUL 24-29, 2000 CL ST PETERSBURG STATE UNIV, RES INST PHYS, ST PETERSBURG, RUSSIA SP Russian Fund Basic Res, NIERSC, NASA, EUMETSAT, NERSC HO ST PETERSBURG STATE UNIV, RES INST PHYS ID HIGH-RESOLUTION RADIOMETER; REFLECTANCE AB Retrieval of aerosol optical depth (AOD) over land from satellite platforms has been limited in comparison to the number of retrievals over oceanic areas. Significantly, the NOAA Advanced Very High Resolution Radiometer (AVHRR) has provided nearly 20 years of AOD retrievals over the oceans with no corresponding retrieval over land. This retrieval gap is primarily due to uncertainties in the surface reflecting properties limiting retrieval performance. However, the length of AVHRR observations allows this variation to be deduced, leaving a residual which we hypothesize is an aerosol signal. First, the aerosol signal is estimated by removing surface and Rayleigh scattering effects. Then this proposed aerosol signal is compared to ground measurements of AOD. Results suggest that this aerosol signal is present and could be used to retrieve AOD over some land regions. C1 CIRA, NOAA, NESDIS, ORA, Camp Springs, MD 20746 USA. RP Knapp, KR (reprint author), CIRA, NOAA, NESDIS, ORA, Camp Springs, MD 20746 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU A DEEPAK PUBLISHING PI HAMPTON PA 101 RESEARCH DRIVE, PO BOX 7390, HAMPTON, VA 23666 USA BN 0-937194-43-3 J9 STUD GEO OP PY 2001 BP 905 EP 908 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Remote Sensing; Spectroscopy SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Remote Sensing; Spectroscopy GA BU75Q UT WOS:000176920100232 ER PT B AU Stowe, LL Zhao, TXP AF Stowe, LL Zhao, TXP BE Smith, WL Timofeyev, YM TI Global oceanic validation of the NOAA/NESDIS second generation aerosol retrieval algorithm with aeronet sun-photometer observations SO IRS 2000: CURRENT PROBLEMS IN ATMOSPHERIC RADIATION SE STUDIES IN GEOPHYSICAL OPTICS AND REMOTE SENSING LA English DT Proceedings Paper CT International Radiation Symposium CY JUL 24-29, 2000 CL ST PETERSBURG STATE UNIV, RES INST PHYS, ST PETERSBURG, RUSSIA SP Russian Fund Basic Res, NIERSC, NASA, EUMETSAT, NERSC HO ST PETERSBURG STATE UNIV, RES INST PHYS AB In this paper, we describe our validation software system and present results of applying it to 1998 2(nd) generation operational aerosol observation (AEROBS) data from NOAA-14/AVHRR. Daily quality controlled (Level 2) sun-photometer (SP) data at AERONET island stations are used to compute aerosol optical thickness (AOT) and its Angstrom wavelength exponent (alpha) for the two solar reflectance channels (630nm and 830nm) of AVHRR. This is done whenever the AERONET data are coincident with "cloud-free" satellite (ST) observation within a 1 hour/100km time/space window. Linear regression analysis is performed, predicting the satellite retrieved values of AOT and alpha as a function of the sun-photometer derived values. Retrieval algorithm performance indicators (e.g., systematic and random error) are inferred from the resulting statistics. The principal causes of large errors, such as incorrect satellite calibration, ocean specular reflection, and aerosol model parameters, will be identified and corrected during on going development of a third generation algorithm. C1 NOAA, NESDIS, ORA, E RAI, Camp Springs, MD 20746 USA. RP Stowe, LL (reprint author), NOAA, NESDIS, ORA, E RAI, RM 712-S,WWBG,5200 Auth Rd, Camp Springs, MD 20746 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU A DEEPAK PUBLISHING PI HAMPTON PA 101 RESEARCH DRIVE, PO BOX 7390, HAMPTON, VA 23666 USA BN 0-937194-43-3 J9 STUD GEO OP PY 2001 BP 929 EP 932 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Remote Sensing; Spectroscopy SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Remote Sensing; Spectroscopy GA BU75Q UT WOS:000176920100238 ER PT B AU Schwarzkopf, MD Ramaswamy, V AF Schwarzkopf, MD Ramaswamy, V BE Smith, WL Timofeyev, YM TI Sensitivity to changes in cloud prediction schemes in a general circulation model SO IRS 2000: CURRENT PROBLEMS IN ATMOSPHERIC RADIATION SE STUDIES IN GEOPHYSICAL OPTICS AND REMOTE SENSING LA English DT Proceedings Paper CT International Radiation Symposium CY JUL 24-29, 2000 CL ST PETERSBURG STATE UNIV, RES INST PHYS, ST PETERSBURG, RUSSIA SP Russian Fund Basic Res, NIERSC, NASA, EUMETSAT, NERSC HO ST PETERSBURG STATE UNIV, RES INST PHYS ID PARAMETERIZATION; ATMOSPHERE AB The GFDL "SKYHI" general circulation model has been modified to include model-predicted clouds. The resulting climatological temperature and moisture fields differ substantially from those obtained in an experiment with the same model horizontal resolution, but using prescribed cloud fields. Cloud frequency of occurrence is similar to ISCCP observations for the free troposphere, but the predicted-cloud experiments overestimate cloudiness near the surface. The climatological outgoing longwave radiation and the net solar radiation at the top of the atmosphere both show substantial longitudinal variation, in contrast to the prescribed cloud version and similar to ERBE observations. The interannual and monthly variability of these fluxes is much larger in the predicted-cloud experiments than in the prescribed-cloud run. C1 NOAA, GFDL, Princeton, NJ 08542 USA. RP Schwarzkopf, MD (reprint author), NOAA, GFDL, Princeton, NJ 08542 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU A DEEPAK PUBLISHING PI HAMPTON PA 101 RESEARCH DRIVE, PO BOX 7390, HAMPTON, VA 23666 USA BN 0-937194-43-3 J9 STUD GEO OP PY 2001 BP 1283 EP 1286 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Remote Sensing; Spectroscopy SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Remote Sensing; Spectroscopy GA BU75Q UT WOS:000176920100329 ER PT S AU Legeckis, R Chang, P AF Legeckis, R Chang, P BE Sedberry, GR TI Geostationary satellite animation of the Gulf Stream at the Charleston Bump SO ISLAND IN THE STREAM: OCEANOGRAPHY AND FISHERIES OF THE CHARLESTON BUMP SE AMERICAN FISHERIES SOCIETY SYMPOSIUM LA English DT Proceedings Paper CT Charleston Bump Colloquium CY OCT, 1999 CL CHARLESTON, SC ID SOUTH-CAROLINA; DEFLECTION; SHELF AB The animation of daily composites of sea surface temperatures (SST) from a National Oceanic and Atmospheric Administration Geostationary Operational Environmental Satellite (GOES) provides a new method for the detection of dynamics at the surface of the ocean. By rapidly viewing the daily SST composites of hourly images, it is possible for the human eye to separate the fast moving residual clouds from the slowly moving SST patterns associated with ocean currents, eddies, and upwelling. Although each individual daily composite is still partly cloud covered, the rapid display provides the appearance of continuity of the SST patterns, The GOES SST animations were used during 1998 and 1999 to monitor the time dependent deflection of the Gulf Stream due to a rise in bottom topography southeast of Charleston, South Carolina, locally known as the Charleston Bump. Examples of the sea surface temperature animations of the Gulf Stream appear at the website: http://www.goes.noaa.gov. C1 Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Camp Springs, MD 20746 USA. RP Legeckis, R (reprint author), Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Rm-102,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Legeckis, Richard/F-5604-2010 NR 13 TC 2 Z9 2 U1 1 U2 1 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 USA SN 0892-2284 BN 1-888569-23-9 J9 AM FISH S S PY 2001 VL 25 BP 37 EP 41 PG 5 WC Fisheries; Oceanography SC Fisheries; Oceanography GA BU51Y UT WOS:000176234800003 ER PT S AU Cramer, J AF Cramer, J BE Sedberry, GR TI Geographic distribution of longline effort and swordfish discard rates in the straits of Florida and oceanic waters of the continental shelf, slope, and Blake Plateau off Georgia and the Carolinas from 1991 to 1995 SO ISLAND IN THE STREAM: OCEANOGRAPHY AND FISHERIES OF THE CHARLESTON BUMP SE AMERICAN FISHERIES SOCIETY SYMPOSIUM LA English DT Proceedings Paper CT Charleston Bump Colloquium CY OCT, 1999 CL CHARLESTON, SC AB The Gulf Stream off the east coasts of Florida, Georgia, and the Carolinas is one of the U. S. pelagic fishery regions in which particularly high swordfish discard rates were reported after a regulation limiting the landings of swordfish less than 25 kg whole weight went into effect in 1991. Swordfish Xiphias gladius fishing and catch locations from mandatory longline logbooks for the years 1991 through 1995 were used to explore the distribution patterns of swordfish discard rates in this region. Every 0.1 degree square of latitude and longitude was assigned a discard rate category (very high, moderate, low, none) for each month of the year based on the percentage of the swordfish catch that was discarded in that month over the five year period. Swordfish discard rates varied with latitude and season. The greatest seasonal changes were seen off the Carolinas where discard rates increased in the fall along with changes in fishing patterns. C1 Natl Marine Fisheries Serv, Miami, FL 33149 USA. RP Cramer, J (reprint author), Natl Marine Fisheries Serv, 75 Virginia Beach Dr, Miami, FL 33149 USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 USA SN 0892-2284 BN 1-888569-23-9 J9 AM FISH S S PY 2001 VL 25 BP 97 EP 103 PG 7 WC Fisheries; Oceanography SC Fisheries; Oceanography GA BU51Y UT WOS:000176234800005 ER PT S AU Vaughan, DS Manooch, CS Potts, JC AF Vaughan, DS Manooch, CS Potts, JC BE Sedberry, GR TI Assessment of the wreckfish fishery on the Blake Plateau SO ISLAND IN THE STREAM: OCEANOGRAPHY AND FISHERIES OF THE CHARLESTON BUMP SE AMERICAN FISHERIES SOCIETY SYMPOSIUM LA English DT Proceedings Paper CT Charleston Bump Colloquium CY OCT, 1999 CL CHARLESTON, SC ID POLYPRION-AMERICANUS AB The status of the wreckfish Polyprion americanus stock caught on the Blake Plateau in the southeastern United States Atlantic was analyzed by calibrated virtual population analysis (VPA) to estimate trends in fishing mortality and population (or stock) biomass. Calibration of the FADAPT VPA program was to fishery-dependent catch-per-unit effort (CPUE) for a range in assumed values for natural mortality (M). Age-length keys were developed from two aging studies of wreckfish (19881992 and 1995-1998). Keys were developed annually (pooled across seasons to create three "annual" age-length keys to represent 1988-1990, 1991-1993, and 1994-1998) and seasonally (pooled across years to create three seasonal age-length keys to represent April-June, July-September, and October to end of fishing year on 15 January). Analyses based on both annual and seasonal catch matrices showed similar patterns and values, with the seasonal catch matrix producing slightly lower estimates of fishing mortality rates (F) and higher estimates of biological reference points based on F. Fishing mortality rates peaked in 1989, as did the maximum annual U.S. landings (4.2 million pounds). Subsequently, both landings and fishing mortality rates have generally declined. Although stock biomass has generally declined over the study period, recruitment at age 7 has risen since about 1994. Meanwhile, annual estimates of static spawning potential ratio (SPR), which are inversely related to F, have risen since 1994. Fishing mortality rates from recent low landings are at or near the South Atlantic Fishery Management Council's threshold definition of overfishing (static SPR of 30%), while the process of rebuilding with improving recruitment appears to be underway. Concern persists because the assessment is based on the underlying assumption that wreckfish from the Blake Plateau form a single stock separate from the eastern North Atlantic and genetic evidence suggests the stock encompasses the entire North Atlantic. C1 NOAA, Beaufort Lab, Beaufort, NC 28516 USA. RP Vaughan, DS (reprint author), NOAA, Beaufort Lab, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. NR 26 TC 11 Z9 11 U1 1 U2 2 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 USA SN 0892-2284 BN 1-888569-23-9 J9 AM FISH S S PY 2001 VL 25 BP 105 EP 119 PG 15 WC Fisheries; Oceanography SC Fisheries; Oceanography GA BU51Y UT WOS:000176234800006 ER PT S AU Govoni, JJ Hare, JA AF Govoni, JJ Hare, JA BE Sedberry, GR TI The Charleston Gyre as a spawning and larval nursery habitat for fishes SO ISLAND IN THE STREAM: OCEANOGRAPHY AND FISHERIES OF THE CHARLESTON BUMP SE American Fisheries Society Symposium LA English DT Proceedings Paper CT Charleston Bump Colloquium CY OCT, 1999 CL CHARLESTON, SC ID SOUTHEASTERN UNITED-STATES; SOUTH-ATLANTIC BIGHT; BLUEFISH POMATOMUS-SALTATRIX; GULF-STREAM MEANDERS; CAPE-HATTERAS; MICROPOGONIAS-UNDULATUS; LEIOSTOMUS-XANTHURUS; SEAWARD DEFLECTION; CONTINENTAL-SHELF; NORTH-CAROLINA AB The region of the outer continental shelf and upper slope, encompassed roughly by 32 and 33degreesN and 78 and 79degreesW, is unique within the southeastern Atlantic coast of the United States because of the frequent presence of large (amplitudes of 50-100 km), cyclonic eddies, These eddies develop continuously north of the deflection of the Gulf Stream at the Charleston Bump and decay downstream. The cyclonic circulation of these eddies brings nutrient-rich water from deep and off the shelf edge to near surface and results in enhanced primary production. Succession of zooplankton assemblages, driven by enhanced primary production, might serve fish production by providing an exceptional, and more continuous food supply for larval fishes spawned in or entrained into eddies. In addition, larval fishes that risk entrainment into the Gulf Stream and consequent loss from local populations, can be retained on, or near, the shelf when embedded within these eddies. The residence of an eddy within the region ranges from a week to a month or two, while the larval period of most fishes ranges from weeks to months. The large-scale eddies in the region develop most frequently in winter when the Gulf Stream is in its strongly deflected mode, coincident with the spawning of a suite of commercially important fishes. Although the region of the Charleston Gyre has the potential to act as an important spawning and nursery habitat, published evidence of usage of the habitat afforded by large scale eddies in this region is weak. High concentrations of larval fishes occasionally occur in the region, but there is no indication of high concentrations of fish eggs. With its high primary and secondary production, succession of zooplankton assemblages, and retention mechanism, the region of the Gyre may constitute an important spawning and nursery habitat for fishes, but more research aimed at assessing Us potential is necessary. C1 NOAA, Natl Ocean Serv, Natl Ctr Coastal Ocean Sci, Ctr Coastal Fisheries & Habitat Res, Beaufort, NC 28516 USA. RP Govoni, JJ (reprint author), NOAA, Natl Ocean Serv, Natl Ctr Coastal Ocean Sci, Ctr Coastal Fisheries & Habitat Res, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. NR 65 TC 11 Z9 11 U1 1 U2 1 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 USA SN 0892-2284 BN 1-888569-23-9 J9 AM FISH S S JI Am. Fish. Soc. Symp. PY 2001 VL 25 BP 123 EP 136 PG 14 WC Fisheries; Oceanography SC Fisheries; Oceanography GA BU51Y UT WOS:000176234800007 ER PT S AU Vecchione, M AF Vecchione, M BE Sedberry, GR TI Cephalopods of the continental slope east of the United States SO ISLAND IN THE STREAM: OCEANOGRAPHY AND FISHERIES OF THE CHARLESTON BUMP SE AMERICAN FISHERIES SOCIETY SYMPOSIUM LA English DT Proceedings Paper CT Charleston Bump Colloquium CY OCT, 1999 CL CHARLESTON, SC ID SUBMERSIBLES; VERRILL AB Recent observations from trawling and submersibles have shown several species of cephalopods to be common in slope-waters of the western North Atlantic Ocean. The slope-water cephalopods include the commercially-important genus Illex, taxonomy of which remains troubling in the area off Charleston because of the possibility that L oxygonius is a hybrid. Other common species include another ommastrephid Ornithoteuthis antillarum, single species of Mastigoteuthis, Brachioteuthis, and Pholidoteuthis, several cranchiids, histioteuthids, and sepiolids, two octopodids, the pelagic incirrate octopod Haliphron atlanticus, and the cirrate octopod Stauroteuthis syrtensis. Behavior and distribution of these species contrast with those of truly open-ocean cephalopods, which also are present in slope waters. In-situ observations have shown that several of the squids are more strongly associated with the bottom than was previously supposed and that many of the slope-water cephalopods exhibit unexpected behaviors. C1 Natl Museum Nat Hist, Natl Systemat Lab, Natl Marine Fisheries Serv, Washington, DC 20560 USA. RP Vecchione, M (reprint author), Natl Museum Nat Hist, Natl Systemat Lab, Natl Marine Fisheries Serv, Washington, DC 20560 USA. NR 24 TC 9 Z9 9 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 USA SN 0892-2284 BN 1-888569-23-9 J9 AM FISH S S PY 2001 VL 25 BP 153 EP 160 PG 8 WC Fisheries; Oceanography SC Fisheries; Oceanography GA BU51Y UT WOS:000176234800009 ER PT S AU Brill, RW Lutcavage, ME AF Brill, RW Lutcavage, ME BE Sedberry, GR TI Understanding environmental influences on movements and depth distributions of tunas and billfishes can significantly improve population assessments SO ISLAND IN THE STREAM: OCEANOGRAPHY AND FISHERIES OF THE CHARLESTON BUMP SE American Fisheries Society Symposium LA English DT Proceedings Paper CT Charleston Bump Colloquium CY OCT, 1999 CL CHARLESTON, SC ID ATLANTIC BLUEFIN TUNA; THUNNUS-ALBACARES; YELLOWFIN TUNA; ULTRASONIC TELEMETRY; KATSUWONUS-PELAMIS; HORIZONTAL MOVEMENTS; ACOUSTIC TELEMETRY; VERTICAL MOVEMENTS; SPORTFISHING GEAR; HAWAIIAN-ISLANDS AB The vulnerability of the highly mobile tunas (family Scombridae) and billfishes (families Istiophoridae and Xiphiidae) to various fishing gears and detection by aerial surveys is influenced by their depth distributions, travel speeds, residency times, and aggregation. As a result, understanding the effects of the physical environment on fish behavior is critical for robust population assessments. Numerous studies have attempted to understand the movements and habitat requirements of tunas and billfishes by correlating catch statistics with environmental conditions averaged over time and space. Such correlations do not necessarily elucidate the requisite relationships because the data are not gathered simultaneously, and because error terms are often too broad to demonstrate meaningful relationships. More important, using catch statistics to determine the effects of environmental conditions on catch statistics can never prove causation and result in tautology, unless independent measures of fish abundance are available. The situation is not necessarily improved when catch statistics are correlated with satellite-derived sea surface temperature data. Tunas and billfish fish do not always live at the surface and, more importantly, regularly move through vertical thermal gradients (approximate to1degreesC m(-1)) that are orders of magnitude steeper than horizontal gradients (approximate to1degreesC km(-1)). Sea surface temperature gradients per se are, therefore, unlikely to influence horizontal movements or aggregation. Direct observations of tuna and billfish behaviors (collected via acoustic telemetry or electronic data-recording tags) can, however, be readily combined with information on their physiologically-based environmental tolerances, forage abundance, and appropriate oceanographic data. The resulting models can correct both traditional catch-per-unit effort data and aerial survey data for differences in gear vulnerability, and thus significantly improve population assessments. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. RP Brill, RW (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, 2570 Dole St, Honolulu, HI 96822 USA. NR 78 TC 103 Z9 106 U1 1 U2 13 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 USA SN 0892-2284 BN 1-888569-23-9 J9 AM FISH S S JI Am. Fish. Soc. Symp. PY 2001 VL 25 BP 179 EP 198 PG 20 WC Fisheries; Oceanography SC Fisheries; Oceanography GA BU51Y UT WOS:000176234800011 ER PT J AU Winchester, MR Miller, JK AF Winchester, MR Miller, JK TI Determination of fifteen elements in grey cast irons using glow discharge optical emission spectrometry SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article ID DEPTH PROFILE ANALYSIS; SPECTROSCOPY; PARAMETERS AB A glow discharge optical emission spectrometric (GD-OES) method for the simultaneous determination of C, P, S, Si, Mn, Cu, Ni, Mo, Cr, Ti, Sn, V, Al, Co and As in grey cast irons is described and demonstrated. White cast irons are used as calibrants, and a long, vigorous, presputtering routine is employed to allow stoichiometric sputtering to be attained prior to data acquisition for both the calibrants and unknowns. This approach effectively eliminates the matrix effect differences between white and grey irons that may occur in the absence of stoichiometric sputtering, thus enabling elemental determinations to be performed without type standardization. Drift correction is utilized to compensate for the effects of drifting instrument sensitivity. Data are presented and statistically evaluated to demonstrate the accuracy of the GD-OES method for each of the 15 elemental analytes. Analytical bias is shown to be inversely related to the mass fraction of the analyte in the sample. Without regard to analyte identity, the median relative bias is observed to be 1.14% when the analyte is present at mass fractions between 1 and 10%, while the median relative error is 15.1% when the analyte is present at mass fractions between 0.001 and 0.01%. C1 Natl Inst Stand & Technol, Div Analyt Chem, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. RP Winchester, MR (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 10 TC 3 Z9 5 U1 1 U2 1 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PY 2001 VL 16 IS 2 BP 122 EP 128 DI 10.1039/b007124m PG 7 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA 399LK UT WOS:000166812900003 ER PT J AU Yu, LL Kelly, WR Fassett, JD Vocke, RD AF Yu, LL Kelly, WR Fassett, JD Vocke, RD TI Determination of sulfur in fossil fuels by isotope dilution electrothermal vaporization inductively coupled plasma mass spectrometry SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article ID ICP-MS; TRACE; GAS; ELEMENTS; RATIOS; ARGON; ION AB The determination of S by solution nebulization quadrupole inductively coupled plasma mass spectrometry (ICP-MS) is difficult because of interferences from oxygen dimer ions. The large O-16(2)+ ion current from the solvent water is a serious interference at S-32, the most abundant of the four isotopes, and precludes its measurement. The isotopic composition of S varies in nature as a consequence of natural mass fractionation; therefore, high accuracy isotope dilution mass spectrometric (IDMS) determination of sulfur requires that the ratio of S-32/S-34 be measured, for the two isotopes represent over 99% of natural sulfur. In this work, electrothermal vaporization was used to generate a water-free aerosol of the sample. Non-solvent sources of oxygen were investigated and the spectral background minimized. Further reduction of the oxygen dimer was achieved by using nitrogen as an oxygen-scavenger in the argon plasma. The isotope ratio of S-32/S-34 was used for the determination of S by IDMS. The repeatability of the S-32/S-34 ratio in terms of the relative standard error (95% confidence level) of 6 replicate measurements of the spiked and the unspiked samples was about 0.3% and 0.7%, respectively. The detection limit of the method was 4 epsilon ng epsilong(-1). Sulfur in two fossil fuel reference materials was measured and the results were in good agreement (within 0.3%) with those obtained by the more precise thermal ionization mass spectrometry (TIMS) method. C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RP Yu, LL (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. RI Yu, Lee/N-7263-2015 OI Yu, Lee/0000-0002-8043-6853 NR 26 TC 44 Z9 47 U1 0 U2 5 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PY 2001 VL 16 IS 2 BP 140 EP 145 DI 10.1039/b008298h PG 6 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA 399LK UT WOS:000166812900006 ER PT J AU Tennyson, JM AF Tennyson, JM TI Seafoods SO JOURNAL OF AOAC INTERNATIONAL LA English DT Article ID BIOGENIC-AMINES; FISH; HISTAMINE C1 Natl Seafood Inspect Lab, Pascagoula, MS 39568 USA. RP Tennyson, JM (reprint author), Natl Seafood Inspect Lab, PO Drawer 1207, Pascagoula, MS 39568 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU AOAC INTERNATIONAL PI GAITHERSBURG PA 481 NORTH FREDRICK AVE, STE 500, GAITHERSBURG, MD 20877-2504 USA SN 1060-3271 J9 J AOAC INT JI J. AOAC Int. PD JAN-FEB PY 2001 VL 84 IS 1 BP 232 EP 235 PG 4 WC Chemistry, Analytical; Food Science & Technology SC Chemistry; Food Science & Technology GA 402RK UT WOS:000167001800044 PM 11234824 ER PT J AU Goldberg, MD Crosby, DS Zhou, LH AF Goldberg, MD Crosby, DS Zhou, LH TI The limb adjustment of AMSU-A observations: Methodology and validation SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID MODEL AB The Advanced Microwave Sounding Unit-A (AMSU-A) is the first of a new generation of polar-orbiting cross-track microwave sounders operated by the National Oceanic and Atmospheric Administration. A feature of a cross-track sounder is that the measurements vary with scan angle because of the change in the optical pathlength between the earth and the satellite. This feature is called the limb effect and can be as much as 30 K. One approach to this problem is to limb adjust the measurements to a fixed view angle. This approach was used for the older series of Microwave Sounding Units. Limb adjusting is important for climate applications and regression retrieval algorithms. This paper describes and evaluates several limb adjustment procedures. The recommended procedure uses a combined physical and statistical technique. The limb adjusted measurements were compared with computed radiances from radiosondes and National Centers for Environmental Prediction models. The model error was found to be less than the instrument noise for most of the temperature sounding channels. The error in the window channels was small relative to the observed range of these channels. Limb adjusted fields appear to be smooth. Statistical tests of the distributions of the adjusted measurements at each scan angle show them to be very similar. C1 NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD 20746 USA. American Univ, Washington, DC 20016 USA. QSS Grp Inc, Lanham, MD USA. RP Goldberg, MD (reprint author), NOAA, NESDIS, Off Res & Applicat, 5200 Auth Rd,Rm 810, Camp Springs, MD 20746 USA. RI Goldberg, Mitch/F-5589-2010; Zhou, Lihang/E-7938-2011 OI Zhou, Lihang/0000-0001-6232-2871 NR 14 TC 70 Z9 78 U1 1 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 1 BP 70 EP 83 DI 10.1175/1520-0450(2001)040<0070:TLAOAA>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 393NF UT WOS:000166476000005 ER PT J AU Li, J Menzel, WPA Schreiner, AJ AF Li, J Menzel, WPA Schreiner, AJ TI Variational retrieval of cloud parameters from GOES sounder longwave cloudy radiance measurements SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID CIRRUS CLOUDS; TIROS-N; WEATHER; CLIMATE; VAS; TEMPERATURE; SIMULATION; ALGORITHM; SOUNDINGS; HEIGHTS AB The optimal nonlinear inversion or one-dimensional variational (1DVAR) method was used to retrieve the cloud-top height and effective cloud amount from Geostationary Operational Environmental Satellite (GOES) sounder longwave spectral-band cloudy radiance measurements. The cloud-top pressure and effective cloud amount derived from the carbon dioxide (CO2)-slicing technique served as the background or first guess in the 1DVAR retrieval process. The atmospheric temperature profile, moisture profile, and surface skin temperature from the forecast analysis were used for the radiative transfer calculation in both the CO2-slicing method and the 1DVAR retrieval processing. Simulation studies were made to investigate the accuracy (the retrievals were compared with truth) of the cloud-top pressures and the effective cloud amounts derived from both the CO2-slicing and 1DVAR algorithms. Significant improvement of 1DVAR over CO2-slicing cloud properties was found in the simulation studies; an improvement of 10-50 hPa for root-mean-square error was obtained in 1DVAR over the CO2-slicing-derived cloud-top pressures, depending on the cloud height (high, mid, or low). This improvement came largely from the reduction of the bias in the 1DVAR retrievals over the CO2-slicing cloud-top pressures. The 1DVAR approach was applied to process the GOES-8 sounder cloudy radiance measurements; consistent with the simulation results, CO2 slicing assigned high and low clouds to lower levels than 1DVAR did. C1 Univ Wisconsin, CIMSS, SSEC, Madison, WI 53706 USA. NOAA, NESDIS, Off Res & Applicat, Madison, WI USA. RP Li, J (reprint author), Univ Wisconsin, CIMSS, SSEC, 1225 W Dayton St, Madison, WI 53706 USA. RI Menzel, W. Paul/B-8306-2011; Li, Jun/H-3579-2015 OI Menzel, W. Paul/0000-0001-5690-1201; Li, Jun/0000-0001-5504-9627 NR 34 TC 20 Z9 23 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 3 BP 312 EP 330 DI 10.1175/1520-0450(2001)040<0312:VROCPF>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 417ZD UT WOS:000167864600002 ER PT J AU Laird, NF Kristovich, DAR Liang, XZ Arritt, RW Labas, K AF Laird, NF Kristovich, DAR Liang, XZ Arritt, RW Labas, K TI Lake Michigan lake breezes: Climatology, local forcing, and synoptic environment SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID GREAT-LAKES; SEA-BREEZE; REGIONAL CLIMATE; SCALE FLOW; OZONE; TEMPERATURE; CLOUDS; WINDS; CAPE AB A method was developed to identify the occurrence of lake-breeze events along the eastern, western, and both shores of Lake Michigan during a 15-yr period (1982-96). Comparison with detailed observations from May through September of 1996-97 showed that the method reasonably identified Lake Michigan lake-breeze events. The method also demonstrated the important ability to distinguish non-lake-breeze events; a problem experienced by previously developed lake-breeze criteria. Analyses of the 15-yr climatological data indicated that lake breezes tended to occur more frequently along the eastern shore of Lake Michigan than along the western shore. On average, a maximum number of lake-breeze events occurred during August at each location. This maximum is most closely associated with weaker monthly average wind speeds. Even though the air-lake temperature difference DT provides the local forcing for the development of the lake-breeze circulation, large temperature differences are not required. Nearly 70% of all events occurred with a daytime maximum DeltaT less than or equal to 12 degreesC. The evaluation of a lake-breeze index epsilon used in past studies and many forecasting applications showed indices computed using offshore or shore-perpendicular wind speeds (U or |U|, respectively) at inland sites resolved greater than or equal to 95% of identified events based on critical epsilon values of 2-6. When wind speed, irrespective of wind direction, was used to calculate epsilon, the success of the critical indices decreased by as much as 26%. Results also showed that the lake-breeze index has a considerable tendency to overestimate the number of events. Although the possibility was suggested by previous investigations, the critical value of epsilon may not be appreciably affected by changes in location along the shoreline. In addition, noteworthy differences in the position of synoptic-scale sea level pressure and wind fields with respect to Lake Michigan were found to occur during eastern, western, and both-shore lake-breeze events. C1 Illinois State Water Survey, Illinois Dept Nat Resources, Atmospher Environm Sect, Champaign, IL 61820 USA. Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. Iowa State Univ, Dept Agron, Ames, IA USA. Natl Weather Serv, Chicago Forecast Off, Romeoville, IL USA. RP Laird, NF (reprint author), Illinois State Water Survey, Illinois Dept Nat Resources, Atmospher Environm Sect, 2204 Griffith Dr, Champaign, IL 61820 USA. OI Kristovich, David/0000-0001-9381-1053 NR 32 TC 26 Z9 28 U1 1 U2 19 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 3 BP 409 EP 424 DI 10.1175/1520-0450(2001)040<0409:LMLBCL>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 417ZD UT WOS:000167864600007 ER PT J AU MacGorman, DR Straka, JM Ziegler, CL AF MacGorman, DR Straka, JM Ziegler, CL TI A lightning parameterization for numerical cloud models SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID STORM ELECTRIFICATION; NEW-MEXICO; THUNDERSTORM; DISCHARGES; CHARGE; PRECIPITATION; THUNDERCLOUDS; HYDROMETEORS; INITIATION; AIRCRAFT AB A new lightning parameterization has been developed to enable cloud models to simulate the location and structure of individual lightning flashes more realistically. To do this, three aspects of previous parameterizations have been modified: 1) To account for subgrid-scale variations, the initiation point is chosen randomly from among grid points at which the electric field magnitude is above a threshold value, instead of being assigned always to the grid point having the maximum electric field magnitude. 2) The threshold value for initiation can either be constant, as in previous parameterizations, or can vary with height to allow different flash initiation hypotheses to be tested. 3) Instead of stopping at larger ambient electric field magnitudes, extensive flash development can continue in regions having a weak ambient electric field but a substantial charge density. This behavior is based on lightning observations and conceptual models of lightning physics. However, like previous parameterizations for cloud models, the new parameterization attempts to mimic only the gross structure of flashes, not the detailed development of lightning channels, the physics of which is only poorly understood. Though the choice of parameter values affects the dimensions of a flash, the qualitative features of simulated flash structure are similar to those of observed lightning as long as the parameter values are consistent with the larger electric field magnitudes measured in storms and with simulated charge densities produced over reasonably large regions. Initial simulations show that, by permitting development of flashes in regions of substantial charge density and weak ambient electric field, the new parameterization produces flash structure much like that of observed flashes, as would be expected from the inferred correlation between observed horizontal lightning structure and thunderstorm charge. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. Univ Oklahoma, Ctr Anal & Predict Storms, Norman, OK 73019 USA. RP MacGorman, DR (reprint author), Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, 100 E Boyd,Room 1110, Norman, OK 73019 USA. OI MacGorman, Donald/0000-0002-2395-8196 NR 61 TC 54 Z9 64 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 3 BP 459 EP 478 DI 10.1175/1520-0450(2001)040<0459:ALPFNC>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 417ZD UT WOS:000167864600010 ER PT J AU Matrosov, SY Reinking, RF Kropfli, RA Martner, BE Bartram, BW AF Matrosov, SY Reinking, RF Kropfli, RA Martner, BE Bartram, BW TI On the use of radar depolarization ratios for estimating shapes of ice hydrometeors in winter clouds SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID DUAL-POLARIZATION RADAR; SCATTERING AB An approach is suggested to relate measurements of radar depolarization ratios and aspect ratios of predominant hydrometeors in nonprecipitating and weakly precipitating layers of winter clouds. The trends of elevation angle dependencies of depolarization ratios are first used to distinguish between columnar-type and plate-type particles. For the established particle type, values of depolarization ratios observed at certain elevation angles, for which the influence of particle orientation is minimal, are then used to estimate aspect ratios when information on particle effective bulk density is assumed or inferred from other measurements. The use of different polarizations, including circular, slant-45 degrees linear, and two elliptical polarizations, is discussed. These two elliptical polarizations are quasi-circular and quasi-linear slant-45 degrees linear, and both are currently achievable with the National Oceanic and Atmospheric Administration Environmental Technology Laboratory's Ka-band radar. In comparison with the true circular and slant-45 degrees linear polarizations, the discussed elliptical polarizations provide a stronger signal in the "weak'' radar receiver channel; however, it is at the expense of diminished dynamic range of depolarization ratio variations. For depolarization measurements at the radar elevation angles that do not show much sensitivity to particle orientations, the available quasi-circular polarization provides a better depolarization contrast between nonspherical and spherical particles than does the available quasi-linear slant-45 degrees polarization. The use of the proposed approach is illustrated with the experimental data collected during a recent field experiment. It is shown that it allows successful differentiation among pristine planar crystals, rimed planar crystals, long columns, blocky columns, and graupel. When a reasonable assumption about particle bulk density is made, quantitative estimates of particle aspect ratios from radar depolarization data are in good agreement with in situ observations. Uncertainties of particle aspect ratios estimated from depolarization measurements due to 0.1 g cm(-3) variations in the assumed bulk density are about 0.1. C1 NOAA, Environm Technol Lab, Boulder, CO USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Matrosov, SY (reprint author), R-E-ET6,325 Broadway, Boulder, CO 80303 USA. NR 19 TC 39 Z9 40 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 3 BP 479 EP 490 DI 10.1175/1520-0450(2001)040<0479:OTUORD>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 417ZD UT WOS:000167864600011 ER PT J AU Keenan, TD Carey, LD Zrnic, DS May, PT AF Keenan, TD Carey, LD Zrnic, DS May, PT TI Sensitivity of 5-cm wavelength polarimetric radar variables to raindrop axial ratio and drop size distribution SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID DIFFERENTIAL PROPAGATION PHASE; POLARIZATION RADAR; LABORATORY MEASUREMENTS; EQUILIBRIUM SHAPE; RAINFALL RATE; OSCILLATIONS; SPECTRA; PRECIPITATION; MODEL; HAIL AB The sensitivity of polarimetric variables at a 5-cm wavelength to raindrop size and axial ratio is examined using T-matrix modeling of the scattering process for gamma raindrop size distributions fitted to tropical rainfall collected at Darwin, Australia. These simulations demonstrate that, while specific differential phase (KDP)-based estimates of rainfall, attenuation (A(H)), and differential attenuation are less affected by drop size distribution (DSD) variations, large drop occurrence can have significant impacts. Attenuation is sensitive to the occurrence of large drops, which can produce anomalously high values associated with resonance effect scattering. The polarimetric variables are sensitive to the relation between the equivolume diameter and axial ratio. Variations in the assumed form of the raindrop axial ratio can result in significant biases in rainfall and attenuation. Combined rainfall estimators, which include differential reflectivity (Z(DR)), such as R(K-DP, Z(DR)) and R(A(H), Z(DR)) are more robust to both DSD and raindrop axial ratio variations. The results also demonstrate that polarimetric techniques employed to classify the phase of hydrometeors are sensitive to the assumed raindrop axial ratio. C1 Bur Meteorol Res Ctr, Melbourne, Vic 3001, Australia. Colorado State Univ, Ft Collins, CO 80523 USA. NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Keenan, TD (reprint author), Bur Meteorol Res Ctr, GPO Box 1289K, Melbourne, Vic 3001, Australia. NR 64 TC 54 Z9 59 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 3 BP 526 EP 545 DI 10.1175/1520-0450(2001)040<0526:SOCWPR>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 417ZD UT WOS:000167864600014 ER PT J AU Plokhenko, Y Menzel, WP AF Plokhenko, Y Menzel, WP TI Mathematical aspects in meteorological processing of infrared spectral measurements from the GOES sounder. Part I: Constructing the measurement estimate using spatial smoothing SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article AB The accuracy of temperature and moisture vertical profiles retrieved from infrared spectral measurements is dependent on accurate definition of all contributions from the observed "surface-atmosphere'' system to the outgoing radiances. The associated inverse problem is ill posed. Instrument noise is a major contributor to errors in modeling spectral measurements. This paper considers an approach for noise reduction in the Geostationary Operational Environmental Satellite (GOES) spectral channels using spatial averaging that is based upon spectral characteristics of the measurements, spatial properties of atmospheric fields of temperature and moisture, and properties of the inverse problem. Spatial averaging over different fields of regard is studied for the GOES-8 sounder spectral bands. Results of the statistical analysis are presented. C1 ROSHYDROMET, Res Ctr Planeta, Moscow, Russia. NOAA, NESDIS, Off Res & Applicat, Madison, WI USA. RP Plokhenko, Y (reprint author), Univ Wisconsin, CIMSS, 1225 W Dayton St, Madison, WI 53706 USA. RI Menzel, W. Paul/B-8306-2011 OI Menzel, W. Paul/0000-0001-5690-1201 NR 5 TC 5 Z9 5 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 3 BP 556 EP 567 DI 10.1175/1520-0450(2001)040<0556:MAIMPO>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 417ZD UT WOS:000167864600016 ER PT J AU Joyce, R Janowiak, J Huffman, G AF Joyce, R Janowiak, J Huffman, G TI Latitudinally and seasonally dependent zenith-angle corrections for geostationary satellite IR brightness temperatures SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID CLOUD AB The equivalent brightness temperature T-b recorded by geosynchronous infrared (geo-IR) "window'' channel (10.7-11.5 mum) satellite sensors is shown to depend on the zenith angle (local angle from the zenith to the satellite for a pixel's ground location) in addition to the mix of clouds and surface that would be observed from a direct overhead viewpoint (nadir view). This zenith-angle dependence is characterized, and two corrections are developed from a collection of half-hourly geo-IR pixel data that have been parallax corrected and averaged to a 0.5 degrees X 0.5 degrees latitude/longitude grid for each geosynchronous satellite separately. First, composites of collocated T-b over tropical regions from the Geostationary Operational Environmental Satellite (GOES)-8/GOES-10 and the Meteosat-5/Meteosat-7 satellite pairs are used to produce robust estimates of isotropic zenith-angle corrections as a function of zenith angle and grid-box-averaged T-b. The corrections range from zero for a zenith angle of similar to 26.5 degrees to increases of more than 20 K at T-b 5 230 K near the limb. Near-limb corrections in clear and very cold thick overcast conditions are smaller but are still positive. This empirical result depends on the surface-tropopause temperature differences, so a second correction was developed. Using collocations from the same two satellite pairs from 60 degreesN to 60 degreesS, differences in uncorrected T-b divided by differences in the corresponding corrected values were accumulated as a function of latitude and season. The resultant ratios smoothly vary from similar to1 in the Tropics to similar to0.5 at 60 degreesN and 60 degreesS, with a quicker decrease in the winter hemisphere. In comparison with the uncorrected geo-IR data, there is a 50% reduction in the root-mean-square differences between collocated values from adjacent satellites by applying the latitude/season-adjusted zenith-angle corrections. Histograms of corrected geo-IR T-b at large zenith angles closely match histograms from collocated near-nadir-view values. Residual difference maps are smooth and indicate intersatellite differences. C1 NOAA, Climate Predict Ctr, NCEP, Washington, DC USA. Res & Data Syst Corp, Greenbelt, MD USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Joyce, R (reprint author), NOAA, Climate Predict Ctr, NCEP, Room 605A,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Huffman, George/F-4494-2014 OI Huffman, George/0000-0003-3858-8308 NR 15 TC 32 Z9 33 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 4 BP 689 EP 703 DI 10.1175/1520-0450(2001)040<0689:LASDZA>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 420TV UT WOS:000168022100002 ER PT J AU Schuur, TJ Ryzhkov, AV Zrnic, DS Schonhuber, M AF Schuur, TJ Ryzhkov, AV Zrnic, DS Schonhuber, M TI Drop size distributions measured by a 2D video disdrometer: Comparison with dual-polarization radar data SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID DIFFERENTIAL PHASE; CONVECTIVE CLOUDS; RAINDROP SPECTRA; RAINFALL; STRATIFORM AB An analysis of drop size distributions (DSDs) measured in four very different precipitation regimes is presented and is compared with polarimetric radar measurements. The DSDs are measured by a 2D video disdrometer, which is designed to measure drop size, shape, and fall speed with unprecedented accuracy. The observations indicate that significant DSD variability exists not only from one event to the next, but also within each system. Also, despite having vastly different storm structures and maximum rain rates, large raindrops with diameters greater than 5 mm occurred with each system. By comparing the occurrence of large drops with rainfall intensity, the authors find that the largest median diameters are not always associated with the heaviest rainfall, but are sometimes located either in advance of convective cores or, occasionally, in stratiform regions where rainfall rates are relatively low. Disdrometer and polarimetric radar measurements of radar reflectivity Z, differential reflectivity Z(DR), specific differential phase K-DP, and R(Z) and R(K-DP) rain-rate estimators are compared in detail. Overall agreement is good, but it is found that both R(Z) and R(K-DP) underestimate rain rate when the DSD is dominated by small drops and overestimate rain rate when the DSD is dominated by large drops. The results indicate that a classification of different rain types (associated with different DSDs) should be an essential part of polarimetric rainfall estimation. Furthermore, observations suggest that Z(DR) is a key parameter for making such a distinction. Last, the authors compute and compare maximum and average of gamma shape, slope, and intercept parameters for all four precipitation events. Potential measurement errors with the 2D video disdrometer are also discussed. C1 Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. Joanneum Res, Graz, Austria. RP Schuur, TJ (reprint author), Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 32 TC 48 Z9 50 U1 0 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 6 BP 1019 EP 1034 DI 10.1175/1520-0450(2001)040<1019:DSDMBA>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 439RZ UT WOS:000169132500004 ER PT J AU Testud, J Oury, S Black, RA Amayenc, P Dou, XK AF Testud, J Oury, S Black, RA Amayenc, P Dou, XK TI The concept of "normalized'' distribution to describe raindrop spectra: A tool for cloud physics and cloud remote sensing SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID DROP-SIZE DISTRIBUTIONS; CONVECTIVE CLOUDS; WEATHER RADAR; TROPICAL RAIN; BREAKUP; COALESCENCE; PARAMETERIZATION; EQUILIBRIUM; EVOLUTION; ATTENUATION AB The shape of the drop size distribution (DSD) reflects the physics of rain. The DSD is the result of the microphysical processes that transform the condensed water into rain. The question of the DSD is also central in radar meteorology, because it rules the relationships between the radar reflectivity and the rainfall rate R. Normalizing raindrop spectra is the only way to identify the shape of the distribution. The concept of normalization of DSD developed in this paper is founded upon two reference variables, the liquid water content LWC and the mean volume diameter D-m. It is shown mathematically that it is appropriate to normalize by N-0* proportional to LWC/D-m(4) with respect to particle concentration and by D-m with respect to drop diameter. Also, N-0* may be defined as the intercept parameter N* 0 that would have an exponential DSD with the same LWC and D-m as the real one. The major point of the authors' approach is that it is totally free of any assumption about the shape of the DSD. This new normalization has been applied to the airborne microphysical data of the Tropical Ocean and Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) collected by the National Center for Atmospheric Research Electra aircraft. The classification of the TOGA COARE raindrop spectra into four categories [one stratiform, and three convective (0-10, 10-30, and 30-100 mm h(-1))] allowed the following features to be identified. 1) There is a distinct behavior of N-0* between stratiform and convective rains; typical values are 2.2 x 10(6) m(-4) for stratiform and 2 x 10(7) m(-4) for convective. 2) In convective rain, there is a clear trend for D-m to increase with R, but there is no correlation between N-0* and R. 3) The "average'' normalized shape of the DSD is remarkably stable among the four rain categories. This normalized shape departs from the exponential, but also from all the analytical shapes considered up to now (e.g., gamma, lognormal, modified gamma). The stability of the normalized DSD shape and the physical variability of N-0* and D-m are discussed in respect to the equilibrium theory of List et al. The stability of the shape implies that two parameters (and only two) are needed to describe the DSD. This stability supports the robustness of rain relations parameterized by. N-0* The same TOGA COARE dataset is used to check that the rain relations parameterized by N-0*are much less dispersed than the classical ones, even after rain-type classification. C1 CETP UVSQ, Inst Pierre Simon Laplace, F-78140 Velizy Villacoublay, France. NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. Univ Sci & Technol China, Dept Earth & Space Sci, Anhua 230026, Peoples R China. RP CETP UVSQ, Inst Pierre Simon Laplace, 10-12 Ave Europe, F-78140 Velizy Villacoublay, France. EM testud@cetp.ipsl.fr RI Black, Robert/C-9617-2009; Dou, xiankang/M-9106-2013 OI Black, Robert/0000-0001-6938-125X; NR 44 TC 231 Z9 238 U1 8 U2 26 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 6 BP 1118 EP 1140 DI 10.1175/1520-0450(2001)040<1118:TCONDT>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 439RZ UT WOS:000169132500012 ER PT J AU Xu, Q Gu, HD Qiu, CJ AF Xu, Q Gu, HD Qiu, CJ TI Simple adjoint retrievals of wet-microburst winds and gust-front winds from single-Doppler radar data SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID PHOENIX-II; 3-DIMENSIONAL WIND; BOUNDARY-LAYER; FIELDS; REFLECTIVITY; AIR AB The simple adjoint method for retrieving the low-altitude winds from single-Doppler scans is modified and tested for two events: the wet-microburst event and the gust-front event observed simultaneously by two radars during the Federal Aviation Administration-1990 summer field experiment at Orlando Airport. For the wet microburst, 42 consecutive wind fields are retrieved from each radar and the rms errors (measured by the rms difference between the retrieved and dual-Doppler analyzed winds) range from 1.1 to 4.9 m s(-1), and the averaged error is 2.4 m s(-1). For the gust front, 22 consecutive wind fields are retrieved from each radar, the rms errors range from 1.2 to 2.9 m s(-1), and the averaged error is 1.9 m s(-1). The rms error and spatial correlation between the retrieved and analyzed cross-beam tangential winds exhibit strong temporal variations for the wet microburst and moderate temporal variations for the gust front. The rms error is found to be temporally correlated to the rms amplitude of the retrieved radial-momentum forcing for the wet microburst. C1 Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. RP Xu, Q (reprint author), Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 14 TC 15 Z9 15 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 8 BP 1485 EP 1499 DI 10.1175/1520-0450(2001)040<1485:SAROWM>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 461ZP UT WOS:000170394000014 ER PT J AU Ba, MB Gruber, A AF Ba, MB Gruber, A TI GOES multispectral rainfall algorithm (GMSRA) SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID PRECIPITATION; RETRIEVAL; GAUGE; CLOUD; SCATTERING AB A multispectral approach is used to optimize the identification of raining clouds located at a given altitude estimated from the cloud-top temperature. The approach combines information from five channels on the National Oceanic and Atmospheric Administration Geostationary Operational Environmental Satellite (GOES): visible (0.65 mum), near infrared (3.9 mum), water vapor (6.7 mum), and window channels (11 and 12 mum). The screening of nonraining clouds includes the use of spatial gradient of cloud-top temperature for cirrus clouds (this screening is applied at all times) and the effective radius of cloud-top particles derived from the measurements at 3.9 mum during daytime. During nighttime, only clouds colder than 230 K are considered for the screening; during daytime, all clouds having a visible reflectance greater than 0.40 are considered for the screening, and a threshold of 15 mum in droplet effective radius is used as a low boundary of raining clouds. A GOES rain rate for each indicated raining cloud group referenced by its cloud-top temperature is obtained by the product of probability of rain (P-b) and mean rain rate (RRmean) and is adjusted by a moisture factor that is designed to modulate the evaporation effects on rain below cloud base for different moisture environments. The calibration of the algorithm for constants P-b and RRmean is obtained using collocated instantaneous satellite and radar data and hourly gauge-adjusted radar products collected during 17 days in June and July 1998. A comparison of the combined visible and a temperature threshold of 230 K (e.g., previous infrared/visible algorithms) with the combined visible and a threshold of 15 mum demonstrates that the latter improves the detection of rain from warm clouds without lowering the skill of the algorithm. The quantitative validation shows that the algorithm performs well at daily and monthly scales. At monthly scales, a comparison with GOES Precipitation Index (GPI) shows that GOES Multispectral Rainfall Algorithm's performance against gauges is much better for September and October 1999. C1 Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. NOAA, NESDIS, Camp Springs, MD USA. RP Ba, MB (reprint author), Raytheon ITSS, 4400 Forbes Blvd, Lanham, MD 20706 USA. NR 29 TC 104 Z9 109 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 8 BP 1500 EP 1514 DI 10.1175/1520-0450(2001)040<1500:GMRAG>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 461ZP UT WOS:000170394000015 ER PT J AU Kuligowski, RJ Barros, AP AF Kuligowski, RJ Barros, AP TI Blending multiresolution satellite data with application to the initialization of an orographic precipitation model SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID SCHEME AB The use of multisensor, multifrequency satellite data to specify initial conditions for numerical weather prediction (NWP) models offers a unique opportunity to improve the depiction of small-scale processes in the atmosphere through a myriad of data assimilation approaches. The authors previously developed an algorithm to retrieve temperature and dewpoint profiles from a combination of infrared [high-resolution infrared radiation sounder (HIRS), 18-20-km resolution] and microwave [Advanced Microwave Sounding Unit-A (AMSU-A), 48-km resolution] data, using collocated radiosondes. Besides (and separately from) the estimation problem, one key question in the context of model initialization is how to blend multiresolution data to generate fields at the spatial resolution of the NWP model of interest. In this paper, a fractal downscaling technique is proposed to blend multiresolution satellite data and generate brightness temperature fields at 1-km resolution. The downscaled HIRS and AMSU-A data subsequently can be processed by the retrieval algorithm to derive temperature and dewpoint fields at the same resolution. The utility of these products as an initial condition for NWP models was assessed in the context of regional quantitative precipitation forecasting (QPF) applications using a limited-area orographic precipitation model nested with a mesoscale model. Results from the simulation of a wintertime storm in the Pocono Mountains of the mid-Atlantic region show improvement in QPF skill when the satellite-derived initial conditions were used. However, the disparity between the sparse times when the satellite data are available (12-h intervals) vis-a-vis the hourly import of boundary conditions from the host model lessens the impact of improved initial conditions. This result suggests that gains in QPF skill are linked to the availability of relevant remote sensing data at time intervals consistent with the useful memory of initial conditions in NWP models. C1 Natl Environm Satellite Data & Informat Serv, Camp Springs, MD USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP Barros, AP (reprint author), 118 Pierce Hall,29 Oxford St, Cambridge, MA 02138 USA. RI Kuligowski, Robert/C-6981-2009; Barros, Ana/A-3562-2011 OI Kuligowski, Robert/0000-0002-6909-2252; Barros, Ana/0000-0003-4606-3106 NR 9 TC 5 Z9 5 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 9 BP 1592 EP 1606 DI 10.1175/1520-0450(2001)040<1592:BMSDWA>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 464WK UT WOS:000170554600004 ER PT J AU Kummerow, C Hong, Y Olson, WS Yang, S Adler, RF McCollum, J Ferraro, R Petty, G Shin, DB Wilheit, TT AF Kummerow, C Hong, Y Olson, WS Yang, S Adler, RF McCollum, J Ferraro, R Petty, G Shin, DB Wilheit, TT TI The evolution of the Goddard profiling algorithm (GPROF) for rainfall estimation from passive microwave sensors SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID PRECIPITATION RETRIEVAL; RADIATIVE-TRANSFER; CLOUD MODEL; TOGA COARE; IMAGER; APPROXIMATION; RESOLUTION; INDEXES; OCEAN; RADAR AB This paper describes the latest improvements applied to the Goddard profiling algorithm (GPROF), particularly as they apply to the Tropical Rainfall Measuring Mission (TRMM). Most of these improvements, however, are conceptual in nature and apply equally to other passive microwave sensors. The improvements were motivated by a notable overestimation of precipitation in the intertropical convergence zone. This problem was traced back to the algorithm's poor separation between convective and stratiform precipitation coupled with a poor separation between stratiform and transition regions in the a priori cloud model database. In addition to now using an improved convective-stratiform classification scheme, the new algorithm also makes use of emission and scattering indices instead of individual brightness temperatures. Brightness temperature indices have the advantage of being monotonic functions of rainfall. This, in turn, has allowed the algorithm to better define the uncertainties needed by the scheme's Bayesian inversion approach. Last, the algorithm over land has been modified primarily to better account for ambiguous classification where the scattering signature of precipitation could be confused with surface signals. All these changes have been implemented for both the TRMM Microwave Imager (TMI) and the Special Sensor Microwave Imager (SSM/I). Results from both sensors are very similar at the storm scale and for global averages. Surface rainfall products from the algorithm's operational version have been compared with conventional rainfall data over both land and oceans. Over oceans, GPROF results compare well with atoll gauge data. GPROF is biased negatively by 9% with a correlation of 0.86 for monthly 2.5 degrees averages over the atolls. If only grid boxes with two or more atolls are used, the correlation increases to 0.91 but GPROF becomes positively biased by 6%. Comparisons with TRMM ground validation products from Kwajalein reveal that GPROF is negatively biased by 32%, with a correlation of 0.95 when coincident images of the TMI and Kwajalein radar are used. The absolute magnitude of rainfall measured from the Kwajalein radar, however, remains uncertain, and GPROF overestimates the rainfall by approximately 18% when compared with estimates done by a different research group. Over land, GPROF shows a positive bias of 17% and a correlation of 0.80 over monthly 5 degrees grids when compared with the Global Precipitation Climatology Center (GPCC) gauge network. When compared with the precipitation radar (PR) over land, GPROF also retrieves higher rainfall amounts (20%). No vertical hydrometeor profile information is available over land. The correlation with the TRMM precipitation radar is 0.92 over monthly 5 degrees grids, but GPROF is positively biased by 24% relative to the radar over oceans. Differences between TMI- and PR- derived vertical hydrometeor profiles below 2 km are consistent with this bias but become more significant with altitude. Above 8 km, the sensors disagree significantly, but the information content is low from both TMI and PR. The consistent bias between these two sensors without clear guidance from the ground-based data reinforces the need for better understanding of the physical assumptions going into these retrievals. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Aerosp Corp, Los Angeles, CA 90009 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, NESDIS, Camp Springs, MD USA. Univ Wisconsin, Madison, WI USA. Texas A&M Univ, College Stn, TX USA. RP Kummerow, C (reprint author), Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RI Petty, Grant/E-3118-2012; Wilheit, Thomas/G-9438-2012; Ferraro, Ralph/F-5587-2010 OI Ferraro, Ralph/0000-0002-8393-7135 NR 56 TC 491 Z9 503 U1 3 U2 30 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 11 BP 1801 EP 1820 DI 10.1175/1520-0450(2001)040<1801:TEOTGP>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 486BF UT WOS:000171798000002 ER PT J AU Kuligowski, RJ Barros, AP AF Kuligowski, RJ Barros, AP TI Combined IR-microwave satellite retrieval of temperature and dewpoint profiles using artificial neural networks SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID NUMERICAL WEATHER PREDICTION; PHYSICAL INITIALIZATION; DIABATIC INITIALIZATION; MESOSCALE ANALYSIS; BACKPROPAGATION ALGORITHM; SURFACE-TEMPERATURE; DATA ASSIMILATION; ERROR FUNCTION; WATER-VAPOR; MODEL AB Radiance measurements from satellites offer the opportunity to retrieve atmospheric variables at much higher spatial resolution than is presently afforded by in situ measurements (e.g., radiosondes). However, the accuracy of these retrievals is crucial to their usefulness, and the ill-posed nature of the problem precludes a straightforward solution. A number of retrieval approaches have been investigated, including empirical techniques, coupling with numerical weather prediction models, and data analysis techniques such as regression. In this paper, artificial neural networks are used to retrieve vertical temperature and dewpoint profiles from infrared and microwave brightness temperatures from a polar-orbiting satellite. This approach allows retrievals to be performed even in cloudy conditions-a limitation of infrared-only retrievals. In a direct comparison of this technique with results from the operational Advanced Television and Infrared Observation Satellite Operational Vertical Sounder (ATOVS) retrievals, it was found that the neural-network temperature retrievals had larger errors than the ATOVS retrievals (though generally smaller than the first guess used in the ATOVS retrievals) but that the dewpoint retrievals showed consistent improvement over the comparable ATOVS retrievals. C1 Natl Environm Satellite Data & Informat Serv, Camp Springs, MD USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP Barros, AP (reprint author), 118 Pierce Hall,29 Oxford St, Cambridge, MA 02138 USA. RI Kuligowski, Robert/C-6981-2009; Barros, Ana/A-3562-2011 OI Kuligowski, Robert/0000-0002-6909-2252; Barros, Ana/0000-0003-4606-3106 NR 52 TC 18 Z9 20 U1 2 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2001 VL 40 IS 11 BP 2051 EP 2067 DI 10.1175/1520-0450(2001)040<2051:CIMSRO>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 486BF UT WOS:000171798000016 ER PT J AU Levin, I Robins, LH Vaudin, MD Tuchman, JA Lakin, E Sherman, MJ Ramer, J AF Levin, I Robins, LH Vaudin, MD Tuchman, JA Lakin, E Sherman, MJ Ramer, J TI Spontaneous compositional modulation in the AlGaN layers of a thick AlGaN/GaN multilayer structure SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SEMICONDUCTOR ALLOYS; ALXGA1-XN FILMS; PHOTOLUMINESCENCE; GAN; SPECTROSCOPY; ORDER; SCALE AB A periodic modulation with the wave vector parallel to the [0001] direction was observed in the AlGaN layers of a thick AlGaN/GaN multilayer heterostructure grown by metalorganic chemical vapor deposition. The modulation was attributed to a nearly sinusoidal spatial variation of the Al/Ga ratio with an average periodicity of about 3 nm. The observed periodicity was highly regular and incommensurate with the periodicity of the underlying lattice. The average Al fraction in the AlxGa1-xN layers was estimated to be x = 0.115 +/-0.010 and the peak-to-valley amplitude of the modulation was estimated to be Deltax = 0.075 +/-0.016. (C) 2001 American Institute of Physics. C1 Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. Principia Lightworks, Pasadena, CA 91103 USA. Technion Israel Inst Technol, Wolfson Ctr Interface Sci, IL-32000 Haifa, Israel. EMCORE Corp, Res Lab, Somerset, NJ 08873 USA. RP Levin, I (reprint author), Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RI Levin, Igor/F-8588-2010 NR 12 TC 9 Z9 9 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 1 PY 2001 VL 89 IS 1 BP 188 EP 193 DI 10.1063/1.1329665 PG 6 WC Physics, Applied SC Physics GA 387JF UT WOS:000166118900030 ER PT J AU Roytburd, AL Alpay, SP Bendersky, LA Nagarajan, V Ramesh, R AF Roytburd, AL Alpay, SP Bendersky, LA Nagarajan, V Ramesh, R TI Three-domain architecture of stress-free epitaxial ferroelectric films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THIN-FILMS; POLYDOMAIN HETEROSTRUCTURES; THERMODYNAMICS; DEPOSITION; RELAXATION AB Epitaxial ferroelectric films undergoing a cubic-tetragonal phase transformation relax internal stresses due to the structural phase transformation and the difference in the thermal expansion coefficients of the film and the substrate by forming polydomain structures. The most commonly observed polydomain structure is the c/a/c/a polytwin which only partially relieves the internal stresses. Relatively thicker films may completely reduce internal stresses if all three variants of the ferroelectric phase are brought together such that the film has the same in-plane size as the substrate. In this article, we provide experimental evidence on the formation of the three-domain structure based on transmission electron microscopy in 450 nm thick (001) PbZr0.2Ti0.8O3 films on (001) SrTiO3 grown by pulsed laser deposition. X-ray diffraction studies show that the film is fully relaxed. Experimental data is analyzed in terms of a domain stability map. It is shown that the observed structure in epitaxial ferroelectric films is due to the interplay between relaxation by misfit dislocations at the deposition temperature and relaxation by polydomain formation below the phase transformation temperature. (C) 2001 American Institute of Physics. C1 Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Roytburd, AL (reprint author), Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. RI Alpay, Pamir/E-2666-2013; valanoor, nagarajan/B-4159-2012 NR 21 TC 69 Z9 71 U1 5 U2 16 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 1 PY 2001 VL 89 IS 1 BP 553 EP 556 DI 10.1063/1.1328781 PG 4 WC Physics, Applied SC Physics GA 387JF UT WOS:000166118900086 ER PT J AU Osborn, DL Leone, SR AF Osborn, DL Leone, SR TI Spectral and intensity dependence of spatially resolved two-photon conductivity defects on a GaAsP photodiode SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SCANNING OPTICAL MICROSCOPY; WAVE-GUIDE; 2-PHOTON PHOTOCONDUCTIVITY; LASER-PULSES; AUTOCORRELATOR; SEMICONDUCTORS; PHOTOCURRENT; ABSORPTION; RESOLUTION; DEVICES AB Femtosecond laser excitation through a near-field scanning optical microscope is used to study spatially resolved defects in the two-photon conductivity of a GaAs0.6P0.4 diffusion type photodiode. Two types of defects are observed when the photodiode is excited with femtosecond pulses below the bulk band gap energy. Photocurrent enhancement defects show a higher photocurrent than the surrounding areas and are driven by both one-and two-photon processes. These defects are often correlated with pits in the photodiode surface. Photocurrent depression defects have the normal two-photon power dependence and are not associated with surface pits. Based on the low measured coverage of both defect sites, the performance of GaAsP in auto- and cross correlators will be unaffected in most situations. A deviation in alloy stoichiometry, in which localized areas are rich in arsenic while poor in phosphorus, provides the best explanation for the origin of the enhancement defects. (C) 2001 American Institute of Physics. C1 Natl Inst Stand & Technol, Quantum Phys Div, Boulder, CO 80309 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Leone, SR (reprint author), Natl Inst Stand & Technol, Quantum Phys Div, 325 Broadway, Boulder, CO 80309 USA. RI Osborn, David/A-2627-2009 NR 27 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 1 PY 2001 VL 89 IS 1 BP 626 EP 633 DI 10.1063/1.1329351 PG 8 WC Physics, Applied SC Physics GA 387JF UT WOS:000166118900097 ER PT J AU Kirk, JP Killgore, KJ Morrow, JV Lamprecht, SD Cooke, DW AF Kirk, JP Killgore, KJ Morrow, JV Lamprecht, SD Cooke, DW TI Movements of triploid grass carp in the Cooper River, South Carolina SO JOURNAL OF AQUATIC PLANT MANAGEMENT LA English DT Article; Proceedings Paper CT 40th Annual Meeting of the Aquatic-Plant-Management-Society CY JUL 16-20, 2000 CL SAN DIEGO, CALIFORNIA DE aquatic plants; migration; Hydrilla verticillata ID CTENOPHARYNGODON-IDELLA; TEXAS AB The movements of triploid grass carp (Ctenopharyngodon idella Valenciennes) were monitored in a coastal river flowing out of the Santee Cooper reservoirs, South Carolina. Twenty-two adult triploid grass carp (90 cm to 110 cm total length) were tagged during 1998 and 1999 with sonic and radio transmitters, released into the Cooper River, South Carolina, and tracked through May 2000. A total of 122 observations were made, of which, approximately 70% were near stands of hydrilla (Hydrilla verticillata (L.f.) Royle). Approximately 98% of the fish locations were within 20 river km of the release site. The average maximum movement was 14.4 km while the longest was 44 kin. We detected no movement into brackish water nor extensive migrations; however, we urge caution where escapement of grass carp to coastal river is possible, and stocking should be evaluated on a case by case basis. C1 USA, Engineer Res & Dev Ctr, Environm Lab, Vicksburg, MS 39180 USA. Natl Marine Fisheries Serv, Boise, ID 83704 USA. Dennis Wildlife Ctr, S Carolina Dept Nat Resources, Bonneau, SC 29431 USA. RP Kirk, JP (reprint author), USA, Engineer Res & Dev Ctr, Environm Lab, 3909 Halls Ferry Rd, Vicksburg, MS 39180 USA. NR 26 TC 6 Z9 7 U1 0 U2 2 PU AQUATIC PLANT MANAGEMENT SOC, INC PI LEHIGH ACRES PA PO BOX 1477, LEHIGH ACRES, FL 33970 USA SN 0146-6623 J9 J AQUAT PLANT MANAGE JI J. Aquat. Plant Manage. PD JAN PY 2001 VL 39 BP 59 EP 62 PG 4 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 534BM UT WOS:000174564800016 ER PT J AU Gao, JD Xue, M Shapiro, A Xu, Q Droegemeier, KK AF Gao, JD Xue, M Shapiro, A Xu, Q Droegemeier, KK TI Three-dimensional simple adjoint velocity retrievals from single-Doppler radar SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID ALTITUDE WIND FIELDS; 3-DIMENSIONAL WIND; SUPERCELL THUNDERSTORM; VARIATIONAL ANALYSIS; BOUNDARY-LAYER; PHOENIX-II; MINIMIZATION; REFLECTIVITY; AIR AB In this paper, the original simple adjoint method of Qiu and Xu is improved and tested for retrieving the 3D storm-scale wind field from single-Doppler radar data. The method incorporates single-radar data and background fields, along with a dynamical constraint, smoothness, and anelastic mass continuity constraint, in a cost function. The minimization of the cost function, with the desired fit to these constraints, is obtained in an iterative procedure. The current method is tested on simulated datasets of supercell storms. It is shown that the circulation inside and around the storms, including the strong updraft and associated downdraft, are well retrieved. Furthermore, the method is robust in the presence of data error. C1 Univ Oklahoma, Sarkeys Energy Ctr, Ctr Anal & Predict Storms, Norman, OK 73019 USA. Univ Oklahoma, Sch Meteorol, Coastal Meteorol Res Program, Ctr Anal & Predict Storms, Norman, OK 73019 USA. Natl Severe Storms Lab, Norman, OK 73069 USA. RP Gao, JD (reprint author), Univ Oklahoma, Sarkeys Energy Ctr, Ctr Anal & Predict Storms, Suite 1110,100 E Boyd, Norman, OK 73019 USA. RI Xue, Ming/F-8073-2011; Shapiro, Alan/G-6116-2011 OI Xue, Ming/0000-0003-1976-3238; NR 29 TC 29 Z9 34 U1 0 U2 1 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. PY 2001 VL 18 IS 1 BP 26 EP 38 DI 10.1175/1520-0426(2001)018<0026:TDSAVR>2.0.CO;2 PG 13 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 393ML UT WOS:000166474200003 ER PT J AU Miloshevich, LM Vomel, H Paukkunen, A Heymsfield, AJ Oltmans, SJ AF Miloshevich, LM Vomel, H Paukkunen, A Heymsfield, AJ Oltmans, SJ TI Characterization and correction of relative humidity measurements from vaisala RS80-A radiosondes at cold temperatures SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID TROPOSPHERIC WATER-VAPOR; ICE NUCLEATION; WAVE CLOUDS; EVOLUTION; PRESSURE AB Radiosonde relative humidity (RH) measurements are known to be unreliable at cold temperatures. This study characterizes radiosonde RH measurements from Vaisala RS80-A thin-film capacitive sensors in the temperature range 0 degrees to -70 degreesC. Sources of measurement error are identified, and two approaches for correcting the errors are presented. The corrections given in this paper apply only to the Vaisala RS80-A sensor, although the RS80-H sensor is briefly discussed for comparison. A temperature-dependent correction factor is derived from statistical analysis of simultaneous RH measurements from RS80-A radiosondes and the NOAA cryogenic frostpoint hygrometer. The mean RS80-A measurement error is shown to be a dry bias that increases with decreasing temperature, and the multiplicative correction factor is about 1.3 at -35 degreesC, 1.6 at -50 degreesC, 2.0 at -60 degreesC, and 2.4 at -70 degreesC. The fractional uncertainty in the mean of corrected measurements, when large datasets are considered statistically, increases from 0.06 at 0 degreesC to 0.11 at -70 degreesC. The fractional uncertainty for correcting an individual sounding is about +/-0.2, which is larger because this statistical approach considers only the mean value of measurement errors that are not purely temperature dependent. The correction must not be used outside the temperature range 0 degrees to -70 degreesC, because it is a meaningless extrapolation of a polynomial curve fit. Laboratory measurements of sensor response conducted at Vaisala are used to characterize some of the individual sources of RS80-A measurement error. A correction factor is derived for the dominant RS80-A measurement error at cold temperatures: an inaccurate approximation for the sensor's temperature dependence in the data processing algorithm. The correction factor for temperature-dependence error is about 1.1 at -35 degreesC, 1.4 at -50 degreesC, 1.8 at -60 degreesC, and 2.5 at -70 degreesC. Dependences and typical magnitudes are given for measurement errors that result from the temperature dependence of the sensor's time constant, and from several smaller bias errors and random uncertainties. C1 Natl Ctr Atmospher Res, MMM, Boulder, CO 80307 USA. Natl Ocean & Atmospher Adm, Boulder, CO USA. Vaisala Oy, Helsinki, Finland. RP Miloshevich, LM (reprint author), Natl Ctr Atmospher Res, MMM, Pob 3000, Boulder, CO 80307 USA. RI Heymsfield, Andrew/E-7340-2011 NR 30 TC 149 Z9 152 U1 0 U2 17 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. PY 2001 VL 18 IS 2 BP 135 EP 156 DI 10.1175/1520-0426(2001)018<0135:CACORH>2.0.CO;2 PG 22 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 398CB UT WOS:000166737400002 ER PT J AU Vemury, S Stowe, LL Anne, VR AF Vemury, S Stowe, LL Anne, VR TI AVHRR pixel level clear-sky classification using dynamic thresholds (CLAVR-3) SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID HIGH-RESOLUTION RADIOMETER; SATELLITE; VALIDATION; NDVI AB Clear-sky classifications from the Clouds from the Advanced Very High Resolution Radiometer (AVHRR) Phase 1 (CLAVR-1) program are used to create an 8-day rotating clear-sky radiation dataset. This dataset is used to create satellite zenith angle dependent, dynamic, cloud/no-cloud albedo and temperature thresholds for ocean and six different vegetation index groups in 10 degrees latitude intervals over the globe. Individual pixels from ambiguously classified 2 X 2 pixel arrays from CLAVR-1 (MIXED and RESTORED-CLEAR) are reexamined at the individual pixel level, using these dynamic thresholds, and reclassified as CLEAR, MIXED, or CLOUDY. This methodology is referred to as the CLAVR-3 algorithm. It is found that many of the MIXED (partially cloudy or mixed overcast) pixels from CLAVR-1 are cloud free after using the dynamic thresholds. A smaller number of RESTORED-CLEAR pixels are found to be CLEAR, while many are classified MIXED. Poleward of about 80 degreesN and 60 degreesS, the CLAVR-1 algorithm does not provide sufficient detection of unambiguous CLEAR pixels for the creation of the necessary albedo and temperature angular distribution models. Other techniques or datasets will have to be employed at these latitudes to provide the necessary dynamic thresholds for reclassification of CLAVR-1 ambiguous pixels. The CLAVR-3 reclassification leads to a 75% increase in CLEAR pixel population, globally, during the ascending segment (mostly daytime portion) of orbits and a 95% increase during the descending segment (mostly nighttime). Maps of differences in albedo and brightness temperature for grid cells containing clear pixels before and after application of CLAVR-3 are used, as well as histogram analyses, to demonstrate the quality of clear pixels derived from the CLAVR-3 algorithm. These analyses show that the quality of CLEAR pixels from CLAVR-3 may be slightly lower compared with CLAVR-1, particularly over oceans, which is most likely the result of cloud contamination. However, this may be an acceptable consequence in exchange for the resulting dramatic increase in CLEAR pixel population. Each CLEAR pixel application (e.g., sea surface temperature) will have to evaluate how CLAVR-3 impacts their products. It is quite possible that by making minor adjustments and modifications to the threshold tests currently used in CLAVR-3, an optimum increase in CLEAR pixels can be achieved with acceptable levels of cloud contamination. Based on the results presented, the authors conclude that the CLAVR-3 algorithm concept has merit and can be used to enhance the spatial coverage of daily operational land, ocean, and atmospheric parameters that depend on clear-sky radiance observations from AVHRR. C1 NOAA, NESDIS ORA, NSC WWB, Camp Springs, MD 20746 USA. Sci Management & Appl Res Technol Inc, Landover, MD USA. IM Syst Grp Inc, Kensington, MD USA. RP Stowe, LL (reprint author), NOAA, NESDIS ORA, NSC WWB, 5200 Auth Rd, Camp Springs, MD 20746 USA. NR 23 TC 20 Z9 23 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. PY 2001 VL 18 IS 2 BP 169 EP 186 DI 10.1175/1520-0426(2001)018<0169:APLCSC>2.0.CO;2 PG 18 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 398CB UT WOS:000166737400004 ER PT J AU Dutton, EG Michalsky, JJ Stoffel, T Forgan, BW Hickey, J Nelson, DW Alberta, TL Reda, I AF Dutton, EG Michalsky, JJ Stoffel, T Forgan, BW Hickey, J Nelson, DW Alberta, TL Reda, I TI Measurement of broadband diffuse solar irradiance using current commercial instrumentation with a correction for thermal offset errors SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SURFACE SHORTWAVE IRRADIANCE; RADIATION MEASUREMENTS; CLIMATE; PYRANOMETERS; ALGORITHM; EARTH AB Diffuse-sky solar irradiance is an important quantity for radiation budget research, particularly as it relates to climate. Diffuse irradiance is one component of the total downwelling solar irradiance and contains information on the amount of downward-scattered, as opposed to directly transmitted, solar radiation. Additionally, the diffuse component is often required when calibrating total irradiance radiometers. A variety of pyranometers are commonly used to measure solar diffuse irradiance. An examination of some instruments for measuring diffuse irradiance using solar tracking shade disks is presented, along with an evaluation of the achieved accuracy. A data correction procedure that is intended to account for the offset caused by thermal IR exchange between the detector and filter domes in certain common diffuse pyranometers is developed and validated. The correction factor is derived from outputs of a collocated pyrgeometer that measures atmospheric infrared irradiance. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. SUNY Albany, Atmospher Sci Res Ctr, Albany, NY USA. Natl Renewable Energy Lab, Golden, CO USA. Bur Meteorol, Melbourne, Vic, Australia. Eppley Lab, Newport, RI USA. Analyt Serv & Mat Inc, Hampton, VA 23666 USA. RP Dutton, EG (reprint author), NOAA, Climate Monitoring & Diagnost Lab, R-CMDL1,325 Broadway, Boulder, CO 80303 USA. NR 41 TC 92 Z9 95 U1 2 U2 9 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. PY 2001 VL 18 IS 3 BP 297 EP 314 DI 10.1175/1520-0426(2001)018<0297:MOBDSI>2.0.CO;2 PG 18 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 415WP UT WOS:000167746800001 ER PT J AU Ryzhkov, AV AF Ryzhkov, AV TI Interpretation of polarimetric radar covariance matrix for meteorological scatterers: Theoretical analysis SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID POLARIZATION MEASUREMENTS; PRECIPITATION; RAIN; ORIENTATION; PROPAGATION; CLOUD; PHASE AB A simple model of the radar scattering by atmospheric particles is used to interpret all elements of the covariance scattering matrix. The components of the covariance scattering matrix and corresponding polarimetric variables are expressed via a limited number of integral parameters that characterize distributions of sizes, shapes, and orientations of meteorological scatterers. The co-cross-polar correlation coefficients rho (xh) and rho (xv) measured in the horizontal-vertical linear polarization basis are the major focus of this study. It is shown that the magnitudes of both coefficients are almost entirely determined by orientation of particles and do not depend on particle sizes and shapes. The phases of these coefficients can be used to detect the presence of melting hail or wet snow in the radar resolution volume. A model of the mean canting angle of raindrops varying along a propagation path is developed to examine effects of propagation on the depolarization variables such as rho (xh), rho (xy), and linear depolarization ratio. Analysis shows that depolarization variables are very sensitive to the mean canting angle averaged over a long propagation path. C1 Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. RP Ryzhkov, AV (reprint author), CIMMS NSSL, 1313 Halley Circle, Norman, OK 73069 USA. NR 41 TC 36 Z9 37 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. PY 2001 VL 18 IS 3 BP 315 EP 328 DI 10.1175/1520-0426(2001)018<0315:IOPRCM>2.0.CO;2 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 415WP UT WOS:000167746800002 ER PT J AU Brandes, EA Ryzhkov, AV Zrnic, DS AF Brandes, EA Ryzhkov, AV Zrnic, DS TI An evaluation of radar rainfall estimates from specific differential phase SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID WIND-TUNNEL; REFLECTIVITY; PRECIPITATION; ATTENUATION; PROPAGATION AB Specific differential propagation phase (K-DP) is examined for estimating convective rainfall in Colorado and Kansas. Estimates are made at S band with K-DP alone and in combination with radar reflectivity (Z(H)). Results are compared to gauge observations by computing bias factors, defined as the sum of gauge-measured rainfalls divided by the sum of radar estimates at gauges reporting rainfall, and the correlation coefficient between the gauge and radar-estimated amounts. Rainfall accumulations computed from positive-only values of K-DP (provided Z(H) greater than or equal to 25 dBZ) yield bias factors that vary from 0.76 to 2.42 for 3 storms in Colorado and from 0.78 to 1.46 for 10 storms in Kansas. Correlation coefficients between gauge-observed and radar-estimated rainfalls are 0.76 to 0.95. When negative K-DP's are included as negative rainfall rates, bias factors range from 0.81 to 3.00 in Colorado and from 0.84 to 2.31 in Kansas. In most storms, the correlation between gauge and radar rainfalls decreases slightly. In an experiment with the K-DP/Z(H) combination, rainfall rates are computed from K-DP when K-DP is greater than or equal to0.4 degrees km(-1) and from Z(H) for K-DP, 0.4 degrees km(-1) and Z(H) greater than or equal to 25 dBZ. Neglect of the negative K-DP's and substitution of the always positive ZH rainfall rates result in a tendency to overestimate rainfall. Bias factors are 0.63-1.46 for Colorado storms and 0.68-0.97 for Kansas storms, and correlation coefficients between gauge and radar amounts are 0.80-0.95. In yet another test with the K-DP/Z(H) pair, rainfall estimates are computed from K-DP when Z(H) greater than or equal to 40 dBZ and from Z(H) when 25 less than or equal to Z(H), 40 dBZ. For this experiment, bias factors range from 0.90 to 1.91 in Colorado and from 0.88 to 1.46 in Kansas. Correlation coefficients are 0.80-0.96. Since bias factors and correlation coefficients between estimated rainfalls and gauge observations for K-DP are similar to those for radar reflectivity, there was no obvious benefit with K-DP rainfalls for a well-calibrated radar. Large underestimates with K-DP in two storms were attributed to rainfalls dominated by small drops. In one storm, the problem was aggravated by widespread negative K-DP's thought related to vertical gradients of precipitation. An advantage of K-DP-derived rainfall estimates confirmed here is an insensitivity to anomalous propagation. C1 Natl Ctr Atmospher Res, RAP, Boulder, CO 80307 USA. Natl Severe Storms Lab, Norman, OK 73069 USA. RP Brandes, EA (reprint author), Natl Ctr Atmospher Res, RAP, POB 3000, Boulder, CO 80307 USA. NR 38 TC 34 Z9 35 U1 0 U2 0 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. PY 2001 VL 18 IS 3 BP 363 EP 375 DI 10.1175/1520-0426(2001)018<0363:AEORRE>2.0.CO;2 PG 13 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 415WP UT WOS:000167746800006 ER PT J AU Grund, CJ Banta, RM George, JL Howell, JN Post, MJ Richter, RA Weickmann, AM AF Grund, CJ Banta, RM George, JL Howell, JN Post, MJ Richter, RA Weickmann, AM TI High-resolution Doppler lidar for boundary layer and cloud research SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID BACKSCATTER HETERODYNE LIDAR; SPECTRAL PEAK ESTIMATION; RADAR; FLOWS; ACCUMULATION; DISPERSION; TERRAIN; LASERS; VORTEX; SYSTEM AB The high-resolution Doppler lidar (HRDL) was developed to provide higher spatial, temporal, and velocity resolution and more reliable performance than was previously obtainable with CO2-laser-based technology. The improved performance is needed to support continued advancement of boundary layer simulation models and to facilitate high-resolution turbulent flux measurements. HRDL combines a unique, eye-safe, near-IR-wavelength, solid-state laser transmitter with advanced signal processing and a high-speed scanner to achieve 30-m range resolution and a velocity precision of similar to 10 cm s(-1) under a variety of marine and continental boundary layer conditions, depending on atmospheric and operating conditions. An attitude-compensating scanner has been developed to facilitate shipboard marine boundary layer observations. Vertical velocities, fine details of the wind profile near the surface, turbulence kinetic energy profiles, and momentum flux are measurable with HRDL. The system is also useful for cloud studies. The HRDL technology, capabilities, and field performance are discussed. C1 NOAA, ERL, Environm Technol Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO USA. RP Banta, RM (reprint author), NOAA, ERL, Environm Technol Lab, ET2,325 Broadway, Boulder, CO 80305 USA. RI Weickmann, Ann/I-4445-2013; Banta, Robert/B-8361-2008 NR 52 TC 135 Z9 140 U1 2 U2 20 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. PY 2001 VL 18 IS 3 BP 376 EP 393 DI 10.1175/1520-0426(2001)018<0376:HRDLFB>2.0.CO;2 PG 18 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 415WP UT WOS:000167746800007 ER PT J AU Berger, BW Davis, KJ Yi, CX Bakwin, PS Zhao, CL AF Berger, BW Davis, KJ Yi, CX Bakwin, PS Zhao, CL TI Long-term carbon dioxide fluxes from a very tall tower in a northern forest: Flux measurement methodology SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID PATH CO2 ANALYZERS; WATER-VAPOR; ATMOSPHERIC CO2; EDDY-COVARIANCE; DECIDUOUS FOREST; SAMPLING TUBES; FLUCTUATIONS; EXCHANGE; HEAT; TEMPERATURE AB Methodology for determining fluxes of CO2 and H2O vapor with the eddy-covariance method using data from instruments on a 447-m tower in the forest of northern Wisconsin is addressed. The primary goal of this study is the validation of the methods used to determine the net ecosystem exchange of CO2. Two-day least squares fits coupled with 30-day running averages limit calibration error of infrared gas analyzers for CO2 and H2O signals to approximate to2%-3%. Sonic anemometers are aligned with local streamlines by fitting a sine function to tilt and wind direction averages, and fitting a third-order polynomial to the residual. Lag times are determined by selecting the peak in lagged covariance with an error of approximate to1.5%-2% for CO2 and approximate to1% for H2O vapor. Theory and a spectral fit method allow determination of the underestimation in CO2 flux (<5% daytime, <12% nighttime) and H2O vapor flux (<21%), which is due to spectral degradation induced by long air-sampling tubes. Scale analysis finds 0.5-h flux averaging periods are sufficient to measure all flux scales at 30-m height, but 1 h is necessary at higher levels, and random errors in the flux measurements due to limited sampling of atmospheric turbulence are fairly large (15%-20% for CO2 and approximate to 20%-40% for H2O vapor at lower levels for a 1-h period). C1 Univ Minnesota, Dept Soil Water & Climate, St Paul, MN 55108 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Berger, BW (reprint author), Penn State Univ, Dept Meteorol, 512 Walker Bldg, University Pk, PA 16802 USA. RI Yi, Chuixiang/A-1388-2013 NR 39 TC 95 Z9 100 U1 0 U2 13 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. PY 2001 VL 18 IS 4 BP 529 EP 542 DI 10.1175/1520-0426(2001)018<0529:LTCDFF>2.0.CO;2 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 424JP UT WOS:000168229400004 ER PT J AU Dickinson, S Kelly, KA Caruso, MJ McPhaden, MJ AF Dickinson, S Kelly, KA Caruso, MJ McPhaden, MJ TI Comparisons between the TAO buoy and NASA scatterometer wind vectors SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID RADAR CROSS-SECTION; OCEAN; STRESS; SYSTEM AB There was an opportunity to compare 10 months of collocated National Aeronautics and Space Administration scatterometer (NSCAT) wind vectors with those from the Tropical Atmosphere Ocean (TAO) buoy array, located in the tropical Pacific Ocean. Over 5500 data pairs, from nearly 70 buoys, were collocated in the calibration/validation effort for NSCAT. These data showed that the wind speeds produced from the NSCAT-1 model function were low by about 7%-8% compared with TAO buoy winds. The revised model function, NSCAT-2, produces wind speeds with a bias of about 1%. The scatterometer directions were within 20 degrees (rms), meeting accuracy requirements, when compared to TAO data. The mean direction bias between the TAO and the NSCAT vectors (regardless of model function) is about 9 degrees with the scatterometer winds to the right of the TAO winds, which may be due to swell. The statistics of the two datasets are discussed, using component biases in lieu of the speed bias, which is naturally skewed. Using ocean currents and buoy winds measured along the equator, it is shown that the scatterometer measures the wind relative to the moving ocean surface. In addition, a systematic effect of rain on the NSCAT wind retrievals is noted. In all analyses presented here, winds less than 3 m s(-1) are removed, due to the difficulty in making accurate low wind measurements. C1 Univ Washington, Appl Phys Lab, Seattle, WA 98195 USA. Woods Hole Oceanog Inst, Dept Phys Oceanog, Woods Hole, MA 02543 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Dickinson, S (reprint author), Univ Washington, Appl Phys Lab, Box 35-5640, Seattle, WA 98195 USA. RI McPhaden, Michael/D-9799-2016 NR 19 TC 18 Z9 20 U1 0 U2 1 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. PY 2001 VL 18 IS 5 BP 799 EP 806 DI 10.1175/1520-0426(2001)018<0799:CBTTBA>2.0.CO;2 PG 8 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 424JR UT WOS:000168229600007 ER PT J AU Zrnic, DS Ryzhkov, A Straka, J Liu, YD Vivekanandan, J AF Zrnic, DS Ryzhkov, A Straka, J Liu, YD Vivekanandan, J TI Testing a procedure for automatic classification of hydrometeor types SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID DUAL-POLARIZATION RADAR; DIFFERENTIAL PHASE; MULTIPARAMETER RADAR; FUZZY-LOGIC; PRECIPITATION; RAIN; STORM; HAIL; THUNDERSTORMS; HAILSTORM AB Examples of automatic interpretation of polarimetric measurements made with an algorithm that classifies precipitation, from an Oklahoma squall line and a Florida airmass storm are presented. Developed in this paper are sensitivity tests of this algorithm to various polarimetric variables. The tests are done subjectively by comparing the fields of hydrometeors obtained using the full set of available polarimetric variables with a diminished set whereby some variables have been left out. An objective way to test the sensitivity of the algorithm to variables and rank their utility is also devised. The test involves definition of a measure, which is the number of data points classified into a category using subsets of available variables. Ratios of various measures (similar to probabilities) define the percentage of occurrence of a class. By comparing these percentages for cases in which some variables are excluded to those whereby all are included, a relative merit can be assigned to the variables. Results of this objective sensitivity study reveal the following: the reflectivity factor and differential reflectivity combined have the strongest discriminating power. Inclusion of the temperature profile helps eliminate a substantial number of spurious errors. Although the absence of temperature information degrades the scheme, it appears that the resultant fields are generally coherent and not far off from the fields obtained by adding temperature to the suite of polarimetric variables. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Zrnic, DS (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Cr, Norman, OK 73069 USA. NR 33 TC 91 Z9 96 U1 1 U2 6 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. PY 2001 VL 18 IS 6 BP 892 EP 913 DI 10.1175/1520-0426(2001)018<0892:TAPFAC>2.0.CO;2 PG 22 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 439RY UT WOS:000169132400007 ER PT J AU Uttal, T Kropfli, RA AF Uttal, T Kropfli, RA TI The effect of radar pulse length on cloud reflectivity statistics SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID GENERAL-CIRCULATION MODEL; RADIATION; SURFACE; CIRRUS AB When observing clouds with radars, there are a number of design parameters, such as transmitted power, antenna size, and wavelength, that can affect the detection threshold. In making calculations of radar thresholds, also known as minimum sensitivities, it is usually assumed that the radar pulse volume is completely filled with targets. In this paper, the issue of partial beam filling, which results, for instance, if a cloud is thin with respect to the pulse length, or measurements are being made near cloud edges, is investigated. This study pursues this question by using measurements of radar reflectivities made with a 35-GHz, surface-based radar with 37.5-m pulse lengths, and computing how reflectivity statistics would be affected if the same clouds and/or precipitation had been observed with a radar with a 450-m pulse length. In a dataset measured during winter over a midcontinental site, partial beamfilling degraded the percentage of clouds detected by about 22% if it was assumed that the minimum detection threshold was -30 dBZ. In a second dataset collected during summer over a summertime subtropical site that was dominated by thin, boundary layer stratus, partial beam filling degraded the percentage of clouds detected by 38%, again assuming a minimum detection threshold of -30 dBZ. This study provides a preliminary indication of how radar reflectivity statistics from a spaceborne cloud radar may be impacted by design constraints, which would mandate a pulse length of around 500 m and a minimum detection threshold of around -30 dBZ. C1 NOAA, Environm Technol Lab, Boulder, CO 80305 USA. RP Uttal, T (reprint author), NOAA, Environm Technol Lab, R-E-ET6,325 Broadway, Boulder, CO 80305 USA. NR 24 TC 7 Z9 7 U1 0 U2 1 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. PY 2001 VL 18 IS 6 BP 947 EP 961 DI 10.1175/1520-0426(2001)018<0947:TEORPL>2.0.CO;2 PG 15 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 439RY UT WOS:000169132400011 ER PT J AU Menne, MJ Duchon, CE AF Menne, MJ Duchon, CE TI A method for monthly detection of inhomogeneities and errors in daily maximum and minimum temperatures SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SERIES AB Two statistical tests are described that can be used to detect potential inhomogeneities and errors in daily temperature observations. These tests, based on neighbor comparisons, differ from existing inhomogeneity tests by evaluating daily rather than monthly or annual observations and by focusing on a very short record length. Standardized difference series one month in length are formed between a candidate station, whose daily temperature time series is being evaluated, and a number of neighboring stations. These series, called D-series, approximate white noise when a candidate is like its neighbors and are other than white noise when the candidate is unlike its neighbors. Two white noise tests are then applied to the D-series in order to detect potential problems at the candidate station: a cross-correlation test and a lag 1 (1-day) autocorrelation test. Examples of errors and inhomogeneities detected through the application of the two tests on observations from the National Weather Service's Cooperative Observer Network are provided. These tests were designed specifically to detect inhomogeneities in an operational environment, that is, while data are being routinely processed. When a potential inhomogeneity is identified, timely action can be taken and feedback given, if necessary, to station field managers to prevent further corruption of the data record. While examples are provided using observations from the Cooperative Observer Network, these tests may be used in any temperature observation network with sufficient station density to provide a pool of neighboring stations. C1 NOAA NESDIS NCDC, Sci Serv Div, Asheville, NC 28801 USA. Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. RP Menne, MJ (reprint author), NOAA NESDIS NCDC, Sci Serv Div, Veach Baley Fed Bldg,151 Patton Ave, Asheville, NC 28801 USA. NR 14 TC 6 Z9 6 U1 0 U2 5 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. PY 2001 VL 18 IS 7 BP 1136 EP 1149 DI 10.1175/1520-0426(2001)018<1136:AMFMDO>2.0.CO;2 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 450ZX UT WOS:000169775700003 ER PT J AU Romashkin, PA Hurst, DF Elkins, JW Dutton, GS Fahey, DW Dunn, RE Moore, FL Myers, RC Hall, BD AF Romashkin, PA Hurst, DF Elkins, JW Dutton, GS Fahey, DW Dunn, RE Moore, FL Myers, RC Hall, BD TI In situ measurements of long-lived trace gases in the lower stratosphere by gas chromatography SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID TRANSPORT; SCALE AB Detailed information on the four-channel Airborne Chromatograph for Atmospheric Trace Species (ACATS-IV), used to measure long-lived atmospheric trace gases, is presented. Since ACATS-IV was last described in the literature, the temporal resolution of some measurements was tripled during 1997-99, chromatography was significantly changed, and data processing improved. ACATS-IV presently measures CCl3F [chlorofluorocarbon (CFC)-11], CCl2FCClF2 (CFC-113), CH3CCl3 (methyl chloroform), CCl4 (carbon tetrachloride), CH4 (methane), H-2 (hydrogen), and CHCl3 (chloroform) every 140 s, and N2O (nitrous oxide), CCl2F2 (CFC-12), CBrClF2 (halon-1211), and SF6 (sulfur hexafluoride) every 70 s. An in-depth description of the instrument operation, standardization, calibration, and data processing is provided, along with a discussion of precision and uncertainties of ambient air measurements for several airborne missions. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Romashkin, PA (reprint author), NOAA, Climate Monitoring & Diagnost Lab, 325 Broadway, Boulder, CO 80303 USA. RI Hurst, Dale/D-1554-2016; Fahey, David/G-4499-2013 OI Hurst, Dale/0000-0002-6315-2322; Fahey, David/0000-0003-1720-0634 NR 17 TC 28 Z9 28 U1 1 U2 5 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. PY 2001 VL 18 IS 7 BP 1195 EP 1204 DI 10.1175/1520-0426(2001)018<1195:ISMOLL>2.0.CO;2 PG 10 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 450ZX UT WOS:000169775700007 ER PT J AU Johnson, GC Robbins, PE Hufford, GE AF Johnson, GC Robbins, PE Hufford, GE TI Systematic adjustments of hydrographic sections for internal consistency SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB A significant legacy of the World Ocean Circulation Experiment (WOCE) is the large number of high quality, high-resolution, full-depth, transoceanic hydrographic sections occupied starting in the mid-1980s. The section data provide an unprecedented survey of World Ocean water properties. Most stations sampled pressure, temperature, salinity, dissolved oxygen, and nutrients (nitrate, phosphate, and silicic acid) at up to 36 depths. While the WOCE Hydrographic Program (WHP) strenuously advocated employing standardized measurement techniques on all sections, small but significant systematic differences among cruise legs are found. A simple method for adjusting measurements to maximize internal consistency is presented and applied to available WOCE data in the Pacific Basin. First, the sections are broken into distinct cruise legs between port stops. Then, crossovers are identified where two different cruise legs cross or approach each other. Using hydrographic data from each cruise leg near each crossover, linear fits are made of properties on potential temperature surfaces against distance along cruise track. These fits are then used to evaluate property differences and their uncertainties at crossovers. A set of least squares models are used to generate sets of adjustments, with related uncertainties, for all the properties of each cruise leg. These adjustments minimize differences of water properties among cruise legs at the crossovers in a least squares sense. The adjustments can be weighted by difference uncertainties, and damped by a priori estimates of the expected differences. Initial standard deviations of crossover differences are 0.0028 for salinity, 2.1% for oxygen, 2.8% for nitrate, 1.6% for phosphate, and 2.1% for silicic acid. The adjustments roughly halve these values, bringing cruise legs into agreement within WHP target accuracies. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. RP Johnson, GC (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE,Bldg 3, Seattle, WA 98115 USA. RI Johnson, Gregory/I-6559-2012 OI Johnson, Gregory/0000-0002-8023-4020 NR 11 TC 31 Z9 32 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. PY 2001 VL 18 IS 7 BP 1234 EP 1244 DI 10.1175/1520-0426(2001)018<1234:SAOHSF>2.0.CO;2 PG 11 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 450ZX UT WOS:000169775700012 ER PT J AU Sibert, H Muschinski, A AF Sibert, H Muschinski, A TI Relevance of a tuning-fork effect for temperature measurements with the gill Solent HS ultrasonic anemometer-thermometer SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SONIC ANEMOMETER AB The performance of a new type of sonic anemometer-thermometer (called a sonic), the Solent-Research HS, manufactured by Gill Instruments, Lymington, United Kingdom, was investigated. Measurements of the three wind-velocity components u, v, w, and temperature T were taken in the laboratory under quiet conditions and in the field at wind speeds of about 10 m s(-1). The power spectra of u, v, w, and T measured in the laboratory follow a -5/3 power law at moderate frequencies. At frequencies higher than (u) over bar /l (here (u) over bar is the mean wind speed along a given path of length l), there is a roll-off in all spectra, an expected effect caused by the spatial averaging along the finite pathlength. Over the bandwidth of f(s)/2 = 50 Hz, the standard deviations due to uncorrelated noise amount to 0.02 m s(-1) for u, v, and w and to 0.02 K for T. In the field, the spectra of u, v, and w show a clean -5/3 power law, except for a flattening at frequencies larger than 30 Hz. The ratio of the spectra of the transverse and longitudinal velocity components was close to 4/3, the ratio predicted by classical theory for isotropic turbulence. The T spectra measured in the field were severely contaminated at frequencies larger than about 5 Hz. Closer inspection of the T time series revealed amplitude-modulated artifacts. These artifacts were presumed to be the result of oscillations of the sonic's pathlengths induced by oscillations of the tower, which was exposed to a turbulently changing wind. The artifacts were reproduced in the laboratory by controlled blows on the sonic's attachment. The mechanical oscillations, which the authors refer to as the tuning-fork effect, were measured with a strain gauge attached to the sonic. The tuning- fork effect was observed simultaneously and independently in the strain-gauge measurements and as artifacts in the temperature time series. C1 Inst Tropospher Res, D-04318 Leipzig, Germany. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Environm Technol Lab, Boulder, CO USA. RP Sibert, H (reprint author), Inst Tropospher Res, Permoserstr 15, D-04318 Leipzig, Germany. NR 13 TC 1 Z9 1 U1 0 U2 1 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. PY 2001 VL 18 IS 8 BP 1367 EP 1376 PG 10 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 464WJ UT WOS:000170554500006 ER PT J AU Perenne, N Lavelle, JW Smith, DC Boyer, DL AF Perenne, N Lavelle, JW Smith, DC Boyer, DL TI Impulsively started flow in a submarine canyon: Comparison of results from laboratory and numerical models SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID OCEAN; CIRCULATION; ERROR AB Intercomparisons have been made of results from laboratory experiments and a numerical model for the flow in the vicinity of an idealized submarine canyon located along an otherwise continuous shelf. Motion in the rotating and continuously stratified fluid was impulsively generated by suddenly changing the period of rotation, so that the resulting flow occurred with the coastline either on the left (upwelling favorable) or right (downwelling favorable) when facing downstream. A principal purpose of the study was to further develop the notion that laboratory experiments can be effectively utilized to provide datasets to benchmark the development of numerical models. Laboratory data are of two types: velocity fields on three horizontal planes at numerous times, and time series of isopycnal movement in the canyon area. Comparison of numerical and laboratory results shows that values for bottom friction and interior mixing in the numerical model are crucial. Once those friction/mixing parameters are set, "skill'' statistics using observed and predicted horizontal velocity components indicate that the high quality of the numerical model description is maintained over the full measurement period. Two principal features of the circulation are early (,one rotation period) along-canyon flow followed by generation of a canyon vortex. In up- (down-) welling cases, the cyclone (anticyclone) develops along the upstream edge of the canyon and then advects into the canyon interior without significant local vortex stretching within the canyon itself. Numerical results for the case of an extra slow rotation rate change show that vortex creation is not an artifact of the fast rate of rotation change. The canyon vortices extend from just slightly above shelf depth to the deepest part of the canyon; the intensities of the up- and downwelling vortices are asymmetric with respect to the direction of forcing at shelf level, but basically symmetric deeper in the canyon. Upper column vorticity generation by stretching over the canyon rim and flow separation around the canyon headlands could explain this upper water column asymmetric response. The symmetric response in the lower water column is shown to be related to the flow separation only. Overall, the results demonstrate that laboratory and numerical experiments work hand in hand to decipher the complexities of circulation and hydrography undergoing rapid change in a model coastal canyon. C1 Arizona State Univ, Coll Engn & Appl Sci, Dept Mech & Aerosp Engn, Environm Fluid Dynam Program, Tempe, AZ 85287 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Boyer, DL (reprint author), Arizona State Univ, Coll Engn & Appl Sci, Dept Mech & Aerosp Engn, Environm Fluid Dynam Program, Box 876106, Tempe, AZ 85287 USA. NR 26 TC 12 Z9 12 U1 0 U2 1 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. PY 2001 VL 18 IS 10 BP 1698 EP 1718 DI 10.1175/1520-0426(2001)018<1699:ISFIAS>2.0.CO;2 PG 21 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 483GG UT WOS:000171624800008 ER PT J AU Murphy, PP Nojiri, Y Fujinuma, Y Wong, CS Zeng, J Kimoto, T Kimoto, H AF Murphy, PP Nojiri, Y Fujinuma, Y Wong, CS Zeng, J Kimoto, T Kimoto, H TI Measurements of surface seawater fCO(2) from volunteer commercial ships: Techniques and experiences from Skaugran SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID ATMOSPHERIC CARBON-DIOXIDE; PARTIAL-PRESSURE; NORTH-ATLANTIC; CO2; PACIFIC; VARIABILITY; TEMPERATURE; PCO(2); WATERS; SEA AB Chemical measurements made in the northern North Pacific from a commercial volunteer observing ship (VOS) program during March 1995-March 1998 are presented. Quasi-continuous measurements of the fugacity of CO2 (fCO(2), which takes into account the nonideal nature of the gas; the values are within 0.5-1.5 mu atm of the partial pressure in surface water) in seawater were made from two independent systems with different designs, and those results are emphasized here. One system used a fast response bubbling equilibrator with measurements each minute; the other system used a showerhead equilibrator with hourly measurements. Comparison of the results from these side-by-side systems provides useful information about the requirements for making high quality measurements of surface seawater and atmospheric fCO(2). From this comparison, the fast response system is deemed to be more stable and potentially more accurate. The utility of this system in waters with high spatial variability is also demonstrated. Factors contributing to the success of this ship-of-opportunity program are discussed as a guidepost for future observing programs. C1 NOAA, NODC, Silver Spring, MD 20910 USA. Natl Inst Environm Studies, Global Environm Forum Fdn, Tsukuba, Ibaraki, Japan. Inst Ocean Sci, Sidney, BC V8L 4B2, Canada. Res Inst Oceanochem, Osaka, Japan. Kimoto Elect Co, Osaka, Japan. RP Murphy, PP (reprint author), NOAA, NODC, 1315 East West Highway, Silver Spring, MD 20910 USA. RI Nojiri, Yukihiro/D-1999-2010 OI Nojiri, Yukihiro/0000-0001-9885-9195 NR 30 TC 12 Z9 13 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. PY 2001 VL 18 IS 10 BP 1719 EP 1734 DI 10.1175/1520-0426(2001)018<1719:MOSSFC>2.0.CO;2 PG 16 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 483GG UT WOS:000171624800009 ER PT J AU Boehlert, GW Costa, DP Crocker, DE Green, P O'Brien, T Levitus, S Le Boeuf, BJ AF Boehlert, GW Costa, DP Crocker, DE Green, P O'Brien, T Levitus, S Le Boeuf, BJ TI Autonomous pinniped environmental samplers: Using instrumented animals as oceanographic data collectors SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID ATLANTIC BLUEFIN TUNA; HAWAIIAN-ISLANDS; ELEPHANT SEALS; NORTH PACIFIC; ARCHIVAL TAGS; TEMPERATURE; BEHAVIOR; PREFERENCES; MOVEMENTS; TRACKING AB Data-recording tags applied to marine animals store data for later retrieval and can return valuable information on animal behavior and ecology, including habitat preference, physiology, and movement patterns, as well as environmental data. If properly instrumented, calibrated, and archived, data from these tags can add to the oceanographic datastream for parts of the ocean where data are sparse or lacking. Such data, from northern elephant seals instrumented with time-temperature-depth recorders (TTDR) and ARGOS platform terminal transmitters, is examined in this study. Northern elephant seals range widely over the northeastern Pacific on long foraging trips. The seals dive continuously on these trips to depths of 400-600 m. Between March 1998 and March 1999, six female and three male elephant seals were tagged in central California and data were collected during subsequent foraging trips. Temperature and depth were measured and stored every 30 s and retrieved after the animals returned to the rookery months later. Portions of the track where both ARGOS and TTDR data were available from these nine animals averaged 4634 km over 67 days with 2.4 ARGOS positions per day. Mean dive duration was 20 min and mean dive depth was 428 m. A comparison of temperature profiles from seal TTDR with Global Temperature-Salinity Profile Program (GTSPP) subsurface data showed very good agreement, as did surface temperatures to other sources of SST. Quality control of the data and entry into the World Ocean Database (WOD) is described. A total of 75 665 autonomous pinniped bathythermograph (APBT) profiles over the 41 702 km of seal trackline were added to the WOD. Biological autonomous sampling systems have immense potential to contribute oceanographic data in a cost-effective manner. The northern elephant seal represents but one species covering portions of the northeast Pacific Ocean. Research programs presently exist on a variety of species, including southern elephant seals and other pinnipeds, tunas and billfish, sharks, seabirds, marine turtles, and whales. With improving technology, such tags will be applied to even more marine animals and the approach described here can be applied to other species to improve ocean data availability. C1 NOAA, NMFS, SW Fisheries Sci Ctr, Pacific Fisheries Environm Lab, Pacific Grove, CA 93950 USA. Univ Calif Santa Cruz, Dept Biol, Santa Cruz, CA 95064 USA. Sonoma State Univ, Dept Biol, Rohnert Pk, CA 94928 USA. NOAA, NESDIS, Natl Oceanog Data Ctr, Silver Spring, MD USA. RP Boehlert, GW (reprint author), NOAA, NMFS, SW Fisheries Sci Ctr, Pacific Fisheries Environm Lab, 1352 Lighthouse Ave, Pacific Grove, CA 93950 USA. RI Logger, Satellite/C-1379-2010 NR 39 TC 60 Z9 62 U1 2 U2 14 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. PY 2001 VL 18 IS 11 BP 1882 EP 1893 DI 10.1175/1520-0426(2001)018<1882:APESUI>2.0.CO;2 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 492DK UT WOS:000172153000010 ER PT J AU Serra, YL A'Hearn, P Freitag, HP McPhaden, MJ AF Serra, YL A'Hearn, P Freitag, HP McPhaden, MJ TI ATLAS self-siphoning rain gauge error estimates SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID PRECIPITATION AB This report describes sampling and error characteristics of self-siphoning rain gauges used on moored buoys designed and assembled at NOAA's Pacific Marine Environmental Laboratory (PMEL) for deployment in the tropical Pacific and Atlantic Oceans in support of climate studies. Self-siphoning rain gauges were chosen for use on these buoys because they can be calibrated at PMEL before and after deployment. The rainfall data are recorded at 1-min intervals, from which daily mean rate, standard deviation, and percent time raining are calculated and telemetered to PMEL in real time. At the end of the deployment, the 1-min, internally recorded data are recovered and processed to produce 10-min rain rates. Field data from a subset of these rain gauges are analyzed to determine data quality and noise levels. In addition, laboratory experiments are performed to assess gauge performance. The field data indicate that the noise level during periods of no rain is 0.3 mm h(-1) for 1-min data, and 0.1 mm h(-1) for 10-min data. The estimated error in the derived rain rates, based on the laboratory data, is 1.3 mm h(-1) for 1-min data, and 0.4 mm h(-1) for 10-min data. The error in the real-time daily rain rates is estimated to be at most 0.03 mm h(-1). These error estimates do not take into account underestimates in accumulations due to effects of wind speed on catchment efficiency, which, though substantial, may be correctable. Estimated errors due to evaporation and sea spray, on the other hand, are found to be insignificant. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. RP Serra, YL (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. RI Serra, Yolande/I-3457-2015; McPhaden, Michael/D-9799-2016 OI Serra, Yolande/0000-0003-3542-1158; NR 21 TC 30 Z9 30 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. PY 2001 VL 18 IS 12 BP 1989 EP 2002 DI 10.1175/1520-0426(2001)018<1989:ASSRGE>2.0.CO;2 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 504XM UT WOS:000172881500004 ER PT J AU Krauss, M AF Krauss, M TI Ab initio structure of the active site of phosphotriesterase SO JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES LA English DT Article; Proceedings Paper CT 219th National Meeting of the American-Chemical-Society CY MAR 26-30, 2000 CL SAN FRANCISCO, CALIFORNIA SP Amer Chem Soc ID BLUE COPPER PROTEINS; BINUCLEAR METAL CENTER; BACTERIAL PHOSPHOTRIESTERASE; SPECTROSCOPIC PROPERTIES; 3-DIMENSIONAL STRUCTURE; ZINC; ENZYMES AB This research exploits two recent developments to obtain a fundamental understanding of the metalloenzyme active site using the bimetallic enzyme phosphotriesterase as an example of this class. First is the theoretical prediction that the structure and spectroscopy of a native metalloenzyme active site is qualitatively determined by the supermolecule complex of the metal(s) and the first shell of ligands with proper charge states including waters directly bonded to ionic ligands. The second is the development of an effective potential for representing the molecular environment interacting with an all-electron active site in the quantum Hamiltonian. The GAMESS suite of electronic structure codes has implemented this new methodology, effective fragment potentials (EFP), to make theoretical calculations on structure, spectroscopy, and reactivity tractable for systems involving hundreds of atoms. Since there are transition metal cations at the active site of these enzymes, the all-electron part of the complex is calculated with relativistic compact effective potentials (CEP) and their concomitant basis sets. A realistic representation of the active site with its protein environment can be obtained using a combination of the CEP and EFP. This presentation will determine the inherent electronic and structural characteristics of phosphotriesterase using ab initio quantum mechanical methods. A single X-ray structure for the Zn-Zn enzyme is leveraged to obtain the structure of the Cd-Cd enzyme and to examine the consequences of protonating the active site. C1 NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. RP Krauss, M (reprint author), NIST, Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. NR 27 TC 14 Z9 15 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0095-2338 J9 J CHEM INF COMP SCI JI J. Chem. Inf. Comput. Sci. PD JAN-FEB PY 2001 VL 41 IS 1 BP 8 EP 17 DI 10.1021/ci000046b PG 10 WC Chemistry, Multidisciplinary; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Chemistry; Computer Science GA 395JY UT WOS:000166578300002 PM 11206385 ER PT J AU Wang, CZ AF Wang, CZ TI A unified oscillator model for the El Nino-Southern Oscillation SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; OCEAN-ATMOSPHERE SYSTEM; TROPICAL PACIFIC; ROSSBY WAVES; EQUATORIAL PACIFIC; INTERANNUAL VARIABILITY; RECHARGE PARADIGM; CONCEPTUAL-MODEL; SEASONAL CYCLE; COUPLED MODEL AB The delayed oscillator, the western Pacific oscillator, the recharge-discharge oscillator, and the advective-reflective oscillator have been proposed to interpret the oscillatory nature of the El Nino-Southern Oscillation (ENSO). All of these oscillator models assume a positive ocean-atmosphere feedback in the equatorial eastern and central Pacific. The delayed oscillator assumes that the western Pacific is an inactive region and wave reflection at the western boundary provides a negative feedback for the coupled system to oscillate. The western Pacific oscillator emphasizes an active role of the western Pacific in ENSO. The recharge-discharge oscillator argues that discharge and recharge of equatorial heat content cause the coupled system to oscillate. The advective-reflective oscillator emphasizes the importance of zonal advection associated with wave reflection at both the western and eastern boundaries. Motivated by the existence of these different oscillator models, a unified oscillator model is formulated and derived from the dynamics and thermodynamics of the coupled ocean-atmosphere system. Consistent with ENSO anomaly patterns observed in the tropical Pacific, this oscillator model considers sea surface temperature anomalies in the equatorial eastern Pacific, zonal wind stress anomalies in both the equatorial central Pacific and the equatorial western Pacific, and thermocline depth anomalies in the off-equatorial western Pacific. If the western Pacific wind-forced response is neglected, thermocline and zonal wind stress anomalies in the western Pacific are decoupled from the coupled system, and the unified oscillator reduces to the delayed oscillator. If wave reflection at the western boundary is neglected, the unified oscillator reduces to the western Pacific oscillator. The mathematical form of the recharge-discharge oscillator can also be derived from this unified oscillator. Most of the physics of the advective-reflective oscillator are implicitly included in the unified oscillator, and the negative feedback of wave reflection at the eastern boundary is added to the unified oscillator. With appropriate model parameters chosen to be consistent with those of previous oscillator models, the unified oscillator model oscillates on interannual timescales. C1 NOAA, Phys Oceanog Div, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. RP Wang, CZ (reprint author), NOAA, Phys Oceanog Div, Atlantic Oceanog & Meteorol Lab, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Wang, Chunzai /C-9712-2009 OI Wang, Chunzai /0000-0002-7611-0308 NR 56 TC 88 Z9 98 U1 0 U2 12 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 1 BP 98 EP 115 DI 10.1175/1520-0442(2001)014<0098:AUOMFT>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 393MK UT WOS:000166474100007 ER PT J AU Schneider, T Held, IM AF Schneider, T Held, IM TI Discriminants of twentieth-century changes in earth surface temperatures SO JOURNAL OF CLIMATE LA English DT Article ID INTERDECADAL VARIATIONS; SULFATE AEROSOLS; AIR-TEMPERATURE; CLIMATE-CHANGE; NORTH PACIFIC; LAND-USE; MODEL; CIRCULATION; VEGETATION AB An approach to identifying climate changes is presented that does not hinge on simulations of natural climate variations or anthropogenic changes. Observed interdecadal climate variations are decomposed into several discriminants, mutually uncorrelated spatiotemporal components with a maximal ratio of interdecadal-to-intradecadal variance. The dominant discriminants of twentieth-century variations in surface temperature exhibit large-scale warming in which, particularly in the Northern Hemisphere summer months, localized cooling is embedded. The structure of the large-scale warming is consistent with expected effects of increases in greenhouse gas concentrations. The localized cooling, with maxima on scales of 1000-2000 km over East Asia, eastern Europe, and North America, is suggestive of radiative effects of anthropogenic sulfate aerosols. C1 Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA. RP Schneider, T (reprint author), NYU, Courant Inst Math Sci, 251 Mercer St, New York, NY 10012 USA. RI Schneider, Tapio /A-7038-2014 OI Schneider, Tapio /0000-0001-5687-2287 NR 32 TC 37 Z9 37 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 3 BP 249 EP 254 DI 10.1175/1520-0442(2001)014<0249:LDOTCC>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 399WC UT WOS:000166836400001 ER PT J AU Kumar, A Wang, WQ Hoerling, MP Leetmaa, A Ji, M AF Kumar, A Wang, WQ Hoerling, MP Leetmaa, A Ji, M TI The sustained North American warming of 1997 and 1998 SO JOURNAL OF CLIMATE LA English DT Article ID SURFACE TEMPERATURE-VARIATIONS; EL-NINO; PACIFIC-OCEAN; ATMOSPHERIC BRIDGE; ENSO; PRECIPITATION; ANOMALIES; VARIABILITY; SYSTEM AB North America experienced sustained and strong surface warming during 1997 and 1998. This period coincided with a dramatic swing of the El Nino-Southern Oscillation (ENSO), with El Nino in 1997 rapidly replaced by La Nina in 1998. An additional aspect of the sea surface temperatures (SSTs) was the warmth of the world oceans as a whole for the entire period, with unprecedented amplitudes within the recent instrumental record. Using a suite of dynamical and empirical model simulations, this study examines the causes for the North American warming, focusing on the role of the sea surface boundary conditions. Two sets of atmospheric general circulation model experiments, one forced with the observed global SSTs and the other with the tropical east Pacific portion only, produce similar North American-wide warming during fall and winter of 1997. The GCM results match empirical estimates of the canonical temperature response related to a strong El Nino and confirm that east equatorial Pacific SST forcing was a major factor in the continental warming of 1997. Perpetuation of that warming from spring through fall of 1998 is shown to be unrelated to equatorial east Pacific SSTs and thus cannot be attributed to the ENSO cycle directly. Yet, simulations using the observed global SSTs are shown to reproduce realistically the continuation of North American warming throughout 1998. The continental warmth occurs in tandem with a warming of the troposphere that, initially confined to tropical latitudes during El Nino's peak in 1997, spreads poleward and covers the entire globe in 1998. This evolutionary aspect of the global circulation anomalies during 1997 and 1998 is found to be a response to global SSTs and not linked directly to ENSO's evolution. Results presented here demonstrate that a significant fraction of the North American warming in 1997 and 1998 is explainable as the forced response to sea surface boundary conditions. The hand-over in the impact of those SSTs, with a classic ENSO driven signal in 1997 but an outwardly independent signal in 1998 related to the disposition of global SSTs outside the ENSO region is emphasized. The high potential predictability of North American climate during this 2-yr period raises new questions on the role of global SSTs in climate variability and the ability to predict them skillfully. C1 Natl Ctr Environm Predict, Washington, DC USA. NOAA, Cooperat Inst Res Environm Studies, Climate Diagnost Ctr, Boulder, CO USA. RP Kumar, A (reprint author), EMC NCEP, Climate Modeling Branch, 5200 Auth Rd,Room 807, Camp Springs, MD 20746 USA. NR 25 TC 28 Z9 28 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 3 BP 345 EP 353 DI 10.1175/1520-0442(2001)014<0345:TSNAWO>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 399WC UT WOS:000166836400008 ER PT J AU Durre, I Wallace, JM AF Durre, I Wallace, JM TI The warm season dip in diurnal temperature range over the eastern United States SO JOURNAL OF CLIMATE LA English DT Article ID SURFACE-TEMPERATURE; CLIMATE MODEL; VARIABILITY; CLOUDINESS; PHENOLOGY; MAXIMUM; CO2; VEGETATION; MINIMUM; TRENDS AB In light of numerous studies documenting a decline in the diurnal temperature range (DTR) over much of the globe, some authors have in recent years examined the annual march of the DTR in an effort to understand better the factors that influence the DTR's seasonal variations. These papers show that, over the southern two-thirds of the eastern United States, the DTR's climatology features peaks in spring and autumn and minima in winter and mid-to-late summer. However, the factors responsible for these characteristics remain uncertain. In this study, the DTR climatology of the eastern United States is analyzed in detail using daily surface and 850-mb data, with emphasis on possible relationships to seasonal changes in vegetation. It is shown that the warm season dip in the DTR deepens and widens from north to south across the study area, in accordance with a lengthening of the growing season. Furthermore, the dip is particularly prominent in the annual march of the DTR on mostly sunny days, indicating that seasonal variations in cloudiness are not responsible for this feature. The climatologies of daily maximum and daily minimum temperatures are found to be very different from each other: the former flattens out after the springtime peak in the DTR whereas the latter exhibits a pronounced mid-to-late summer maximum. These findings suggest that, by inhibiting daytime surface heating, evapotranspiration from vegetation contributes significantly to the dip in the DTR during the warm season in the eastern United States. C1 Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. RP Durre, I (reprint author), Natl Climat Data Ctr, 151 Patton Ave, Asheville, NC 28801 USA. NR 29 TC 31 Z9 31 U1 0 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 3 BP 354 EP 360 DI 10.1175/1520-0442(2001)014<0354:TWSDID>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 399WC UT WOS:000166836400009 ER PT J AU Mestas-Nunez, AM Enfield, DB AF Mestas-Nunez, AM Enfield, DB TI Eastern equatorial Pacific SST variability: ENSO and non-ENSO components and their climatic associations SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; EL-NINO; DECADAL VARIABILITY; NORTH PACIFIC; OSCILLATION; TELECONNECTIONS; MODULATION; AMERICA AB Using an updated Kaplan et al. global SST anomaly (SSTA) dataset (1870-1999) a canonical representation of El Nino-Southern Oscillation (ENSO) is constructed. When this canonical ENSO is subtracted from the data, a residual (non-ENSO) dataset for SSTA is left that includes interseasonal to multidecadal variability. Over the eastern equatorial Pacific (Nino-3) the canonical ENSO accounts for about 79% of the total SSTA variability, and the residual, dominated by decadal timescales, accounts for the rest. In particular, about 40%-50% of the amplitudes of the strong 1982-83 and 1997-98 El Nino events were accounted for by the residual variability. The non-ENSO variability is characterized by the known shift from cold to warm eastern tropical Pacific in the mid-to late 1970s as well as by a (nonstationary) interannual variance increase during the 1980s and 1990s. Composite maps of surface (SST, sea level pressure, and winds) and tropospheric (divergent winds, velocity potential, and vertical velocity) variables are used to compare the spatial patterns characterizing the canonical ENSO and the residual components of the Nino-3 variability. The residual composites are found to only share large-amplitude fluctuations of SST anomalies in the equatorial Pacific east of the date line. When these composites are separated into decadal and interannual components, the decadal part closely resembles the structure of the Pacific decadal oscillation. The major patterns of tropospheric variability associated with the ENSO and decadal non-ENSO components are very different. At low latitudes, they imply nearly opposite impacts on farfield regional climates, based on their respective warming (or cooling) phases within the Nino-3 region. This unexpected result for low-latitude climate associations runs contrary to the naive expectation (recently shown to be true for North America) that a decadally warm tropical east Pacific will reinforce the climate effects associated with ENSO alone. This indicates that, in the Tropics, climate outlooks may be more accurate if based on separately analyzed relationships between these SSTA components and their associated climate fluctuations. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. Univ Miami, Cooperat Inst Marine & Atmosphere Studies, Miami, FL 33152 USA. RP Mestas-Nunez, AM (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Mestas-Nunez, Alberto/A-1427-2012; Enfield, David/I-2112-2013 OI Mestas-Nunez, Alberto/0000-0002-3546-3668; Enfield, David/0000-0001-8107-5079 NR 34 TC 48 Z9 49 U1 1 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. PY 2001 VL 14 IS 3 BP 391 EP 402 DI 10.1175/1520-0442(2001)014<0391:EEPSVE>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 399WC UT WOS:000166836400011 ER PT J AU Higgins, RW Shi, W AF Higgins, RW Shi, W TI Intercomparison of the principal modes of interannual and intraseasonal variability of the North American Monsoon System SO JOURNAL OF CLIMATE LA English DT Article ID OUTGOING LONGWAVE RADIATION; SUMMER PRECIPITATION REGIME; 40-50 DAY OSCILLATION; CIRCULATION ANOMALIES; ZONAL WIND; WINTER; CONVECTION; TROPICS AB Time series of seasonal-, monthly, and pentad-mean precipitation are subjected to empirical orthogonal function analysis, regression analysis, and compositing techniques to study the principal modes of interannual and intraseasonal variability of the North American Monsoon System (NAMS). The leading principal component (PC) from the summertime seasonal- mean data is associated with El Nino-Southern Oscillation (ENSO) variability while the leading PC from the pentad-mean data is associated with 30-60-day intraseasonal (Madden-Julian) oscillations (MJOs). The leading PC from the monthly mean data is a hybrid of the two above-mentioned modes, capturing aspects of both. The leading PCs are used as reference time series for regressions and composites that reveal the structure of the principal modes and their manifestation in the NAMS. The leading PCs are also used to estimate the fraction of the variance of summer precipitation that is explained by ENSO and by interannual variations of MJO activity. ENSO-related impacts on the NAMS are linked to meridional adjustments of the ITCZ. In its positive polarity, the leading PC of interannual variability is associated with warm (ENSO) episodes and is characterized by an expansion of the ITCZ toward the south, increased precipitation in a zonally oriented band just north of the equator, and decreased precipitation over Mexico and portions of the Caribbean. MJO-related impacts on the NAMS are linked to more regional meridional adjustments in the precipitation pattern over the eastern tropical Pacific. In its positive polarity, the leading PC of intraseasonal variability is associated with an intensification and northward adjustment of the precipitation pattern in the eastern tropical Pacific, with increased precipitation over the warm pool to the west of Mexico and over portions of Mexico and the southwestern United States. Both the interannual and intraseasonal modes have well-defined, but distinct, sea level pressure and surface wind signatures in the eastern tropical Pacific. These features extend to the middle troposphere and are capped by circulation features in the opposite sense in the upper troposphere. The relationship of the MJO to the NAMS is examined in more detail using the leading PC of intraseasonal variability and an objective procedure to identify the phase of MJO events. The leading PC is strongly related to the eastward progression of centers of enhanced (reduced) convection around the global Tropics on intraseasonal timescales. Notably, a strong relationship between the leading mode of intraseasonal variability of the NAMS, the MJO, and the points of origin of tropical cyclones in the Pacific and Atlantic basins is also present. C1 NOAA, Natl Weather Serv, NCEP, Anal Branch,Climate Predict Ctr, Washington, DC 20233 USA. RP Higgins, RW (reprint author), NOAA, Natl Weather Serv, NCEP, Anal Branch,Climate Predict Ctr, Washington, DC 20233 USA. RI Shi, Wei/F-5625-2010 NR 28 TC 138 Z9 148 U1 3 U2 20 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 3 BP 403 EP 417 DI 10.1175/1520-0442(2001)014<0403:IOTPMO>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 399WC UT WOS:000166836400012 ER PT J AU Vitart, F Anderson, JL AF Vitart, F Anderson, JL TI Sensitivity of Atlantic tropical storm frequency to ENSO and interdecadal variability of SSTs in an ensemble of AGCM integrations SO JOURNAL OF CLIMATE LA English DT Article ID GENERAL-CIRCULATION MODEL; SEA-SURFACE TEMPERATURE; HURRICANE-TYPE VORTICES; WEST-AFRICAN RAINFALL; CYCLONE FORMATION; OBSERVATIONAL ANALYSIS; STRONG ASSOCIATION; GCM INTEGRATIONS; SPECTRAL MODEL; EL-NINO AB A significant reduction (increase) of tropical storm activity over the Atlantic basin is observed during El Nino (La Nina) events. Furthermore, the number of Atlantic tropical storms displays an interdecadal variability with more storms in the 1950s and 1960s than in the 1970s and 1980s. Ensembles of simulations with an atmospheric general circulation model (AGCM) are used to explore the mechanisms responsible for this observed variability. The interannual variability is investigated using a 10-member ensemble of AGCM simulations forced by climatological SSTs of the 1980s everywhere except over the tropical Pacific and Indian Oceans. Significantly fewer tropical storms are simulated with El Nino SSTs imposed over the tropical Pacific and Indian Oceans than with La Nina conditions. Increased simulated vertical wind shear over the Atlantic is the most likely explanation for the reduction of simulated tropical storms during El Nino years. SST forcing from different El Nino events has distinct impacts on Atlantic tropical storms in the simulation: simulated tropical storms are significantly less numerous with 1982 SSTs imposed over the tropical Pacific and Indian Oceans than with 1986 SSTs. The interdecadal variability of tropical storm activity seems to coincide with an interdecadal variability of the North Atlantic SSTs with colder SSTs in the 1970s than in the 1950s. Ensembles of AGCM simulations produce significantly more tropical storms when forced by observed SSTs of the 1950s than when forced by SSTs of the 1970s. This supports the theory that the interdecadal variability of SSTs has a significant impact on the expected number of Atlantic tropical storms and suggests that Atlantic tropical storms may be more numerous in coming years if North Atlantic SSTs are getting warmer. A significant increase of vertical wind shear and a significant decrease in the convective available potential energy over the tropical Atlantic in the 1970s may explain the simulated interdecadal variability of Atlantic tropical storms. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08544 USA. RP Vitart, F (reprint author), European Ctr Medium Range Weather Forecasts, Shinfield Pk, Reading RG2 9AX, Berks, England. NR 41 TC 52 Z9 53 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 4 BP 533 EP 545 DI 10.1175/1520-0442(2001)014<0533:SOATSF>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 400DW UT WOS:000166857800005 ER PT J AU Marengo, JA Liebmann, B Kousky, VE Filizola, NP Wainer, IC AF Marengo, JA Liebmann, B Kousky, VE Filizola, NP Wainer, IC TI Onset and end of the rainy season in the Brazilian Amazon Basin SO JOURNAL OF CLIMATE LA English DT Article ID OUTGOING LONGWAVE RADIATION; AUSTRALIAN SUMMER MONSOON; SOUTH-AMERICAN SECTOR; INTERANNUAL VARIABILITY; ANNUAL CYCLE; SURFACE TEMPERATURE; CONVECTIVE ACTIVITY; SST ANOMALIES; CIRCULATION; RAINFALL AB Onset and end of the rainy season in the Amazon Basin are examined for the period 1979- 96. The onset and end dates are determined by averaging daily rainfall data from many stations, and then constructing 5- day averages (pentads). Onset (end) is defined as the pentad in which rainfall exceeds (falls below) a given threshold, provided that average rainfall was well below (above) the threshold for several pentads preceding onset (end), and well above (below) the threshold for several pentads after onset (end). For the criteria chosen, the climatological onset progresses toward the southeast, arriving in mid- October, and then toward the mouth of the Amazon, arriving near the end of the year. The end dates are earliest in the southeast and progress toward the north, but withdrawal is slower than onset. The onset dates, however, are quite sensitive to changes in the threshold. If the threshold is doubled, for example, the sense of onset is reversed, with onset occurring toward the northwest. Changes in threshold do not change the direction of the progression of the end of the rainy season. The central Amazon shows the largest variation in the date of onset. In several years, onset in the southeast occurs before that in the central Amazon, but onset near the mouth is always latest. There is an unexpectedly low relationship between the length of the rainy season and total accumulation. Likewise, there is little relationship between the onset (and end) date and the total accumulation. Composites of outgoing longwave radiation and the low- level wind field show that in the central Amazon, onset is associated with an anomalous anticyclone and enhanced trade winds in the Atlantic. Near the mouth of the Amazon, however, onset is associated with large- scale northerly anomalies, and the zonal component of the trade winds is reduced. There is an apparent association between sea surface temperature anomalies in the tropical Atlantic and Pacific and the pentads of onset and end of the rainy season in the northern and central Amazon, and near its mouth. The sense is that a warm Pacific and cold Atlantic result in a delayed onset and early withdrawal. Although the strong El Nino of 1982/ 83 and La Nina 1988/ 89 were examples of a delayed and early onset, respectively, the relationships it still holds these years are not considered. C1 INPE, Ctr Previsao Tempo & Estud Climat, Sao Paulo, Brazil. Univ Colorado, Ctr Climate Diagnost, Boulder, CO USA. NOAA, Natl Weather Serv, NCEP, Climate Predict Ctr, Washington, DC 20233 USA. Agcy Nacl Aguas & Energia Elect, Brasilia, DF, Brazil. Univ Sao Paulo, Inst Oceanog, Dept Oceanog Fis, Sao Paulo, Brazil. RP Marengo, JA (reprint author), INPE, Ctr Previsao Tempo & Estud Climat, Cachocira Paulista, Sao Paulo, Brazil. RI Marengo, Jose /J-9382-2012; Wainer, Ilana/B-4540-2011 OI Marengo, Jose /0000-0002-8154-2762; Wainer, Ilana/0000-0003-3784-623X NR 45 TC 141 Z9 156 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 5 BP 833 EP 852 DI 10.1175/1520-0442(2001)014<0833:OAEOTR>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 410VG UT WOS:000167461300014 ER PT J AU Schneider, T AF Schneider, T TI Analysis of incomplete climate data: Estimation of mean values and covariance matrices and imputation of missing values SO JOURNAL OF CLIMATE LA English DT Article ID SURFACE AIR-TEMPERATURE; OCEAN-ATMOSPHERE MODEL; NONORTHOGONAL PROBLEMS; RIDGE REGRESSION; PARAMETER AB Estimating the mean and the covariance matrix of an incomplete dataset and filling in missing values with imputed values is generally a nonlinear problem, which must be solved iteratively. The expectation maximization (EM) algorithm for Gaussian data, an iterative method both for the estimation of mean values and covariance matrices from incomplete datasets and for the imputation of missing values, is taken as the point of departure for the development of a regularized EM algorithm. In contrast to the conventional EM algorithm, the regularized EM algorithm is applicable to sets of climate data, in which the number of variables typically exceeds the sample size. The regularized EM algorithm is based on iterated analyses of linear regressions of variables with missing values on variables with available values, with regression coefficients estimated by ridge regression, a regularized regression method in which a continuous regularization parameter controls the filtering of the noise in the data. The regularization parameter is determined by generalized cross- validation, such as to minimize, approximately, the expected mean- squared error of the imputed values. The regularized EM algorithm can estimate, and exploit for the imputation of missing values, both synchronic and diachronic covariance matrices, which may contain information on spatial covariability, stationary temporal covariability, or cyclostationary temporal covariability. A test of the regularized EM algorithm with simulated surface temperature data demonstrates that the algorithm is applicable to typical sets of climate data and that it leads to more accurate estimates of the missing values than a conventional noniterative imputation technique. C1 Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ USA. RP Schneider, T (reprint author), NYU, Courant Inst Math Sci, 251 Mercer St, New York, NY 10012 USA. EM tapio@cims.nyu.edu RI Schneider, Tapio /A-7038-2014 OI Schneider, Tapio /0000-0001-5687-2287 NR 39 TC 297 Z9 311 U1 3 U2 29 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 EI 1520-0442 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 5 BP 853 EP 871 DI 10.1175/1520-0442(2001)014<0853:AOICDE>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 410VG UT WOS:000167461300015 ER PT J AU Huck, T Vallis, GK de Verdiere, AC AF Huck, T Vallis, GK de Verdiere, AC TI On the robustness of the interdecadal modes of the thermohaline circulation SO JOURNAL OF CLIMATE LA English DT Article ID LARGE-SCALE CIRCULATION; OCEAN-ATMOSPHERE MODEL; PARAMETER SENSITIVITY; BOUNDARY-CONDITIONS; SURFACE FLUXES; HEAT-FLUX; VARIABILITY; RESOLUTION; DIFFUSION; CLIMATE AB Ocean models in box geometry forced by constant surface fluxes of density have been found to spontaneously generate interdecadal oscillations of the thermohaline circulation. This paper analyzes the sensitivity of these oscillations to various physical effects, including the presence of mesoscale turbulence, various thermal surface boundary conditions, and the presence of wind forcing or bottom topography. The role of unstable long baroclinic waves is also reexamined in an attempt to understand the oscillation period. In idealized geometry, it is found that the low- frequency variability of the thermohaline circulation under quasi- constant surface fluxes is a robust feature of the large- scale circulation. It is not strongly affected by energetic mesoscale turbulence; the oscillation period is relatively invariant with respect to varying resolution and momentum and tracer horizontal mixing coefficients, although it loses some regularity as shorter and longer periods of variability emerge when the mesoscale activity increases in strength with smaller mixing coefficients. The oscillations are also retained as the ocean model is coupled to an interactive atmospheric energy balance model; the thermohaline modes are robust to a range of exchange coefficients that widens with the amplitude of the mean circulation. The presence of an additional wind- forced component generally weakens the oscillation, and depending on the relative strength of thermodynamic and dynamic forcings, the oscillation may be completely killed. A simple interpretation is given, highlighting the role of upward Ekman pumping in damping density anomalies. Finally, the interaction of these baroclinic modes with bottom topography depends strongly on the relative directions of the mean topographic features and the mean currents and baroclinic waves, but usually results in a damping influence. C1 Univ Bretagne Occidentale, Lab Phys Oceans, UFR Sci F308, F-29285 Brest, France. Princeton Univ, AOS, GFDL, Princeton, NJ USA. RP Huck, T (reprint author), Univ Bretagne Occidentale, Lab Phys Oceans, UFR Sci F308, 6 Ave Le Gorgeu,BP 809, F-29285 Brest, France. RI Huck, Thierry/L-5549-2015 OI Huck, Thierry/0000-0002-2885-5153 NR 38 TC 34 Z9 34 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. PY 2001 VL 14 IS 5 BP 940 EP 963 DI 10.1175/1520-0442(2001)014<0940:OTROTI>2.0.CO;2 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 410VG UT WOS:000167461300020 ER PT J AU Van Woert, ML AF Van Woert, ML TI The role of conservation of mass in the satellite-derived poleward moisture transport over the Southern Ocean SO JOURNAL OF CLIMATE LA English DT Article ID ANTARCTIC PRECIPITATION; WATER-VAPOR; ICE; DATASET; FLUXES; MODELS AB Poleward meridional moisture transport across the Southern Ocean during 1988 is investigated by applying conservation of mass to the wind derivation approach of Slonaker and Van Woert. The moisture field is from the Television and Infrared Observational Satellite (TIROS) Operational Vertical Sounder (TOVS) Pathfinder A dataset. The wind field is first derived from a combination of the TOVS temperature profiles and a satellite-based surface wind field using the thermal wind relationship. Then a Lagrange multiplier is introduced in a variational procedure to constrain the wind to conserve mass. The introduction of the conservation of mass reduces the estimates of the moisture flux and net precipitation dramatically in comparison with the nonmass-conserved method in Slonaker and Van Woert. For instance, the estimates of the zonally averaged, vertically integrated moisture flux across 50 degreesS are reduced by 56% and the net precipitation between the 50 degreesS and 60 degreesS latitude belt are reduced by 63%. The reason for the difference is that the nonmass-conserved approach leads to unrealistically strong annual-mean winds in the lower troposphere, which results in an exaggerated mean moisture transport. In contrast, the mass-conserved annual-mean wind compares favorably with the radiosonde observations at Macquarie Island and European Centre for Medium-Range Weather Forecasts and National Centers for Environmental Prediction-National Center for Atmospheric Research reanalyses, and it yields a mean moisture flux consistent with historical estimates. In contrast, the satellite-derived eddy moisture flux is underestimated by about 45% when compared with the radiosonde and analysis studies. This underestimation is probably due to the lower spatial and temporal resolutions of the satellite observations and lack of certain types of ageostrophic winds in the wind derivation. C1 US Natl Ice Ctr, Washington, DC USA. QSS Grp Inc, Lanham, MD USA. RP Van Woert, ML (reprint author), NOAA, NESDIS, ORA, Ctr Sci, 5200 Auth Rd,Room 711, Camp Springs, MD 20746 USA. NR 42 TC 0 Z9 0 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. PY 2001 VL 14 IS 6 BP 997 EP 1016 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 414NY UT WOS:000167674000001 ER PT J AU Cash, BA Lee, S AF Cash, BA Lee, S TI Observed nonmodal growth of the Pacific-North American teleconnection pattern SO JOURNAL OF CLIMATE LA English DT Article ID SURFACE TEMPERATURE ANOMALIES; FREQUENCY; INSTABILITY; OSCILLATION; FLOW; GCM AB A linear-stochastic model is applied to the 10-day low-pass streamfunction field at 300, 500, and 850 mb for 40 winter seasons of Northern Hemisphere NCEP-NCAR reanalysis data. The linear operator is derived from the observed multilevel covariances, allowing for statistical representation of nonlinear processes. While all empirical normal modes of the system are decaying, increase in the streamfunction variance is possible through nonmodal growth. When the evolution of the streamfunction field following the optimal perturbation is predicted, the Pacific-North American teleconnection pattern (PNA) is found to be the most probable state of the atmosphere. Sixty-eight percent (70%) of positive (negative) PNA events are found to follow high projections onto the leading optimal, suggesting the PNA arises through constructive interference between the decaying modes and may be treated as a linear response to Gaussian white noise stochastic forcing. Implications for PNA timescale and onset mechanisms are also discussed. C1 Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. RP Cash, BA (reprint author), Geophys Fluid Dynam Lab, POB 308,Forrestal Campus, Princeton, NJ 08542 USA. NR 24 TC 22 Z9 25 U1 1 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. PY 2001 VL 14 IS 6 BP 1017 EP 1028 DI 10.1175/1520-0442(2001)014<1017:ONGOTP>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 414NY UT WOS:000167674000002 ER PT J AU Hoerling, MP Kumar, A Xu, TY AF Hoerling, MP Kumar, A Xu, TY TI Robustness of the nonlinear climate response to ENSO's extreme phases SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; EL-NINO EVENT; ANOMALIES; TELECONNECTIONS; VARIABILITY; SIMULATIONS; HEMISPHERE; RAINFALL; STATES; MODEL AB Analysis of a suite of atmospheric GCM experiments for 1950-94 shows that both the tropical and the extratropical wintertime climate respond nonlinearly with respect to opposite phases of ENSO. Such behavior is found to be reproducible among four different GCMs studied and confirms that several observed asymmetries in wintertime anomalies with respect to ENSO phases are symptomatic of nonlinearity rather than sampling error. Nonlinearity in the tropical Pacific rainfall response is related to an SST threshold for convection that leads to saturation at modestly cold SST forcing but a linear increase for warmer SST forcing. A spatial shift in the rainfall response is also a feature of the various GCMs' nonlinear behavior, that is, accentuated by the large zonal gradient of climatological SSTs across the equatorial Pacific and the fact that convection responds to the total rather than the anomalous SST. Regarding upper-tropospheric teleconnection responses over the Pacific-North American region, nonlinearity exists in both the strength of the midlatitude response and its spatial phase. The four GCMs are found to be unanimous in having a 500-mb height response whose amplitude is roughly double for extreme warm tropical Pacific SSTs as compared with extreme cold SST forcing. The longitudinal phase of the GCMs' teleconnections is also shifted eastward during warm events as compared with cold events, though this displacement is smaller than that observed. Further analysis of model simulations reveals that nonlinearity in climate responses emerges mainly for stronger ENSO events, and a predominantly linear response is found for weaker tropical Pacific SST forcing. In particular, climate simulations using both realistic and idealized SSTs indicate that tropical Pacific SST anomalies greater than one standard deviation of the interannual variation are required for initiating an appreciable nonlinear climate response. C1 NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO 80303 USA. NOAA, NCEP, Washington, DC USA. RP Hoerling, MP (reprint author), NOAA, CIRES, Climate Diagnost Ctr, R-E-CD,325 Broadway, Boulder, CO 80303 USA. NR 25 TC 99 Z9 99 U1 2 U2 21 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 6 BP 1277 EP 1293 DI 10.1175/1520-0442(2001)014<1277:ROTNCR>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 414NY UT WOS:000167674000018 ER PT J AU Chelton, DB Esbensen, SK Schlax, G Thum, N Freilich, MH Wentz, FJ Gentemann, CL McPhaden, MJ Schopf, PS AF Chelton, DB Esbensen, SK Schlax, G Thum, N Freilich, MH Wentz, FJ Gentemann, CL McPhaden, MJ Schopf, PS TI Observations of coupling between surface wind stress and sea surface temperature in the eastern tropical Pacific SO JOURNAL OF CLIMATE LA English DT Article ID EQUATORIAL PACIFIC; INSTABILITY WAVES; OCEAN ALGORITHM; SEASONAL CYCLE; MIXED-LAYER; VARIABILITY; CIRCULATION; GRADIENTS; OSCILLATIONS; CONVECTION AB Satellite measurements of surface wind stress from the QuikSCAT scatterometer and sea surface temperature (SST) from the Tropical Rainfall Measuring Mission Microwave Imager are analyzed for the three-month period 21 July-20 October 1999 to investigate ocean-atmosphere coupling in the eastern tropical Pacific. Oceanic tropical instability waves (TIWs) with periods of 20-40 days and wavelengths of 1000-2000 km perturb the SST fronts that bracket both sides of the equatorial cold tongue, which is centered near 1 degreesS to the east of 130 degreesW. These perturbations are characterized by cusp-shaped features that propagate systematically westward on both sides of the equator. The space-time structures of these SST perturbations are reproduced with remarkable detail in the surface wind stress field. The wind stress divergence is shown to be linearly related to the downwind component of the SST gradient with a response on the south side of the cold tongue that is about twice that on the north side. The wind stress curl is linearly related to the crosswind component of the SST gradient with a response that is approximately half that of the wind stress divergence response to the downwind SST gradient. The perturbed SST and wind stress fields propagate synchronously westward with the TIWs. This close coupling between SST and wind stress supports the Wallace et al. hypothesis that surface winds vary in response to SST modification of atmospheric boundary layer stability. C1 Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. Remote Sensing Syst, Santa Rosa, CA USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. George Mason Univ, Inst Comp Sci & Informat, Fairfax, VA 22030 USA. Ctr Ocean Land Atmosphere Studies, Calverton, MD USA. RP Chelton, DB (reprint author), Oregon State Univ, Coll Ocean & Atmospher Sci, 104 Ocean Adm Bldg, Corvallis, OR 97331 USA. RI McPhaden, Michael/D-9799-2016 NR 52 TC 268 Z9 282 U1 1 U2 23 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 7 BP 1479 EP 1498 DI 10.1175/1520-0442(2001)014<1479:OOCBSW>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 418CR UT WOS:000167872600009 ER PT J AU Huang, HP Weickmann, KM Hsu, CJ AF Huang, HP Weickmann, KM Hsu, CJ TI Trend in atmospheric angular momentum in a transient climate change simulation with greenhouse gas and aerosol forcing SO JOURNAL OF CLIMATE LA English DT Article ID EL-NINO; EARTH ROTATION; INTERANNUAL VARIABILITY; GENERAL-CIRCULATION; GLOBAL CIRCULATION; HEAT-SOURCES; ZONAL WINDS; LENGTH; MODEL; FLUCTUATIONS AB The authors investigate the change of atmospheric angular momentum (AAM) in long, transient, coupled atmosphere-ocean model simulations with increasing atmospheric greenhouse gas concentration and sulfate aerosol loading. A significant increase of global AAM, on the order of 4 x 10(25) kg m(2) s(-1) for 3 x CO2-1 x CO2, was simulated by the Canadian Centre for Climate Modelling and Analysis (CCCma) coupled model. The increase was mainly contributed by the relative component of total AAM in the form of an acceleration of zonal mean zonal wind in the tropical-subtropical upper troposphere. Thus, under strong global warming, a super-rotational state emerged in the tropical upper troposphere. The trend in zonal mean zonal wind in the meridional plane was characterized by 1) a tropical-subtropical pattern with two maxima near 30 degrees in the upper troposphere, and 2) a tripole pattern in the Southern Hemisphere extending through the entire troposphere and having a positive maximum at 60 degreesS. The implication of the projected increase of global AAM for future changes of the length of day is discussed. The CCCma coupled global warming simulation, like many previous studies, shows a significant increase of tropical SST and includes a zonally asymmetric component that resembles El Nino SST anomalies. In the CCCma transient simulations, even though the tropical SST and global AAM both increased nonlinearly with time, the ratio of their time increments Delta AAM/Delta SST remained approximately constant at about 0.9 x 10(25) kg m(2) s(-1) (degreesC)(-1). This number is close to its counterpart for the observed global AAM response to El Nino. It is suggested that this ratio may be useful as an index for intercomparisons of different coupled model simulations. C1 NOAA, CIRES Climate Diagnost Ctr, Boulder, CO 80303 USA. Canadian Ctr Climate Modelling & Anal, Victoria, BC, Canada. RP Huang, HP (reprint author), NOAA, CIRES Climate Diagnost Ctr, R-CDC1,325 Broadway, Boulder, CO 80303 USA. RI Hsu, Juno/A-7221-2011 NR 46 TC 21 Z9 21 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. PY 2001 VL 14 IS 7 BP 1525 EP 1534 DI 10.1175/1520-0442(2001)014<1525:TIAAMI>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 418CR UT WOS:000167872600012 ER PT J AU Ross, RJ Elliott, WP AF Ross, RJ Elliott, WP TI Radiosonde-based Northern Hemisphere tropospheric water vapor trends SO JOURNAL OF CLIMATE LA English DT Article ID CLIMATE; TEMPERATURE; CARDS AB Trends in tropospheric water vapor at Northern Hemisphere radiosonde stations are presented for two periods; 1973-95 and 1958-95. Stations with incomplete or inhomogeneous temporal records were identified and excluded from the analysis. For the 1973-95 period, trends in surface-500-mb precipitable water and in specific humidity, dewpoint, and temperature at the 850-mb level are shown. At most stations in this analysis, precipitable water, specific humidity, and dewpoint temperature have increased along with temperature over the period. An exception is Europe, over which temperature increased but humidity slightly decreased. Water vapor increases are larger, more uniform, and more significant over North America than over Eurasia, and the differences in trend magnitude and sign between the two regions may be attributable to changes in the late 1970s that affected North America more than Eurasia. Seasonal and annual correlations of surface-500-mb precipitable water with temperature, dewpoint temperature, and specific and relative humidity at the surface, 850, and 700 mb indicate a strong and relatively geographically invariant relationship between 850-mb specific humidity and surface-500-mb precipitable water. Specific humidity at 850 mb is then used as a surrogate for the surface-500-mb precipitable water over the 1958-95 period to avoid data quality problems in the pre-1973 precipitable water time series. Generally, 850-mb specific humidity trends at a small set of stations for 1958-95 show that only small increases occurred and that most of the overall increase probably occurred since 1973. C1 NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. RP Ross, RJ (reprint author), NOAA, Air Resources Lab, 1315 EW Highway, Silver Spring, MD 20910 USA. NR 21 TC 94 Z9 99 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 7 BP 1602 EP 1612 DI 10.1175/1520-0442(2001)014<1602:RBNHTW>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 418CR UT WOS:000167872600017 ER PT J AU Wong, APS Bindoff, NL Church, JA AF Wong, APS Bindoff, NL Church, JA TI Freshwater and heat changes in the North and South Pacific Oceans between the 1960s and 1985-94 SO JOURNAL OF CLIMATE LA English DT Article ID SEA-LEVEL RISE; ATLANTIC OCEAN; INTERANNUAL VARIABILITY; DECADAL CHANGES; CLIMATE VARIABILITY; HYDROGRAPHIC DATA; SUBTROPICAL GYRE; MODE WATER; TEMPERATURE; CIRCULATION AB Comparisons of hydrographic conditions in the North and South Pacific Oceans in the 1960s and 1985-94 have been made along five World Ocean Circulation Experiment sections. Below the seasonal mixed layer, statistically significant temporal differences in salinity and temperature have been detected in the water masses that occur in the upper 2000 dbar of the water column. These water mass property differences have been used to estimate the freshwater and heat storage trends in the Pacific over the study period. Along 24 degreesN, 10 degreesN, and 17 degreesS, where either North Pacific Intermediate Water or Antarctic Intermediate Water is present, the upper waters have increased in salinity, while the intermediate and deep waters have decreased in salinity. Although the depth-integrated salinity changes observed along these sections are small, the regional redistribution of freshwater associated with the water mass changes is significant and implies significant redistribution of surface freshwater fluxes over the Pacific. Heat loss has occurred along 47 degreesN and 17 degreesS, but significant warming has occurred along 24 degrees and 10 degreesN, giving the Pacific a net heat gain of 1.79 x 10(8) J m(-2). The resulting steric sea level change for the area in the Pacific between 60 degreesN and 31.5 degreesS over the roughly 20-yr study period is estimated to be a rise of 0.85 mm yr(-1), consistent with those in existing literature, but larger than that estimated from numerical models reported in the Intergovernmental Panel on Climate Change Second Assessment Report. C1 Univ Tasmania, Inst Antarctic & So Ocean Studies, Hobart, Tas 7001, Australia. Antarctic Cooperat Res Ctr, Hobart, Tas, Australia. CSIRO, Div Marine Res, Hobart, Tas, Australia. RP Wong, APS (reprint author), NOAA, Pacific Marine Environm Lab, OCRD, 7600 Sand Point Way,Bldg 3, Seattle, WA 98115 USA. RI Church, John/A-1541-2012; Bindoff, Nathaniel/C-8050-2011 OI Church, John/0000-0002-7037-8194; Bindoff, Nathaniel/0000-0001-5662-9519 NR 60 TC 41 Z9 43 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. PY 2001 VL 14 IS 7 BP 1613 EP 1633 DI 10.1175/1520-0442(2001)014<1613:FAHCIT>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 418CR UT WOS:000167872600018 ER PT J AU Kumar, A Barnston, AG Hoerling, MP AF Kumar, A Barnston, AG Hoerling, MP TI Seasonal predictions, probabilistic verifications, and ensemble size SO JOURNAL OF CLIMATE LA English DT Article AB For the case of probabilistic seasonal forecasts verified by the rank probability skill score, the dependence of the expected value of seasonal forecast skill on a hypothesized perfect atmospheric general circulation model's ensemble size is examined. This score evaluates the distributional features of the forecast as well as its central tendency. The context of the verification is that of interannual variability of the extratropical climate anomalies forced by sea surface temperatures in the tropical Pacific associated with ENSO. It is argued that because of the atmospheric internal variability, the seasonal predictability is inherently limited, and that this upper limit in the average skill is the one that can be achieved using infinite ensemble size. Next, for different assumptions of signal-to-noise ratios, the ensemble size required to deliver average predictive skill close to inherent skill is evaluated. Results indicate that for signal-to-noise ratios of magnitudes close to 0.5, the typical ensemble size currently used for the seasonal prediction efforts (i.e., 10-20 members), is sufficient to ensure average skill close to what is expected based on infinite ensemble size. For smaller standardized seasonal mean atmospheric anomalies, the ensemble size required to obtain predictive skill close to the inherent limit increases dramatically. But for these cases the expected skill itself is very low and the use of larger ensemble size has to be judged against the marginal level of prediction skill. Further, for small signal-to-noise ratios, forecasting the climatological distribution becomes nearly as effective as accurately defining the slight deviations from climatology. C1 NOAA, NWS, NCEP, Environm Modeling Ctr, Camp Springs, MD 20746 USA. Columbia Univ, Lamont Doherty Earth Observ, Int Res inst Climate Predict, Palisades, NY USA. NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO USA. RP Kumar, A (reprint author), NOAA, NCEP, Climate Modelling Branch, Camp Springs, MD 20746 USA. NR 8 TC 61 Z9 63 U1 0 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 7 BP 1671 EP 1676 DI 10.1175/1520-0442(2001)014<1671:SPPVAE>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 418CR UT WOS:000167872600021 ER PT J AU Bergman, JW Hendon, HH Weickmann, KM AF Bergman, JW Hendon, HH Weickmann, KM TI Intraseasonal air-sea interactions at the onset of El Nino SO JOURNAL OF CLIMATE LA English DT Article ID MADDEN-JULIAN OSCILLATION; SURFACE TEMPERATURE ANOMALIES; WESTERN EQUATORIAL PACIFIC; DATA ASSIMILATION SYSTEM; 40-50 DAY OSCILLATION; SOUTHERN OSCILLATION; TROPICAL CONVECTION; HEAT FLUXES; WIND BURST; TOGA COARE AB The role of the Madden-Julian Oscillation (MJO) for the onset of El Nino is examined. A preliminary analysis compares tropical Pacific variability during three boreal winters that initially had similar distributions of sea surface temperature (SST). During the winter of 1996-97, strong MJO activity led to west Pacific cooling and central Pacific warming. Subsequently, convective activity migrated from the west Pacific into the central Pacific and the accompanying westerly surface wind anomalies promoted further central Pacific warming. Strong MJO activity was also evident during winter 1989-90 and the early stages of El Nino development were evident that winter with similar evolution to that during 1996-97. However, the development of El Nino was aborted in May 1990. It is speculated that a full El Nino did not develop during 1990 because the subsurface ocean structure would not support that development. The MJO was relatively quiescent during the winter of 1981-82. A strong El Nino developed during 1982, but not as rapidly as it did during 1997. Thus, MJO might be relevant to the timing and initial growth of El Nino rather than responsible for the event itself. A detailed analysis of dynamical interactions is performed for the winter of 1996-97, when two exceptionally strong MJOs accompanied substantial SST fluctuations in the Pacific. SST cooling in the west Pacific was, for the most part, forced by surface flux variations. Surface cooling was initiated by the reduction of short-wave surface fluxes due to enhanced cloud cover. Later, evaporative cooling during westerly wind anomalies reinforced that cooling. In February 1997, ocean dynamics were also important for the SST perturbation; off-equatorial upwelling, through an anomalously large vertical temperature gradient, contributed substantially to west Pacific cooling. During late March and early April 1997, central Pacific SSTs warmed in response to a downwelling Kelvin wave that was forced during the February MJO. That warming was primarily due to zonal temperature advection, promoted by strong eastward currents acting on an east-west temperature gradient. After the passage of the Kelvin wave, zonal currents, surface winds, and SST gradients did not revert to their pre-Kelvin wave values. As a result, temperature advection was negligible after the Kelvin wave, and SST continued to warm due to the positive surface heat flux that is typical for the region. So, if the MJO did contribute to this important SST warming through nonlinear interactions, then those interactions involve the coupling of atmospheric and oceanic dynamics. C1 NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO USA. RP Bergman, JW (reprint author), Mail Code R-CDC1,325 Broadway, Boulder, CO 80303 USA. NR 42 TC 94 Z9 100 U1 3 U2 16 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 8 BP 1702 EP 1719 DI 10.1175/1520-0442(2001)014<1702:IASIAT>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 419XD UT WOS:000167973300002 ER PT J AU Sun, BM Groisman, PY Mokhov, II AF Sun, BM Groisman, PY Mokhov, II TI Recent changes in cloud-type frequency and inferred increases in convection over the United States and the former USSR SO JOURNAL OF CLIMATE LA English DT Article ID MODEL INTERCOMPARISON PROJECT; AIR-TEMPERATURE VARIATIONS; SEA-SURFACE TEMPERATURE; NORTHERN-HEMISPHERE; CLIMATE-CHANGE; SOIL-MOISTURE; WATER-VAPOR; GISS GCM; PRECIPITATION; TRENDS AB Significant changes and a general redistribution in the frequencies of various cloud types have been observed during the past 40-50 years over the midlatitude land areas of the Northern Hemisphere. This is evident for North America and northern Eurasia in the daytime synoptic data of the United States and the former Soviet Union (FUSSR). An abrupt increase prior to the 1960s largely contributed to the upward trend in the frequency of convective clouds over both regions, particularly in the warm season. However, over both regions during the intermediate seasons and during the winter season over the FUSSR, the frequencies of convective clouds still showed gradual increase after the 1960s. The increase in the frequency of convective clouds has been accompanied by increases in the frequency of observation of high-level cloudiness (at elevations above 6 km) and heavy precipitation. Low cloudiness (stratiform types) has decreased over the FUSSR but increased over the contiguous United States. The latter increase was due to an increase in the frequency of stratocumulus clouds, while the frequency of stratus clouds has decreased. Generally, it appears that during the post-World War II period over the FUSSR high cloud-type frequencies increased and low cloudiness decreased with a relatively small change (increase) in total cloud cover, while over the United States cloud cover has increased at both low and high levels. The analyses of cloudiness information from the United States and the FUSSR reveal noticeable differences in definitions and observational practices that affect the estimates of climatology and interpretation of the results presented here in terms of changes of convective activity and its relation to precipitation in these two regions of Eurasia and North America. C1 Natl Climat Data Ctr, Asheville, NC 28801 USA. Univ Massachusetts, Morrill Sci Ctr, Dept Geosci, Amherst, MA 01003 USA. Russian Acad Sci, AM Oboukhov Inst Atmospher Phys, Moscow, Russia. RP Groisman, PY (reprint author), Natl Climat Data Ctr, Fed Bldg,151 Patton ave, Asheville, NC 28801 USA. RI Sun, Bomin/P-8742-2014 OI Sun, Bomin/0000-0002-4872-9349 NR 67 TC 49 Z9 55 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. PY 2001 VL 14 IS 8 BP 1864 EP 1880 DI 10.1175/1520-0442(2001)014<1864:RCICTF>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 419XD UT WOS:000167973300012 ER PT J AU Harrison, DE Larkin, NK AF Harrison, DE Larkin, NK TI Comments on "Comparison of 1997-98 US temperature and precipitation anomalies to historical ENSO warm phases" SO JOURNAL OF CLIMATE LA English DT Article ID EL-NINO C1 NOAA, Pacific Marine Environm Lab, OCRD, Hayes Ctr JISAO, Seattle, WA 98115 USA. Univ Washington, JISAO, Seattle, WA 98195 USA. RP Harrison, DE (reprint author), NOAA, Pacific Marine Environm Lab, OCRD, Hayes Ctr JISAO, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. RI Harrison, Don/D-9582-2013 NR 4 TC 1 Z9 1 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. PY 2001 VL 14 IS 8 BP 1894 EP 1895 DI 10.1175/1520-0442(2001)014<1894:COCOUS>2.0.CO;2 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 419XD UT WOS:000167973300014 ER PT J AU Stensrud, DJ Anderson, JL AF Stensrud, DJ Anderson, JL TI Is midlatitude convection an active or a passive player in producing global circulation patterns? SO JOURNAL OF CLIMATE LA English DT Article ID ROSSBY-WAVE PROPAGATION; TROPOSPHERIC JET STREAK; UNITED-STATES; WEATHER SYSTEMS; SUMMER FLOODS; 1988 DROUGHT; WARM-SEASON; 1993 FLOODS; MESOSCALE; PRECIPITATION AB The ability of persistent midlatitude convective regions to influence hemispheric circulation patterns during the Northern Hemisphere summer is investigated. Global rainfall data over a 15-yr period indicate anomalously large July total rainfalls occurred over mesoscale-sized, midlatitude regions of North America and/or Southeast Asia during the years of 1987, 1991, 1992, and 1993. The anomalous 200-hPa vorticity patterns for these same years are suggestive of Rossby wave trains emanating from the regions of anomalous rainfall in the midlatitudes. Results from an analysis of an 11-yr mean monthly 200-hPa July wind field indicate that, in the climatological mean, Rossby waveguides are present that could assist in developing a large-scale response from mesoscale-sized regions of persistent convection in the midlatitudes. This hypothesis is tested using a barotropic model linearized about the 200-hPa July time-mean flow and forced by the observed divergence anomalies. The model results are in qualitative agreement in the observed July vorticity anomalies for the four years investigated. Model results forced by observed tropical forcings for the same years do not demonstrate any significant influence on the midlatitude circulation. It is argued that persistent midlatitude convective regions may play a role in the development, maintenance, and dissipation of the large-scale circulations that help to support the convective regions. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA. RP Stensrud, DJ (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 43 TC 5 Z9 5 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. PY 2001 VL 14 IS 10 BP 2222 EP 2237 DI 10.1175/1520-0442(2001)014<2222:IMCAAO>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 432YT UT WOS:000168724900003 ER PT J AU Kushner, PJ Held, IM Delworth, TL AF Kushner, PJ Held, IM Delworth, TL TI Southern Hemisphere atmospheric circulation response to global warming SO JOURNAL OF CLIMATE LA English DT Article ID ZONAL FLOW VACILLATION; ANNULAR MODES; EXTRATROPICAL CIRCULATION; TRANSIENT-RESPONSE; VARIABILITY; JETS; CO2 AB The response of the Southern Hemisphere (SH), extratropical, atmospheric general circulation to transient, anthropogenic, greenhouse warming is investigated in a coupled climate model. The extratropical circulation response consists of a SH summer half-year poleward shift of the westerly jet and a year-round positive wind anomaly in the stratosphere and the tropical upper troposphere. Along with the poleward shift of the jet, there is a poleward shift of several related fields, including the belt of eddy momentum-flux convergence and the mean meridional overturning in the atmosphere and in the ocean. The tropospheric wind response projects strongly onto the model's "Southern Annular Mode'' (also known as the "Antarctic oscillation''), which is the leading pattern of variability of the extratropical zonal winds. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Kushner, PJ (reprint author), NOAA, Geophys Fluid Dynam Lab, POB 308,Forrestal Campus, Princeton, NJ 08542 USA. RI Delworth, Thomas/C-5191-2014; Kushner, Paul/H-6716-2016 OI Kushner, Paul/0000-0002-6404-4518 NR 26 TC 270 Z9 273 U1 2 U2 27 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 10 BP 2238 EP 2249 DI 10.1175/1520-0442(2001)014<0001:SHACRT>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 432YT UT WOS:000168724900004 ER PT J AU Knutson, TR Tuleya, RE Shen, WX Ginis, I AF Knutson, TR Tuleya, RE Shen, WX Ginis, I TI Impact of CO2-induced warming on hurricane intensities as simulated in a hurricane model with ocean coupling SO JOURNAL OF CLIMATE LA English DT Article ID TROPICAL CYCLONES; PREDICTION SYSTEM; CLIMATE-CHANGE; INCREASE; TRENDS AB This study explores how a carbon dioxide (CO2) warming-induced enhancement of hurricane intensity could be altered by the inclusion of hurricane-ocean coupling. Simulations are performed using a coupled version of the Geophysical Fluid Dynamics Laboratory hurricane prediction system in an idealized setting with highly simplified background flow fields. The large-scale atmospheric boundary conditions for these high-resolution experiments (atmospheric temperature and moisture profiles and SSTs) are derived from control and high-CO2 climatologies obtained from a low-resolution (R30) global coupled ocean-atmosphere climate model. The high-CO2 conditions are obtained from years 71-120 of a transient +1% yr(-1) CO2-increase experiment with the global model. The CO2-induced SST changes from the global climate model range from +2.2 degrees to +2.7 degreesC in the six tropical storm basins studied. In the storm simulations, ocean coupling significantly reduces the intensity of simulated tropical cyclones, in accord with previous studies. However, the net impact of ocean coupling on the simulated CO2 warming-induced intensification of tropical cyclones is relatively minor. For both coupled and uncoupled simulations, the percentage increase in maximum surface wind speeds averages about 5%-6% over the six basins and varies from about 3% to 10% across the different basins. Both coupled and uncoupled simulations also show strong increases of near-storm precipitation under high-CO2 climate conditions, relative to control (present day) conditions. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. RP Knutson, TR (reprint author), NOAA, Geophys Fluid Dynam Lab, POB 308,Forrestal Campus,US Rt 1, Princeton, NJ 08542 USA. NR 21 TC 68 Z9 74 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 11 BP 2458 EP 2468 DI 10.1175/1520-0442(2001)014<2458:IOCIWO>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 437NY UT WOS:000168998800008 ER PT J AU Broccoli, AJ Delworth, TL Lau, NC AF Broccoli, AJ Delworth, TL Lau, NC TI The effect of changes in observational coverage on the association between surface temperature and the Arctic oscillation SO JOURNAL OF CLIMATE LA English DT Article ID NORTH-ATLANTIC OSCILLATION; ANNULAR MODES; EXTRATROPICAL CIRCULATION; TRENDS; VARIABILITY AB The effect of changes in observational coverage on the association between the Arctic oscillation (AO) and extratropical Northern Hemisphere surface temperature is examined. A coupled atmosphere-ocean model, which produces a realistic simulation of the circulation and temperature patterns associated with the AO, is used as a surrogate for the real climate system. The association between the AO and spatial mean temperature, as quantified by regressing the latter on the AO index, is subject to a positive bias due to the incomplete spatial coverage of the observational network. The bias is largest during the early part of the twentieth century and decreases, but does not vanish, thereafter. C1 Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Broccoli, AJ (reprint author), Princeton Univ, NOAA, Geophys Fluid Dynam Lab, POB 308,Forrestal Campus,US Route 1, Princeton, NJ 08542 USA. RI Delworth, Thomas/C-5191-2014; Broccoli, Anthony/D-9186-2014 OI Broccoli, Anthony/0000-0003-2619-1434 NR 21 TC 2 Z9 2 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 11 BP 2481 EP 2485 DI 10.1175/1520-0442(2001)014<2481:TEOCIO>2.0.CO;2 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 437NY UT WOS:000168998800010 ER PT J AU Lucas, LE Waliser, DE Xie, P Janowiak, JE Liebmann, B AF Lucas, LE Waliser, DE Xie, P Janowiak, JE Liebmann, B TI Estimating the satellite equatorial crossing time biases in the daily, global outgoing longwave radiation dataset SO JOURNAL OF CLIMATE LA English DT Article ID MADDEN-JULIAN OSCILLATION; BUDGET EXPERIMENT ERBE; NINO SOUTHERN OSCILLATION; SEA-SURFACE TEMPERATURE; ENERGY SYSTEM CERES; DIURNAL VARIABILITY; NORTHERN-HEMISPHERE; TROPICAL PACIFIC; CLIMATE; FLUXES AB Due to its long record length (approximately 25 years), the outgoing longwave radiation (OLR) dataset has been used in a multitude of climatological studies including studies on tropical circulation and convection, the El Nino-Southern Oscillation (ENSO) phenomenon, and the earth's radiation budget. Although many of the climatological studies using OLR have proven invaluable, proper interpretation of the low-frequency components of the data could be limited by the presence of biases introduced by changes in the satellite equatorial crossing time (ECT). Since long-term global changes could be masked or contaminated by this instrumental bias, it is necessary to take steps to ensure that the daily, global OLR dataset is free from such biases and is as accurate as possible. The goal of this study is to derive a method for estimating the ECT biases in the daily, global OLR dataset. Our analysis utilizes a Procrustes targeted empirical orthogonal function rotation (REOF) on an interpolated OLR dataset to try to isolate and remove the two major ECT biases-afternoon satellite orbital drift and the abrupt transitions from a morning satellite to an afternoon satellite-from the dataset. Two targeted REOF analyses are performed to separate and distinguish between these two artificial satellite bias modes. A "common ECT'' of approximately 0245 LST is established for the dataset by removing an estimate of these two ECT biases. Results from the analysis indicate that changes in ECTs can cause large regional biases over both ocean and tropical landmasses. The afternoon satellite ECT drift-bias accounts for 0.4% of the pentad anomaly variance. During a single satellite series (e.g., NOAA-11), the afternoon drift-bias can introduce a difference as large as 10.5 W m(-2) in the OLR values collected over most tropical landmasses. The morning to afternoon satellite transition bias accounts for 0.9% of the pentad anomaly variance, and is shown to cause a bias of 12 W m(-2) in the OLR values over most tropical landmasses during the NOAA-SR satellite series. The data are corrected by removing a statistically derived synthetic eigenvector that is associated with each of the ECT bias modes. This synthetic eigenvector is used instead of the exact values of the satellite bias eigenvector to ensure that only the artificial variability is removed from the dataset. The two REOF modes produced in this study are nearly orthogonal to each other having a correlation of only 0.17. This near orthogonality suggests that the use of the two-mode method presented in this study can more adequately describe the individual nature of each of the two ECT biases than a single REOF mode examined in previous studies. However, due to the presence of other forms of variability, it is likely that this study's estimate of the ECT bias includes ECT-related bias as well as some aspects of variability that may be associated with sensor changes, intersatellite calibration and/or natural climate variability. The strengths and limitations of the above technique are discussed, as are suggestions for future efforts. C1 SUNY Stony Brook, Inst Terr & Planetary Atmospheres, Stony Brook, NY 11794 USA. NOAA, Climate Predict Ctr, NCEP, NWS, Camp Springs, MD USA. Univ Colorado, Climate Diagnost Ctr, Boulder, CO 80309 USA. RP Lucas, LE (reprint author), SUNY Stony Brook, Inst Terr & Planetary Atmospheres, Stony Brook, NY 11794 USA. NR 58 TC 32 Z9 32 U1 3 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 12 BP 2583 EP 2605 DI 10.1175/1520-0442(2001)014<2583:ETSECT>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 441PQ UT WOS:000169239100007 ER PT J AU Mo, KC Hakkinen, S AF Mo, KC Hakkinen, S TI Interannual variability in the tropical Atlantic and linkages to the Pacific SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; HEAT-FLUX ANOMALIES; SST VARIABILITY; NORTHERN OCEANS; OSCILLATION; CIRCULATION; SCALES; LATENT; ENSO AB The variability of sea surface temperature anomalies (SSTAs) in the tropical Atlantic is examined using data from 1900 to the present. SSTAs are filtered to focus on the interannual band with fluctuations less than 60 months. Both SSTAs over the northern tropical Atlantic (NTA) and the southern tropical Atlantic (STA) are associated with the El Nino-Southern Oscillation (ENSO) variability in the tropical Pacific. SSTAs over the STA are associated with the quasi-biennial component of ENSO with a timescale of 22-32 months, and SSTAs over the NTA are influenced by the low-frequency part of the ENSO signal with a timescale of 36-48 months. The ENSO influence is seasonally dependent. The strongest linkages occur in the spring of each hemisphere. In addition to ENSO, SSTAs in the north equatorial Atlantic are also modulated by the circulation and net heat flux anomalies associated with the North Atlantic oscillation (NAO). The atmospheric impact on the ocean is different in the STA and NTA regions. When the quasi-biennial signal is strong in the central Pacific during September-November, warm SSTAs excite the Pacific South American wave train extending from the Pacific to the South Atlantic. The associated wind-driven dynamics initiates the changes in the STA. The local net heat flux anomalies and ocean wave dynamics influence the location and the strength of the SSTA maximum. The SSTAs over the NTA region are driven by the local heat flux anomalies related to the trade wind changes associated with the low-frequency component of ENSO in the Pacific. The magnitudes of SSTAs depend on the phase of the NAO. The net heat flux anomalies associated with the NAO may enhance or diminish the impact of ENSO over the NTA region and modulate SSTAs in the North Atlantic. C1 NOAA, Climate Predict Ctr, NCEP, NWS, Camp Springs, MD 20746 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Mo, KC (reprint author), NOAA, Climate Predict Ctr, NCEP, NWS, 5200 Auth Rd, Camp Springs, MD 20746 USA. RI Hakkinen, Sirpa/E-1461-2012 NR 32 TC 40 Z9 41 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. PY 2001 VL 14 IS 12 BP 2740 EP 2762 DI 10.1175/1520-0442(2001)014<2740:IVITTA>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 441PQ UT WOS:000169239100016 ER PT J AU Fasullo, J Sun, DZ AF Fasullo, J Sun, DZ TI Radiative sensitivity to water vapor under all-sky conditions SO JOURNAL OF CLIMATE LA English DT Article ID COMMUNITY CLIMATE MODEL; TEMPERATURE; FEEDBACK; BUDGET AB Using the National Center for Atmospheric Research Community Climate Model, version 3, radiation transfer model and a realistic tropospheric environment including the International Satellite Cloud Climatology Project cloud fields, all-sky radiative sensitivity to water vapor is assessed. The analysis improves upon previous clear-sky and model-based studies by using observed clouds, assessing realistic vertically varying perturbations, and considering spatial gradients in sensitivity through the Tropics and subtropics. The linearity of sensitivity is also explored. The dry zones of the subtropics and the eastern Pacific Ocean are found to be particularly sensitive to the water vapor distribution, especially for variations in the upper troposphere. The cloud field is instrumental in determining spatial gradients in sensitivity both at the top of the atmosphere and the surface. Throughout the Tropics, outgoing longwave radiation is most sensitive to water vapor in the upper troposphere, especially when perturbations characteristic of either natural variations or measurement uncertainties are considered. In contrast, surface radiative fluxes are everywhere most sensitive to specific humidity variations in the lower troposphere. C1 Univ Colorado, PAOS, CB 311, Boulder, CO 80309 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Climate Diagnost Ctr, Boulder, CO 80309 USA. RP Fasullo, J (reprint author), Univ Colorado, PAOS, CB 311, Boulder, CO 80309 USA. OI FASULLO, JOHN/0000-0003-1216-892X NR 23 TC 10 Z9 11 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 12 BP 2798 EP 2807 DI 10.1175/1520-0442(2001)014<2798:RSTWVU>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 441PQ UT WOS:000169239100021 ER PT J AU Wang, JXL Gaffen, DJ AF Wang, JXL Gaffen, DJ TI Late-twentieth-century climatology and trends of surface humidity and temperature in China SO JOURNAL OF CLIMATE LA English DT Article ID WATER-VAPOR; MINIMUM TEMPERATURE; VARIABILITY; MAXIMUM AB Climatological surface temperature and humidity variables for China are presented based on 6-hourly data from 196 stations for the period of 1961-90. Seasonal and annual means for daytime, nighttime, and the full day are shown. The seasonal cycle of moisture is primarily controlled by the east Asia monsoon system, with dominant factors of temperature change in northern and western China and of moisture advection associated with monsoon circulations in the southeast. Trends during 1951-94 are estimated for each station and for four regions of the country, with attention paid to the effects of changes in instrumentation, observing time, and station locations. The data show evidence of increases in both temperature and atmospheric moisture content. Temperature and specific humidity trends are larger at nighttime than daytime and larger in winter than summer. Moisture increases are observed over most of China. The increases are several percent per decade for specific humidity, and several tenths of a degree per decade for temperature and dewpoint. Increasing trends in summertime temperature and humidity contribute to upward trends in apparent temperature, a measure of human comfort. C1 NOAA, Air Resources Lab, Silver Spring, MD 20910 USA. RP Wang, JXL (reprint author), NOAA, Air Resources Lab, 1315 East-West Highway, Silver Spring, MD 20910 USA. RI Wang, Julian/C-3188-2016 NR 22 TC 64 Z9 71 U1 2 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 13 BP 2833 EP 2845 DI 10.1175/1520-0442(2001)014<2833:LTCCAT>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 451HR UT WOS:000169796600003 ER PT J AU Lau, NC Nath, MJ AF Lau, NC Nath, MJ TI Impact of ENSO on SST variability in the North Pacific and North Atlantic: Seasonal dependence and role of extratropical sea-air coupling SO JOURNAL OF CLIMATE LA English DT Article ID SURFACE TEMPERATURE ANOMALIES; ATMOSPHERE OCEAN INTERACTION; LOW-FREQUENCY VARIABILITY; HEAT-FLUX ANOMALIES; EL-NINO; INTERANNUAL VARIABILITY; CLIMATE; MODEL; CIRCULATION; GCM AB The influences of El Nino-Southern Oscillation (ENSO) events in the tropical Pacific on interannual variability of the coupled ocean-atmosphere systems in the North Pacific and North Atlantic have been studied using a suite of experiments with a rhomboidal 30-wavenumber, 14-layer general circulation model (GCM). Observed month-to-month fluctuations of the sea surface temperature (SST) in the tropical Pacific during the 1950-95 period were prescribed as the lower boundary condition for the GCM. The SST conditions outside of the tropical Pacific were predicted by a simple ocean mixed layer model with a constant depth. Four independent integrations under this "Tropical Ocean-Global Atmosphere-Mixed Layer (TOGA-ML)'' scenario were conducted. Both observational and model results indicate that the imposed ENSO forcing during midwinter is accompanied by prominent atmospheric circulation changes over the North Pacific and Atlantic. These teleconnection patterns in turn alter the heat exchange across the local sea-air interface. The extratropical SST anomalies generated by this "atmospheric bridge'' mechanism typically attain maximum amplitudes in late winter or early spring. Detailed diagnoses of the monthly evolution of the surface heat budget during ENSO episodes at selected sites have been performed. The simulated SST response exhibits a 1-2 month delay relative to temperature changes in the overlying atmosphere. This lag relationship is associated with a polarity change of sea-to-air gradients in anomalous temperature and water vapor mixing ratio in late winter. From late autumn through midwinter, the action of the climatological wind on these gradients results in enhancement of the developing SST anomalies. In the months thereafter, the reversed gradients lead to attenuation of the SST signal. Shortwave radiative fluxes associated with variations in cloud cover play an important role in SST variability at some of the subtropical sites. The nature of sea-air feedbacks in the extratropics has been studied by contrasting the output from the TOGA-ML experiment and from another "TOGA'' experiment in which two-way interactions between the atmosphere and ocean outside of the tropical Pacific were eliminated. Incorporation of sea-air coupling in TOGA-ML is seen to enhance the persistence of the ENSO-related atmospheric anomalies in the extratropics through late winter and early spring. Comparison with results from previous studies on midlatitude sea-air interactions suggests that part of the atmospheric signal in TOGA-ML may be attributed to forcing from extratropical SST anomalies produced by the atmospheric bridge mechanism. C1 Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Lau, NC (reprint author), Princeton Univ, NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. NR 49 TC 68 Z9 72 U1 1 U2 10 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 13 BP 2846 EP 2866 DI 10.1175/1520-0442(2001)014<2846:IOEOSV>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 451HR UT WOS:000169796600004 ER PT J AU Peng, SL Robinson, WA AF Peng, SL Robinson, WA TI Relationships between atmospheric internal variability and the responses to an extratropical SST anomaly SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; DECADAL CLIMATE VARIABILITY; MIDLATITUDE STORM TRACKS; NORTH PACIFIC; GENERAL-CIRCULATION; ATLANTIC; GCM; DEPENDENCE; PATTERN; OCEAN AB The January and February responses of a GCM to an imposed extratropical Pacific SST anomaly are compared with the patterns of the model's internal variability. Relevant patterns of internal variability are diagnosed from ensembles of model control runs by regressing monthly mean geopotentials and temperatures against low-level temperatures in the vicinity of the SST anomaly and by EOF analysis. These patterns are found to play a significant role in determining the local and the remote responses to the SST anomaly. Different responses to the SST anomaly in the GCM's January and February climates are largely explained by the differences in the regression patterns and in the leading EOF. The GCM response may be considered as comprising a direct linear response to low-level heating, that is local to the forcing and baroclinic, and an eddy-forced component that closely resembles patterns of the model's internal variability-it is equivalent barotropic and extends over the entire hemisphere. The results suggest that for a warm SST anomaly over the Kuroshio Extension to induce an equivalent-barotropic ridge immediately east of the anomaly, the internal variability must have a well-defined center of action over the central Pacific. In this GCM, this is nearly true in February but not in January. Similar analyses are performed for the observed flow to determine the patterns of variability in nature and thereby to suggest the potential response to SST forcing. The natural variability in January and February has a strong large-scale center over the Pacific, which, according to the model results, should favor the development of an equivalent-barotropic ridge in response to a warm SST anomaly. C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Climate Diagnost Ctr,RCDC1, Boulder, CO 80305 USA. Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. RP Peng, SL (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Climate Diagnost Ctr,RCDC1, 325 Broadway, Boulder, CO 80305 USA. RI Robinson, Walter/I-3782-2012 OI Robinson, Walter/0000-0002-6669-7408 NR 26 TC 45 Z9 48 U1 0 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 13 BP 2943 EP 2959 DI 10.1175/1520-0442(2001)014<2943:RBAIVA>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 451HR UT WOS:000169796600010 ER PT J AU Hwang, SO Schemm, JKE Barnston, AG Kwon, WT AF Hwang, SO Schemm, JKE Barnston, AG Kwon, WT TI Long-lead seasonal forecast skill in far eastern Asia using canonical correlation analysis SO JOURNAL OF CLIMATE LA English DT Article ID SURFACE AIR-TEMPERATURE; SOUTHERN OSCILLATION; INTERDECADAL CHANGES; NORTHERN-HEMISPHERE; DECADAL VARIATIONS; PRECIPITATION; CCA; PREDICTABILITY; PACIFIC; TRENDS AB Canonical correlation analysis (CCA), a linear statistical method designed to find correlated patterns between predictor and predictand fields, is applied to the eastern Asian region of Korea and Japan. The cross-validation technique is used to estimate the levels and sources of forecast skill for 3-month-averaged surface air temperature and total precipitation for the 37-yr time period of 1961-97. Quasi-global SST, Northern Hemisphere 700-hPa height, and prior values of the predictand field itself are used as predictor fields in an attempt to maximize the strength of the predictive relationships. The global SST field turns out generally to contribute the most to the final skill, with the exception of the winter season, in which the geopotential height field contributes most. The highest skill for temperature forecasts occurs in early spring, with relative insensitivity to the forecast lead time. This skill is statistically significant, averaging over 0.3 but including higher values locally. A secondary seasonal skill maximum appears in late summer. The forecast skill of precipitation is not high overall but is relatively highest in early winter, with area-averaged skill of nearly 0.2. Diagnostic analysis of the CCA loading patterns indicates that the strongest predictive mode for temperature is a long-term warming trend that pervades the entire seasonal cycle and contributes to skill during both the cold and the warm peak skill seasons. Interannual temperature fluctuations related to ENSO are captured in the second mode. Because of the dominant role of trends, CCA skill decreases substantially when the datasets are detrended. Forecast skill for precipitation is found to be due to a combination of interdecadal variations and ENSO-related variations. C1 Korea Meteorol Adm, Meteorol Res Inst, Marine Meteorol & Earthquake Res Lab, Tongjak Ku, Seoul 156720, South Korea. NOAA, Natl Weather Serv, Climate Predict Ctr, Natl Ctr Environm Predict, Washington, DC 20233 USA. Korea Meteorol Adm, Meteorol Res Inst, Forecast Res Lab, Seoul, South Korea. RP Hwang, SO (reprint author), Korea Meteorol Adm, Meteorol Res Inst, Marine Meteorol & Earthquake Res Lab, Tongjak Ku, Shindaebang-Dong 460-18, Seoul 156720, South Korea. NR 22 TC 22 Z9 22 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. PY 2001 VL 14 IS 13 BP 3005 EP 3016 DI 10.1175/1520-0442(2001)014<3005:LLSFSI>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 451HR UT WOS:000169796600014 ER PT J AU Kessler, WS AF Kessler, WS TI EOF representations of the Madden-Julian oscillation and its connection with ENSO SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; 1997-98 EL-NINO; TROPICAL CONVECTION; INTRASEASONAL OSCILLATION; EQUATORIAL PACIFIC; ZONAL WINDS; VARIABILITY; OCEAN; PREDICTABILITY; COMPONENTS AB Although recent El Nino events have seen the occurrence of strong intraseasonal winds apparently associated with the Madden-Julian oscillation (MJO), the usual indices of interannual variability of the MJO are uncorrelated with measures of the ENSO cycle. An EOF decomposition of intraseasonal outgoing longwave radiation and zonal wind identifies two modes of interannual variability of the MJO: a zonally stationary variation of amplitude that is unrelated to ENSO and a roughly 20 degrees -longitude eastward extension of the MJO envelope during El Nino events. The stationary mode is represented by the first two EOFs, which form the familiar lag-correlated quadrature pair, and the eastward-extending mode is represented by the third EOF, which is usually ignored although it is statistically significant. However, the third EOF also has a systematic phase relation with the first pair, and all three should be considered as a triplet; rotating the EOFs makes the phase relation clear. The zonal shift represents about 20% of total MJO variance (which itself is about 55% of intraseasonal variance over the tropical strip). Although the eastward shift is small when compared with the global scale of the MJO, it produces a large proportional shift of MJO activity over the open Pacific, where physical interactions with ENSO processes can occur. C1 NOAA, Pacific Marine Environm Lab, OC, Seattle, WA 98115 USA. RP Kessler, WS (reprint author), NOAA, Pacific Marine Environm Lab, OC, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. NR 31 TC 133 Z9 136 U1 0 U2 17 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 13 BP 3055 EP 3061 DI 10.1175/1520-0442(2001)014<3055:EROTMJ>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 451HR UT WOS:000169796600018 ER PT J AU Dutton, EG Bodhaine, BA AF Dutton, EG Bodhaine, BA TI Solar irradiance anomalies caused by clear-sky transmission variations above Mauna Loa: 1958-99 SO JOURNAL OF CLIMATE LA English DT Article ID SURFACE SHORTWAVE IRRADIANCE; ATMOSPHERIC TRANSMISSION; CLIMATE; AEROSOLS; PINATUBO; ERUPTION; TRANSPORT; HAWAII AB The clear-sky transmission of the atmosphere contributes to determining the amount of solar irradiance that reaches various levels in the atmosphere, which in turn is fundamental to defining the climate of the earth. As of the end of 1999, sustained clear-sky solar transmission over the mid-Pacific, as viewed from Mauna Loa, Hawaii, reached its highest level of clarity since before the eruption of Mount Pinatubo in 1991 and appears to be continuing to increase toward baseline levels established during 1958-62 and not sustained since. This record is used to answer the question as to impact of transmission variations, which can be attributed to either upward scattering or absorption above the station, on the net solar irradiance at 3.4 km, the altitude of the isolated mountain-top observing site. Net solar irradiance at a given level describes the total solar irradiance absorbed below that level. Monthly mean net solar anomalies caused by transmission variations, relative to the 1958-62 baseline, range from -14 to 2 W m(-2) and averaged -1.45 W m(-2) (-0.7%) between 1963 and 1999. Because of inherent attributes of this transmission record, the observed fluctuations in the record are of unusually high precision over the entire period of record and are also representative of an extended surrounding region. Irradiance anomalies have a long-term precision of better than 0.1 W m(-2) (similar to0.05%) per decade. Any possible linear trend for the entire 42 yr is limited by the data to between about 0.0 and -0.1 W m(-2) decade(-1), or any net shift over the 42 yr must be in the range of about 0.0 to -0.35 W m(-2) (0.0% to -0.15%). The transmission fluctuations are potentially caused by various atmospheric constituents, primarily aerosols, ozone, and water vapor, but the role of a specific constituent cannot be uniquely isolated on the basis of the transmission record alone. Aerosols have the greatest potential influence on the record and in general have the ability to cause both scattering and absorption such that the net radiative heating effect in the entire atmospheric column cannot be determined from the transmission data alone. However, because the largest anomalies in the record are known to be due to volcanic eruptions that produce predominantly conservative scattering aerosols, those large anomalies resulted in net radiative cooling tendencies in the entire associated atmospheric column. C1 NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. RP NOAA, Climate Monitoring & Diagnost Lab, R-CMDL1,325 Broadway, Boulder, CO 80303 USA. EM edutton@cmdl.noaa.gov NR 30 TC 27 Z9 27 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 EI 1520-0442 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 15 BP 3255 EP 3262 DI 10.1175/1520-0442(2001)014<3255:SIACBC>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 458VM UT WOS:000170216200006 ER PT J AU Whitaker, JS Weickmann, KM AF Whitaker, JS Weickmann, KM TI Subseasonal variations of tropical convection and week-2 prediction of wintertime western North American rainfall SO JOURNAL OF CLIMATE LA English DT Article ID MADDEN-JULIAN OSCILLATION; EXTREME PRECIPITATION EVENTS; UNITED-STATES; EL-NINO; CALIFORNIA; TEMPERATURES; NCEP; ENSO AB A statistical prediction model for weekly rainfall during winter over western North America is developed that uses tropical outgoing longwave radiation (OLR) anomalies as a predictor. The effects of El Nino-Southern Oscillation (ENSO) are linearly removed from the OLR to isolate the predictive utility of subseasonal variations in tropical convection. A single canonical correlation (CCA) mode accounts for most of the predictable signal. The rank correlation between this mode and observed rainfall anomalies over southern California is 0.2 for a 2-week lag, which is comparable to correlation between a weekly ENSO index and weekly rainfall in this region. This corresponds to a doubling of the risk of extreme rainfall in southern California when the projection of tropical OLR on the leading CCA mode two weeks prior is extremely large, as compared with times when it is extremely small. "Extreme'' is defined as being in the upper or lower quintile of the probability distribution. The leading CCA mode represents suppressed convection in the equatorial Indian Ocean and enhanced convection just south of the equator east of the date line. OLR regressed on the time series of this mode shows an eastward progression of the suppressed region to just south of the Philippines at the time of maximum California rainfall enhancement. The region of enhanced convection east of the date line remains quasi stationary. Associated with this tropical OLR evolution is the development of upper-tropospheric westerly wind anomalies near 30 degreesN in the eastern Pacific. Synoptic-scale weather systems are steered farther east toward California by these enhanced westerlies. Because most operational weather prediction models do not accurately simulate subseasonal variations in tropical convection, statistical prediction models such as the one presented here may prove useful in augmenting numerical predictions. An analysis of 4 yr of operational week-2 ensemble predictions indicates that the level of skill provided by the statistical model is comparable to that of the operational ensemble mean. Given that by week 2 the operational forecast model has lost its ability to represent convectively coupled circulation associated with the subseasonal tropical convective variability, the statistical model provides essentially independent information for the forecaster. C1 NOAA, CIRES Climate Diagnost Ctr, Boulder, CO 80303 USA. RP Whitaker, JS (reprint author), NOAA, CIRES Climate Diagnost Ctr, 325 Broadway, Boulder, CO 80303 USA. NR 23 TC 12 Z9 15 U1 1 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. PY 2001 VL 14 IS 15 BP 3279 EP 3288 DI 10.1175/1520-0442(2001)014<3279:SVOTCA>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 458VM UT WOS:000170216200008 ER PT J AU Compo, GP Sardeshmukh, PD Penland, C AF Compo, GP Sardeshmukh, PD Penland, C TI Changes of subseasonal variability associated with El Nino SO JOURNAL OF CLIMATE LA English DT Article ID HEMISPHERE WINTERTIME CIRCULATION; ROSSBY-WAVE DYNAMICS; NORTH PACIFIC; INTRASEASONAL VARIABILITY; SOUTHERN-OSCILLATION; HIGH-FREQUENCY; UNITED-STATES; ENSO; ANOMALIES; BLOCKING AB This paper is concerned with assessing the impact of the El Nino-Southern Oscillation (ENSO) on atmospheric variability on synoptic, intraseasonal, monthly, and seasonal timescales. Global reanalysis data as well as atmospheric general circulation model (AGCM) simulations are used for this purpose. For the observational analysis, 53 yr of NCEP reanalyses are stratified into El Nino, La Nina, and neutral winters [Jan-Feb-Mar (JFM)]. The AGCM analysis is based on three sets of 180 seasonal integrations made with prescribed global sea surface temperatures corresponding to an observed El Nino event (JFM 1987), an observed La Nina event (JFM 1989), and climatological mean JFM conditions. These ensembles are large enough to estimate the ENSO-induced changes of variability even in regions not usually associated with an ENSO effect. The focus is on the anomalous variability of precipitation and 500-mb heights. The most important result from this analysis is that the patterns of the anomalous extratropical height variability change sharply from the synoptic to the intraseasonal to monthly timescales, but are similar thereafter. In contrast, the patterns of the anomalous tropical rainfall variability are nearly identical across these timescales. On the synoptic and monthly scales, the anomalous extratropical height variability is generally opposite for El Nino and La Nina, and is also roughly symmetric about the equator. On the intraseasonal scale, however, the anomalous height variability is of the same sign for El Nino and La Nina in the Atlantic sector, and is antisymmetric about the equator in the Pacific sector. In the North Pacific, these intraseasonal variance anomalies (which are consistent with a decrease of blocking activity during El Nino and an increase during La Nina) are of opposite sign to the monthly and seasonal variance anomalies. The sharp differences across timescales in the ENSO-induced changes of extratropical variability suggest that different dynamical mechanisms dominate on different timescales. They also have implications for the predictability of extreme events on those timescales. Finally, there is evidence here that these impacts on extratropical variability may differ substantially from ENSO event to event, especially in the northern Atlantic and over Europe. C1 NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO 80305 USA. RP Compo, GP (reprint author), NOAA, CIRES, Climate Diagnost Ctr, 325 Broadway,R CDC1, Boulder, CO 80305 USA. OI COMPO, GILBERT/0000-0001-5199-9633 NR 46 TC 34 Z9 34 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 16 BP 3356 EP 3374 DI 10.1175/1520-0442(2001)014<3356:COSVAW>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 464WF UT WOS:000170554200002 ER PT J AU Wang, WM McPhaden, MJ AF Wang, WM McPhaden, MJ TI Surface layer temperature balance in the equatorial Pacific during the 1997-98 El Nino and 1998-99 La Nina SO JOURNAL OF CLIMATE LA English DT Article ID MADDEN-JULIAN OSCILLATION; SEA-SURFACE; SOLAR IRRADIANCE; CONCEPTUAL-MODEL; HEAT-BALANCE; OCEAN; ENSO; VARIABILITY; CYCLE; EVOLUTION AB The surface layer temperature balance in the equatorial Pacific has been examined for the period of 1996-99 by using data obtained from Tropical Atmosphere-Ocean buoy array at four locations along the equator, namely, 165 degreesE, 170 degreesW, 140 degreesW, and 110 degreesW. Time rate change of SST, horizontal temperature advection, and heat fluxes at the sea surface are estimated directly from the data. Vertical fluxes of heat out of the base of the mixed layer, related to changes in vertical mixing and upwelling, are calculated as a residual. Results indicate that all terms in the temperature balance contributed to SST variations during different stages of the 1997-98 El Nino and the 1998-99 La Nina. Zonal advection was particularly important during the onset of the El Nino in the central Pacific. The inferred vertical heat flux out of the base of the mixed layer was important most of the time, and was especially pronounced in the eastern Pacific during the termination phase of the El Nino. Meridional advection due to eddies was a negative feedback on SST change in the eastern Pacific during both the El Nino and La Nina, tending to counteract the development of warm and cold anomalies. Likewise, the net surface heat flux generally represented a negative feedback, tending to damp SST anomalies created by ocean dynamical processes. The relevance of these results to recent theoretical developments concerning ENSO timescale physical processes is discussed. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. RP McPhaden, MJ (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. RI McPhaden, Michael/D-9799-2016 NR 50 TC 48 Z9 48 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 16 BP 3393 EP 3407 DI 10.1175/1520-0442(2001)014<3393:SLTBIT>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 464WF UT WOS:000170554200004 ER PT J AU Donner, LJ Seman, CJ Hemler, RS Fan, SM AF Donner, LJ Seman, CJ Hemler, RS Fan, SM TI A cumulus parameterization including mass fluxes, convective vertical velocities, and mesoscale effects: Thermodynamic and hydrological aspects in a general circulation model SO JOURNAL OF CLIMATE LA English DT Article ID TROPICAL CLOUD CLUSTERS; LARGE-SCALE MODELS; MICROPHYSICAL PROCESSES; SCHEME; CLIMATE; WATER; ENSEMBLE; PRECIPITATION; SIMULATIONS; SENSITIVITY AB A cumulus parameterization based on mass fluxes, convective-scale vertical velocities, and mesoscale effects has been incorporated in an atmospheric general circulation model (GCM). Most contemporary cumulus parameterizations are based on convective mass fluxes. This parameterization augments mass fluxes with convective-scale vertical velocities as a means of providing a method for incorporating cumulus microphysics using vertical velocities at physically appropriate (subgrid) scales. Convective-scale microphysics provides a key source of material for mesoscale circulations associated with deep convection, along with mesoscale in situ microphysical processes. The latter depend on simple, parameterized mesoscale dynamics. Consistent treatment of convection, microphysics, and radiation is crucial for modeling global-scale interactions involving clouds and radiation. Thermodynamic and hydrological aspects of this parameterization in integrations of the Geophysical Fluid Dynamics Laboratory SKYHI GCM are analyzed. Mass fluxes, phase changes, and heat and moisture transport by the mesoscale components of convective systems are found to be large relative to those of convective (deep tower) components, in agreement with field studies. Partitioning between the convective and mesoscale components varies regionally with large-scale flow characteristics and agrees well with observations from the Tropical Rainfall Measuring Mission (TRMM) satellite. The effects of the mesoscale components of convective systems include stronger Hadley and Walker circulations, warmer upper-tropospheric Tropics, and moister Tropics. The mass fluxes for convective systems including mesoscale components differ appreciably in both magnitude and structure from those for convective systems consisting of cells only. When mesoscale components exist, detrainment is concentrated in the midtroposphere instead of the upper troposphere, and the magnitudes of mass fluxes are smaller. The parameterization including mesoscale components is consistent with satellite observations of the size distribution of convective systems, while the parameterization with convective cells only is not. The parameterization of convective vertical velocities is an important control on the intensity of the mesoscale stratiform circulations associated with deep convection. The mesoscale components are less intense than in TRMM observations if spatially and temporally invariant convective vertical velocities are used instead of parameterized, variable velocities. C1 Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08542 USA. RP Donner, LJ (reprint author), Princeton Univ, NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. NR 42 TC 84 Z9 86 U1 1 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. PY 2001 VL 14 IS 16 BP 3444 EP 3463 DI 10.1175/1520-0442(2001)014<3444:ACPIMF>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 464WF UT WOS:000170554200008 ER PT J AU Stone, DA Weaver, AJ Stouffer, RJ AF Stone, DA Weaver, AJ Stouffer, RJ TI Projection of climate change onto modes of atmospheric variability SO JOURNAL OF CLIMATE LA English DT Article ID SURFACE AIR-TEMPERATURE; HEMISPHERE; CIRCULATION; OCEAN; OSCILLATION; SIGNATURE; REGIMES; WINTER; HEIGHT; TRENDS AB Two possible interpretations of forced climate change view it as projecting, either linearly or nonlinearly, onto the dominant modes of variability of the climate system. An evaluation of these two interpretations is performed using annual mean sea level pressure (SLP) and surface air temperature (SAT) fields obtained from integrations of the Geophysical Fluid Dynamics Laboratory coupled general circulation model forced with varying concentrations of greenhouse gases. The dominant modes of SLP both represent much of the total variability and remain important in warmer climates. With SAT, however, the dominant modes are often related to variations in the sea-ice edge and so do not remain important once the ice has retreated; those unrelated to sea ice remain dominant in the warmer climates but represent smaller fractions of the total variability. In general, climate change tends to project most strongly onto the more dominant modes. The change in SLP projects partially onto the top two modes in the Northern Hemisphere, reflecting both an overall decrease in hemispheric SLP as well as the pattern of change. In the Southern Hemisphere the change projects negligibly onto the dominant patterns between equilibrium climates but very strongly onto the Antarctic oscillation-like mode in the transient integrations. Changes in SAT project partially onto the dominant modes but relate more to the mean warming rather than the pattern of change. In general, the change projects most strongly onto the more dominant modes. In all SLP domains, the projection of climate change overwhelmingly manifests itself as a linear translation in the mode, consistent with the linear interpretation. In SAT domains related to sea-ice variability, the projection reflects an increased tendency toward ice-free regimes, consistent with the nonlinear perspective; however this nonlinear projection represents only a small portion of the overall climate change. C1 Univ Victoria, Sch Earth & Ocean Sci, Victoria, BC V8W 3P6, Canada. Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08544 USA. RP Stone, DA (reprint author), Univ Victoria, Sch Earth & Ocean Sci, POB 3055, Victoria, BC V8W 3P6, Canada. RI Weaver, Andrew/E-7590-2011 NR 26 TC 43 Z9 43 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. PY 2001 VL 14 IS 17 BP 3551 EP 3565 DI 10.1175/1520-0442(2001)014<3551:POCCOM>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 474YH UT WOS:000171134200003 ER PT J AU Bates, GT Hoerling, MP Kumar, A AF Bates, GT Hoerling, MP Kumar, A TI Central US springtime precipitation extremes: Teleconnections and relationships with sea surface temperature SO JOURNAL OF CLIMATE LA English DT Article ID UNITED-STATES DROUGHT; ATMOSPHERE-OCEAN INTERACTION; 1988 DROUGHT; EL-NINO; NORTH-AMERICA; 1993 FLOODS; LA NINA; PACIFIC; ANOMALIES; SUMMER AB Dynamical methods are used to investigate atmospheric teleconnections associated with extreme seasonal precipitation anomalies over the central United States during April-June. The importance of sea surface temperature (SST) anomalies in forcing atmospheric teleconnections is specifically addressed through analyses of atmospheric general circulation model (GCM) simulations forced with the monthly varying SSTs of the years 1950-98. The results from three different models, each run in ensemble mode, are compared with observations of extreme April-June precipitation events in the central United States during the last half of the twentieth century. Analysis of GCM simulations of April-June 1988 indicates that the atmospheric circulation anomalies associated with the 1988 drought were not forced by SST anomalies and that the coexistence of central U.S. drought and La Nina during that spring was coincidental. Likewise, composite analysis reveals no SST forcing for the teleconnections associated with extreme dry spring seasons over the central United States during the last half of the twentieth century in either observations or GCMs. Nonetheless, this characteristic teleconnection pattern of the composite analysis resembles the circulation anomalies of 1988. The results imply that such drought events and the teleconnections related with them have little SST-based predictability. A somewhat different conclusion is drawn regarding the role of tropical SSTs in the occurrence of extreme wet spring seasons over the central United States. Simulations of the 1993 flood period exhibit skill in reproducing the seasonal circulation anomalies over the Pacific-North American region, and the ensemble mean precipitation anomalies in one GCM nearly replicate the observed strength and distribution of positive rainfall anomalies over the United States. Further composite analysis of extreme wet spring seasons over the last half of the twentieth century confirms the impression gathered from the 1993 case study, with observations and all three GCMs possessing positive tropical east Pacific SST anomalies in conjunction with extreme wet spring seasons over the central United States. Some SST-based potential predictability of extreme wet springs over the central United States consequently exists. C1 NOAA, CIRES Climat Diagnost Ctr, Boulder, CO 80305 USA. NOAA, NCEP, EMC, Climate Modeling Branch, Camp Springs, MD USA. RP Bates, GT (reprint author), NOAA, CIRES Climat Diagnost Ctr, 325 Broadway,R-CDC1, Boulder, CO 80305 USA. NR 34 TC 15 Z9 15 U1 2 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 17 BP 3751 EP 3766 DI 10.1175/1520-0442(2001)014<3751:CUSSPE>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 474YH UT WOS:000171134200016 ER PT J AU Larkin, NK Harrison, DE AF Larkin, NK Harrison, DE TI Tropical Pacific ENSO cold events, 1946-95: SST, SLP, and surface wind composite anomalies SO JOURNAL OF CLIMATE LA English DT Article ID EL-NINO; SOUTHERN OSCILLATION; LA-NINA; TEMPERATURE; TELECONNECTIONS; CIRCULATION; VARIABILITY; SIGNAL AB ENSO cold (La Nina) events are shown to exhibit a distinctive life cycle. The first near-global description of ENSO cold (La Nina)-event anomaly features is described using ocean surface data. It is found that cold-event anomalies are not simply the mirror image of warm (El Nino) events. The Comprehensive Ocean-Atmosphere Data Set marine surface record [SST, sea level pressure (SLP), and wind] is used to identify the statistically significant features of the nine cold-event periods during 1946-95 and to focus on the large-scale elements that are typical of most events. By examining time series, the most robust features of the composite that have occurred during nearly all of the post-World War II cold events are identified. These robust cold-event features are more numerous and cover more of the globe than their warm-event counterparts. Of the 90 composite features examined, 57 (63%) are found to be robust. Most of these are located in the Tropics (70%) and in the Pacific (65%). However, robust elements are found in all the ocean basins (Indian-14%; Atlantic-21%) and in both hemispheres (Northern-18%; Southern-12%), making cold events truly global. In addition, a true life cycle for the cold event is found, with different anomalies occurring at different phases of the evolution of the event and not just during the peak (largest amplitude) phase. The evolution and simulation of these characteristic features of cold events offer as important a challenge to coupled models as the more familiar warm-event anomalies. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Ocean, Seattle, WA 98195 USA. RP Larkin, NK (reprint author), NOAA, Pacific Marine Environm Lab, Bldg 3,7600 Sand Point Way NE, Seattle, WA 98115 USA. RI Harrison, Don/D-9582-2013 NR 21 TC 20 Z9 21 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 19 BP 3904 EP 3931 DI 10.1175/1520-0442(2001)014<3904:TPECES>2.0.CO;2 PG 28 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 478JV UT WOS:000171344000002 ER PT J AU Yang, FL Kumar, A Wang, WQ Juang, HMH Kanamitsu, M AF Yang, FL Kumar, A Wang, WQ Juang, HMH Kanamitsu, M TI Snow-albedo feedback and seasonal climate variability over North America SO JOURNAL OF CLIMATE LA English DT Article ID SOUTHERN OSCILLATION AB Interannual variations in the tropical Pacific sea surface temperatures related to El Nino-Southern Oscillation (ENSO) are known to influence wintertime surface climate anomalies over North America. However, the role of local land surface processes in this phenomenon is not well understood. Here, using a suite of atmospheric general circulation model simulations, it is demonstrated that the North American surface climate anomalies related to ENSO are greatly enhanced by a local snow-albedo feedback. Implications of this feedback mechanism on seasonal climate predictions and greenhouse gas-induced climate changes are discussed. C1 Natl Ctr Environm Predict, Environm Modeling Ctr, Washington, DC USA. Gen Sci Corp, Washington, DC USA. Natl Ctr Environm Predict, Climate Predict Ctr, Washington, DC USA. RP Yang, FL (reprint author), Natl Ctr Environm Predict, Environm Modeling Ctr, 5200 Auth Rd, Camp Springs, MD 20746 USA. RI Yang, Fanglin/A-1948-2013 NR 10 TC 37 Z9 38 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 22 BP 4245 EP 4248 DI 10.1175/1520-0442(2001)014<4245:SAFASC>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 488FB UT WOS:000171924600001 ER PT J AU Liebmann, B Marengo, JA AF Liebmann, B Marengo, JA TI Interannual variability of the rainy season and rainfall in the Brazilian Amazon basin SO JOURNAL OF CLIMATE LA English DT Article ID SOUTH-AMERICAN SECTOR; SURFACE CLIMATE; OSCILLATION; PRECIPITATION; CONVECTION AB Interannual variability of seasonal rainfall in the Brazilian Amazon basin is examined in context of its relationship to sea surface temperatures in the tropical Pacific and Atlantic Oceans. Linear correlations reveal strong relationships, but rainfall patterns are of regional scale. Areas of rainfall exhibiting strong relationships with SST are confined to the equatorial region of the Brazilian Amazon. The best relationships are found either during the season of transition between wet and dry regimes, or entirely within the dry season. It is hypothesized, and results are shown in support, that during the transition seasons, an important contributor to the SST control on seasonal totals is its influence on the timing on the rainy season onset or end. That influence appears to be stronger than the SST influence on the rainy season rain rate. C1 NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO 80303 USA. Ctr Previsao Tempo & Estudos Climat, Sao Paulo, Brazil. RP Liebmann, B (reprint author), NOAA, CIRES, Climate Diagnost Ctr, R CDC1,325 Broadway, Boulder, CO 80303 USA. RI Marengo, Jose /J-9382-2012 OI Marengo, Jose /0000-0002-8154-2762 NR 27 TC 132 Z9 141 U1 1 U2 10 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 22 BP 4308 EP 4318 DI 10.1175/1520-0442(2001)014<4308:IVOTRS>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 488FB UT WOS:000171924600005 ER PT J AU Winkler, CR Newman, M Sardeshmukh, PD AF Winkler, CR Newman, M Sardeshmukh, PD TI A linear model of wintertime low-frequency variability. Part I: Formulation and forecast skill SO JOURNAL OF CLIMATE LA English DT Article ID OSCILLATION PATTERN-ANALYSIS; SURFACE TEMPERATURE ANOMALIES; SINGULAR-VALUE DECOMPOSITION; NINO-SOUTHERN OSCILLATION; ROSSBY-WAVE DYNAMICS; CIRCULATION ANOMALIES; TROPICAL CONVECTION; EL-NINO; INTRASEASONAL OSCILLATION; GEOPOTENTIAL HEIGHT AB A linear inverse model (LIM) suitable for studies of atmospheric extratropical variability on longer than weekly timescales is constructed using observations of the past 30 years. Notably, it includes tropical diabatic heating as an evolving model variable rather than as a forcing, and also includes, in effect, the feedback of the extratropical weather systems on the more slowly varying circulation. Both of these features are shown to be important contributors to the model's realism. Forecast skill is an important test of any model's usefulness as a diagnostic tool. The LIM is better at forecasting week 2 anomalies than a dynamical model based on the linearized baroclinic equations of motion (with many more than the LIM's 37 degrees of freedom) that is forced with observed (as opposed to the LIM's predicted) tropical heating throughout the forecast. Indeed, at week 2 the LIM's skill is competitive with that of the global nonlinear medium-range forecast (MRF) model with nominally 0(10(6)) degrees of freedom in use at the National Centers for Environmental Prediction (NCEP). Importantly, this encouraging model performance is not limited to years of El Nino or La Nina episodes. This suggests that accurate prediction of tropical diabatic heating, rather than of tropical sea surface temperatures per se, is key to enhancing extratropical predictability. The LIM assumes that the dynamics of extratropical low-frequency variability are linear, stable, and stochastically forced. The approximate validity of these assumptions is demonstrated through several tests. A potentially limiting aspect of such a stable linear model with decaying eigenmodes concerns its ability to predict anomaly growth. It is nevertheless found, through a singular vector analysis of the model's propagator, that predictable anomaly growth can and does occur in this dynamical system through constructive modal interference. Examination of the dominant growing singular vectors further confirms the importance of tropical heating anomalies associated with El Nino/La Nina as well as Madden-Julian oscillation episodes in the predictable dynamics of the extratropical circulation. The relative contribution of initial streamfunction and heating perturbations to the development of amplifying anomalies is similarly examined. This analysis suggests that without inclusion of the effects of tropical heating, extratropical weekly averages may be predictable about two weeks ahead, but with tropical heating included, they may be predictable as far as seven weeks ahead. C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Climate Diagnost Ctr, Boulder, CO 80305 USA. RP Newman, M (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Climate Diagnost Ctr, Mail Code R-CDC,325 Broadway, Boulder, CO 80305 USA. RI Newman, Matthew /F-8336-2010 OI Newman, Matthew /0000-0001-5348-2312 NR 64 TC 75 Z9 75 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. PY 2001 VL 14 IS 24 BP 4474 EP 4494 DI 10.1175/1520-0442(2001)014<4474:ALMOWL>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 504XE UT WOS:000172880800002 ER PT J AU Percival, DB Overland, JE Mofjeld, HO AF Percival, DB Overland, JE Mofjeld, HO TI Interpretation of North Pacific variability as a short- and long-memory process SO JOURNAL OF CLIMATE LA English DT Article ID TIME-SERIES MODELS; REGIME SHIFTS; CLIMATE; FIT; OSCILLATIONS; NOISE AB A major difficulty in investigating the nature of interdecadal variability of climatic time series is their shortness. An approach to this problem is through comparison of models. In this paper a first-order autoregressive [AR(1)] model is contrasted with a fractionally differenced (FD) model as applied to the winter-averaged sea level pressure time series for the Aleutian low [the North Pacific (NP) index] and the Sitka winter air temperature record. Both models fit the same number of parameters. The AR(1) model is a "short-memory'' model in that it has a rapidly decaying autocovariance sequence, whereas an FD model exhibits "long memory'' because its autocovariance sequence decays more slowly. Statistical tests cannot distinguish the superiority of one model over the other when fit with 100 NP or 146 Sitka data points. The FD model does equally well for short-term prediction and has potentially important implications for long-term behavior. In particular, the zero crossings of the FD model tend to be farther apart, so they have more of a "regimelike'' character; a quarter century interval between zero crossings is 4 times more likely with the FD than the AR(1) model. The long-memory parameter delta for the FD model can be used as a characterization of regimelike behavior. The estimated deltas for the NP index (spanning 100 yr) and the Sitka time series (168 yr) are virtually identical, and their size implies moderate long-memory behavior. Although the NP index and the Sitka series have broadband low-frequency variability and modest long-memory behavior, temporal irregularities in their zero crossings are still prevalent. Comparison of the FD and AR(1) models indicates that regimelike behavior cannot be ruled out for North Pacific processes. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA. RP Overland, JE (reprint author), NOAA, Pacific Marine Environm Lab, Bldg No 3,7600 Sand Point Way NE, Seattle, WA 98115 USA. EM overland@pmel.noaa.gov NR 34 TC 42 Z9 42 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 EI 1520-0442 J9 J CLIMATE JI J. Clim. PY 2001 VL 14 IS 24 BP 4545 EP 4559 DI 10.1175/1520-0442(2001)014<4545:IONPVA>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 504XE UT WOS:000172880800006 ER PT J AU Moon, KW Boettinger, WJ Kattner, UR Handwerker, CA Lee, DJ AF Moon, KW Boettinger, WJ Kattner, UR Handwerker, CA Lee, DJ TI The effect of Pb contamination on the solidification behavior of Sn-Bi solders SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE cooling curves; pasty range; Pb contamination; Sn-Bi solders; and Sn-Bi-Pb ternary eutectic AB This paper presents experimental results and theoretical calculations to evaluate the effects of Pb contamination on the solidification behavior of Sn - x Bi alloys (x = 5, 10, and 58 mass %). The pasty (mushy) range, the type of solidification path, and the fraction of the ternary eutectic are described. The experimental results are obtained from thermal analysis and quantitative metallography, and the solidification calculations are performed using Lever and Scheil assumptions. The experimental, results agree with the Scheil calculations. The freezing range of Pb contaminated Sn-Bi solders is greatly increased due to the formation of a ternary eutectic reaction at (95.3 +/- 0.5)degrees C. This increase is a likely cause of porosity in contaminated solder joints. The results provide an example of an analysis method for use in solder alloys in general. C1 NIST, Div Met, Gaithersburg, MD 20899 USA. Chonnam Natl Univ, Dept Met, Kwangju 500757, South Korea. RP Moon, KW (reprint author), NIST, Div Met, 100 Bur Dr Stop 8555, Gaithersburg, MD 20899 USA. NR 13 TC 44 Z9 44 U1 0 U2 5 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD JAN PY 2001 VL 30 IS 1 BP 45 EP 52 DI 10.1007/s11664-001-0213-x PG 8 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 388VF UT WOS:000166203200008 ER PT J AU Pennington, PL Daugomah, JW Colbert, AC Fulton, MH Key, PB Thompson, BC Strozier, ED Scott, GI AF Pennington, PL Daugomah, JW Colbert, AC Fulton, MH Key, PB Thompson, BC Strozier, ED Scott, GI TI Analysis of pesticide runoff from mid-Texas estuaries and risk assessment implications for marine phytoplankton SO JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART B-PESTICIDES FOOD CONTAMINANTS AND AGRICULTURAL WASTES LA English DT Article DE aldicarb; carbofuran; atrazine; agricultural runoff; mid-Texas coast; phytoplankton ID DEGRADATION PRODUCTS; ATRAZINE; HERBICIDES; SURFACE; WATERS; RIVER AB During 1993, estuarine surface water samples were collected from the mid-Texas coast (Corpus Christi to Port Lavaca, TX). Agricultural watershed areas as well as tidal creeks immediately downstream were chosen as sampling sites along with adjoining bay sampling stations. Collections were made throughout the growing season (February to October 1993) before and after periods of significant (> 1.25 cm) rainfall. All samples were initially screened for the presence of pesticides using enzyme-linked immunosorbent assay (ELISA) test kits (EnviroGard (TM)) for triazine herbicides and carbamate insecticides. All samples were extracted and then analyzed using gas chromatography (GC) for quantification of atrazine. Only samples testing positive for carbamate insecticides via ELISA were further extracted for GC analysis to quantify aldicarb and carbofuran. Additionally, laboratory toxicity tests using phytoplankton were examined from published, peer-reviewed literature and compared with the atrazine field levels found in Texas. Results of ELISA screening indicated the presence of triazine herbicides in nearly all samples (>93%). GC analysis further confirmed the presence of atrazine concentrations ranging from <0.01-62.5 g/L. Screening tests also found detectable levels of carbamate insecticides (aldicarb and carbofuran) that were also confirmed and quantified by CC. Comparison of measured concentrations of atrazine compared with published toxicity tests results indicated that there was a potential environmental risk for marine/estuarine phytoplankton in surface waters of Texas estuaries, particularly when the chronic nature of atrazine exposure is considered. C1 NOAA, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res Charleston, Charleston, SC 29412 USA. Univ S Carolina, Sch Publ Hlth, Dept Environm Hlth Sci, Columbia, SC 29208 USA. Fed Bur Invest, New Orleans, LA 70113 USA. RP Pennington, PL (reprint author), NOAA, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res Charleston, 219 Ft Johnson Rd, Charleston, SC 29412 USA. RI Key, Peter/D-1787-2010 NR 27 TC 24 Z9 25 U1 1 U2 11 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0360-1234 J9 J ENVIRON SCI HEAL B JI J. Environ. Sci. Health Part B-Pestic. Contam. Agric. Wastes PY 2001 VL 36 IS 1 BP 1 EP 14 DI 10.1081/PFC-100000912 PG 14 WC Environmental Sciences; Public, Environmental & Occupational Health SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health GA 409FT UT WOS:000167374400001 PM 11281251 ER PT J AU Davis, MW Olla, BL Schreck, CB AF Davis, MW Olla, BL Schreck, CB TI Stress induced by hooking, net towing, elevated sea water temperature and air in sablefish: lack of concordance between mortality and physiological measures of stress SO JOURNAL OF FISH BIOLOGY LA English DT Article DE bycatch; capture; physiology; temperature ID COHO SALMON; NORTH-SEA; FISH; DURATION; CORTISOL; SURVIVAL AB In a series of laboratory studies designed to simulate bycatch processes. sablefish Anoplopoma fimbria were either hooked for up to 24 h or towed in a net for 4 h and then subjected to an abrupt transfer to elevated sea water temperature and air. Mortality did not result from hooking or net towing followed by exposure to air, but increased for both capture methods as fish were exposed to elevated temperatures, reflecting the magnifying effect of elevated temperature on mortality. Hooking and exposure to air resulted in increased plasma cortisol and lactate concentrations, while the combination of hooking and exposure to elevated temperature and air resulted in increased lactate and potassium concentrations. In fish that were towed in a net and exposed to air. cortisol, lactate. potassium and sodium concentrations increased. but when subjected to elevated temperature and air, no further increases occurred above the concentrations induced by net towing and air, suggesting a possible maximum of the physiological stress response. The results suggest that caution should be exercised when using physiological measures to quantify stress induced by capture and exposure to elevated temperature and air. that ultimately result in mortality, since the connections between physiological stress and mortality in bycatch processes remain to be fully understood. C1 Natl Marine Fisheries Serv, Hatfield Marine Sci Ctr, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. Oregon State Univ, US Geol Survey, Dept Fisheries & Wildlife, Oregon Cooperat Fishery Res Unit, Corvallis, OR 97331 USA. RP Davis, MW (reprint author), Natl Marine Fisheries Serv, Hatfield Marine Sci Ctr, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. NR 32 TC 63 Z9 66 U1 4 U2 13 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD JAN PY 2001 VL 58 IS 1 BP 1 EP 15 DI 10.1006/jfbi.2000.1399 PG 15 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 397FL UT WOS:000166682600001 ER PT J AU MacCrehan, WA Patierno, ER Duewer, DL Reardon, MR AF MacCrehan, WA Patierno, ER Duewer, DL Reardon, MR TI Investigating the effect of changing ammunition on the composition of organic additives in gunshot residue (OGSR) SO JOURNAL OF FORENSIC SCIENCES LA English DT Article DE forensic science; capillary electrophoresis; compositional analysis; diphenylamine; ethyl centralite; gunpowder; gun shot residue; handgun; nitroglycerin ID ELECTROKINETIC CAPILLARY ELECTROPHORESIS; IDENTIFICATION; PARTICLES; CONSTITUENTS AB The measurement of the organic additives in smokeless gunpowder is an attractive approach for the detection of handgun use because it provides compositional information that can help associate residues and unfired gunpowder. We investigate several factors that will be required to advance the characterization of organic gunshot residue (OGSR) as a useful forensic tool, including evaluating residue contamination from previously fired ammunition, particle-to-particle compositional variability, and compositional features resulting from the type of firing primer used. Using ammunition loaded with known smokeless powders containing different stabilizers, a sequence of shots was fired from a.357 magnum revolver, and the muzzle exit residues were collected. Compositional analysis of the residues, both in bulk and as single particles, showed only a trace of the previously fired powder in the first shot and none in subsequent shots. In an additional experiment testing conventional leaded and the new lend-free firing primers, the OGSR composition was found not to depend on the primer type. C1 Natl Inst Stand & Technol, Div Analyt Chem, Gaithersburg, MD 20899 USA. George Washington Univ, Dept Forens Sci, Washington, DC 20052 USA. RP MacCrehan, WA (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, 100 Bur Dr,Stop 8394, Gaithersburg, MD 20899 USA. RI Duewer, David/B-7410-2008 NR 15 TC 18 Z9 20 U1 1 U2 16 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0022-1198 J9 J FORENSIC SCI JI J. Forensic Sci. PD JAN PY 2001 VL 46 IS 1 BP 57 EP 62 PG 6 WC Medicine, Legal SC Legal Medicine GA 451JA UT WOS:000169797900008 PM 11210924 ER PT J AU Galand, M AF Galand, M TI Introduction to special section: Proton precipitation into the atmosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Editorial Material C1 Natl Ocean & Atmospher Adm, Space Environm Ctr, Boulder, CO USA. RP Galand, M (reprint author), Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. RI Galand, Marina/C-6804-2009 NR 10 TC 9 Z9 9 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 JAN 1 PY 2001 VL 106 IS A1 BP 1 EP 6 DI 10.1029/2000JA002015 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 391WQ UT WOS:000166379600001 ER PT J AU Lummerzheim, D Galand, M AF Lummerzheim, D Galand, M TI The profile of the hydrogen H-beta emission line in proton aurora SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TRANSPORT-THEORETIC MODEL; ATOM FLUXES; DOPPLER PROFILES; ATMOSPHERE; PRECIPITATION; IONOSPHERE; BEAM AB Models of hydrogen-proton transport in proton aurora predict the line profile of the hydrogen emissions from specified incident proton precipitation. We are using a model that includes collisional angular redistribution which leads to upward moving proton and hydrogen fluxes. For ground-based observation in the magnetic zenith this causes a small Doppler broadening toward the red in the line profile. The precipitating energetic hydrogen atoms are responsible for the prominent Doppler shift toward the blue. The resulting line profile has thus both a widened red and a widened blue wing. Using a spectrometer with sufficient spectral resolution to distinguish the red-shifted wing of the line from the instrumental line broadening, we obtain Hg line pro files (486.1 nm). Comparing the predicted line shapes to our observations, we find the red-shifted wing is due to upward moving hydrogen as predicted by the angular redistribution in the model calculations. The shape of the blue-shifted wing, rather than the location of the peak of the blue- shifted line profile, is a suitable indicator of the mean energy of the precipitating proton flux. C1 Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. NOAA, Space Environm Ctr, Boulder, CO USA. RP Lummerzheim, D (reprint author), Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. RI Galand, Marina/C-6804-2009 NR 22 TC 19 Z9 19 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 JAN 1 PY 2001 VL 106 IS A1 BP 23 EP 31 DI 10.1029/2000JA002014 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 391WQ UT WOS:000166379600003 ER PT J AU Galand, M Richmond, AD AF Galand, M Richmond, AD TI Ionospheric electrical conductances produced by auroral proton precipitation SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HEIGHT-INTEGRATED CONDUCTIVITIES; TRANSPORT-THEORETIC MODEL; HYDROGEN ATOM AURORA; ENERGY DEPOSITION; STATISTICAL-MODEL; ION PRECIPITATION; ATMOSPHERE; ELECTRODYNAMICS; ELECTRONS; THERMOSPHERE AB From incoherent scatter radar observations and space-borne particle detector data, it appears that energetic proton precipitation can sometimes, for same locations, be a major source of ionization in the auroral ionosphere and contribute significantly to the electrical conductances. Here we propose a simple parameterization for the Pedersen and Hall conductances produced by proton precipitation. The derivation is based on a proton transport code for computing the electron production rate and on an effective recombination coefficient for deducing the electron density. The atmospheric neutral densities and temperatures and the geomagnetic-field strength are obtained from standard models. The incident protons are assumed to have a Maxwellian distribution in energy with a mean energy < E > in the 2-40 keV range and an energy flux Q(0). The parameterized Pedersen and Hall conductances are functions of < E > and Q(0), as well as of the geomagnetic-field strength. The dependence on these quantities is compared with those obtained for electron precipitation and for solar EUV radiation. To add the contribution of proton precipitation to the total conductances for electrodynamic studies in auroral regions, the conductances produced by electron and proton precipitations can be combined by applying a root-sum-square approximation. C1 Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80301 USA. Natl Ocean & Atmospher Adm, Space Environm Ctr, Boulder, CO USA. RP Galand, M (reprint author), Boston Univ, Ctr Space Phys, 725 Commonwealth Ave, Boston, MA 02215 USA. RI Galand, Marina/C-6804-2009 NR 52 TC 47 Z9 47 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 JAN 1 PY 2001 VL 106 IS A1 BP 117 EP 125 DI 10.1029/1999JA002001 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 391WQ UT WOS:000166379600010 ER PT J AU Galand, M Fuller-Rowell, TJ Codrescu, MV AF Galand, M Fuller-Rowell, TJ Codrescu, MV TI Response of the upper atmosphere to auroral protons SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HEIGHT-INTEGRATED CONDUCTIVITIES; ELECTRON-PRECIPITATION; STATISTICAL-MODEL; IONOSPHERIC CONDUCTANCES; ENERGY DEPOSITION; ION PRECIPITATION; THERMOSPHERE; MESOSPHERE; CHATANIKA; SYSTEM AB three-dimensional, time-dependent, coupled model of the thermosphere and ionosphere has been used to assess the influence of proton auroral precipitation on Earth's upper atmosphere. Statistical patterns of auroral electron and proton precipitation, derived from DMSP satellite observations, have been used to drive the model, Overall, electrons are the dominant particle energy source, with protons contributing similar to 15% of the total energy. However, owing to the offset of the proton auroral oval toward dusk, in certain spatial regions protons can carry most of the energy. This is the case particularly at the equatorward edge of the dusk sector and at the poleward edge of the dawn sector of the auroral oval. The increase in Pedersen conductivity raises the average Joule heating by similar to 10%, so raising the E and F region temperature by as much as 7%. The enhanced E region ionization also drives stronger neutral winds in the lower thermosphere through ion drag, which alters the temperature structure through transport, adiabatic heating, and adiabatic cooling. The neutral wind velocity modifications in the E region can reach 40% in some sectors. In addition, the upwelling of neutral gas raises the N-2/O ratio, depleting the F region and so reducing the ion-drag driven winds in this region. This study illustrates the modest yet significant impact of auroral proton precipitation on the upper atmosphere. C1 NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Galand, M (reprint author), Boston Univ, Ctr Space Phys, 725 Commonwealth Ave, Boston, MA 02215 USA. RI Galand, Marina/C-6804-2009 NR 45 TC 34 Z9 34 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 JAN 1 PY 2001 VL 106 IS A1 BP 127 EP 139 DI 10.1029/2000JA002009 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 391WQ UT WOS:000166379600011 ER PT J AU Lummerzheim, D Galand, M Semeter, J Mendillo, MJ Rees, MH Rich, FJ AF Lummerzheim, D Galand, M Semeter, J Mendillo, MJ Rees, MH Rich, FJ TI Emission of OI(630 nm) in proton aurora SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID H-ATOM FLUXES; TRANSPORT-THEORETIC MODEL; DOPPLER PROFILES; HYDROGEN; ATMOSPHERE; ENERGY; IONOSPHERE; DEGRADATION; COLLISIONS AB A red aurora occurred over southern Canada and central Maine on April 11, 1997, producing a brightness of O I(630 nm) of several Kilorayleighs, which lasted for several hours. Two passes of the Defense Meteorological Satellite Program (DMSP) F12 satellite occurred during this time, and optical data were obtained from four CEDAR Optical Tomographic Imaging Facility (COTIF) sites. The DMSP F12 particle spectrometers observed proton precipitation south of the electron aurora with energy fluxes of several mW m(-2). Tomographic inversion of the COTIF optical observations gives the altitude profile of emissions along a magnetic meridian. We combine all available data using an ionospheric auroral model. Our analysis shows that the model produces the observed auroral brightness from the proton precipitation alone. C1 Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. NOAA, Space Environm Ctr, Boulder, CO USA. Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. SRI Int, Menlo Park, CA 94025 USA. Univ Southampton, Dept Phys, Southampton SO17 1BJ, Hants, England. USAF, Res Lab, Space Vehicle Directorate, VSB, Bedford, MA 01731 USA. RP Lummerzheim, D (reprint author), Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. RI Galand, Marina/C-6804-2009; Mendillo, Michael /H-4397-2014 NR 28 TC 22 Z9 22 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 JAN 1 PY 2001 VL 106 IS A1 BP 141 EP 148 DI 10.1029/2000JA002005 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 391WQ UT WOS:000166379600012 ER PT J AU Raeder, J McPherron, RL Frank, LA Kokubun, S Lu, G Mukai, T Paterson, WR Sigwarth, JB Singer, HJ Slavin, JA AF Raeder, J McPherron, RL Frank, LA Kokubun, S Lu, G Mukai, T Paterson, WR Sigwarth, JB Singer, HJ Slavin, JA TI Global simulation of the Geospace Environment Modeling substorm challenge event SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; 3-DIMENSIONAL MHD SIMULATION; IONOSPHERIC ELECTRIC-FIELDS; ALIGNED CURRENTS; PLASMA SHEET; SOLAR-WIND; SYNCHRONOUS ALTITUDE; AURORAL ACTIVITY; COUPLING MODEL; MAGNETOSPHERE AB We use a global model of Earth's magnetosphere and ionosphere to simulate the Geospace Environment Modeling (GEM) substorm challenge event of November 24, 1996. We compare our results to International Monitor for Auroral Geomagnetic Effects (IMAGE) ground magnetometer data, assimilative mapping of ionospheric electrodynamics (AMIE) polar cap potential and field aligned current patterns, Polar Visible Imaging System (VIS) estimates of the polar cap magnetic flux, GOES 8 geosynchronous magnetometer data, IMP 8 magnetometer data, and Geotail plasma and magnetic field data. We find generally good agreement between the simulation and the data. The modeled evolution of this substorm generally follows the phenomenological near-Earth neutral line model. However, reconnection in the tail is very localized, which makes establishing a causal relation between tail dynamics and auroral dynamics difficult, if not impossible. We also find that the model results critically depend on the parameterization of auroral Hall and Pedersen conductances and anomalous resistivity in the magnetosphere. For many combinations of parameters that enter these parameterizations, no substorm develops in the model, but instead the magnetosphere enters a steady convection mode. The main deviation of the model from the data is excessive convection, which leads to a strong, driven westward electrojet in the growth phase, only partial tail loading, and a reduced recovery phase. Possible remedies are a better model for auroral conductances, an improved anomalous resistivity model, and a more realistic treatment of the ring current. C1 Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Nagoya Univ, Solar Terr Environm Lab, Aichi 442, Japan. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Raeder, J (reprint author), Univ Calif Los Angeles, Inst Geophys & Planetary Phys, 405 Hilgard Ave, Los Angeles, CA 90095 USA. RI Lu, Gang/A-6669-2011; Paterson, William/F-5684-2012; Slavin, James/H-3170-2012 OI Slavin, James/0000-0002-9206-724X NR 67 TC 150 Z9 155 U1 0 U2 6 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 JAN 1 PY 2001 VL 106 IS A1 BP 381 EP 395 DI 10.1029/2000JA000605 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 391WQ UT WOS:000166379600032 ER PT J AU Lu, G Richmond, AD Ruohoniemi, JM Greenwald, RA Hairston, M Rich, FJ Evans, DS AF Lu, G Richmond, AD Ruohoniemi, JM Greenwald, RA Hairston, M Rich, FJ Evans, DS TI An investigation of the influence of data and model inputs on assimilative mapping of ionospheric electrodynamics SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; ELECTRIC-POTENTIAL PATTERNS; INCOHERENT-SCATTER RADAR; HIGH-LATITUDE IONOSPHERE; CONVECTION RESPONSE; PARTICLE-PRECIPITATION; ALIGNED CURRENTS; LOCALIZED OBSERVATIONS; CONDUCTIVITIES; MAGNETOSPHERE AB The Geospace Environment Modeling (GEM) substorm challenge event of November 24, 1996, has been used as a test case to investigate the influence of different data and model inputs on the assimilative mapping of ionospheric electrodynamics (AMIE) outputs. During that period the interplanetary magnetic field (IMF) went from northward to southward and then returned to northward. In the later part of the day a moderate substorm with AL similar to -600 nT took place. The AMIE convection patterns derived from the Super Dual Auroral Radar Network (SuperDARN) data alone are generally similar to those derived using ground magnetometer alone, especially during the relatively stable southward IMF period. However, some differences are found during the northward IMF period and during the substorm; namely, the reversed convection configuration near local noon imaged by SuperDARN is absent in the magnetometer observations while the strong convection on the nightside recorded by the magnetometers during the substorm expansion phase is not seen by the radars. Different conductance models do not seem to have a big effect on the large-scale distributions of ionospheric convection and Joule heating, but they do alter the cross polar cap potential drop and the hemispheric integrated Joule heating rate by nearly a factor of 2. When the AMIE-derived electric potential drop was compared with the in situ measurements along the satellite track, it is found that AMIE underestimated the potential drop by 20 kV, amounting to a 22% underestimation. The analysis of the AMIE results based on the SuperDARN and ground magnetometer data reiterates the view that the response of ionospheric convection to a sudden IMF southward turning is global and nearly simultaneous. C1 Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Texas, Ctr Space Sci, Richardson, TX 75083 USA. Phillips Lab, Hanscom AFB, MA 01731 USA. RP Lu, G (reprint author), Natl Ctr Atmospher Res, High Altitude Observ, 345 Mitchell Lane, Boulder, CO 80307 USA. RI Lu, Gang/A-6669-2011 NR 44 TC 25 Z9 26 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 JAN 1 PY 2001 VL 106 IS A1 BP 417 EP 433 DI 10.1029/2000JA000606 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 391WQ UT WOS:000166379600035 ER PT J AU Gardner, WS Yang, LY Cotner, JB Johengen, TH Lavrentyev, PJ AF Gardner, WS Yang, LY Cotner, JB Johengen, TH Lavrentyev, PJ TI Nitrogen dynamics in sandy freshwater sediments (Saginaw Bay, Lake Huron) SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE ammonium flux; sediment-water nitrogen dynamics; nitrification; denitrification; Saginaw Bay; zebra mussels ID MUSSEL DREISSENA-POLYMORPHA; ZEBRA MUSSEL; BENTHIC DENITRIFICATION; CHROMATOGRAPHIC METHOD; ESTUARINE SEDIMENTS; WATER; AMMONIUM; NITRIFICATION; SALINITY; FLUX AB Sediment-water nitrogen fluxes and transformations were examined at two sites in Saginaw Bay, Lake Huron, as a model for sandy freshwater sediments. Substantial ammonium release rates (74 to 350 mu mole NH4+/m(2)/h(1)) were observed in flow-through cores and in situ benthic chamber experiments. Sediment-water ammonium fluxes were similar at the inner and outer bay stations even though inner bay water are enriched with nutrients from the Saginaw River. The high net flux of remineralized ammonium into the overlying water from these sandy sediments resembles typical data for marine systems (11 to 470 mu mole NH4+/m(2)/h(1)) but were higher than those reported for depositional freshwater sediments (0 to 15 mu mole NH4+/m(2)/h(1); Seitzinger 1988). Addition of montmorillonite clay (ca. 1 kg dry weight/m(2)) to the top of the sandy cores reduced ammonium flux. Mean "steady-state" ammonium flux following clay addition was 46 +/- 2 (SE) % of the initial rates as compared to 81 +/- 8% of the initial rates without clay addition. Zebra mussel excretion dominated ammonium regeneration in the inner bay where the bivalve was abundant, but addition of zebra mussel feces/psuedofeces (3.0 g dw/m(2)) to sediments did not increase ammonium or nitrate flux. Partial nitrification of ammonium at the sediment-water interface was suggested by removal of added (NH4+)-N-15 from lake water passing over dark sediment cores. Sediment-water fluxes of nitrogen obtained from flow-through sediment cores resembled those from in situ benthic chambers. However, extended static incubations in gas-tight denitrification chambers caused more of the regenerated nitrogen to be nitrified and denitrified than occurred with the other two measurement systems. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Chinese Acad Sci, Nanjing Inst Geog & Limnol, Nanjing 210008, Jiangsu, Peoples R China. Texas A&M Univ, College Stn, TX 77843 USA. Univ Michigan, Cooperat Inst Limnol & Ecosyst Res, Ann Arbor, MI 48109 USA. RP Gardner, WS (reprint author), Univ Texas, Inst Marine Sci, 750 Channelview Dr, Port Aransas, TX 78373 USA. NR 40 TC 25 Z9 31 U1 2 U2 13 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2205 COMMONWEALTH BLVD, ANN ARBOR, MI 48105 USA SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PY 2001 VL 27 IS 1 BP 84 EP 97 PG 14 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 417KR UT WOS:000167834600008 ER PT J AU Landrum, PF Tigue, EA Driscoll, SK Gossiaux, DC Van Hoof, PL Gedeon, ML Adler, M AF Landrum, PF Tigue, EA Driscoll, SK Gossiaux, DC Van Hoof, PL Gedeon, ML Adler, M TI Bioaccumulation of PCB congeners by Diporeia spp.: Kinetics and factors affecting bioavailability SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE Diporeia spp.; PCB; toxicokinetics; organism size; temperature; BSAF ID POLYCHLORINATED BIPHENYL CONGENERS; PONTOPOREIA-HOYI; LAKE-MICHIGAN; ORGANIC XENOBIOTICS; TOXICOKINETICS; ACCUMULATION; AMPHIPOD; MODEL; INVERTEBRATES AB The toxicokinetics of four polychlorinated biphenyl (PCB) congeners were determined for the amphipod Diporeia spp. exposed to selected PCB congeners through both water and sediment to determine the effect of temperature and organism size (mass). For compounds with log K-ow 6 or greater, the water-only uptake coefficient (k(u)) was inversely proportional to the size of the organism at all temperatures. For monochlorobiphenyl, k(u) was directly proportional to organism mass only at 16 degreesC. Increasing temperature resulted in increasing uptake rare coefficients for all compounds except hexachlorobiphenyl (HCBP) where k(u) did not appear to depend on temperature. The hydrophobicity of the contaminants did not contribute significantly to changes in uptake rate from water. The elimination rare constant (k(e)) was inversely proportional to organism size bur was not significantly affected by temperature. The elimination rare constant declined e;exponentially with increasing log K-ow. As log K-ow increased, the effect of organism mass on k(e) was greatly reduced. The uptake from sediment was affected by temperature and the congener log K-ow. At lower temperatures, the uptake coefficient from sediment (k(s)) declined with increasing log K-ow while at higher temperatures, it exhibited a slight upward trend. Smaller animals had much higher uptake rates from sediment than large or medium size animals. Small animals exhibited very high biotasediment accumulation factors (5.4 to 20.8) over 4 to 16 degreesC for HCBP (BSAF, concentration in the organ ism normalized to the lipid content divided by the concentration in the sediment normalized to the organic carbon content). The relationship between BSAF and log K-ow was exponential for both laboratory and field data. C1 Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Michigan, Cooperat Inst Limnol & Ecosyst Res, Ann Arbor, MI 48105 USA. RP Landrum, PF (reprint author), Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. NR 27 TC 17 Z9 18 U1 4 U2 9 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2205 COMMONWEALTH BLVD, ANN ARBOR, MI 48105 USA SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PY 2001 VL 27 IS 2 BP 117 EP 133 PG 17 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 446VY UT WOS:000169535900002 ER PT J AU Nalepa, TF Schloesser, DW Pothoven, SA Hondorp, DW Fanslow, DL Tuchman, ML Fleischer, GW AF Nalepa, TF Schloesser, DW Pothoven, SA Hondorp, DW Fanslow, DL Tuchman, ML Fleischer, GW TI First finding of the amphipod Echinogammarus ischnus and the mussel Dreissena bugensis in Lake Michigan SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE nonindigenous species; amphipod; quagga mussels; zebra mussels; Lake Michigan ID GREAT-LAKES; NORTH-AMERICA; COMMUNITY; SPP.; ERIE; POLYMORPHA; HABITATS; DENSITY; SIZE AB The first finding of the amphipod Echinogammarus ischnus and the mussel Dreissena bugensis in Lake Michigan is documented. These two species are widespread and abundant in the lower lakes, but had not yet been reported from Lake Michigan. E. ischnus is generally considered a warm-water form that is typically associated with hard substrates and Dreissena clusters in the nearshore zone. Along the eastern shoreline of Lake Michigan, this species was present at rocky, breakwall habitats along the entire north-south axis of the lake. Although not abundant, this species was also found at soft-bottomed sites as deep as 94 m in the southern basin. The finding of this species in deep offshore waters apparently extends the known habitat range for this species in the Great Lakes, but it is found in deep water areas within its native range (Caspian Sea). D. bugensis was not abundant, but was present in both the southern and northern portions of the lake. Individuals of up to 36 mm in length were collected, indicating that it had probably been present in the lake for 2 or more years. Also presented are depth-defined densities of D. polymorpha at 37 sites in the Straits of Mackinac in 1997, and densities at up to 55 sites in the southern basin in 1992/93 and 1998/99. Mean densities decreased with increased water depth in both regions. Maximum mean density in the Straits in 1997 was 13,700/m(2) (less than or equal to 10 m), and maximum density in the southern basin in 1999 was 2, 100/m(2) (less than or equal to 30 m). Mean densities at the less than or equal to 30-m interval in the southern basin remained relatively unchanged between 1993 and 1999, but increased from 25/m(2) to 1,100/m(2) at the 31 to 50 m interval over the same time period. D. polymorpha was rare at sites > 50 m. The presence of E. ischnus and the expected population expansion of D. bugensis will likely contribute to further food-web changes in the lake. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48015 USA. USGS, Great Lakes Sci Ctr, Ann Arbor, MI 48015 USA. Univ Michigan, Cooperat Inst Limnol & Ecosyst Res, Ann Arbor, MI 48109 USA. US EPA, Great Lakes Natl Program Off, Chicago, IL 60604 USA. RP Nalepa, TF (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48015 USA. OI Pothoven, Steven/0000-0002-7992-5422 NR 33 TC 42 Z9 43 U1 0 U2 9 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2205 COMMONWEALTH BLVD, ANN ARBOR, MI 48105 USA SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PY 2001 VL 27 IS 3 BP 384 EP 391 PG 8 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 479RD UT WOS:000171416600013 ER PT J AU Rodionov, S Assel, R Herche, L AF Rodionov, S Assel, R Herche, L TI Tree-structured modeling of the relationship between Great Lakes ice cover and atmospheric circulation patterns SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE ice cover; Great Lakes; teleconnections; ice models; atmospheric circulation ID CLIMATIC VARIATIONS; NORTH-ATLANTIC; TELECONNECTIONS; WINTER; VARIABILITY; PREDICTION; SURFACE; PACIFIC; REGION; ENSO AB Seasonal maximum ice concentration (percentage of lake surface covered by ice) for the entire Laurentian Great Lakes and for each Great Lake separately is modeled using atmospheric teleconnection indices. Two methods, Linear Regression (LR) and Classification and Regression Trees (CART), are used to develop empirical models of the interannual variations of maximum ice cover. Thirty-four winter seasons between 1963 and 1998 and nine teleconnection indices were used in the analysis. The ice cover characteristics were different for each Great Lake. The ice cover data lent itself better to CART analysis, because CART does not require a priori assumptions about data distributions characteristics to perform well. The stepwise LR models needed more variables, and in general, did not explain as much of the variance as the CART models. Two variables, the Multivariate ENSO index and Tropical/Northern Hemisphere index, explained much of the interannual variations in ice cover in the CART models. Composite atmospheric circulation patterns for threshold values of these two indices were found to be associated with above-and below-normal ice cover in the Great Lakes. Thus, CART also provided insight into physical mechanisms (atmospheric circulation characteristics) underlying the statistical relationships identified in the models. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Assel, R (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. OI Rodionov, Sergei/0000-0002-5318-9746 NR 36 TC 10 Z9 10 U1 0 U2 2 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2205 COMMONWEALTH BLVD, ANN ARBOR, MI 48105 USA SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PY 2001 VL 27 IS 4 BP 486 EP 502 PG 17 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 507CY UT WOS:000173010400008 ER PT J AU Holcombe, TL Warren, JS Reid, DF Virden, WT Divins, DL AF Holcombe, TL Warren, JS Reid, DF Virden, WT Divins, DL TI Small rimmed depression in Lake Ontario: An impact crater? SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE bathymetry; impact crater; Lake Ontario; charity shoal; geophysics AB Detailed bathymetry of Lake Ontario reveals a small circular feature and adjoining SW-trending ridge associated with a small topographic high identified as Charity Shoal on nautical charts. The feature consists of a circular basin 1, 000 in in diameter and 19+ in deep, completely surrounded by a low-relief rim that rises to within 5 m of the water surface over much of its extent. A N53E tapering ridge is contiguous with the feature and extends southwestward. Bedrock consists of middle Ordovician limestones 100-150 m thick overlying rocks of Precambrian age. The limited information available suggests that the feature may be an extraterrestrial impact crater, but other origins such as sinkhole, volcanic cone, or kettle, are not ruled out. Time of formation is not known, but likely times include the Pleistocene when the area was exposed by glacial erosion, the middle Ordovician near the time of deposition of limestones, or the Cambro-Ordovician or Precambrian when erosion surfaces of this age were exposed. A subtle negative magnetic anomaly coincides with the feature and is consistent with an impact origin, though not positively diagnostic. Relief of the feature is low compared to that typical of an impact crater of this size. Glaciation may have diminished relief by eroding the rim and filling the central basin with drift. Verification as an impact crater will require detailed geophysical surveys and collection and analyses of samples from in and around the structure. C1 NOAA, Natl Geophys Data Ctr, Boulder, CO 80305 USA. Canadian Hydrog Serv, Almonte, ON K0A 1A0, Canada. NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Holcombe, TL (reprint author), NOAA, Natl Geophys Data Ctr, 325 Broadway, Boulder, CO 80305 USA. NR 11 TC 2 Z9 2 U1 1 U2 2 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2205 COMMONWEALTH BLVD, ANN ARBOR, MI 48105 USA SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PY 2001 VL 27 IS 4 BP 510 EP 517 PG 8 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 507CY UT WOS:000173010400010 ER PT J AU Basist, A Williams, C Grody, N Ross, TF Shen, S Chang, ATC Ferraro, R Menne, MJ AF Basist, A Williams, C Grody, N Ross, TF Shen, S Chang, ATC Ferraro, R Menne, MJ TI Using the special sensor microwave imager to monitor surface wetness SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID SOIL-MOISTURE; SNOW COVER; SSM/I; TEMPERATURE; VEGETATION; BASIN AB The frequencies flown on the Special Sensor Microwave Imager (SSM/I) are sensitive to liquid water near the earth's surface. These frequencies are primarily atmospheric window channels, which receive the majority of their radiation from the surface. Liquid water near the surface depresses the emissivity as a function of wavelength. The relationship between brightness temperatures at different frequencies is used to dynamically derive the amount of liquid water in each SSM/I observation at 1/3 degrees resolution. These data are averaged at 1 degrees resolution throughout the globe for each month during the period of 1992-97, and the 6-yr monthly means and the monthly anomalies of the wetness index are computed from this base period. To quantify the relationship between precipitation and surface wetness, these anomalies are compared with precipitation anomalies derived from the Global Precipitation Climate Program. The analysis was performed for six agricultural regions across six continents. There is generally a good correspondence between the two variables. The correlation generally increases when the wetness index is compared with precipitation anomalies accumulated over a 2-month period. These results indicate that the wetness index has a strong correspondence to the upper layer of the soil moisture in many cultivated areas of the world. The region in southeastern Australia had the best relationship, with a correlation coefficient of 0.76. The Sahel, France, and Argentina showed that the wetness index had memory of precipitation anomalies from the previous months. The memory is shorter for southeastern Australia and central China. The weakest correlations occurred over the southeastern United States, where the surface is covered by dense vegetation. The unique signal, strengths, and weaknesses of the wetness index in each of the six study regions are discussed. C1 NOAA, Natl Climat Data Ctr, NESDIS, Asheville, NC 28801 USA. NOAA, Atmospher Res & Applicat Div, Off Res & Applicat, NESDIS, Camp Springs, MD USA. Univ Alberta, Dept Math, Edmonton, AB, Canada. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Basist, A (reprint author), NOAA, Natl Climat Data Ctr, NESDIS, 151 Patton Ave,Rm 120, Asheville, NC 28801 USA. RI Ferraro, Ralph/F-5587-2010 OI Ferraro, Ralph/0000-0002-8393-7135 NR 28 TC 30 Z9 31 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1525-755X J9 J HYDROMETEOROL JI J. Hydrometeorol. PY 2001 VL 2 IS 3 BP 297 EP 308 DI 10.1175/1525-7541(2001)002<0297:UTSSMI>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 447DQ UT WOS:000169554900006 ER PT J AU Crawford, TM Stensrud, DJ Mora, F Merchant, JW Wetzel, PJ AF Crawford, TM Stensrud, DJ Mora, F Merchant, JW Wetzel, PJ TI Value of incorporating satellite-derived land cover data in MM5/PLACE for simulating surface temperatures SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID NUMERICAL WEATHER PREDICTION; LEAF-AREA INDEX; SOIL-MOISTURE; NOAA-AVHRR; BOUNDARY-LAYER; GLOBAL CHANGE; MODEL; VEGETATION; PARAMETERIZATION; SENSITIVITY AB The Parameterization for Land-Atmosphere-Cloud Exchange (PLACE) module is used within the Fifth-Generation Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model (MM5) to determine the importance of individual land surface parameters in simulating surface temperatures. Sensitivity tests indicate that soil moisture and the coverage and thickness of green vegetation [as manifested by the values of fractional green vegetation coverage (fVEG) and leaf area index (LAI)] have a large effect on the magnitudes of surface sensible heat fluxes. The combined influence of LAI and fVEG is larger than the influence of soil moisture on the partitioning of the surface energy budget. Values for fVEG, albedo, and LAI, derived from 1-km-resolution Advanced Very High Resolution Radiometer data, are inserted into PLACE, and changes in model-simulated 1.5-m air temperatures in Oklahoma during July of 1997 are documented. Use of the land cover data provides a clear improvement in afternoon temperature forecasts when compared with model runs with monthly climatological values for each land cover type. However, temperature forecasts from MM5 without PLACE are significantly more accurate than those with PLACE, even when the land cover data are incorporated into the model. When only the temperature observations above 37 degreesC are analyzed, however, the simulations from the high-resolution land cover dataset with PLACE significantly outperform MM5 without PLACE. Previous land surface models have simply used (at best) climatological values of these crucial land cover parameters. The ability to improve model simulations of surface energy fluxes and the resultant temperatures in a diagnostic sense provides promise for future attempts at ingesting satellite-derived land cover data into numerical models. These model improvements would likely be most helpful in predictions of extreme temperature events (during drought or extremely wet conditions) for which current numerical weather prediction models often perform poorly. The potential value of real-time land cover information for model initialization is substantial. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Nebraska, Ctr Adv Land Management Informat Technol, Lincoln, NE USA. NASA, Goddard Space Flight Ctr, Mesoscale Atmospher Proc Branch, Greenbelt, MD 20771 USA. RP Stensrud, DJ (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 56 TC 40 Z9 43 U1 3 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1525-755X J9 J HYDROMETEOROL JI J. Hydrometeorol. PY 2001 VL 2 IS 5 BP 453 EP 468 DI 10.1175/1525-7541(2001)002<0453:VOISDL>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 478MC UT WOS:000171349100002 ER PT J AU Smith, JA Baeck, ML Zhang, Y Doswell, CA AF Smith, JA Baeck, ML Zhang, Y Doswell, CA TI Extreme rainfall and flooding from supercell thunderstorms SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID UNITED-STATES; METHODOLOGY AB Supercell thunderstorms, the storm systems responsible for most tornadoes, have often been dismissed as flood hazards. The role of supercell thunderstorms as flood agents is examined through analyses of storm systems that occurred in Texas (5-6 May 1995), Florida (26 March 1992), Nebraska (20-21 June 1996), and Pennsylvania (18-19 July 1996). Particular attention is given to the "Dallas Supercell,'' which resulted in 16 deaths from flash flooding and more than $1 billion in property damage during the evening of 5 May 1995. Rainfall analyses using Weather Surveillance Radar-1988 Doppler (WSR-88D) reflectivity observations and special mesonet rain gauge observations from Dallas, Texas, show that catastrophic flash flooding resulted from exceptional rainfall rates at 5-60- min timescales. The spatial structure of extreme rainfall was linked to supercell structure and motion. The "Orlando Supercell'' produced extreme rainfall rates (greater than 300 mm h(-1)) at 1-5-min timescales over a dense rain gauge network. The Nebraska and Pennsylvania storm systems produced record flooding over larger spatial scales than the Texas and Florida storms, by virtue of organization and motion of multiple storms over the same region. For both the Nebraska and Pennsylvania storms, extreme rainfall and tornadoes occurred in tandem. Severe rainfall measurement problems arise for supercell thunderstorms, both from conventional gauge networks and weather radar. It is hypothesized that supercell storms play a significant role in the "climatology'' of extreme rainfall rates (100-yr return interval and greater) at short time intervals (1-60 min) in much of the central and eastern United States. C1 Princeton Univ, Dept Civil & Environm Engn, Princeton, NJ 08544 USA. Natl Severe Storms Lab, Norman, OK 73069 USA. RP Smith, JA (reprint author), Princeton Univ, Dept Civil & Environm Engn, Princeton, NJ 08544 USA. RI Doswell III, Charles/E-7662-2010 NR 35 TC 50 Z9 53 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1525-755X J9 J HYDROMETEOROL JI J. Hydrometeorol. PY 2001 VL 2 IS 5 BP 469 EP 489 DI 10.1175/1525-7541(2001)002<0469:ERAFFS>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 478MC UT WOS:000171349100003 ER PT J AU Chant, RJ Stoner, AW AF Chant, RJ Stoner, AW TI Particle trapping in a stratified flood-dominated estuary SO JOURNAL OF MARINE RESEARCH LA English DT Article ID DIEL VERTICAL MIGRATION; PARTIALLY MIXED ESTUARY; LINEAR TIDAL PROPAGATION; SHALLOW ESTUARIES; TURBIDITY; CURRENTS; DYNAMICS; FLOWS; TURBULENCE; DISPERSION AB Observations in the Navesink River estuary in northern New Jersey demonstrate that buoyancy augments the particle trapping tendencies of hood-dominated systems because these estuaries heighten tidal period asymmetries in stratification. During the long and slow ebb which typifies flood-dominated systems, a positive feedback between tidal straining and weak vertical mixing stratifies the estuary. In contrast, during hood, turbulence generated by the stronger tidal currents augments overstraining of the density field and the water column becomes well mixed. The tidal period asymmetries in stratification have profound effects on the vertical structure and transport of suspended matter. During ebb, weak vertical mixing allows suspended material to settle downward. In contrast, strong turbulence during hood mixes suspended matter into the water column where it is transported up estuary. Furthermore, observations reveal that resuspension events are marked by multiple turbidity spikes, suggestive of multiple, limited layers of erodible material. The transport of the turbid waters is consistent with horizontal advection modified by horizontal dispersion. Periods of enhanced stratification are also marked by relatively low levels of turbidity during the ebb, consistent with more complete settling of suspended material following times of high river discharge. The interplay between buoyancy and tidal asymmetries are further elucidated with a one-dimensional numerical model featuring a turbulent closure scheme and a passively settling tracer. Model results are generally consistent with the field observations, both emphasizing the robust particle trapping tendencies of a stratified flood-dominated estuary. We speculate that enhanced particle trapping following times of high river discharge may have important biological consequences. C1 Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08901 USA. Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Highland, NJ 07732 USA. RP Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08901 USA. EM chant@imcs.rutgers.edu NR 40 TC 36 Z9 37 U1 0 U2 2 PU SEARS FOUNDATION MARINE RESEARCH PI NEW HAVEN PA YALE UNIV, KLINE GEOLOGY LAB, 210 WHITNEY AVENUE, NEW HAVEN, CT 06520-8109 USA SN 0022-2402 EI 1543-9542 J9 J MAR RES JI J. Mar. Res. PD JAN PY 2001 VL 59 IS 1 BP 29 EP 51 DI 10.1357/002224001321237353 PG 23 WC Oceanography SC Oceanography GA 416GN UT WOS:000167772100002 ER PT J AU Reisner, BA Tripathi, A Parise, JB AF Reisner, BA Tripathi, A Parise, JB TI Na-8[Zn4Ge8O18(OH)(12)]center dot 2H(2)O: An interrupted-framework zincogermanate built from [GeO3(OH)] and [Ge-2(OH)(2)] units SO JOURNAL OF MATERIALS CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE; CONDUCTIVITY AB A new layered germanate, Na-8[Zn4Ge8O18(OH)(12)]. 2H(2)O, has been synthesized from an aqueous solution containing germanium dioxide, zinc acetate and sodium hydroxide. Room temperature single crystal X-ray diffraction data indicate an orthorhombic cell with a = 13.036(3) Angstrom, b = 8.7286(17) Angstrom, c = 12.938(3) Angstrom, space group Pbcn (no. 60), and Z = 4. Chains of orthogonal four-rings, consisting of corner-sharing [Ge2Zn2] units bridged at the zinc centers, are connected to form a new tetrahedral sheet structure containing bifurcated 10-membered rings and the unique building blocks, [GeOn(OH)(4-n)] (n = 1, 2). The zincogermanate sheets are stacked along the c-axis and connected both by Na-O electrostatic interactions and a hydrogen bonding network composed of bound water molecules and terminal hydroxide anions. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. RP Reisner, BA (reprint author), James Madison Univ, Dept Chem, Harrisonburg, VA 22807 USA. OI Reisner, Barbara/0000-0003-3160-0351 NR 16 TC 29 Z9 29 U1 0 U2 5 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0959-9428 J9 J MATER CHEM JI J. Mater. Chem. PY 2001 VL 11 IS 3 BP 887 EP 890 DI 10.1039/b004668j PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 414ZA UT WOS:000167695000030 ER PT J AU Miranda, P Pajares, A Guiberteau, F Cumbrera, FL Lawn, BR AF Miranda, P Pajares, A Guiberteau, F Cumbrera, FL Lawn, BR TI Contact fracture of brittle bilayer coatings on soft substrates SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID SILICON-NITRIDE BILAYERS; CERAMIC COATINGS; MECHANICAL CHARACTERIZATION; CRACK SUPPRESSION; DAMAGE; GLASS; INDENTATION; RESTORATIONS; DEFORMATION; FATIGUE AB Contact-induced fracture modes in trilayers consisting of a brittle bilayer coating on a soft substrate were investigated. Experiments were performed on model transparent glass/sapphire/polycarbonate structures bonded with epoxy adhesive, to enable in situ observation during the contact. Individual layer surfaces were preferentially abraded to introduce uniform flaw states and so allowed each crack type to be studied separately and controllably. Fracture occurred by cone cracking at the glass top surface or by radial. cracking at the glass or sapphire bottom surfaces. Critical loads for each crack type were measured, for fixed glass thickness and several specified sapphire thicknesses. Finite element modeling (FEM) was used to evaluate the critical load data for radial cracking, using as essential input material parameters evaluated from characterization tests on constituent materials and supplemental glass/polymer and sapphire/polymer bilayer structures. The FEM calculations demonstrated pronounced stress transfer from the applied contact to the underlying sapphire layer, explaining a tendency for preferred fracture of this relatively stiff component. Factors affecting the design of optimal trilayer structures for maximum fracture resistance of practical layer systems were considered. C1 Univ Extremadura, Escuela Ingn Ind, Dept Elect & Ingn Electromecan, E-06071 Badajoz, Spain. Univ Extremadura, Fac Ciencias, Dept Fis, E-06071 Badajoz, Spain. NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP Univ Extremadura, Escuela Ingn Ind, Dept Elect & Ingn Electromecan, E-06071 Badajoz, Spain. RI Miranda, Pedro/C-4465-2008; Pajares, Antonia/I-3881-2015 OI Miranda, Pedro/0000-0003-4348-110X; Pajares, Antonia/0000-0002-1086-7586 NR 36 TC 51 Z9 53 U1 0 U2 4 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD JAN PY 2001 VL 16 IS 1 BP 115 EP 126 DI 10.1557/JMR.2001.0021 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA 390DV UT WOS:000166281200021 ER PT J AU Xu, HHK Eichmiller, FC Barndt, PR AF Xu, HHK Eichmiller, FC Barndt, PR TI Effects of fiber length and volume fraction on the reinforcement of calcium phosphate cement SO JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE LA English DT Article ID ACRYLIC BONE-CEMENT; MECHANICAL-PROPERTIES; POLY(METHYL METHACRYLATE); HYDROXYAPATITE CEMENT; FRACTURE-TOUGHNESS; FAILURE MECHANISMS; COMPOSITES; RESIN; RECONSTRUCTION; BEHAVIOR AB A self-setting calcium phosphate cement (CPC) transforms into solid hydroxyapatite during setting at body temperature, and has been used in a number of medical and dental procedures. However, the inferior mechanical properties of CPC prohibits its use in unsupported defects, stress-bearing locations or reconstruction of thin bones. The aim of the present study was to strengthen CPC with fiber reinforcement, to examine the effect of fiber length and volume fraction, and to investigate the reinforcement mechanisms. Previous studies employed either short fibers for random distributions, or continuous fibers that were as long as the specimen size with preferred orientations such as unidirectional alignment. In the present study, a novel methodology was developed in which fibers several times longer than the specimen mold size were randomly mixed with the CPC paste to approximate the isotropy associated with short fibers, and at the same time achieve the high reinforcement efficacy associated with continuous fibers. Carbon fibers of 8 mum diameter were used with fiber lengths ranging from 3 mm to 200 mm, and fiber volume fraction from 1.9% to 9.5%. A three-point flexural test was used to fracture the specimens. Scanning electron microscopy was used to examine crack-fiber interactions and specimen fracture surfaces. The composite containing fibers of 75 mm in length at a volume fraction of 5.7% achieved a flexural strength about 4 times, and work-of-fracture 100 times, greater than the unreinforced CPC. It is concluded that randomly mixing the CPC paste with carbon fibers that were several times longer than the specimen mold size resulted in substantial improvements in strength and fracture resistance; the reinforcement mechanisms were crack bridging and fiber pullout; and fiber length and volume fraction were key microstructural parameters that determined the cement properties. (C) 2001 Kluwer Academic Publishers. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. RP Xu, HHK (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. NR 50 TC 30 Z9 32 U1 1 U2 13 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0957-4530 J9 J MATER SCI-MATER M JI J. Mater. Sci.-Mater. Med. PD JAN PY 2001 VL 12 IS 1 BP 57 EP 65 DI 10.1023/A:1026753020208 PG 9 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 389ZH UT WOS:000166268200009 PM 15348378 ER PT J AU Small, JA Michael, JR AF Small, JA Michael, JR TI Phase identification of individual crystalline particles by electron backscatter diffraction SO JOURNAL OF MICROSCOPY-OXFORD LA English DT Article DE EBSD; individual-particle analysis; phase identification analysis; SEM ID MICROSCOPE; PATTERNS AB Recently, an electron backscatter diffraction (EBSD) system was developed that uses a 1024 x 1024 CCD camera coupled to a thin phosphor. This camera has been shown to produce excellent EBSD patterns. In this system, crystallographic information is determined from the EBSD pattern and coupled with the elemental information from energy or wavelength dispersive X-ray spectrometry. Identification of the crystalline phase of a sample is then made through a link to a commercial diffraction database. To date, this system has been applied almost exclusively to conventional, bulk samples that have been polished to a flat surface. In this investigation, rye report on the application of the EBSD system to the phase identification analysis of individual micrometre and submicrometre particles rather than flat surfaces. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Small, JA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 11 TC 21 Z9 21 U1 1 U2 12 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0022-2720 J9 J MICROSC-OXFORD JI J. Microsc.-Oxf. PD JAN PY 2001 VL 201 BP 59 EP 69 DI 10.1046/j.1365-2818.2001.00788.x PN 1 PG 11 WC Microscopy SC Microscopy GA 405NK UT WOS:000167165700005 PM 11136440 ER PT J AU Meacham, SP Stephens, JC AF Meacham, SP Stephens, JC TI Instabilities of gravity currents along a slope SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID DEEP-WATER; STABILITY CHARACTERISTICS; AGEOSTROPHIC INSTABILITY; CONTINENTAL-SHELF; DENMARK-STRAIT; PARALLEL FLOWS; SHALLOW-WATER; FRONTS; SOUTHWEST; DYNAMICS AB This work examines the linear stability of rotationally influenced density currents with zero potential vorticity flowing over a sloping seafloor at the base of an ocean of finite depth. This configuration serves as a crude model of a type of current that is common in the ocean. The normal modes of the jet are classified according to the physical process primarily responsible for the mode in the limit of long alongjet wavelengths. Several classes of unstable normal mode are found. The theory of resonant instabilities provides a simple explanation of the origin of these instabilities and allows one to identify the physical mechanisms primarily responsible for the instabilities. In addition to previously recognized instabilities, two new types of instability that rely on the presence of topography are found. The first, which is relatively weak, arises as a result of a resonance between gravity waves on the jet and topographic Rossby waves. The second is more powerful, occurs at relatively long wavelengths, and is brought about by resonance between a vortical wave on the jet and topographic Rossby waves. C1 Atmospher & Environm Res Inc, Cambridge, MA 02139 USA. Geophys Fluid Dynam Lab, Princeton, NJ USA. RP Stephens, JC (reprint author), Natl Sci Fdn, GEO-OCE Room 725,4201 Wilson Blvd, Arlington, VA 22230 USA. NR 38 TC 8 Z9 8 U1 0 U2 1 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. PY 2001 VL 31 IS 1 BP 30 EP 53 DI 10.1175/1520-0485(2001)031<0030:IOGCAA>2.0.CO;2 PG 24 WC Oceanography SC Oceanography GA 393ND UT WOS:000166475800003 ER PT J AU Sloyan, BM Rintoul, SR AF Sloyan, BM Rintoul, SR TI The Southern Ocean limb of the global deep overturning circulation SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Review ID TOTAL GEOSTROPHIC CIRCULATION; WESTERN-BOUNDARY CURRENT; LARGE-SCALE CIRCULATION; ANTARCTIC BOTTOM WATER; INDIAN-OCEAN; NORTH-ATLANTIC; HYDROGRAPHIC SECTION; PACIFIC-OCEAN; THERMOHALINE CIRCULATION; GENERAL-CIRCULATION AB Nine hydrographic sections are combined in an inverse box model of the Southern Ocean south of similar to 12 degreesS. The inclusion of independent diapycnal flux unknowns for each property and air-sea (heat, freshwater, and momentum) fluxes make it possible to estimate the three-dimensional deep water circulation. The authors find a vigorous 50 x 10(6) m(3) s(-1) deep overturning circulation that is dominated by an equatorward flow of Lower Circumpolar Deep Water and Antarctic Bottom Water and poleward flow of upper deep water including Indian and Pacific Deep Water below 1500 dbar. In the subtropical Indian and Pacific Oceans the deep overturning cell is essentially isolated from the thermocline and intermediate waters of the subtropical gyre. The southward flowing upper deep water shoals south of the Antarctic Circumpolar Current, where air-sea fluxes convert outcropping upper deep water to Antarctic surface water and drive a net air-sea transformation of 34 x 10(6) m(3) s(-1) to lighter intermediate water. It is the outcropping of upper deep water and transformation by air-sea fluxes that connects the deep and intermediate circulation cells. The significant poleward transport of relatively light (i.e., above all topography at the latitude of Drake Passage) upper deep water, as required here to balance lateral and diapycnal divergence and air-sea exchange, provides observational evidence that advection by standing and transient eddies carries significant meridional transport in the Southern Ocean. C1 Alfred Wegener Inst Polar & Marine Res, D-2850 Bremerhaven, Germany. CSIRO, Div Marine Res, Hobart, Tas, Australia. Univ Tasmania, Anyarctic CRC, Hobart, Tas, Australia. RP Sloyan, BM (reprint author), NOAA, Pacific Marine Environm Lab, OCRD, Bldg 3,7600 Sand Point Way Ne, Seattle, WA 98115 USA. RI Rintoul, Stephen /A-1471-2012; Sloyan, Bernadette/N-8989-2014 OI Rintoul, Stephen /0000-0002-7055-9876; NR 102 TC 196 Z9 199 U1 1 U2 22 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. PY 2001 VL 31 IS 1 BP 143 EP 173 DI 10.1175/1520-0485(2001)031<0143:TSOLOT>2.0.CO;2 PG 31 WC Oceanography SC Oceanography GA 393ND UT WOS:000166475800010 ER PT J AU Smith, KS Vallis, GK AF Smith, KS Vallis, GK TI The scales and equilibration of midocean eddies: Freely evolving flow SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID QUASI-GEOSTROPHIC TURBULENCE; VERTICAL STRUCTURE; BETA-PLANE; ATLANTIC-OCEAN; VARIABILITY; ENERGY; MODELS; CIRCULATION; GENERATION; TOPOGRAPHY AB Quasigeostrophic turbulence theory and numerical simulation are used to study the mechanisms determining the scale, structure, and equilibration of mesoscale ocean eddies. The present work concentrates on using freely decaying geostrophic turbulence to understand and explain the vertical and horizontal flow of energy through a stratified, horizontally homogeneous geostrophic fluid. It is found that the stratification profile, in particular the presence of a pycnocline, has significant, qualitative effects on the efficiency and spectral pathways of energy flow. Specifically, with uniform stratification, energy in high baroclinic modes transfers directly, quickly (within a few eddy turnaround times), and almost completely to the barotropic mode. By contrast, in the presence of oceanlike stratification, kinetic energy in high baroclinic modes transfers intermediately to the first baroclinic mode, whence it transfers inefficiently (and incompletely) to the barotropic mode. The efficiency of transfer to the barotropic mode is reduced as the pycnocline is made increasingly thin. The beta effect, on the other hand, improves the efficiency of barotropization, but for oceanically realistic parameters this effect is relatively unimportant compared to the effects of nonuniform stratification. Finally, the nature of turbulent cascade dynamics is such as to lead to a concentration of first baroclinic mode kinetic energy near the first radius of deformation, which, in the case of a nonuniform and oceanically realistic stratification, has a significant projection at the surface. This may in part explain recent observations of surface eddy scales by TOPEX/Poseidon satellite altimetry, which indicate a correlation of surface-height variance with the scale of the first deformation radius. C1 Princeton Univ, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Smith, KS (reprint author), Princeton Univ, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. OI Smith, K Shafer/0000-0003-0740-3067 NR 29 TC 70 Z9 70 U1 0 U2 4 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. PY 2001 VL 31 IS 2 BP 554 EP 571 DI 10.1175/1520-0485(2001)031<0554:TSAEOM>2.0.CO;2 PG 18 WC Oceanography SC Oceanography GA 404RH UT WOS:000167114100015 ER PT J AU Mellor, GL AF Mellor, GL TI One-dimensional, ocean surface layer modeling: A problem and a solution SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID BOUNDARY-LAYER; TURBULENCE CLOSURE; MIXED-LAYER; STRATIFIED FLUIDS; ENERGY-MODEL; SIMULATIONS; PREDICTION; FLOWS; WAVES; PAPA AB The first part of this paper is generic; it demonstrates a problem associated with one-dimensional, ocean surface layer model comparisons with ocean observations. Unlike three-dimensional simulations or the real ocean, kinetic energy can inexorably build up in one-dimensional simulations, which artificially enhances mixing. Adding a sink term to the momentum equations counteracts this behavior. The sink term is a surrogate for energy divergence available to three-dimensional models but not to one-dimensional models. The remainder of the paper deals with the Mellor-Yamada boundary layer model. There exists prior evidence that the model's summertime surface temperatures are too warm due to overly shallow mixed layer depths. If one adds a sink term to approximate three-dimensional model behavior, the warming problem is exacerbated, creating added incentive to seek an appropriate model change. Guided by laboratory data, a Richardson-number-dependent dissipation is introduced and this simple modification yields a favorable improvement in the comparison of model calculations with data even with the momentum sink term in place. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Mellor, GL (reprint author), Princeton Univ, Program Atmospher & Ocean Sci, Box CN710,Sayre Hall, Princeton, NJ 08544 USA. NR 43 TC 75 Z9 85 U1 0 U2 2 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. PY 2001 VL 31 IS 3 BP 790 EP 809 DI 10.1175/1520-0485(2001)031<0790:ODOSLM>2.0.CO;2 PG 20 WC Oceanography SC Oceanography GA 411AN UT WOS:000167476100010 ER PT J AU Lavelle, JW Wetzler, MA Baker, ET Embley, RW AF Lavelle, JW Wetzler, MA Baker, ET Embley, RW TI Prospecting for hydrothermal vents using moored current and temperature data: Axial Volcano on the Juan de Fuca Ridge, northeast Pacific SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID MID-ATLANTIC RIDGE; 1998 ERUPTION; SEAMOUNT; DIFFUSE; VARIABILITY; DISCHARGE; DISCRETE; SUMMIT; PLUMES; FIELD AB Tidal and inertial currents and profuse hydrothermal discharge at recently erupted Axial Volcano, Juan de Fuca Ridge, cause relatively large and rapid temperature (T) changes in the near-bottom water column. Measurements show short-term T variations of as much as 0.13 degreesC at 30 m and 0.18 degreesC at 150 m above bottom and currents that have strong tidal components and means of 3-5 cm s(-1). Locations and magnitudes of the hydrothermal sources leading to the observed T variations have been inferred via an inverse calculation. Results imply noncongruent source regions around the mooring site for plumes from low- and high-buoyancy flux sources. Water column and seafloor observations in the volcano's caldera region generally support the distribution of source types and sites inferred. A high-buoyancy flux, ephemeral venting site, unexpected on the eastern shoulder of the volcano, is also indicated by the inverse calculation and supported by water-column survey data. Over the O(10 km(2)) calculation region, heat flux from low- buoyancy hydrothermal sources is apparently less than heat flux from high-buoyancy hydrothermal sources, a result that is in disagreement with previous reports on the balance of heat flux between vent source types. C1 NOAA, Pacific Marine Environm Lab, Ocean Environm Res Div, Seattle, WA 98115 USA. RP Lavelle, JW (reprint author), NOAA, Pacific Marine Environm Lab, Ocean Environm Res Div, NOAA Bldg 3,7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 38 TC 9 Z9 9 U1 1 U2 3 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. PY 2001 VL 31 IS 3 BP 827 EP 838 DI 10.1175/1520-0485(2001)031<0827:PFHVUM>2.0.CO;2 PG 12 WC Oceanography SC Oceanography GA 411AN UT WOS:000167476100012 ER PT J AU Johnson, GC McPhaden, MJ Firing, E AF Johnson, GC McPhaden, MJ Firing, E TI Equatorial Pacific ocean horizontal velocity, divergence, and upwelling SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID SUBSURFACE COUNTERCURRENTS; INSTABILITY WAVES; TROPICAL PACIFIC; EL-NINO; BALANCE; UNDERCURRENT; CIRCULATION; THERMOCLINE; THROUGHFLOW; VARIABILITY AB Upper-ocean horizontal velocity and divergence were estimated from shipboard observations taken from 1991 1999 in the equatorial Pacific between 170 degreesW and 95 degreesW. Mean transports were estimated for the zonal currents at the mean longitude of the sections, 136 degreesW. Mean meridional currents for the entire longitude range included poleward surface flows reaching -0.09 m s-(1) in the south and 0.13 m s(-1) in the north as well as equatorward flow within the thermocline reaching 0.05 m s(-1) in the south and -0.04 m s(-1) in the north near 23 degreesC (85 m). Vertical velocity was diagnosed by integrating horizontal divergence estimated for the entire region down from the surface. Equatorial upwelling velocities peaked at 1.9 (+/-0.9) x 10(-5) m s(-1) at 50 m. The upwelling transport in the area bounded by 3.6 degreesS-5.2 degreesN, 170 degreesW-95 degreesW was 62 (+/-18) x 10(6) m(3) s(-1) at 50 m. Strong downwelling was apparent within the North Equatorial Countercurrent. An asymmetry in the meridional flows suggested that on the order of 10 x 10(6) m(3) s(-1) of thermocline water from the Southern Hemisphere was upwelled at the equator and moved into the Northern Hemisphere as surface water. This interhemispheric exchange path could be part of the route for water from the Southern Hemisphere to supply the Indonesian Throughflow. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA. RP Johnson, GC (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE,Bldg 3, Seattle, WA 98115 USA. RI Johnson, Gregory/I-6559-2012; McPhaden, Michael/D-9799-2016 OI Johnson, Gregory/0000-0002-8023-4020; NR 35 TC 77 Z9 78 U1 3 U2 15 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. PY 2001 VL 31 IS 3 BP 839 EP 849 DI 10.1175/1520-0485(2001)031<0839:EPOHVD>2.0.CO;2 PG 11 WC Oceanography SC Oceanography GA 411AN UT WOS:000167476100013 ER PT J AU Sloyan, BM Rintoul, SR AF Sloyan, BM Rintoul, SR TI Circulation, renewal, and modification of Antarctic mode and intermediate water SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID SOUTH INDIAN-OCEAN; TOTAL GEOSTROPHIC CIRCULATION; AIR-SEA FLUXES; HYDROGRAPHIC SECTION; ATLANTIC OCEAN; NORTH-ATLANTIC; GENERAL-CIRCULATION; CIRCUMPOLAR CURRENT; BOUNDARY CURRENT; MASS FORMATION AB Nine hydrographic sections are combined in an inverse box model of the Southern Ocean south of similar to 12 degreesS. The inverse model has two novel features: the inclusion of independent diapycnal flux unknowns for each property and the explicit inclusion of air-sea fluxes (heat, freshwater, and momentum) and the water mass transformation they drive. Transformation of 34 x 10(6) m(3) s(-1) of Antarctic Surface Water by air-sea buoyancy fluxes, and cooling and freshening where Subantarctic Mode Water outcrops, renews cold, fresh Antarctic Intermediate Water of the southeast Pacific and southwest Atlantic. Relatively cold, fresh mode and intermediate water enter the subtropical gyres, are modified by air-sea fluxes and interior mixing, and return poleward as warmer, saltier mode and intermediate water. While the zonally integrated meridional transport in these layers is small, the gross exchange is approximately 80 x 10(6) m(3) s(-1). The air-sea transformation of Antarctic surface water to intermediate water is compensated in the Southern Ocean by an interior diapycnal flux of 32 x 10(6) m(3) s(-1) of intermediate water to upper deep water. The small property differences between slightly warmer, saltier intermediate water and cold, fresh Antarctic Surface Water results in a poleward transfer of heat and salt across the Polar Front zone. Mode and intermediate water are crucial participants in the North Atlantic Deep Water overturning and Indonesian Throughflow circulation cells. The North Atlantic Deep Water overturning is closed by cold, fresh intermediate water that is modified to warm, salty varieties by air-sea fluxes and interior mixing in the Atlantic and southwest Indian Oceans. The Indonesian Throughflow is part of a circum-Australia circulation. In the Indian Ocean, surface water is converted to denser thermocline and mode water by air-sea fluxes and interior mixing, excess mode water flows eastward south of Australia, and air-sea fluxes convert mode water to thermocline water in the Pacific. C1 Alfred Wegener Inst Polar & Marine Res, Bremerhaven, Germany. Univ Tasmania, Antarctic CRC, Hobart, Tas, Australia. CSIRO, Div Marine Res, Hobart, Tas, Australia. RP Sloyan, BM (reprint author), NOAA, PMEL OCRD, Bldg 3,7600 Sand Point Way NE, Seattle, WA 98115 USA. RI Rintoul, Stephen /A-1471-2012; Sloyan, Bernadette/N-8989-2014 OI Rintoul, Stephen /0000-0002-7055-9876; NR 79 TC 164 Z9 165 U1 2 U2 22 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. PY 2001 VL 31 IS 4 BP 1005 EP 1030 DI 10.1175/1520-0485(2001)031<1005:CRAMOA>2.0.CO;2 PG 26 WC Oceanography SC Oceanography GA 420EE UT WOS:000167990800010 ER PT J AU Zhang, DX Lee, TN Johns, WE Liu, CT Zantopp, R AF Zhang, DX Lee, TN Johns, WE Liu, CT Zantopp, R TI The Kuroshio east of Taiwan: Modes of variability and relationship to interior ocean mesoscale eddies SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID SUBTROPICAL NORTH-ATLANTIC; FLORIDA CURRENT; GULF-STREAM; APRIL 1982; CHINA-SEA; TRANSPORT; CIRCULATION; PACIFIC; MEANDERS; VOLUME AB Observations from the World Ocean Circulation Experiment PCM-1 moored current meter array in the East Taiwan Channel are analyzed and combined with TOPEX/Poseidon altimetry data and the Parallel Ocean Climate Model simulation to study Kuroshio variability and relationships to westward propagating sea surface height anomalies in the Philippine Sea. Approximately 60% of the total subinertial velocity and temperature variance in the Kuroshio east of Taiwan is associated with so-called "transport'' and "meandering'' modes revealed from empirical orthogonal function analysis. The transport mode is dominated by a 100-day peak, while the most coherent energetic meandering signals are found in three limited frequency bands centered near periods of 100 days, 40 days, and 18 days. The detailed structure of the meanders is studied by frequency domain EOF analysis, which also reveals a higher frequency meander centered near 10 days confined to the western side of the channel. On the 100-day timescale, the Kuroshio transport entering the East China Sea is strongly related to meandering of the Kuroshio, which in turn is caused by westward propagating anticyclonic eddies from the interior ocean. During low transport events, the Kuroshio meanders offshore and partly bypasses the East Taiwan Channel to flow northward along the eastern side of the Ryukyu islands. The interior eddy features that lead to the meandering can be identified as far east as 134 degreesE, propagating westward to the coast of Taiwan at about 10 km day(-1). The 100-day variability that is so dominant in the Kuroshio is virtually absent in the Florida Current but is strongly present east of Bahamas in the Antilles Current and deep western boundary current, presumably being blocked from entering the Straits of Florida by the Bahamas Island chain. C1 Univ Florida, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL USA. Natl Taiwan Univ, Inst Oceanog, Taipei, Taiwan. RP Zhang, DX (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 43 TC 91 Z9 102 U1 1 U2 17 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. PY 2001 VL 31 IS 4 BP 1054 EP 1074 DI 10.1175/1520-0485(2001)031<1054:TKEOTM>2.0.CO;2 PG 21 WC Oceanography SC Oceanography GA 420EE UT WOS:000167990800012 ER PT J AU Meinen, CS McPhaden, MJ AF Meinen, CS McPhaden, MJ TI Interannual variability in warm water volume transports in the equatorial Pacific during 1993-99 SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID MERIDIONAL HEAT-TRANSPORT; OCEAN RECHARGE PARADIGM; 1982-1983 EL-NINO; TROPICAL PACIFIC; EXPENDABLE BATHYTHERMOGRAPH; TEMPERATURE ANALYSES; NUMERICAL-MODEL; ZONAL CURRENTS; LA-NINA; ENSO AB Previous studies have indicated that the volume of warm water (WWV) in the equatorial Pacific is intrinsically related to the dynamics of the El Nino-Southern Oscillation (ENSO) cycle. A gridded subsurface temperature dataset, which incorporates temperature measurements from expendable bathythermograph profiles as well as measurements from the moorings in the Tropical Atmosphere and Ocean Array, was used along with historical hydrography to quantify the variability of the WWV (with temperatures greater than 20 degreesC) within the region 8 degreesS-8 degreesN, 156 degreesE-95 degreesW during 1993-99. These data were also used to estimate geostrophic transports of warm water relative to a level of no motion at 1000 dbar (1 dbar = 10(4) Pa). Ekman transports were estimated using wind data from gridded observations, assimilating model output, and satellite scatterometer measurements. The results indicate that the buildup of WWV between the weak 1994-95 El Nino event and the onset of the strong 1997-98 El Nino event resulted primarily from an anomalous decrease in the net southward transport (geostrophic plus Ekman) across 8 degreesS in the western and central Pacific combined with an anomalous increase in eastward flow across 156 degreesE. Afterward, beginning in April 1997, WWV in the equatorial region was reduced by about 26% coincident with the 1997-98 El Nino. Approximately half of the warm water lost during this period is accounted for by poleward transport across a wide range of longitudes, while the remaining half is accounted for by vertical water mass transformations. The implications of the results for understanding and modeling the ENSO cycle are discussed. C1 Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Meinen, CS (reprint author), Univ Hawaii Manoa, Dept Oceanog, 1000 Pope Rd,MSB 205, Honolulu, HI 96822 USA. RI Meinen, Christopher/G-1902-2012; McPhaden, Michael/D-9799-2016 OI Meinen, Christopher/0000-0002-8846-6002; NR 56 TC 54 Z9 54 U1 0 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. PY 2001 VL 31 IS 5 BP 1324 EP 1345 DI 10.1175/1520-0485(2001)031<1324:IVIWWV>2.0.CO;2 PG 22 WC Oceanography SC Oceanography GA 427UD UT WOS:000168423100010 ER PT J AU Ladd, C Thompson, L AF Ladd, C Thompson, L TI Water mass formation in an isopycnal model of the North Pacific SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID ATLANTIC OCEAN; CLIMATOLOGICAL DATA; TEMPORAL COHERENCE; SUBTROPICAL GYRE; TRANSITION ZONE; EL-NINO; SEA; TEMPERATURE; SUBDUCTION; CIRCULATION AB An isopycnal model coupled with a mixed layer model is used to study transformation and formation rates in the North Pacific. When annual formation rates are averaged over the entire North Pacific, a large peak in water mass formation is found at a density of approximately sigma (theta) = 26 kg m(-3). This peak in formation rate corresponds to the formation of North Pacific Central Mode Water (CMW) in the model. No corresponding peaks in formation rate are found at the densities of Subtropical Mode Water (STMW; sigma (theta) similar to 25.4 kg m(-3)) or Eastern Subtropical Mode Water (ESMW; sigma (theta) similar to 24-25.4 kg m(-3)) when averaged over the entire model basin. However, when calculated locally, enhanced formation rates are found at the densities of these mode water masses. The formation of each of the three types of North Pacific mode water in the model occurs because of different circumstances. As expected, STMW formation is dependent on the strong cooling and resultant deep mixed layers over the Kuroshio Current region. However, formation rates in the STMW formation region (west of the date line) imply that most of the thickness maximum formed there each winter is subsequently reentrained into the mixed layer during the next winter where it is further cooled, preconditioning it to become denser varieties of STMW farther east. Similarly, preconditioning west of the formation region is important in CMW formation. Only 33% of the STMW escapes reentrainment the next winter. The STMW signature (minimum in vertical stratification) remains in the region in the next winter owing to a tight recirculation that carries the mode water south before the mixed layer deepens again the next winter. The renewal times calculated from the model are 1.5-5.5 yr for STMW and approximately 10-14 yr for CMW. The ESMW formation is due to a band of weak positive formation combined with a wide layer outcrop. The only region where forcing by the atmosphere can directly influence an isopycnal layer is where the isopycnal layer outcrops into the mixed layer. The wide layer outcrop at ESMW densities (similar to 30 degreesN, 140 degreesW) is at least partially due to weak summer heating in the southeastern part of the formation region. Only 13% of the ESMW volume escapes reentrainment by the mixed layer in the succeeding year contributing to a renewal time of only 1-2 yr. C1 Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. RP Ladd, C (reprint author), NOAA, PMEL, 7600 Sandpoint Way, Seattle, WA 98115 USA. EM carol.ladd@noaa.gov RI Ladd, Carol/M-6159-2014 OI Ladd, Carol/0000-0003-1065-430X NR 51 TC 32 Z9 32 U1 0 U2 0 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. PY 2001 VL 31 IS 6 BP 1517 EP 1537 DI 10.1175/1520-0485(2001)031<1517:WMFIAI>2.0.CO;2 PG 21 WC Oceanography SC Oceanography GA 443UR UT WOS:000169360500008 ER PT J AU Vialard, J Menkes, C Boulanger, JP Delecluse, P Guilyardi, E McPhaden, MJ Madec, G AF Vialard, J Menkes, C Boulanger, JP Delecluse, P Guilyardi, E McPhaden, MJ Madec, G TI A model study of oceanic mechanisms affecting equatorial Pacific sea surface temperature during the 1997-98 El Nino SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID GENERAL-CIRCULATION MODEL; MEAN SEASONAL CYCLE; TROPICAL PACIFIC; WIND STRESS; INTERANNUAL VARIABILITY; HEAT-BALANCE; MIXED-LAYER; TOGA DECADE; FAST-WAVE; PART I AB In this study, the processes affecting sea surface temperature variability over the 1992-98 period, encompassing the very strong 1997-98 El Nino event, are analyzed. A tropical Pacific Ocean general circulation model, forced by a combination of weekly ERS1-2 and TAO wind stresses, and climatological heat and freshwater fluxes, is first validated against observations. The model reproduces the main features of the tropical Pacific mean state, despite a weaker than observed thermal stratification, a 0.1 m s(-1) too strong (weak) South Equatorial Current (North Equatorial Countercurrent), and a slight underestimate of the Equatorial Undercurrent. Good agreement is found between the model dynamic height and TOPEX/Poseidon sea level variability, with correlation/rms differences of 0.80/4.7 cm on average in the 10 degreesN-10 degreesS band. The model sea surface temperature variability is a bit weak, but reproduces the main features of interannual variability during the 1992-98 period. The model compares well with the TAO current variability at the equator, with correlation/rms differences of 0.81/0.23 m s(-1) for surface currents. The model therefore reproduces well the observed interannual variability, with wind stress as the only interannually varying forcing. This good agreement with observations provides confidence in the comprehensive three-dimensional circulation and thermal structure of the model. A close examination of mixed layer heat balance is thus undertaken, contrasting the mean seasonal cycle of the 1993-96 period and the 1997-98 El Nino. In the eastern Pacific, cooling by exchanges with the subsurface (vertical advection, mixing, and entrainment), the atmospheric forcing, and the eddies (mainly the tropical instability waves) are the three main contributors to the heat budget. In the central-western Pacific, the zonal advection by low-frequency currents becomes the main contributor. Westerly wind bursts (in December 1996 and March and June 1997) were found to play a decisive role in the onset of the 1997-98 El Nino. They contributed to the early warming in the eastern Pacific because the downwelling Kelvin waves that they excited diminished subsurface cooling there. But it is mainly through eastward advection of the warm pool that they generated temperature anomalies in the central Pacific. The end of El Nino can be linked to the large-scale easterly anomalies that developed in the western Pacific and spread eastward, from the end of 1997 onward. In the far-western Pacific, because of the shallower than normal thermocline, these easterlies cooled the SST by vertical processes. In the central Pacific, easterlies pushed the warm pool back to the west. In the east, they led to a shallower thermocline, which ultimately allowed subsurface cooling to resume and to quickly cool the surface layer. C1 Lab Oceanog Dynam & Climatol, Paris, France. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Vialard, J (reprint author), European Ctr Medium Range Weather Forecasts, Shinfield Pk, Reading RG2 9AX, Berks, England. RI Vialard, Jerome/C-2809-2008; madec, gurvan/E-7825-2010; Guilyardi, Eric/D-4868-2011; McPhaden, Michael/D-9799-2016; menkes, christophe/H-9085-2016 OI Vialard, Jerome/0000-0001-6876-3766; madec, gurvan/0000-0002-6447-4198; Guilyardi, Eric/0000-0002-2255-8625; menkes, christophe/0000-0002-1457-9696 NR 69 TC 143 Z9 145 U1 0 U2 16 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. PY 2001 VL 31 IS 7 BP 1649 EP 1675 DI 10.1175/1520-0485(2001)031<1649:AMSOOM>2.0.CO;2 PG 27 WC Oceanography SC Oceanography GA 450ZM UT WOS:000169774800001 ER PT J AU Grachev, AA Fairall, CW AF Grachev, AA Fairall, CW TI Upward momentum transfer in the marine boundary layer SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID AIR-SEA INTERFACE; DRAG COEFFICIENT; TURBULENT-FLOW; SURFACE-LAYER; INDUCED STRESS; WIND STRESS; WATER-WAVES; FLUX; OCEAN; STATE AB This paper focuses on the study of momentum flux between ocean and atmosphere in light winds and is based on the data collected during several field campaigns, the Atlantic Stratocumulus Transition Experiment, the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment, and the San Clemente Ocean Probing Experiment. Weak wind at sea is frequently accompanied by the presence of fast-traveling ocean swell, which dramatically affects momentum transfer. It is found that the mean momentum flux (uw covariance) decreases monotonically with decreasing wind speed, and reaches zero around a wind speed U approximate to 1.5-2 m s(-1), which corresponds to wave age c(p)/U approximate to 10 for wave/swell conditions of the experiments in this study. Further decrease of the wind speed (i.e., increase of the wave age) leads to a sign reversal of the momentum flux, implying negative drag coefficient. Upward momentum transfer is associated with fast-traveling swell running in the same direction as the wind, and this regime can be treated as swell regime or mature sea state. In the swell regime the surface stress vector is nearly opposite to wind and swell directions, and the wind is roughly aligned in the swell direction. Thus, a weak wind over ocean swell can be frequently associated with upward momentum transfer (i.e., from ocean to atmosphere). C1 Russian Acad Sci, AM Obukhov Inst Atmospher Phys, Moscow, Russia. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP Grachev, AA (reprint author), NOAA, Environm Technol Lab, R-ET7,325 Broadway, Boulder, CO 80305 USA. OI GRACHEV, ANDREY/0000-0002-7143-0820 NR 58 TC 82 Z9 83 U1 0 U2 6 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. PY 2001 VL 31 IS 7 BP 1698 EP 1711 DI 10.1175/1520-0485(2001)031<1698:UMTITM>2.0.CO;2 PG 14 WC Oceanography SC Oceanography GA 450ZM UT WOS:000169774800003 ER PT J AU Hallberg, R AF Hallberg, R TI Mode conversion for Rossby waves over topography: Comments on "Localized coupling between surface- and bottom-intensified flow over topography'' - Reply SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Editorial Material ID OCEAN C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA. RP Hallberg, R (reprint author), Princeton Univ, Geophys Fluid Dynam Lab, Forrestal Campus,US Route 1,POB 308, Princeton, NJ 08542 USA. NR 9 TC 3 Z9 3 U1 0 U2 0 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. PY 2001 VL 31 IS 7 BP 1926 EP 1930 DI 10.1175/1520-0485(2001)031<1926:R>2.0.CO;2 PG 5 WC Oceanography SC Oceanography GA 450ZM UT WOS:000169774800018 ER PT J AU Polyakov, I AF Polyakov, I TI An eddy parameterization based on maximum entropy production with application to modeling of the Arctic Ocean circulation SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID DEVELOPED BAROCLINIC INSTABILITY; TOPOGRAPHIC STRESS; STATISTICAL-MECHANICS; GENERAL-CIRCULATION; SEA ICE; DYNAMICS; ATLANTIC; CLIMATE; MASS; FLOWS AB An eddy parameterization derived from statistical mechanics of potential vorticity is applied for inviscid shallow-water equations. The solution of a variational problem based on the maximum entropy production (MEP) principle provides, with some physical constraints, several viscous terms. Along with the traditional Laplacian operator, MEP parameterization includes the "Neptune effect,'' which is similar to that described by Holloway. The Neptune effect describes the interaction of eddies with seafloor topography. MEP parameterization is then incorporated into a high-resolution tidal model of the Arctic Ocean. MEP viscosity does not substantially affect the distribution of amplitudes, phases, and tidal currents; however, residual tidal circulation is sensitive to employed parameterization in areas of maximum bottom slope. The Neptune effect is the main contributor among other viscosities. The combined effect of the new viscous terms and nonlinear terms results in cyclonic residual tidal circulation. The MEP viscosity is also used in a coarse, 55.56-km-resolution Arctic Ocean general circulation model. The model produces cyclonic subsurface circulation in major arctic basins. This pattern is supported by observational studies. The model maintains the proper level of water transport through narrow (relative to the model resolution) Fram Strait, conserving the heat content in the Arctic interior. C1 Univ Alaska, Int Arctic Res Ctr, Fairbanks, AK 99775 USA. Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. RP Polyakov, I (reprint author), Univ Alaska, Int Arctic Res Ctr, POB 757335, Fairbanks, AK 99775 USA. EM igor@iarc.uaf.edu NR 57 TC 28 Z9 29 U1 0 U2 3 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. PY 2001 VL 31 IS 8 BP 2255 EP 2270 DI 10.1175/1520-0485(2001)031<2255:AEPBOM>2.0.CO;2 PG 16 WC Oceanography SC Oceanography GA 461ZR UT WOS:000170394200018 ER PT J AU Wright, CW Walsh, EJ Vandemark, D Krabill, WB Garcia, AW Houston, SH Powell, MD Black, PG Marks, FD AF Wright, CW Walsh, EJ Vandemark, D Krabill, WB Garcia, AW Houston, SH Powell, MD Black, PG Marks, FD TI Hurricane directional wave spectrum spatial variation in the open ocean SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article AB The sea surface directional wave spectrum was measured for the first time in all quadrants of a hurricane's inner core over open water. The NASA airborne scanning radar altimeter (SRA) carried aboard one of the NOAA WP-3D hurricane research aircraft at 1.5-km height acquired the open-ocean data on 24 August 1998 when Bonnie, a large hurricane with 1-min sustained surface winds of nearly 50 m s(-1), was about 400 km east of Abaco Island, Bahamas. The NOAA aircraft spent more than five hours within 180 km of the eye and made five eye penetrations. Grayscale coded images of Hurricane Bonnie wave topography include individual waves as high as 19 m peak to trough. The dominant waves generally propagated at significant angles to the downwind direction. At some positions, three different wave fields of comparable energy crossed each other. Partitioning the SRA directional wave spectra enabled determination of the characteristics of the various components of the hurricane wave field and mapping of their spatial variation. A simple model was developed to predict the dominant wave propagation direction. C1 NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. USA, Engineer Res & Dev Ctr, Vicksburg, MS USA. NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. RP Wright, CW (reprint author), NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Code 972, Wallops Isl, VA 23337 USA. RI Marks, Frank/A-5733-2011; Powell, Mark/I-4963-2013 OI Marks, Frank/0000-0003-0371-5514; Powell, Mark/0000-0002-4890-8945 NR 19 TC 78 Z9 80 U1 1 U2 6 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. PY 2001 VL 31 IS 8 BP 2472 EP 2488 DI 10.1175/1520-0485(2001)031<2472:HDWSSV>2.0.CO;2 PG 17 WC Oceanography SC Oceanography GA 461ZR UT WOS:000170394200032 ER PT J AU As-Salek, JA Yasuda, T AF As-Salek, JA Yasuda, T TI Tide-surge interaction in the Meghna estuary: Most severe conditions SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID STORM SURGES; BENGAL; BAY; BANGLADESH AB A numerical model with a (1/120)degrees resolution is used in studying 1) the effects of tide-surge interaction and 2) the effects of cyclone landfall on the Noakhali-Cox's Bazar coast of Bangladesh (i) on the time deviation of the surge arrival from the landfall time of a cyclone and (ii) on the duration of the maximum surge. The present study found that the tide-surge interaction in the Meghna estuary shows, in general, the progressive wave nature of the local tide. If the peak of the maximum surge coincides with the tidal peak near the landfall, the surge propagates toward the north faster than when the surge peak coincides with the tidal trough. Cyclones that make landfall before the arrival of the tidal peak produce higher but shorter duration surges than those that make landfall after the arrival of the tidal peak. If the landfall time of the cyclone is kept fixed, the surge peaks are found to arrive earlier and to be of shorter duration with (i) an increase in the propagation speed of the cyclone and (ii) a decrease in the radius of the maximum cyclonic wind. For the peak of the maximum surge, it may take about 3-4 h to propagate from the southern estuary to the northernmost estuary. The surge, which propagates northward, reaches the northernmost estuary earlier and becomes longer in duration with smaller angles of crossing of the cyclone with the coastline. A slow moving cyclone with a larger radius of cyclonic wind, making landfall in the northernmost area, with a small angle of crossing relative to the Noakhali-Cox's Bazar coastline, and landfall just before the high tide is found to be the most severe cyclone, capable of producing the highest surges in the vast and shallow estuary. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. Gifu Univ, Dept Civil Engn, Gifu, Japan. RP NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. EM as-salek@glerl.noaa.gov NR 27 TC 10 Z9 10 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 EI 1520-0485 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PY 2001 VL 31 IS 10 BP 3059 EP 3072 DI 10.1175/1520-0485(2001)031<3059:TSIITM>2.0.CO;2 PG 14 WC Oceanography SC Oceanography GA 478LB UT WOS:000171346700017 ER PT J AU Meinen, CS McPhaden, MJ Johnson, GC AF Meinen, CS McPhaden, MJ Johnson, GC TI Vertical velocities and transports in the equatorial Pacific during 1993-99 SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID ZONAL MOMENTUM BALANCE; LAYER HEAT-BALANCE; 1997-98 EL-NINO; TROPICAL PACIFIC; EXPENDABLE BATHYTHERMOGRAPH; SEASONAL VARIABILITY; OCEAN; MODEL; CURRENTS; SYSTEM AB Geostrophic and Ekman transports calculated from observations of subsurface thermal structure and surface winds are used to determine vertical velocities and transports as a function of time, depth, and longitude in the equatorial Pacific within 5 degreesS-5 degreesN, 165 degreesE-95W during 1993-99 via a box volume balance. The vertical transports are determined in boxes of 10 degrees of latitude by generally 15 degrees in longitude. The corresponding vertical velocities represent a spatial average over these regions. Both the total vertical velocity and the cross-isopycnal component of the vertical velocity (approximated by the cross-isothermal component) are calculated on seasonal and interannual timescales. For the eastern equatorial Pacific (5 degreesS-5 degreesN, 155 degrees -95 degreesW) the mean vertical transport across 50 m is (24 +/- 3) x 10(6) m(3) s(-1). Variability in the vertical velocity is large relative to the mean. On interannual timescales this variability is well correlated with the local winds in the western portion of the study area, while the correspondence is weaker in the east where wind variability is much smaller. At seasonal timescales there is good correspondence between the vertical velocity and the local winds throughout the study region. The cross-isothermal vertical velocity is significantly smaller than the total vertical velocity, and the means of both compare well with the few historical estimates available. C1 Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP Meinen, CS (reprint author), Univ Hawaii Manoa, Dept Oceanog, 1000 Pope Rd,MSB 205, Honolulu, HI 96822 USA. RI Meinen, Christopher/G-1902-2012; Johnson, Gregory/I-6559-2012; McPhaden, Michael/D-9799-2016 OI Meinen, Christopher/0000-0002-8846-6002; Johnson, Gregory/0000-0002-8023-4020; NR 53 TC 27 Z9 27 U1 0 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. PY 2001 VL 31 IS 11 BP 3230 EP 3248 DI 10.1175/1520-0485(2001)031<3230:VVATIT>2.0.CO;2 PG 19 WC Oceanography SC Oceanography GA 487NK UT WOS:000171881400007 ER PT J AU Hallberg, R Gnanadesikan, A AF Hallberg, R Gnanadesikan, A TI An exploration of the role of transient eddies in determining the transport of a zonally reentrant current SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID ANTARCTIC CIRCUMPOLAR CURRENT; OCEAN CIRCULATION MODELS; BETA-PLANE CHANNEL; LINEAR HOMOGENEOUS MODEL; SOUTHERN-OCEAN; WIND-DRIVEN; MOMENTUM BALANCE; DRAKE PASSAGE; THERMOHALINE CIRCULATION; EDDY TRANSFER AB The meridional Ekman transport in a zonally reentrant channel may be balanced by diabatic circulations, standing eddies associated with topography, or by Lagrangian mean eddy mass fluxes. A simple model is used to explore the interaction between these mechanisms. A key assumption of this study is that diabatic forcing in the poleward edge of the channel acts to create lighter fluid, as is the case with net freshwater fluxes into the Southern Ocean. For weak wind forcing or strong diabatic constraint, a simple scaling argument accurately predicts the level of baroclinic shear. However, given our understanding of the relative magnitudes of Ekman flux and deep upwelling, this is not the appropriate parameter range for the Antarctic Circumpolar Current. With stronger wind stresses, eddies are prominent, with baroclinic instability initially developing in the vicinity of large topography. Arguments have been advanced by a number of authors that baroclinic instability should limit the velocity shear, leading to a stiff upper limit on the transport of the current. However, in the simulations presented here baroclinic instability is largely confined to the region of topographic highs, and the approach to a current that is independent of the wind stress occurs gradually. Several recent parameterizations of transient eddy fluxes do not reproduce key features of the observed behavior. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. RP NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. EM rwh@gfdl.gov RI Gnanadesikan, Anand/A-2397-2008 OI Gnanadesikan, Anand/0000-0001-5784-1116 NR 53 TC 66 Z9 67 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 EI 1520-0485 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PY 2001 VL 31 IS 11 BP 3312 EP 3330 DI 10.1175/1520-0485(2001)031<3312:AEOTRO>2.0.CO;2 PG 19 WC Oceanography SC Oceanography GA 487NK UT WOS:000171881400013 ER PT J AU Chung, IP Presser, C AF Chung, IP Presser, C TI Fluid property effects on sheet disintegration of a simplex pressure-swirl atomizer SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID LIQUID SHEET; INSTABILITY C1 NIST, Chem Sci & Technol Lab, Thermal & React Proc Grp, Gaithersburg, MD 20899 USA. RP Chung, IP (reprint author), Koch Ind Co, Technol & Commercial Dev Grp, John Zink Co, 11920 E Apache, Tulsa, OK 74121 USA. NR 16 TC 6 Z9 6 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 2001 VL 17 IS 1 BP 212 EP 216 DI 10.2514/2.5730 PG 5 WC Engineering, Aerospace SC Engineering GA 393FG UT WOS:000166458100028 ER PT J AU Swyt, DA AF Swyt, DA TI Length and dimensional measurements at NIST SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE atomic-force; dimensional; interferometry; length; measurements; microscopes; optical; scanning-electron; scanning-tunneling traceability ID LASER; INTERFEROMETRY; UNCERTAINTY; MICROSCOPE; METROLOGY; CALIBRATIONS AB This paper discusses the past, present, and future of length and dimensional measurements at NIST. It covers the evolution of the SI unit of length through its three definitions and the evolution of NBS-NIST dimensional measurement from early linescales and gage blocks to a future of atom-based dimensional standards. Current capabilities include dimensional measurements over a range of fourteen orders of magnitude. Uncertainties of measurements on different types of material artifacts range down to 7x10(-8) m at 1 m and 8 picometers (pm) at 300 pm. Current work deals with a broad range of areas of dimensional metrology. These include: large-scale coordinate systems; complex form; microform; surface finish; two-dimensional grids; optical, scanning-electron, atomic-force, and scanning-tunneling microscopies; atomic-scale displacement; and atom-based artifacts. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Swyt, DA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM dennis.swyt@nist.gov NR 74 TC 12 Z9 12 U1 0 U2 8 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 2001 VL 106 IS 1 BP 1 EP 23 DI 10.6028/jres.106.002 PG 23 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 401HC UT WOS:000166921300002 PM 27500015 ER PT J AU Jabbour, ZJ Yaniv, SL AF Jabbour, ZJ Yaniv, SL TI The kilogram and measurements of mass and force SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE force; kilogram; mass; uncertainty AB This paper describes the facilities, measurement capabilities, and ongoing research activities in the areas of mass and force at the National Institute of Standards and Technology (NIST). The first section of the paper is devoted to mass metrology and starts with a brief historical perspective on the developments that led to the current definition of the kilogram. An overview of mass measurement procedures is given with a brief discussion of current research on alternative materials for mass standards and surface profiles of the U.S. national prototype kilograms. A brief outlook into the future possible redefinition of the unit of mass based on fundamental principles is included. The second part of this paper focuses on the unit of force and describes the realization of the unit, measurement procedures, uncertainty in the realized force, facilities, and current efforts aimed at the realization of small forces. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Jabbour, ZJ (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM zeina.jabbour@nist.gov NR 38 TC 19 Z9 21 U1 0 U2 4 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 2001 VL 106 IS 1 BP 25 EP 46 DI 10.6028/jres.106.003 PG 22 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 401HC UT WOS:000166921300003 PM 27500016 ER PT J AU Sullivan, DB Bergquist, JC Bollinger, JJ Drullinger, RE Itano, WM Jefferts, SR Lee, WD Meekhof, D Parker, TE Walls, FL Wineland, DJ AF Sullivan, DB Bergquist, JC Bollinger, JJ Drullinger, RE Itano, WM Jefferts, SR Lee, WD Meekhof, D Parker, TE Walls, FL Wineland, DJ TI Primary atomic frequency standards at NIST SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE atomic clock; atomic frequency standard; cesium-beam frequency standard; cesium-fountain frequency standard; clock; fountain frequency standard; frequency; frequency standard; ion frequency standard; laser-cooling of atoms; stored-ion frequency standard; time ID LASER; BEAM; FOUNTAIN; SPECTROSCOPY; MICROWAVE; RADIATION; SHIFT; TRAP AB The development of atomic frequency standards at NIST is discussed and three of the key frequency-standard technologies of the current era are described. For each of these technologies, the most recent NIST implementation of the particular type of standard is described in greater detail. The best relative standard uncertainty achieved to date for a NIST frequency standard is 1.5x10(-15). The uncertainties of the most recent NIST standards are displayed relative to the uncertainties of atomic frequency standards of several other countries. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Sullivan, DB (reprint author), Natl Inst Stand & Technol, Boulder, CO 80305 USA. EM dbs@boulder.nist.gov; berky@boulder.nist.gov; jjb@boulder.nist.gov; rdrullinger@boulder.nist.gov; itano@boulder.nist.gov; jefferts@boulder.nist.gov; davidlee@boulder.nist.gov; meekhof@boulder.nist.gov; tparker@boulder.nist.gov; walls@boulder.nist.gov; wineland@boulder.nist.gov NR 46 TC 13 Z9 13 U1 0 U2 11 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 2001 VL 106 IS 1 BP 47 EP 63 DI 10.6028/jres.106.004 PG 17 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 401HC UT WOS:000166921300004 PM 27500017 ER PT J AU Elmquist, RE Cage, ME Tang, YH Jeffery, AM Kinard, JR Dziuba, RF Oldham, NM Williams, ER AF Elmquist, RE Cage, ME Tang, YH Jeffery, AM Kinard, JR Dziuba, RF Oldham, NM Williams, ER TI The ampere and electrical standards SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Review DE calibration; electrical engineering; Internet; Josephson arrays; measurement units; resistance measurements ID QUANTIZED HALL RESISTANCE; FINE-STRUCTURE CONSTANT; JOSEPHSON VOLTAGE STANDARD; FUNDAMENTAL PHYSICAL CONSTANTS; NIST CALCULABLE CAPACITOR; PROTON GYROMAGNETIC RATIO; AUTOMATED GUARDED BRIDGE; CALIBRATION SYSTEM; FREQUENCY RELATION; AC MEASUREMENTS AB This paper describes some of the major contributions to metrology and physics made by the NIST Electricity Division, which has existed since 1901. It was one of the six original divisions of the National Bureau of Standards. The Electricity Division provides dc and low-frequency calibrations for industrial, scientific, and research organizations, and conducts research on topics related to electrical metrology and fundamental constants. The early work of the Electricity Division staff included the development of precision standards, such as Rosa and Thomas standard resistors and the ac-dc thermal converter. Research contributions helped define the early international system of measurement units and bring about the transition to absolute units based on fundamental principles and physical and dimensional measurements. NIST research has helped to develop and refine electrical standards using the quantum Hall effect and the Josephson effect, which are both based on quantum physics. Four projects covering a number of voltage and impedance measurements are described in detail. Several other areas of current research at NIST are described, including the use of the Internet for international compatibility in metrology, determination of the fine-structure and Planck constants, and construction of the electronic kilogram. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Elmquist, RE (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM randolph.elmquist@nist.gov; marvin.cage@nist.gov; yi-hua.tang@nist.gov; anne-marie.jeffery@nist.gov; joseph.kinard@nist.gov; ronald.dziuba@nist.gov; nile.oldham@nist.gov; edwin.williams@nist.gov RI Messier, Claude/A-2322-2008 OI Messier, Claude/0000-0002-4791-1763 NR 129 TC 5 Z9 6 U1 0 U2 8 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 2001 VL 106 IS 1 BP 65 EP 103 DI 10.6028/jres.106.005 PG 39 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 401HC UT WOS:000166921300005 PM 27500018 ER PT J AU Mangum, BW Furukawa, GT Kreider, KG Meyer, CW Ripple, DC Strouse, GF Tew, WL Moldover, MR Johnson, BC Yoon, HW Gibson, CE Saunders, RD AF Mangum, BW Furukawa, GT Kreider, KG Meyer, CW Ripple, DC Strouse, GF Tew, WL Moldover, MR Johnson, BC Yoon, HW Gibson, CE Saunders, RD TI The Kelvin and temperature measurements SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Review DE acoustic thermometry; blackbody sources; calibrations; gas thermometry; Johnson noise thermometry; Kelvin; pyrometers; radiation thermometry; SPRTs; thermocouples ID STEFAN-BOLTZMANN CONSTANT; THERMODYNAMIC TEMPERATURES; RESISTANCE THERMOMETERS; CRYOGENIC RADIOMETER; NATIONAL-INSTITUTE; BLACKBODY SOURCE; TRIPLE-POINTS; RANGE; NIST; PLATINUM AB The International Temperature Scale of 1990 (ITS-90) is defined from 0.65 K upwards to the highest temperature measurable by spectral radiation thermometry, the radiation thermometry being based on the Planck radiation law. When it was developed, the ITS-90 represented thermodynamic temperatures as closely as possible. Part I of this paper describes the realization of contact thermometry up to 1234.93 K, the temperature range in which the ITS-90 is defined in terms of calibration of thermometers at 15 fixed points and vapor pressure/temperature relations which are phase equilibrium states of pure substances. The realization is accomplished by using fixed-point devices, containing samples of the highest available purity, and suitable temperature-controlled environments. All components are constructed to achieve the defining equilibrium states of the samples for the calibration of thermometers. The high quality of the temperature realization and measurements is well documented. Various research efforts are described, including research to improve the uncertainty in thermodynamic temperatures by measuring the velocity of sound in gas up to 800 K, research in applying noise thermometry techniques, and research on thermocouples. Thermometer calibration services and high-purity samples and devices suitable for "on- site" thermometer calibration that are available to the thermometry community are described. Part II of the paper describes the realization of temperature above 1234.93 K for which the ITS-90 is defined in terms of the calibration of spectroradiometers using reference blackbody sources that are at the temperature of the equilibrium liquid-solid phase transition of pure silver, gold, or copper. The realization of temperature from absolute spectral or total radiometry over the temperature range from about 60 K to 3000 K is also described. The dissemination of the temperature scale using radiation thermometry from NIST to the customer is achieved by calibration of blackbody sources, tungsten-strip lamps, and pyrometers. As an example of the research efforts in absolute radiometry, which impacts the NIST spectral irradiance and radiance scales, results with filter radiometers and a high-temperature blackbody are summarized. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Mangum, BW (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM billy.mangum@nist.gov; george.furukawa@nist.gov; kenneth.krieder@nist.gov; christopher.meyer@nist.gov; dean.ripple@nist.gov; gregory.strouse@nist.gov; weston.tew@nist.gov; michael.moldover@nist.gov; c.johnson@nist.gov; howard.yoon@nist.gov; charles.gibson@nist.gov; robert.saunders@nist.gov RI Moldover, Michael/E-6384-2013 NR 166 TC 13 Z9 14 U1 3 U2 26 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 2001 VL 106 IS 1 BP 105 EP 149 DI 10.6028/jres.106.006 PG 45 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 401HC UT WOS:000166921300006 PM 27500019 ER PT J AU Parr, AC AF Parr, AC TI The candela and photometric and radiometric measurements SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE cryogenic radiometer; laser power; photodiodes; photometry; radiation temperature; radiometry; standards ID ABSOLUTE SPECTRAL RESPONSE; STANDARDS-AND-TECHNOLOGY; ACCURACY CRYOGENIC RADIOMETER; NATIONAL-INSTITUTE; SILICON PHOTODIODES; INTEGRATING SPHERE; ULTRAVIOLET RADIOMETRY; QUANTUM EFFICIENCY; X-RAY; SCALE AB The national measurement system for photometric and radiometric quantities is presently based upon techniques that make these quantities traceable to a high-accuracy cryogenic radiometer. The redefinition of the candela in 1979 provided the opportunity for national measurement laboratories to base their photometric measurements on optical detector technology rather than on the emission from high-temperature blackbody optical sources. The ensuing technical developments of the past 20 years, including the significant improvements in cryogenic radiometer performance, have provided the opportunity to place the fundamental maintenance of photometric quantities upon absolute detector based technology as was allowed by the 1979 redefinition. Additionally, the development of improved photodetectors has had a significant impact on the methodology in most of the radiometric measurement areas. This paper will review the status of the NIST implementation of the technical changes mandated by the 1979 redefinition of the candela and its effect upon the maintenance and dissemination of optical radiation measurements. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Parr, AC (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM albert.parr@nist.gov NR 98 TC 8 Z9 8 U1 1 U2 5 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 2001 VL 106 IS 1 BP 151 EP 186 DI 10.6028/jres.106.007 PG 36 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 401HC UT WOS:000166921300007 PM 27500020 ER PT J AU Cappelletti, RL Glinka, CJ Krueger, S Lindstrom, RA Lynn, JW Prask, HJ Prince, E Rush, JJ Rowe, JM Satija, SK Toby, BH Tsai, A Udovic, TJ AF Cappelletti, RL Glinka, CJ Krueger, S Lindstrom, RA Lynn, JW Prask, HJ Prince, E Rush, JJ Rowe, JM Satija, SK Toby, BH Tsai, A Udovic, TJ TI Materials research with neutrons at NIST SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Review DE activation-analysis; bio-membrane; condensed-matter; diffraction; neutron; materials; polymer; reflectivity; residual-stress; scattering; vibration ID RAY ACTIVATION-ANALYSIS; STANDARD REFERENCE MATERIALS; SMALL-ANGLE SCATTERING; CAMP RECEPTOR PROTEIN; LIGHT-CHAIN KINASE; X-RAY; MAGNETIC ORDER; POWDER DIFFRACTION; RESIDUAL-STRESS; SINGLE-CRYSTAL AB The NIST Materials Science and Engineering Laboratory works with industry, standards bodies, universities, and other government laboratories to improve the nation's measurements and standards infrastructure for materials. An increasingly important component of this effort is carried out at the NIST Center for Neutron Research (NCNR), at present the most productive center of its kind in the United States. This article gives a brief historical account of the growth and activities of the Center with examples of its work in major materials research areas and describes the key role the Center can expect to play in future developments. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Cappelletti, RL (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM ronald.cappelletti@nist.gov; charles.glinka@nist.gov; susan.krueger@nist.gov; richard.lindstrom@nist.gov; jeffery.lynn@nist.gov; henry.prask@nist.gov; edward.prince@nist.gov; john.rush@nist.gov; j.rowe@nist.gov; sushil.satija@nist.gov; brian.toby@nist.gov; amos.tsai@nist.gov; terrence.udovic@nist.gov RI Rowe, J Michael Rowe/D-2943-2013; Toby, Brian/F-3176-2013 OI Toby, Brian/0000-0001-8793-8285 NR 173 TC 8 Z9 8 U1 0 U2 5 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 2001 VL 106 IS 1 BP 187 EP 230 DI 10.6028/jres.106.008 PG 44 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 401HC UT WOS:000166921300008 PM 27500021 ER PT J AU Evans, DD Mulholland, GW Baum, HR Walton, WD McGrattan, KB AF Evans, DD Mulholland, GW Baum, HR Walton, WD McGrattan, KB TI In situ burning of oil spills SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE ALOFT; combustion; large eddy simulation; offshore drilling; oil spills; pool fires; smoke plumes; smoke sampling; smoke yield ID CRUDE-OIL; SMOKE PLUMES; FIRES; DISPERSION; EMISSIONS; PARTICLES AB For more than a decade NIST conducted research to understand, measure and predict the important features of burning oil on water. Results of that research have been included in nationally recognized guidelines for approval of intentional burning. NIST measurements and predictions have played a major role in establishing in situ burning as a primary oil spill response method. Data are given for pool fire burning rates, smoke yield, smoke particulate size distribution, smoke aging, and polycyclic aromatic hydrocarbon content of the smoke for crude and fuel oil fires with effective diameters up to 17.2 m. New user-friendly software, ALOFT, was developed to quantify the large-scale features and trajectory of wind blown smoke plumes in the atmosphere and estimate the ground level smoke particulate concentrations. Predictions using the model were tested successfully against data from large-scale tests. ALOFT software is being used by oil spill response teams to help assess the potential impact of intentional burning. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Evans, DD (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM dave.evans@nist.gov; george.mulholland@nist.gov; howard.baum@nist.gov; william.walton@nist.gov; kevin.mcgrattan@nist.gov NR 74 TC 15 Z9 15 U1 1 U2 10 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 2001 VL 106 IS 1 BP 231 EP 278 DI 10.6028/jres.106.009 PG 48 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 401HC UT WOS:000166921300009 PM 27500022 ER PT J AU Croarkin, MC AF Croarkin, MC TI Statistics and measurements SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE calibration and measurement assurance; error analysis and uncertainty; design of experiments; history of NBS; interlaboratory testing; measurement methods; standard reference materials; statistical computing; uncertainty analysis ID CALIBRATION; RELIABILITY; SOFTWARE AB For more than 50 years, the Statistical Engineering Division (SED) has been instrumental in the success of a broad spectrum of metrology projects at NBS/NIST. This paper highlights fundamental contributions of NBS/NIST statisticians to statistics and to measurement science and technology. Published methods developed by SED staff, especially during the early years, endure as cornerstones of statistics not only in metrology and standards applications, but as data-analytic resources used across all disciplines. The history of statistics at NBS/NIST began with the formation of what is now the SED. Examples from the first five decades of the SED illustrate the critical role of the division in the successful resolution of a few of the highly visible, and sometimes controversial, statistical studies of national importance. A review of the history of major early publications of the division on statistical methods, design of experiments, and error analysis and uncertainty is followed by a survey of several thematic areas. The accompanying examples illustrate the importance of SED in the history of statistics, measurements and standards: calibration and measurement assurance, interlaboratory tests, development of measurement methods, Standard Reference Materials, statistical computing, and dissemination of measurement technology. A brief look forward sketches the expanding opportunity and demand for SED statisticians created by current trends in research and development at NIST. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM carroll.croarkin@nist.gov NR 35 TC 3 Z9 3 U1 0 U2 8 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 2001 VL 106 IS 1 BP 279 EP 292 DI 10.6028/jres.106.010 PG 14 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 401HC UT WOS:000166921300010 PM 27500023 ER PT J AU Boisvert, RF Donahue, MJ Lozier, DW McMichael, R Rust, BW AF Boisvert, RF Donahue, MJ Lozier, DW McMichael, R Rust, BW TI Mathematics and measurement SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE deconvolution; digital libraries; history of NBS; linear algebra; mathematical reference data; mathematical software; micromagnetic modeling; parameter estimation; software testing; scientific computing AB In this paper we describe the role that mathematics plays in measurement science at NIST. We first survey the history behind NIST's current work in this area, starting with the NBS Math Tables project of the 1930s. We then provide examples of more recent efforts in the application of mathematics to measurement science, including the solution of ill-posed inverse problems, characterization of the accuracy of software for micromagnetic modeling, and in the development and dissemination of mathematical reference data. Finally, we comment on emerging issues in measurement science to which mathematicians will devote their energies in coming years. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Boisvert, RF (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM ronald.boisvert@nist.gov; michael.donahue@nist.gov; daniel.lozier@nist.gov; robert.mcmichael@nist.gov; bert.rust@nist.gov RI McMichael, Robert/J-8688-2012; OI McMichael, Robert/0000-0002-1372-664X; Boisvert, Ronald/0000-0002-4445-1044 NR 10 TC 0 Z9 0 U1 0 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 2001 VL 106 IS 1 BP 293 EP 313 DI 10.6028/jres.106.011 PG 21 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 401HC UT WOS:000166921300011 PM 27500024 ER PT J AU Gills, TE Dittman, S Rumble, JR Brickenkamp, CS Harris, GL Trahey, NM AF Gills, TE Dittman, S Rumble, JR Brickenkamp, CS Harris, GL Trahey, NM TI NIST mechanisms for disseminating measurements SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE calibrations; certified reference materials; critically evaluated data; commerce and trade; legal metrology; measurement systems; SRM (R); standard reference data; traceability; weights and measures AB The national responsibilities assigned to the National Bureau of Standards (NBS) early in the last century for providing measurement assistance and service are carried out today by the four programs that comprise the National Institute of Standards and Technology (NIST) Office of Measurement Services (OMS). They are the Calibration Program (CP), the Standard Reference Materials Program (SRMP), the Standard Reference Data Program (SRDP), and the Weights and Measures Program (W&MP). Organized when the U.S. Congress changed the NBS name to NIST, the OMS facilitates access to the measurement and standards activities of NIST laboratories and programs through the dissemination of NIST products, data, and services. A brief historical introduction followed by a perspective of pivotal measurement developments from 1901 to the present and concluding with a look to the future of NIST measurement services in the next decade of the new millennium are presented for each OMS program. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Gills, TE (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM thomas.gills@nist.gov; sharrill.dittmann@nist.gov; john.rumble@nist.gov; carroll.brickenkamp@nist.gov; georgia.harris@nist.gov; nancy.trahey@nist.gov NR 13 TC 1 Z9 1 U1 0 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 2001 VL 106 IS 1 BP 315 EP 340 DI 10.6028/jres.106.012 PG 26 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 401HC UT WOS:000166921300012 PM 27500025 ER PT J AU Hogan, MD Carnahan, LJ Carpenter, RJ Flater, DW Fowler, JE Frechette, SP Gray, MM Johnson, LA McCabe, RM Montgomery, D Radack, SM Rosenthal, R Shakarji, CM AF Hogan, MD Carnahan, LJ Carpenter, RJ Flater, DW Fowler, JE Frechette, SP Gray, MM Johnson, LA McCabe, RM Montgomery, D Radack, SM Rosenthal, R Shakarji, CM TI Information technology measurement and testing activities at NIST SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE conformance; hardware; information technology; interoperability; measurement; performance; reference data; software; testing AB Our high technology society continues to rely more and more upon sophisticated measurements, technical standards, and associated testing activities. This was true for the industrial society of the 20th century and remains true for the information society of the 21st century. Over the last half of the 20th century, information technology (IT) has been a powerful agent of change in almost every sector of the economy. The complexity and rapidly changing nature of IT have presented unique technical challenges to the National Institute of Standards and Technology (NIST) and to the scientific measurement community in developing a sound measurement and testing infrastructure for IT. This measurement and testing infrastructure for the important non-physical and non-chemical properties associated with complex IT systems is still in an early stage of development. This paper explains key terms and concepts of IT metrology, briefly reviews the history of the National Bureau of Standards/National Institute of Standards and Technology (NBS/NIST) in the field of IT, and reviews NIST's current capabilities and work in measurement and testing for IT. It concludes with a look at what is likely to occur in the field of IT over the next ten years and what metrology roles NIST is likely to play. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. EM michael.hogan@nist.gov; lisa.carnahan@nist.gov; robert.carpenter@nist.gov; david.flater@nist.gov; james.fowler@nist.gov; simon.frechette@nist.gov; martha.gray@nist.gov; arnold.johnson@nist.gov; robert.mccabe@nist.gov; douglas.montgomery@nist.gov; shirley.radack@nist.gov; robert.rosenthal@nist.gov; craig.shakarji@nist.gov NR 52 TC 2 Z9 2 U1 1 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD JAN-FEB PY 2001 VL 106 IS 1 BP 341 EP 370 DI 10.6028/jres.106.013 PG 30 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 401HC UT WOS:000166921300013 PM 27500026 ER PT J AU Davidson, YY Soper, SA Margolis, S Sander, LC AF Davidson, YY Soper, SA Margolis, S Sander, LC TI Immobilization of the restriction enzymes HaeIII and HindIII on porous silica particles via a glutaraldehyde linkage for the micro-digestion of dsDNA with analysis by capillary electrophoresis SO JOURNAL OF SEPARATION SCIENCE LA English DT Article DE immobilization; restriction enzymes; silica; capillary electrophoresis; digestion; DNA; glutaraldehyde ID ZONE ELECTROPHORESIS; DNA; SEPARATION; FRAGMENTS; OLIGONUCLEOTIDES; TRYPSIN; ALBUMIN AB Solid-phase DNA restriction digest reactors have been developed consisting of silica particles modified with a covalently tethered restriction enzyme. This solid-phase restriction reactor enables digestion and separation of minute quantities of DNA with minimal reagent consumption. In this study, the restriction enzymes, HaeIII, Psd, and HindIII, were successfully immobilized via glutaraldehyde linkages to porous silica micro-particles. Studies were carried out to examine the impact of immobilization on enzymatic activity. Digestions of phi X174-RF DNA phage and SV40 viral DNA were performed with the immobilized enzymes by placing the silica particles in solution with the target DNA with digestion times of 120 min and 240 min respectively. The digests were analyzed off-line using capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection. Timed studies were performed to establish optimal conditions for complete digestion. Digests utilizing immobilized HaeIII and HindIII were similar in composition to homogeneous, free solution digests. PstI showed no evidence of activity upon immobilization. The immobilized restriction enzymes could also be used for multiple rounds of digestion; however, longer incubation times were required for successive runs probably due to partial denaturation of the restriction enzyme. Digests also were prepared and isolated by use of a simple micro-spin column consisting of a layer of immobilized enzyme-coated silica on a molecular weight cut-off filter. Using this approach, digestion times were comparable to solution digests as previously mentioned; however, enzyme reuse and reaction product isolation was facilitated. C1 Natl Inst Stand & Technol, Div Analyt Chem, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. RP Davidson, YY (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. NR 28 TC 6 Z9 7 U1 3 U2 12 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 1615-9314 J9 J SEP SCI JI J. Sep. Sci. PD JAN PY 2001 VL 24 IS 1 BP 10 EP 16 DI 10.1002/1615-9314(20010101)24:1<10::AID-JSSC10>3.0.CO;2-N PG 7 WC Chemistry, Analytical SC Chemistry GA 410TC UT WOS:000167454400003 ER PT J AU Levin, I Chan, JY Geyer, RG Maslar, JE Vanderah, TA AF Levin, I Chan, JY Geyer, RG Maslar, JE Vanderah, TA TI Cation ordering types and dielectric properties in the complex perovskite Ca(Ca1/3Nb2/3)O-3 SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE perovskite; cation ordering; 1 : 1 ordering; 2 : 1 ordering; octahedral tilting; dielectric properties; microwave dielectrics; Ca4Nb2O9; polymorphs; Rietveld refinement ID TEMPERATURE-COEFFICIENT; CERAMICS; TRANSITION; DISORDER; CRYSTAL; SYSTEM; OXIDES AB In the present work the effects of cation ordering on dielectric properties were isolated by investigating three polymorphs of Ca(Ca1/3Nb2/3)O-3 that feature different arrangements of the Ca2+ and Nb5+ cations on the B-sites of the perovskite structure. Dielectric measurements at frequencies above 1 GHz revealed a systematic dependence of the properties on the type of cation ordering. In particular, the structure with 2:1 ordering exhibited a lower dielectric constant and a significantly more negative temperature coefficient of resonance frequency than the structures with 1:1 and newly described k = 1/4[1 1 1](c)* ordering. Rietveld refinements of structural models for the three Ca4Nb2O9 polymorphs were conducted using X-ray and neutron powder diffraction data to elucidate structural details that could be correlated with the changes in dielectic properties, In all three polymorphs the cation ordering was combined with the same b(-)b(-)c(+) octahedral tilt system, and the structural refinements yielded similar magnitudes of the tilting angles. The most significant crystal-chemical difference between the three polymorphs was in the coordination environment of Nb5+. Analysis of the refined bond distances indicated increasing average distortion of the Nb nearest-neighbor environment in going from the 1:1 to the k = 1/4[1 1 1](c)* to the 2:1 ordered structure. The increased fraction of strongly compressed Nb-O bonds in the 2:1 structure associated with the large distortion was correlated with the decrease in dielectic constant and more negative value of temperature coefficient of the resonant frequency obtained for this polymorph. Raman spectra obtained for the three polymorphs exhibited differences that were consistent with the observed structural chemistry. (C) 2001 Academic Press. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Colorado, NIST, Elect & Elect Engn Lab, Boulder, CO 80309 USA. NIST, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. RP Levin, I (reprint author), NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RI Levin, Igor/F-8588-2010; Chan, Julia/C-5392-2008 OI Chan, Julia/0000-0003-4434-2160 NR 25 TC 63 Z9 64 U1 2 U2 23 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JAN PY 2001 VL 156 IS 1 BP 122 EP 134 DI 10.1006/jssc.2000.8971 PG 13 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 404WW UT WOS:000167126000018 ER PT J AU Bentz, DP Jensen, OM Hansen, KK Olesen, JF Stang, H Haecker, CJ AF Bentz, DP Jensen, OM Hansen, KK Olesen, JF Stang, H Haecker, CJ TI Influence of cement particle-size distribution on early age autogenous strains and stresses in cement-based materials SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MODELING DRYING SHRINKAGE; PORTLAND-CEMENT; SILICA FUME; PASTE; HYDRATION; MICROSTRUCTURE; DEFORMATION; AGGREGATE AB The influence of cement particle-size distribution on autogenous strains and stresses in cement pastes of identical water-to-cement ratios is examined for cement powders of four different finenesses, Experimental measurements include chemical shrinkage, to quantify degree of hydration; internal relative humidity development; autogenous deformation; and eigenstress development, using a novel embedded spherical stress sensor. Because the latter three measurements are conducted under sealed conditions, whereas chemical-shrinkage measurements are made under "saturated" conditions, the National Institute of Standards and Technology cement hydration and microstructure development model is used to separate the effects of differences in hydration rates (kinetics) from those caused by the different initial spatial arrangement of the cement particles. The initial arrangement of the cement particles controls the initial pore-size distribution of the cement paste, which, in turn, regulates the magnitude of the induced autogenous shrinkage stresses produced by the water/air menisci in the air-filled pores formed throughout the hydration process, The experimental results indicate that a small autogenous expansion (probably the result of ettringite formation), as opposed to a shrinkage, may be produced and early age cracking possibly avoided through the use of coarser cements. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Tech Univ Denmark, DK-2800 Lyngby, Denmark. Univ Aalborg, DK-9000 Aalborg, Denmark. Wilhelm Dyckerhoff Inst, D-65203 Wiesbaden, Germany. RP Bentz, DP (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. OI Olesen, John Forbes/0000-0001-6695-7719; Stang, Henrik/0000-0002-5812-4028 NR 35 TC 46 Z9 49 U1 1 U2 10 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JAN PY 2001 VL 84 IS 1 BP 129 EP 135 PG 7 WC Materials Science, Ceramics SC Materials Science GA 407HC UT WOS:000167265300020 ER PT J AU Krause, RF Wiederhorn, SM Kubler, JJ AF Krause, RF Wiederhorn, SM Kubler, JJ TI Misalignment-induced bending in pin-loaded tensile-creep specimens SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT 100th Annual Meeting of the American-Ceramic-Society CY MAY 03-06, 1998 CL CINCINNATI, OHIO SP Amer Ceram Soc ID SILICON-NITRIDE AB In this paper, we have examined the possibility that elastic bending Induced by load misalignment can affect creep measurements on pin-loaded tension specimens of silicon nitride (Si3N4). We have shown that elastic bending at room temperature can be as great as 42% of the axial strain when clean pins were used but was reduced to similar to3% when lubricated pins were used. Creep tests at the same applied stress and temperature were conducted on two groups of Si3N4 test specimens: one group used clean pins, and the other group used lubricated pins. By measuring the shapers of the specimens before and after the creep tests, we have determined that the loading holes were slightly misaligned before the creep tests and that small amounts of bonding were induced by the creep tests. Bending occurred both in the gauge section of the specimen and in the transition region between the gauge section and the heads of the specimen (the latter phenomenon is defined as hinge bending). Our study indicated that the secondary creep rate, the hinge bending, and the bending of the gauge section was not dependent on pin lubrication, because the results from the clean and lubricated groups were statistically indistinguishable. Hinge bending was dependent on initial misalignment of the loading holes, whereas bending of the gauge section was independent of such factors. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Swiss Fed Labs Mat Testing & Res, Dubendorf, Switzerland. RP Krause, RF (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 12 TC 1 Z9 1 U1 0 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JAN PY 2001 VL 84 IS 1 BP 145 EP 152 PG 8 WC Materials Science, Ceramics SC Materials Science GA 407HC UT WOS:000167265300023 ER PT J AU Chung, TJ Lee, JS Kim, DY Kim, GH Song, H AF Chung, TJ Lee, JS Kim, DY Kim, GH Song, H TI Morphology and phase stability of nitrogen-partially stabilized zirconia (N-PSZ) SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID DOPED TETRAGONAL ZIRCONIA; SYSTEM; TRANSFORMATION; NITRIDATION; ZRO2 AB The surface layer of yttria-doped tetragonal zirconia materials that have been heat-treated with zirconium nitride was observed to consist of a nitrogen-rich cubic matrix with nitrogen-poor tetragonal precipitates. The precipitates had a thin, oblate-lens shape, similar to those observed in magnesia-partially stabilized zirconia. Because of the fast diffusion of N4- ions, the precipitates grew rather large, up to similar to5 mum in length, and remained stabilized in the tetragonal form at room temperature. Because the nitrided layer grew in the two-phase field, the size and distribution of the precipitates each was very irregular. The nitrogen content was observed to determine the proportion of cubic and tetragonal phases in the same way as in conventional cation-stabilized partially stabilized zirconia. A ternary phase diagram for the zirconium(yttrium)-nitrogen-oxygen system was suggested to explain the concentration gradient in the cubic matrix and the phase distribution of the nitrided layer. C1 Seoul Natl Univ, Ctr Microstruct Sci Mat, Seoul 151742, South Korea. Seoul Natl Univ, Sch Mat Sci & Engn, Seoul 151742, South Korea. Korea Inst Sci & Technol, Ceram Proc Ctr, Seoul 136791, South Korea. RP Chung, TJ (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Lee, Jong-Sook/D-1035-2013 OI Lee, Jong-Sook/0000-0002-2227-0808 NR 22 TC 17 Z9 17 U1 1 U2 6 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JAN PY 2001 VL 84 IS 1 BP 172 EP 178 PG 7 WC Materials Science, Ceramics SC Materials Science GA 407HC UT WOS:000167265300027 ER PT J AU Zilitinkevich, SS Grachev, AA Fairall, CW AF Zilitinkevich, SS Grachev, AA Fairall, CW TI Scaling reasoning and field data on the sea surface roughness lengths for scalars SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID WAVE BOUNDARY-LAYER; WATER-VAPOR; HEAT; EXCHANGE; COEFFICIENT AB The heat and mass transfer over the sea is considered in terms of the sea surface roughness lengths for scalars, z(OT) for potential temperature theta, and z(Oq) for specific humidity q, or alternatively, in terms of the roughness-layer scalar increments, delta theta and deltaq. A new scaling reasoning is proposed in support of the familiar square root dependence of the above increments on the roughness Reynolds number, Re-Ou = z(Ou) u(*)/nu, where z(Ou) is the sea surface aerodynamic roughness length, u(*) is the friction velocity, and nu is the molecular viscosity of the air. Scaling predictions are validated using data from measurements made by the National Oceanic and Atmospheric Administration's Environmental Technology Laboratory aboard the R/V Moana Wave in the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment in 1992-93 and the R/P FLIP in the San Clemente Ocean Probing Experiment in September 1993. Data presented as the dimensionless scalar increments (or the ratios z(Ou)/z(OT) and z(Ou)/z(Oq)) versus Re-Ou show a good agreement with theoretical predictions, especially at Re-Ou. > 2 (over stormy sea). The resulting roughness-length formulations are recommended for practical use in climate and mesoscale air-sea interaction models. C1 Uppsala Univ, Dept Earth Sci Meteorol, SE-75236 Uppsala, Sweden. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Environm Technol Lab, Boulder, CO 80309 USA. RP Zilitinkevich, SS (reprint author), Uppsala Univ, Dept Earth Sci Meteorol, Villavagen 16, SE-75236 Uppsala, Sweden. NR 24 TC 22 Z9 22 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 3 BP 320 EP 325 DI 10.1175/1520-0469(2001)058<0320:NACRAF>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 393BT UT WOS:000166449900006 ER PT J AU Koshyk, JN Hamilton, K AF Koshyk, JN Hamilton, K TI The horizontal kinetic energy spectrum and spectral budget simulated by a high-resolution troposphere-stratosphere-mesosphere GCM SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GENERAL-CIRCULATION MODEL; WAVE-NUMBER SPECTRA; PACIFIC EXPLORATORY MISSIONS; AIRCRAFT N2O MEASUREMENTS; STRATIFIED TURBULENCE; MIDDLE-ATMOSPHERE; GRAVITY-WAVES; COMMERCIAL AIRCRAFT; TRACE GASES; TEMPERATURE AB Horizontal kinetic energy spectra simulated by high-resolution versions of the Geophysical Fluid Dynamics Laboratory SKYHI middle-atmosphere general circulation model are examined. The model versions considered resolve heights between the ground and similar to 80 km, and the horizontal grid spacing of the highest-resolution version is about 35 km. Tropospheric kinetic energy spectra show the familiar similar to -3 power-law dependence on horizontal wavenumber for wavelengths between about 5000 and 500 km and have a slope of similar to -5/ 3 at smaller wavelengths. Qualitatively similar behavior is seen in the stratosphere and mesosphere, but the wavelength marking the transition to the shallow regime increases with height, taking a value of similar to 2000 km in the stratosphere and similar to 4000 km in the mesosphere. The global spectral kinetic energy budget for various height ranges is computed as a function of total horizontal wavenumber. Contributions to the kinetic energy tendency from nonlinear advective processes, from conversion of available potential energy, from mechanical fluxes through the horizontal boundaries of the region, and from parameterized subgrid-scale dissipation are all examined. In the troposphere, advective contributions are negative at large scales and positive over the rest of the spectrum. This is consistent with a predominantly downscale nonlinear cascade of kinetic energy into the mesoscale. The global kinetic energy budget in the middle atmosphere differs significantly from that in the troposphere, with the positive contributions at most scales coming predominantly from vertical energy fluxes. The kinetic energy spectra calculated from two model versions with different horizontal resolution are compared. Differences between the spectra over the resolved range of the lower-resolution version are smallest in the troposphere and increase with height, owing mainly to large differences in the divergent components. The result suggests that the parameterization of dynamical subgrid-scale processes in middle-atmosphere general circulation models, as well as in high-resolution tropospheric general circulation models, may need to be critically reevaluated. C1 Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA. RP Koshyk, JN (reprint author), Univ Toronto, Dept Phys, 60 St George St, Toronto, ON M5S 1A7, Canada. EM koshyk@mam.physics.utoronto.ca NR 52 TC 88 Z9 91 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 4 BP 329 EP 348 DI 10.1175/1520-0469(2001)058<0329:THKESA>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 393NA UT WOS:000166475500001 ER PT J AU Mapes, BE Wu, XQ AF Mapes, BE Wu, XQ TI Convective eddy momentum tendencies in long cloud-resolving model simulations SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GENERAL-CIRCULATION MODELS; SQUALL LINE; PHASE-III; TRANSPORT; SYSTEMS; GATE; PARAMETERIZATION; PARAMETRIZATION; CUMULONIMBUS; EQUILIBRIUM AB Domain-average momentum budgets are examined in several multiday cloud-resolving model simulations of deep tropical convection in realistic shears. The convective eddy momentum tendency F, neglected in many global circulation models, looks broadly similar in two- and three-dimensional simulations. It has a large component in quadrature with the mean wind profile, tending to cause momentum profile features to descend. This component opposes, and exceeds in magnitude, the corresponding large-scale vertical advective tendency, which would tend to make features ascend in convecting regions. The portion of F in phase with the mean wind is isolated by vertically integrating F . u, yielding a kinetic energy tendency that is overwhelmingly negative. The variation of this energy damping with shear flow kinetic energy and convection intensity (measured by rain rate) gives a "cumulus friction'' coefficient around -40% to -80% per centimeter of rain in 3D runs. Large scatter reflects the effects of varying convective organization. Two-dimensional runs overestimate this friction coefficient for the upsilon (out of plane) wind component and underestimate it for the u (in plane) component. Another 2D artifact is that 460-hPa-wavelength shear is essentially undamped, consistent with the descending jets reported by Held et al. in a free-running 2D cloud model. C1 NOAA, CIRES, Climate Diagnost Ctr, RCDC, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Mapes, BE (reprint author), NOAA, CIRES, Climate Diagnost Ctr, RCDC, 325 S Broadway, Boulder, CO 80303 USA. RI Mapes, Brian/A-5647-2010; Wu, Xiangqian/F-5634-2010 OI Wu, Xiangqian/0000-0002-7804-5650 NR 25 TC 27 Z9 27 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 5 BP 517 EP 526 DI 10.1175/1520-0469(2001)058<0517:NACCEM>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 402AX UT WOS:000166964400008 ER PT J AU Worthington, RM Muschinski, A Balsley, BB AF Worthington, RM Muschinski, A Balsley, BB TI Bias in mean vertical wind measured by VHF radars: Significance of radar location relative to mountains SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID RADIAL-VELOCITY CORRECTIONS; BEAM INCIDENCE ANGLES; JET-STREAM; GRAVITY-WAVES; TROPICAL PACIFIC; BOUNDARY-LAYER; DOPPLER RADARS; MOMENTUM FLUX; STABLE LAYERS; LEE WAVES AB Measurements by VHF wind-profiling radars worldwide have, for many years, shown long-term downward atmospheric motion in most of the troposphere. Various explanations have been proposed, some atmospheric and some caused by the radar measurement method. At many sites, except those in the Tropics, the authors suggest a new model, in which the long-term downward vertical wind ((W) over bar) is real and atmospheric, a consequence of radars being constructed on low ground near or within mountain ranges, so that they tend to view on average the same phase of mountain waves. A coincidence consisting of five factors-low-lying radar locations near mountains, the upwind slope of untrapped mountain wave phase lines with height, the inability of wind-profiling radars to measure both the lowest few kilometers of the troposphere and far into the stratosphere, decreasing tropospheric static stability with height, and increasing tropospheric wind speed with height-has led to downward W measurements in most of the troposphere. The new mountain wave model applies to all types of wind-profiling radars and lidars, and may account for unexplained (W) over bar observations at many sites. C1 Univ Colorado, CIRES, Boulder, CO 80309 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Environm Technol Lab, Boulder, CO 80309 USA. RP Univ Colorado, CIRES, Campus Box 216, Boulder, CO 80309 USA. EM worth@terra.colorado.edu OI Worthington, Richard/0000-0003-0681-5596 NR 72 TC 23 Z9 23 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 7 BP 707 EP 723 DI 10.1175/1520-0469(2001)058<0707:BIMVWM>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 412JB UT WOS:000167550300003 ER PT J AU Held, IM AF Held, IM TI The partitioning of the poleward energy transport between the tropical ocean and atmosphere SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SUBTROPICAL CELL; CIRCULATIONS; EXCHANGE AB The mass transport in the shallow, wind-driven, overturning cells in the tropical oceans is constrained to be close to the mass transport in the atmospheric Hadley cell, assuming that zonally integrated wind stresses on land are relatively small. Therefore, the ratio of the poleward energy transport in low latitudes in the two media is determined by the ratio of the atmospheric gross static stability to that of the ocean. A qualitative discussion of the gross stability of each medium suggests that the resulting ratio of oceanic to atmospheric energy transport, averaged over the Hadley cell, is roughly equal to the ratio of the heat capacity of water to that of air at constant pressure, multiplied by the ratio of the moist- to the dry-adiabatic lapse rates near the surface. The ratio of oceanic to atmospheric energy transport should be larger than this value near the equator and smaller than this value near the poleward boundary of the Hadley cell. C1 Princeton Univ, Geophys Fluid Dynam Lab, NOAA, Princeton, NJ 08542 USA. RP Held, IM (reprint author), Princeton Univ, Geophys Fluid Dynam Lab, NOAA, Princeton, NJ 08542 USA. NR 17 TC 81 Z9 83 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 8 BP 943 EP 948 DI 10.1175/1520-0469(2001)058<0943:TPOTPE>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 414NV UT WOS:000167673700013 ER PT J AU Chen, P AF Chen, P TI Thermally forced stationary waves in a quasigeostrophic system SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GENERAL-CIRCULATION; ATMOSPHERE AB Analytical solutions of thermally forced stationary waves in a linear quasigeostrophic model are obtained. It is found that the zonal flow has a profound impact on the structure of the responses. The inviscid solutions on a resting basic state are the Sverdrup solutions that are confined to the heating region. The solutions on a westerly zonal flow are composed of a local and a vertically propagating part. The local response exists only in the heating region. The vertically propagating response exists in the far field as well as in the heating region. The thermally forced vertically propagating response can be conceptualized as a response to an "equivalent topography,'' the height of which is proportional to the intensity and zonal scale of the heating, and inversely proportional to the strength of the zonal flow. Particular solutions forced by realistic summer heating fields reveal that, for weak westerlies, the height of the equivalent topography is much larger than that of the real topography, suggesting that heating is more important than topography in forcing the summer stationary waves in the subtropics. It is also found that Newtonian cooling has a significant effect on the structure of the thermally forced stationary waves. C1 NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO 80303 USA. RP Chen, P (reprint author), NOAA, CIRES, Climate Diagnost Ctr, Mail Code R-CDCI,325 Broadway, Boulder, CO 80303 USA. NR 13 TC 8 Z9 13 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 12 BP 1585 EP 1594 DI 10.1175/1520-0469(2001)058<1585:TFSWIA>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 433HB UT WOS:000168753200008 ER PT J AU Koracin, D Lewis, J Thompson, WT Dorman, CE Businger, JA AF Koracin, D Lewis, J Thompson, WT Dorman, CE Businger, JA TI Transition of stratus into fog along the California coast: Observations and modeling SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID TURBULENCE CLOSURE-MODEL; MARINE BOUNDARY-LAYER; NUMERICAL SIMULATIONS; MIXED-LAYER; STRATOCUMULUS; ENTRAINMENT; RADIATION; CLOUDS; AIR AB A case of fog formation along the California coast is examined with the aid of a one-dimensional, higher-order, turbulence-closure model in conjunction with a set of myriad observations. The event is characterized by persistent along-coast winds in the marine layer, and this pattern justifies a Lagrangian approach to the study. A slab of marine layer air is tracked from the waters near the California-Oregon border to the California bight over a 2-day period. Observations indicate that the marine layer is covered by stratus cloud and comes under the influence of large-scale subsidence and progressively increasing sea surface temperature along the southbound trajectory. It is hypothesized that cloud-top cooling and large-scale subsidence are paramount to the fog formation process. The one-dimensional model, evaluated with various observations along the Lagrangian path, is used to test the hypothesis. The principal findings of the study are 1) fog forms in response to relatively long preconditioning of the marine layer, 2) radiative cooling at the cloud top is the primary mechanism for cooling and mixing the cloud-topped marine layer, and 3) subsidence acts to strengthen the inversion above the cloud top and forces lowering of the cloud. Although the positive fluxes of sensible and latent heat at the air-sea interface are the factors that govern the onset of fog, sensitivity studies with the one-dimensional model indicate that these sensible and latent heat fluxes are of secondary importance as compared to subsidence and cloud-top cooling. Sensitivity tests also suggest that there is an optimal inversion strength favorable to fog formation and that the moisture conditions above the inversion influence fog evolution. C1 Desert Res Inst, Reno, NV 89512 USA. Natl Severe Storms Lab, Norman, OK 73069 USA. USN, Res Lab, Monterey, CA USA. San Diego State Univ, San Diego, CA 92182 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Univ Washington, Seattle, WA 98195 USA. RP Koracin, D (reprint author), Desert Res Inst, 2215 Raggio Pkwy, Reno, NV 89512 USA. NR 41 TC 52 Z9 61 U1 0 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 13 BP 1714 EP 1731 DI 10.1175/1520-0469(2001)058<1714:TOSIFA>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 450UK UT WOS:000169762400006 ER PT J AU Chen, P Hoerling, MP Dole, RM AF Chen, P Hoerling, MP Dole, RM TI The origin of the subtropical anticyclones SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID STATIONARY WAVES; CIRCULATION; REANALYSIS AB The origin of the Northern Hemisphere summer subtropical anticyclones is investigated using a linear quasigeostrophic model. It is found that the broad features in the model solutions forced by realistic heating fields acting on observed zonal flows agree well with those in the observations. The realistic features of the model solutions include the subtropical continental lows and oceanic highs in the lower troposphere, and continental ridges and midoceanic troughs in the upper troposphere. The forced responses are largest near the surface and the tropopause with a vertical node around 500 hPa as observed. The results indicate that the model stationary waves owe their existence largely to the Asian heat source. The authors thus propose that the observed low-level subtropical anticyclones over the North Pacific and North Atlantic Oceans be interpreted as a remote response of Rossby waves forced by the large-scale heat sources over Asia. The results support the existing theory that the observed low-level cyclones and upper-level anti-cyclones over Asia and North America are a local response to monsoonal latent heat release in the midtroposphere. The sensitivity of model solutions to the basic state is discussed, emphasizing the effects of the meridional and vertical shear of the zonal flow on the structure of the stationary waves. C1 NOAA, CIRES Climate Diagnost Ctr, Boulder, CO 80303 USA. RP Chen, P (reprint author), NOAA, CIRES Climate Diagnost Ctr, Mail Code R-CDC1,325 Broadway, Boulder, CO 80303 USA. NR 14 TC 58 Z9 63 U1 2 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 13 BP 1827 EP 1835 DI 10.1175/1520-0469(2001)058<1827:TOOTSA>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 450UK UT WOS:000169762400013 ER PT J AU Willoughby, HE Jones, RW AF Willoughby, HE Jones, RW TI Nonlinear motion of a barotropic vortex in still air and in an environmental zonal flow SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID TROPICAL-CYCLONE MOTION; BETA-DRIFT; MEAN FLOW; MODEL; PROPAGATION; EVOLUTION; VORTICES AB This study employs a Vortex Tracking Semispectral (VTSS) model cast in cylindrical coordinates that move with the vortex. Variables are represented spectrally in azimuth only, so that the model becomes a set of linear equations for each azimuthal wavenumber component, forced by the environmental flow and coupled by wave-wave interactions that account for all of the nonlinearity. The vortex is advected by the surrounding wind and propagates when potential vorticity (PV) gradients due to the surrounding flow or the beta effect force wavenumber one (WN1) asymmetries. Nonlinearity generally plays a dissipative role. Although propagation is faster in stronger PV gradients, nonlinear interactions cause the motions due to superposed PV gradients to be slower than the sum of their individual motions. In still air or uniform wind on a b plane, the wave energy spectrum falls off rapidly with wavenumber. For most situations, the calculations converge for truncation at WN6 on a 4000-km domain. In an anticyclonically sheared environmental zonal flow, the spectrum of asymmetric energy narrows because the WN2 asymmetry is forced directly by the environmental deformation. The deformation-induced asymmetry interferes destructively with WN2 due to internal wave-wave interaction. In a cyclonically sheared zonal flow, the deformation-induced and nonlinearly induced asymmetries interfere constructively, resulting in a broader spectrum. Energy cascades from WN2 to wavenumbers greater than or equal to2. A reverse cascade also carries energy to WN1, changing the beta gyres and the motion. Consequent perturbation of WN1 leads to slow convergence of the predicted vortex position after 10 simulated days with increasing spectral resolution. When imposed mass sources and sinks are used to supply energy directly to the asymmetries in the middle of the spectrum, similar wave-wave interactions force WN1, leading to a trochoidal vortex track. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. RP NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, 4301 Rickenbacker Cswy, Miami, FL 33149 USA. EM Hugh.Willoughby@noaa.gov NR 23 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 14 BP 1907 EP 1923 DI 10.1175/1520-0469(2001)058<1907:NMOABV>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 450UL UT WOS:000169762500005 ER PT J AU Ooyama, KV AF Ooyama, KV TI A dynamic and thermodynamic foundation for modeling the moist atmosphere with parameterized microphysics SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID POTENTIAL TEMPERATURE; NUMERICAL-SIMULATION; BOUNDARY-CONDITIONS; RESOLUTION; EXTENSION; WIND AB Moist convection is an exquisite yet powerful participant in the creation of weather on our planet. To facilitate numerical modeling of weather systems in a moist atmosphere, a direct and consistent application of dynamic and thermodynamic principles, in conjunction with parameterized microphysics, is proposed. An earlier formulation of reversible thermodynamics, in terms of the mass of air and water substance and the total entropy, is now extended to include the irreversible process of precipitation through parameterized microphysics. The dynamic equations are also formulated to account consistently for the mass and momentum of precipitation. The theoretical proposal is tested with a two-dimensional model that utilizes a versatile and accurate spectral method based on a cubic-spline representation of the spatial fields. In order to allow a wide range of scale interactions, the model is configured on multiply nested domains of outwardly decreasing resolution, with noise-free, two-way interfaces. The semi-implicit method provides efficient time integration for the nested spectral model. The tests performed are the simulation of the growth of single-cell clouds and also the generation of self-sustaining multicell squall lines, and the effects of various resolutions on the simulations are examined. The results favorably compare with similar results found in the literature, but also offer new insights into the interplay between dynamics and precipitation. C1 NOAA, Hurricane Res Div, AOML, Miami, FL 33149 USA. RP Ooyama, KV (reprint author), NOAA, Hurricane Res Div, AOML, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. NR 42 TC 43 Z9 47 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 15 BP 2073 EP 2102 DI 10.1175/1520-0469(2001)058<2073:ADATFF>2.0.CO;2 PG 30 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 454ZU UT WOS:000170002300004 ER PT J AU Schafer, R May, PT Keenan, TD McGuffie, K Ecklund, WL Johnston, PE Gage, KS AF Schafer, R May, PT Keenan, TD McGuffie, K Ecklund, WL Johnston, PE Gage, KS TI Boundary layer development over a tropical island during the maritime continent thunderstorm experiment SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SEA-BREEZE FRONT; WIND-PROFILER; CONVECTION; MCTEX AB Data collected during the Maritime Continent Thunderstorm Experiment (MCTEX) (10 November-10 December 1995) have been used to analyze boundary layer development and circulations over two almost flat, tropical islands. The two adjacent islands have a combined length of about 170 km from east to west and 70 km from north to south. Intense thunderstorms formed over these islands every day of the field campaign. The boundary layer depth, temperature, and circulation over the island have been measured over the full diurnal cycle using a multiple radar analysis combined with surface and radiosonde measurements. On average, the island boundary layer depth reaches 1.5 km by early to midafternoon coinciding with the development of the deep convection. Thus, the island boundary layer is significantly deeper than the typical tropical oceanic boundary layer. In the midafternoon, thunderstorm outflows and their associated cold pool stabilize the lower boundary layer, suppressing late convection. This is followed by a period of partial boundary layer recovery for 1-2 h. After sunset, cooling leads to a deepening ground-based inversion below a residual mixed layer. Near the island center, the residual mixed layer of island-modified air is replaced by air of oceanic origin by about 2300 LST (local standard time) that then persists until sunrise the next day. The advection of boundary layer air of oceanic origin over the islands every evening resets the boundary layer development cycle. It is shown that much of the variation in the diurnal temperature profile is a result of thunderstorm activity, radiative processes, and the advection of island and oceanic boundary layer air. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Bur Meteorol, Res Ctr, Melbourne, Vic, Australia. Univ Technol Sydney, Dept Appl Phys, Sydney, NSW, Australia. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Schafer, R (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, CIRES Bldg,Rm 318, Boulder, CO 80309 USA. RI Johnston, Paul/E-1914-2016 OI Johnston, Paul/0000-0002-4046-9351 NR 27 TC 17 Z9 18 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 15 BP 2163 EP 2179 DI 10.1175/1520-0469(2001)058<2163:BLDOAT>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 454ZU UT WOS:000170002300009 ER PT J AU Reasor, PD Montgomery, MT AF Reasor, PD Montgomery, MT TI Three-dimensional alignment and corotation of weak, TC-like vortices via linear vortex Rossby waves SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID VERTICAL-SHEAR; BAROTROPIC VORTICES; GEOSTROPHIC VORTEX; SHALLOW-WATER; INNER-CORE; EVOLUTION; DYNAMICS; MODEL; AXISYMMETRIZATION; STABILITY AB The vertical alignment of an initially tilted geostrophic vortex is shown here to be captured by linear vortex Rossby wave dynamics when the vortex cores at upper and lower levels overlap. The vortex beta Rossby number, defined as the ratio of nonlinear advection in the potential vorticity equation to linear radial advection, is less than unity in this case. A useful means of characterizing a tilted vortex flow in this parameter regime is through a wave-mean flow decomposition. From this perspective the alignment mechanism is elucidated using a quasigeostrophic model in both its complete and linear equivalent barotropic forms. Attention is focused on basic-state vortices with continuous and monotonically decreasing potential vorticity profiles. For internal Rossby deformation radii larger than the horizontal scale of the tilted vortex an azimuthal wavenumber 1 quasi mode exists. The quasi mode is characterized by its steady cyclonic propagation, long lifetime, and resistance to differential rotation, behaving much like a discrete vortex Rossby wave. The quasi mode traps disturbance energy causing the vortex to precess, or corotate, and thus prevents alignment. For internal deformation radii smaller than the horizontal vortex scale, the quasi mode disappears into the continuous spectrum of vortex Rossby waves. Alignment then proceeds through the irreversible redistribution of potential vorticity by the sheared vortex Rossby waves. Further decreases in the internal deformation radius result in a decreased dependence of vortex evolution on initial tilt magnitude, consistent with a reduction of the vortex beta Rossby number. These results are believed to have relevance to the problem of tropical cyclone (TC) genesis. Cyclogenesis initiated through the merger and alignment of low-level convectively generated positive potential vorticity within a weak incipient vortex is captured by quasi-linear dynamics. A potential dynamical barrier to TC development in which the quasi mode frustrates vertical alignment can be identified using the linear alignment theory in this case. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RP NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. EM reasor@aoml.noaa.gov RI Reasor, Paul/B-2932-2014 OI Reasor, Paul/0000-0001-6407-017X NR 50 TC 61 Z9 62 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 16 BP 2306 EP 2330 DI 10.1175/1520-0469(2001)058<2306:TDAACO>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 465XM UT WOS:000170615300003 ER PT J AU Thomas, SJ Browning, GL AF Thomas, SJ Browning, GL TI The accuracy and efficiency of semi-implicit time stepping for mesoscale storm dynamics SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID DIFFERENTIAL-EQUATIONS; FORECAST MODEL; SYSTEMS; SCALES AB The semi-implicit time-stepping scheme is often applied to the terms responsible for fast waves in large-scale global weather prediction and general circulation models to remove the time step restrictions associated with these waves. Both the phase and amplitude of fast gravity waves are distorted in such models. Because gravity waves carry very little energy, this distortion does not significantly impact the large-scale flow. At mesoscale resolutions the semi-implicit scheme can also be applied, but it has been generally assumed that the treatment of gravity waves is inaccurate at these scales as well. In this paper mesoscale convective systems in the midlatitudes driven by diabatic heating are studied. According to a recently developed mathematical theory, only gravity waves with wavelengths larger than the characteristic length scale of the heat source contain a significant amount of energy, and here it is shown that these gravity waves are accurately reproduced by a semiimplicit discretization of the 3D compressible governing equations with a time step appropriate for the dominant solution component. It will also be shown that the structure equation reduces to the gravity wave equation of the mathematical theory when the appropriate scaling arguments are applied. C1 Natl Ctr Atmospher Res, Div Comp Sci, Boulder, CO 80307 USA. NOAA, Forecast Syst Lab, Boulder, CO USA. RP Thomas, SJ (reprint author), Natl Ctr Atmospher Res, Div Comp Sci, 1850 Table Mesa Dr, Boulder, CO 80307 USA. NR 24 TC 3 Z9 3 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 20 BP 3053 EP 3063 DI 10.1175/1520-0469(2001)058<3053:TAAEOS>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 478LF UT WOS:000171347100006 ER PT J AU Schubert, WH Hausman, SA Garcia, M Ooyama, KV Kuo, HC AF Schubert, WH Hausman, SA Garcia, M Ooyama, KV Kuo, HC TI Potential vorticity in a moist atmosphere SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GENERATION; EVOLUTION; CYCLONES; VORTEX AB The potential vorticity principle for a nonhydrostatic, moist, precipitating atmosphere is derived. An appropriate generalization of the well-known (dry) Ertel potential vorticity is found to be P=rho (-1)(2 Ohm + del x u).del theta (rho), where rho is the total density, consisting of the sum of the densities of dry air, airborne moisture (vapor and cloud condensate), and precipitation; u is the velocity of the dry air and airborne moisture; and theta (rho) = T rho (p(0)/p)(R a/C Pa) is the virtual potential temperature, with T-rho = p/(rhoR(a)) the virtual temperature, p the total pressure (the sum of the partial pressures of dry air and water vapor), p(0) the constant reference pressure, R-a the gas constant for dry air, and c(Pa) the specific heat at constant pressure for dry air. Since theta (rho) is a function of total density and total pressure only, its use as the thermodynamic variable in P leads to the annihilation of the solenoidal term, that is, del theta (rho).(del rho x delp)=0. In the special case of an absolutely dry atmosphere, P reduces to the usual (dry) Ertel potential vorticity. For balanced flows, there exists an invertibility principle that determines the balanced mass and wind fields from the spatial distribution of P. It is the existence of this invertibility principle that makes P such a fundamentally important dynamical variable. In other words, P (in conjunction with the boundary conditions associated with the invertibility principle) carries all the essential dynamical information about the slowly evolving balanced part of the flow. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL USA. Natl Taiwan Univ, Dept Atmospher Sci, Taipei, Taiwan. RP Schubert, WH (reprint author), Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RI Garcia, Matthew/K-9286-2013 OI Garcia, Matthew/0000-0002-9637-4204 NR 18 TC 36 Z9 41 U1 1 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 21 BP 3148 EP 3157 DI 10.1175/1520-0469(2001)058<3148:PVIAMA>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 489QC UT WOS:000172002000005 ER PT J AU Nolan, DS Montgomery, MT Grasso, LD AF Nolan, DS Montgomery, MT Grasso, LD TI The wavenumber-one instability and trochoidal motion of hurricane-like vortices SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID TROPICAL CYCLONE MOTION; BAROTROPIC VORTICES; VORTEX MOTION; BACKGROUND SHEAR; OUTFLOW-LAYER; DOPPLER RADAR; ANDREW 1992; BALANCE; EVOLUTION; MODEL AB In a previous paper, the authors discussed the dynamics of an instability that occurs in inviscid, axisymmetric, two-dimensional vortices possessing a low-vorticity core surrounded by a high-vorticity annulus. Hurricanes, with their low-vorticity cores (the eye of the storm), are naturally occurring examples of such vortices. The instability is for asymmetric perturbations of azimuthal wavenumber-one about the vortex, and grows in amplitude as t(1/2) for long times, despite the fact that there can be no exponentially growing wavenumber-one instabilities in inviscid, two-dimensional vortices. This instability is further studied in three fluid flow models: with high-resolution numerical simulations of two-dimensional flow, for linearized perturbations in an equivalent shallow-water vortex, and in a three-dimensional, baroclinic, hurricane-like vortex simulated with a high-resolution mesoscale numerical model. The instability is found to be robust in all of these physical models. Interestingly, the algebraic instability becomes an exponential instability in the shallow-water vortex, though the structures of the algebraic and exponential modes are nearly identical. In the three-dimensional baroclinic vortex, the instability quickly leads to substantial inner-core vorticity redistribution and mixing. The instability is associated with a displacement of the vortex center (as defined by either minimum pressure or streamfunction) that rotates around the vortex core, and thus offers a physical mechanism for the persistent, small-amplitude trochoidal wobble often observed in hurricane tracks. The instability also indicates that inner-core vorticity mixing will always occur in such vortices, even when the more familiar higher-wavenumber barotropic instabilities are not supported. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA. RP Nolan, DS (reprint author), NOAA, GFDL, POB 308, Princeton, NJ 08542 USA. NR 73 TC 56 Z9 56 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 21 BP 3243 EP 3270 DI 10.1175/1520-0469(2001)058<3243:TWOIAT>2.0.CO;2 PG 28 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 489QC UT WOS:000172002000010 ER PT J AU Hamilton, K Wilson, RJ Hemler, RS AF Hamilton, K Wilson, RJ Hemler, RS TI Spontaneous stratospheric QBO-like oscillations simulated by the GFDL SKYHI general circulation model SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID QUASI-BIENNIAL OSCILLATION; MEAN FLOW INTERACTION; MIDDLE ATMOSPHERE; GRAVITY-WAVES; HORIZONTAL RESOLUTION; WIND; GCM; CYCLE AB The tropical stratospheric mean flow behavior in a series of integrations with high vertical resolution versions of the Geophysical Fluid Dynamics Laboratory (GFDL) "SKYHI'' model is examined. At sufficiently high vertical and horizontal model resolution, the simulated stratospheric zonal winds exhibit a strong equatorially centered oscillation with downward propagation of the wind reversals and with formation of strong vertical shear layers. This appears to be a spontaneous internally generated oscillation and closely resembles the observed quasi-biennial oscillation (QBO) in many respects, although the simulated oscillation has a period less than half that of the real QBO. The same basic mean flow oscillation appears in both seasonally varying and perpetual equinox versions of the model, and most of the analysis in this paper is focused on the perpetual equinox cases. The mean flow oscillation is shown to be largely driven by eddy momentum fluxes associated with a broad spectrum of vertically propagating waves generated spontaneously in the tropical troposphere of the model. Several experiments are performed with the model parameters perturbed in various ways. The period of the simulated tropical stratospheric mean flow oscillation is found to change in response to large alterations in the sea surface temperatures (SSTs) employed. This is a fairly direct demonstration of the link between the stratospheric mean flow behavior and tropical convection that is inherent in current theories of the QBO. It is also shown in another series of experiments that the oscillation is affected by the coefficients used for the subgrid-scale diffusion parameterization. These experiments demonstrate that at least one key reason why reasonably fine horizontal resolution is needed for the model to simulate a mean flow oscillation is the smaller horizontal diffusion that can be used at high resolution. C1 Univ Hawaii Manoa, Dept Meteorol, Honolulu, HI 96822 USA. Univ Hawaii Manoa, Int Pacific Res Ctr, Honolulu, HI 96822 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA. RP Hamilton, K (reprint author), Univ Hawaii Manoa, Dept Meteorol, Honolulu, HI 96822 USA. NR 43 TC 31 Z9 31 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 21 BP 3271 EP 3292 DI 10.1175/1520-0469(2001)058<3271:SSQLOS>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 489QC UT WOS:000172002000011 ER PT J AU Mo, K Bell, GD Thiaw, WM AF Mo, K Bell, GD Thiaw, WM TI Impact of sea surface temperature anomalies on the Atlantic tropical storm activity and West African rainfall SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SEASONAL HURRICANE FREQUENCY; SAHELIAN MONSOON RAINFALL; NINO SOUTHERN-OSCILLATION; EL-NINO; EASTERLY WAVES; NORTH-AFRICA; LANDFALLING HURRICANES; CLIMATE ASSESSMENT; STRONG ASSOCIATION; SUMMER RAINFALL AB The association between rainfall over the Sahel and Sudan region and tropical storm activity in the Atlantic is examined using the NCEP-NCAR reanalysis and sea surface temperature anomalies (SSTAs) from 1949 to 1998. Evidence indicates that both are influenced by global SSTAs. The SSTA modes generating favorable atmospheric conditions for tropical storms to develop are also in favor of a wet rainfall season in the Sahel and Sudan region. The easterly waves over West Africa become tropical storms only if the atmospheric conditions over the Atlantic are favorable. These conditions are responses to SSTAs. In addition to ENSO, a multidecadal trend mode also plays a role. The positive phase of the trend mode features positive loadings in the North Pacific and the North Atlantic, and negative loadings over the three southern oceans. The positive (negative) phases of both modes are associated with increased (reduced) Atlantic tropical storm activity, and with wet (dry) West African monsoon seasons. The SSTAs over the tropical South Atlantic (S-ATL) are related to the rainfall dipole over West Africa, but the influence on tropical storms is not large. Warm (cold) SSTAs over the tropical North Atlantic enhance (suppress) the occurrence of tropical storms, but have little influence on rainfall over West Africa. The most prominent circulation features associated with the positive phases of SSTA modes are enhanced upper-level 200-hPa easterly winds and reduced vertical wind shear in the main development region of the tropical Atlantic, which are well-known features of active Atlantic tropical storm seasons. The associated low-level flow shows enhanced anomalous westerly winds across the Atlantic to Africa. That allows more moisture transport into Africa and, therefore, more rainfall. C1 NOAA, Climate Predict Ctr, NCEP, NWS, Camp Springs, MD 20746 USA. RP Mo, K (reprint author), NOAA, Climate Predict Ctr, NCEP, NWS, Rm 605,5200 Auth Rd, Camp Springs, MD 20746 USA. EM kingste.mo@noaa.gov NR 54 TC 25 Z9 25 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2001 VL 58 IS 22 BP 3477 EP 3496 DI 10.1175/1520-0469(2001)058<3477:IOSSTA>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 488FC UT WOS:000171924700008 ER PT J AU Ledbetter, H Kim, S Dunn, M Xu, Z Crudele, S Kriven, W AF Ledbetter, H Kim, S Dunn, M Xu, Z Crudele, S Kriven, W TI Elastic constants of mullite containing alumina platelets SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT Mullite 2000 CY AUG 28-30, 2000 CL OBAN, SCOTLAND DE composites; elastic constants; internal friction; mullite; platelets ID SPECTROSCOPY; COMPOSITES AB Using dynamic methods, we measured the elastic constants of a composite comprising alumina platelets (0.2 volume fraction) in a 3:2 mullite matrix. Instead of the expected elastic stiffening, we found an elastic softening. For example, the Young modulus was 222 GPa, below mullite's value of 228 GPa, and far below the value predicted by a solid-mechanics model assuming good alumina mullite interfaces: 256 GPa. As possible softening sources, we considered voids, cracks., poor particle-matrix-interface bonding, and an enveloping third phase, either around the platelets or around the mullite particles. We concluded that the mullite particles must be enveloped by silica, an elastically soft phase. Solid-mechanics modeling considering a three-phase composite supports our conjecture. Our conjecture received further confirmation from careful SEM and STEM observations. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Boulder, CO USA. Univ Colorado, Dept Mech Engn, Boulder, CO 80309 USA. Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. RP Ledbetter, H (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO USA. OI DUNN, MARTIN/0000-0002-4531-9176; XU, Zhengkui/0000-0002-7465-8513 NR 18 TC 7 Z9 7 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 2001 VL 21 IS 14 BP 2569 EP 2576 DI 10.1016/S0955-2219(01)00269-2 PG 8 WC Materials Science, Ceramics SC Materials Science GA 472RD UT WOS:000170998000015 ER PT J AU Bendersky, LA Krajewski, JJ Cava, RJ AF Bendersky, LA Krajewski, JJ Cava, RJ TI Dielectric properties and microstructure of Ca5Nb2TiO12 and Ca5Ta2TiO12 SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT Meeting of the Microwave Materials and their Applications 2000 CY AUG 30-SEP 02, 2000 CL BLED, SLOVENIA DE Ca5Nb2TiO12; Ca5Ta2TiO1; dielectric properties; electron microscopy; functional applications; sintering ID PEROVSKITE; CERAMICS; TEMPERATURES; DIFFRACTION AB The 1 MHz dielectric properties of Ca5Nb2TiO12 and Ca5Ta2TiO12 compounds were reported recently. Both compounds have a common characteristic dependence of the temperature coefficient of dielectric constant (TCK) and dielectric constant (epsilon (r)) on sintering temperature. For both compounds a TCK < 5 ppm/deg can be achieved by selecting the right processing conditions. It was suggested that an order-disorder transition among the B-site ions in these perovskite-based compounds plays a major role in the determination of TCK. Since X-ray powder diffraction does not appear to be a good technique to detect the structural changes, transmission electron microscopy (TEM) was applied in this work. It was found that different types of ordering between (111) planes, namely 1:1, 1:2 and 1:3, as well as distortions by tilting of octahedra, are involved in the formation of a microstructural state at an ambient temperature. The compounds in the as-sintered conditions both have a microdomain structure but with a different type of ordering, 1:3 for Ca5Nb2TiO12 and 1:2 for Ca5Ta2TiO12. Both compounds have a tilting phase transition from the disordered Pm<(3)over bar>m to distorted Pnma (with the a(-)b(+)a(-) tilt of octahedra) structures at temperatures that coincide with the observed kinks at T-A1 and T-A2 in the TCK(T-s) and K(T-s) curves. (C) 2001 Published by Elsevier Science Ltd. All rights reserved. C1 NIST, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07574 USA. Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. Princeton Univ, Mat Inst, Princeton, NJ 08544 USA. RP Bendersky, LA (reprint author), NIST, Mat Sci & Engn Lab, 100 Bur Dr,Stop 8554, Gaithersburg, MD 20899 USA. NR 15 TC 19 Z9 19 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 2001 VL 21 IS 15 BP 2653 EP 2658 DI 10.1016/S0955-2219(01)00332-6 PG 6 WC Materials Science, Ceramics SC Materials Science GA 494ZU UT WOS:000172316400013 ER PT J AU Krupka, J Gregory, AP Rochard, OC Clarke, RN Riddle, B Baker-Jarvis, J AF Krupka, J Gregory, AP Rochard, OC Clarke, RN Riddle, B Baker-Jarvis, J TI Uncertainty of complex permittivity measurements by split-post dielectric resonator technique SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT International Conference on Microwave Materials and their Applications (MMA 2000) CY AUG 30-SEP 02, 2000 CL BLED, SLOVENIA DE complex permittivity; permittivity measurements; split-post dielectric resonators; standard reference materials ID CRYSTALS AB Split-post dielectric resonators operating at frequencies 1.4-5.5 GHz were used to measure complex permittivity of single crystal standard reference dielectric materials with well known dielectric properties previously measured by other techniques. Detailed error analysis of permittivity and dielectric loss tangent measurements has been performed. It was proved both theoretically and experimentally that using split post resonators it is possible to measure permittivity with uncertainty about 0.3% and dielectric loss tangent with resolution 2 x 10(-5) for well-machined laminar specimens. (C), 2001 Elsevier Science Ltd. All rights reserved. C1 Politech Warszaw, Inst Mikroelektroniki & Optoelektroniki, PL-00662 Warsaw, Poland. Natl Phys Lab, Ctr Electromagnet Metrol, Teddington TW11 0LW, Middx, England. Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Politech Warszaw, Inst Mikroelektroniki & Optoelektroniki, Koszykowa 75, PL-00662 Warsaw, Poland. EM j.krupka@imio.pw.edu.pl NR 13 TC 78 Z9 79 U1 1 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 EI 1873-619X J9 J EUR CERAM SOC JI J. Eur. Ceram. Soc. PY 2001 VL 21 IS 15 BP 2673 EP 2676 DI 10.1016/S0955-2219(01)00343-0 PG 4 WC Materials Science, Ceramics SC Materials Science GA 494ZU UT WOS:000172316400017 ER PT J AU Hryniewicz, P Szeri, AZ Jahanmir, S AF Hryniewicz, P Szeri, AZ Jahanmir, S TI Application of lubrication theory to fluid flow in grinding: Part I - Flow between smooth surfaces SO JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID ZONE AB The present paper, which consists of two parts, proposes models of fluid flow in grinding with nonporous wheels. In this first part, a smooth wheel is employed instead of a rough grinding wheel to simplify the analysis. Fluid flow is investigated for laminar and turbulent regimes using the classical Reynolds equation of lubrication and a modified Reynolds equation for turbulent flows, respectively. The applicability of the proposed models is discussed and verified experimentally in terms of the developed hydrodynamic pressure. It is found that the classical Reynolds equation reliably predicts the hydrodynamic pressure if the Reynolds number Re (based on the minimum gay size) is lower than about 300. Experimental results for 300 < Re < 1500 agree with the proposed turbulent flow model. This suggests that the flow in this range of Re is turbulent, and that the fluid inertia is negligible. The influence of wheel roughness is investigated in Part II. C1 Univ Delaware, Dept Mech Engn, Newark, DE 19716 USA. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. RP Hryniewicz, P (reprint author), Univ Delaware, Dept Mech Engn, Newark, DE 19716 USA. NR 31 TC 14 Z9 15 U1 1 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4787 J9 J TRIBOL-T ASME JI J. Tribol.-Trans. ASME PD JAN PY 2001 VL 123 IS 1 BP 94 EP 100 DI 10.1115/1.1331277 PG 7 WC Engineering, Mechanical SC Engineering GA 395UR UT WOS:000166600100013 ER PT J AU Hryniewicz, P Szeri, AZ Jahanmir, S AF Hryniewicz, P Szeri, AZ Jahanmir, S TI Application of lubrication theory to fluid flow in grinding: Part II - Influence of wheel and workpiece roughness SO JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID TOPOGRAPHY AB The objective of this study is to model fluid flow in grinding with nonporous wheels. While Part I focused on the flow in a simplified smooth geometry, in this part the wheel surface roughness is introduced. The applicability of the modified Reynolds equation for laminar flow's between rough surfaces is verified experimentally in terms of the developed hydrodynamic pressure, using a resin-bonded diamond grinding wheel. The experiments were performed under the spark-out condition (i.e., with the wheel just touching the workpiece) and in actual grinding. Agreement between theory and experiment is shown Sol Re<100, but a significant discrepancy (most likely due to turbulence is observed for 300 5d(9)6s(2) D-2(5/2) (F = 2, m(F) = 0) electric-quadrupole transition of a single laser-cooled Hg-199(+) ion stored in a cryogenic radio-frequency ion trap. We observed Fourier-transform limited linewidths as narrow as 6.7 Hz at 282 nm (1.06 x 10(15) Hz). The functional form and estimated values of some of the frequency shifts of the S-2(1/2) <----> D-2(5/2) "clock" transition (including the quadrupole shift), which have been calculated using a combination of measured atomic parameters and ab initio calculations, are given. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Bergquist, JC (reprint author), Natl Inst Stand & Technol, 325 Broadway,MS 847, Boulder, CO 80305 USA. NR 20 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3947-9 J9 P SOC PHOTO-OPT INS PY 2001 VL 4269 BP 1 EP 7 DI 10.1117/12.424455 PG 7 WC Optics; Physics, Applied SC Optics; Physics GA BS41H UT WOS:000169777100001 ER PT S AU Yoon, TH Marian, A Hall, JL Ye, J AF Yoon, TH Marian, A Hall, JL Ye, J BE Hall, JL Ye, J TI High-resolution Rb two-photon spectroscopy with ultrafast lasers SO LASER FREQUENCY STABILIZATION, STANDARDS, MEASUREMENT AND APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Frequency Stabilization, Standards, Measurement, and Applications CY JAN 24-26, 2001 CL SAN JOSE, CA SP SPIE DE femtosecond comb; two-photon spectroscopy; quantum interference; frequency stabilization of fs laser ID MODE-LOCKED LASER; FREQUENCY-MEASUREMENT; 2-PHOTON TRANSITION; ABSOLUTE FREQUENCY; FEMTOSECOND LASER; PHASE-CONTROL; SODIUM VAPOR; ABSORPTION; SPECTRUM; RB-87 AB A two-photon transition in cold Rb atoms will be probed with a phase-coherent wide-bandwidth femtosecond laser comb. Frequency domain analysis yields a high resolution picture where phase coherence among various transition pathways through different intermediate states produces interference effects on the resonantly-enhanced transition probability. This result is supported by the time domain Ramsey interference effect. The two-photon transition spectrum is analyzed in terms of the pulse repetition rate and carrier frequency offset, leading to a cold-atom-based frequency stabilization scheme for both degrees of freedom of the femtosecond laser. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RP Ye, J (reprint author), Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 21 TC 0 Z9 0 U1 1 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3947-9 J9 P SOC PHOTO-OPT INS PY 2001 VL 4269 BP 50 EP 58 DI 10.1117/12.424486 PG 9 WC Optics; Physics, Applied SC Optics; Physics GA BS41H UT WOS:000169777100007 ER PT S AU Diddams, SA Udem, T Vogel, KR Oates, CW Curtis, EA Windeler, RS Bartels, A Bergquist, JC Hollberg, L AF Diddams, SA Udem, T Vogel, KR Oates, CW Curtis, EA Windeler, RS Bartels, A Bergquist, JC Hollberg, L BE Hall, JL Ye, J TI A compact femtosecond-laser-based optical clockwork SO LASER FREQUENCY STABILIZATION, STANDARDS, MEASUREMENT AND APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Frequency Stabilization, Standards, Measurement, and Applications CY JAN 24-26, 2001 CL SAN JOSE, CA SP SPIE DE optical frequency metrology; femtosecond lasers; frequency standards ID MODE-LOCKED LASERS; FREQUENCY-MEASUREMENT; SPECTROSCOPY; TRANSITION; FIBERS; NM; MICROWAVE; COMB AB We describe in detail an optical clockwork based on a 1 GHz repetition rate femtosecond laser and silica microstructure optical fiber, This system has recently been used for the absolute frequency measurements of the Ca and Hg+ optical standards at the National Institute of Standards and Technology (NIST). The simplicity of the system makes it an ideal clockwork for dividing down high optical frequencies to the radio frequency domain where they can readily be counted and compared to the existing cesium frequency standard. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Diddams, SA (reprint author), Natl Inst Stand & Technol, 325 Broadway,MS 847, Boulder, CO 80305 USA. RI Diddams, Scott/L-2819-2013 NR 23 TC 19 Z9 19 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3947-9 J9 P SOC PHOTO-OPT INS PY 2001 VL 4269 BP 77 EP 83 DI 10.1117/12.424456 PG 7 WC Optics; Physics, Applied SC Optics; Physics GA BS41H UT WOS:000169777100010 ER PT S AU Shelton, RK Ma, LS Kapteyn, HC Murnane, MM Hall, JL Ye, J AF Shelton, RK Ma, LS Kapteyn, HC Murnane, MM Hall, JL Ye, J BE Hall, JL Ye, J TI Synchronization and phase lock of two mode-locked femtosecond lasers SO LASER FREQUENCY STABILIZATION, STANDARDS, MEASUREMENT AND APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Frequency Stabilization, Standards, Measurement, and Applications CY JAN 24-26, 2001 CL SAN JOSE, CA SP SPIE ID TI-SAPPHIRE LASER; SCATTERING; PULSES AB Two independent mode-locked femtosecond lasers are synchronized to an unprecedented precision. The rms timing jitter between the lasers is 4.3 fs observed within a 160 Hz bandwidth over tens of seconds, or 26 fs within a 50 kHz bandwidth. Novel multi-stage phase locked loops help to preserve this ultrahigh timing resolution throughout the entire delay range between pulses (10 ns). We also demonstrate that the same level of synchronization can be achieved with two lasers at different repetition frequencies. Under such synchronization, phase lock between the carrier frequencies of the two fs lasers has been achieved. C1 Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. RP Shelton, RK (reprint author), Natl Inst Stand & Technol, JILA, 325 Broadway, Boulder, CO 80309 USA. RI Kapteyn, Henry/H-6559-2011 OI Kapteyn, Henry/0000-0001-8386-6317 NR 15 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3947-9 J9 P SOC PHOTO-OPT INS PY 2001 VL 4269 BP 105 EP 111 DI 10.1117/12.424459 PG 7 WC Optics; Physics, Applied SC Optics; Physics GA BS41H UT WOS:000169777100013 ER PT S AU Walls, FL AF Walls, FL BE Hall, JL Ye, J TI Phase noise issues in femtosecond lasers SO LASER FREQUENCY STABILIZATION, STANDARDS, MEASUREMENT AND APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Frequency Stabilization, Standards, Measurement, and Applications CY JAN 24-26, 2001 CL SAN JOSE, CA SP SPIE DE PM noise; FM noise; AM noise; frequency stability; timing jitter; phase jitter; frequency multiplication AB This paper explores the affect of phase modulation (PM), amplitude modulation (AM), and thermal noise on the rf spectrum, phase jitter, timing jitter, and frequency stability of femtosecond lasers and other precision sources. Using these concepts we can suggest how some noise aspects of femtosecond pulsed lasers should scale. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Walls, FL (reprint author), Total Frequency, 4120 Evans Dr, Boulder, CO 80303 USA. NR 10 TC 5 Z9 5 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3947-9 J9 P SOC PHOTO-OPT INS PY 2001 VL 4269 BP 170 EP 177 DI 10.1117/12.424466 PG 8 WC Optics; Physics, Applied SC Optics; Physics GA BS41H UT WOS:000169777100019 ER PT S AU Gilbert, SL Swann, WC Dennis, T AF Gilbert, SL Swann, WC Dennis, T BE Hall, JL Ye, J TI Wavelength standards for optical communications SO LASER FREQUENCY STABILIZATION, STANDARDS, MEASUREMENT AND APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Frequency Stabilization, Standards, Measurement, and Applications CY JAN 24-26, 2001 CL SAN JOSE, CA SP SPIE DE atomic spectroscopy; molecular spectroscopy; optical fiber communications; pressure shift; Standard Reference Material; wavelength calibration; wavelength division multiplexing; wavelength standards; WDM ID CALIBRATION LINES; FREQUENCY; NM; ACETYLENE; LASER AB We review wavelength accuracy and calibration issues for wavelength division multiplexed (WDM) optical fiber communication and describe our work on wavelength calibration references. We have developed wavelength references for National institute of Standards and Technology (NIST) internal calibration and transfer standards to help industry calibrate their instrumentation. The transfer standards are:NIST Standard Reference Materials that utilize the absorption lines of acetylene and hydrogen cyanide in the 1500 nm region. Two higher accuracy references for NIST internal use are based on laser stabilization to absorption lines of rubidium (at 1560 nm) and methane (at 1314 nm). We are developing calibration references for the WDM L-band (similar to 1565-1625 nm) and are investigating references for the 1300-1400 nm region. C1 NIST, Boulder, CO 80305 USA. RP Gilbert, SL (reprint author), NIST, M-S 815 03,325 Broadway, Boulder, CO 80305 USA. NR 15 TC 8 Z9 8 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3947-9 J9 P SOC PHOTO-OPT INS PY 2001 VL 4269 BP 184 EP 191 DI 10.1117/12.424468 PG 8 WC Optics; Physics, Applied SC Optics; Physics GA BS41H UT WOS:000169777100021 ER PT S AU Stone, JA Stejskal, A Howard, L AF Stone, JA Stejskal, A Howard, L BE Albertazzi, AJ TI Sources of error in absolute distance interferometry SO LASER METROLOGY FOR PRECISION MEASUREMENT AND INSPECTION IN INDUSTRY SE Proceedings of SPIE LA English DT Proceedings Paper CT International Symposium on Laser Metrology for Precision Measurement and Inspection in Industry CY OCT 13-15, 1999 CL FLORIANOPOLIS, BRAZIL SP Mercedes Benz Brazil, Siemens, Embraco, Minist Dev, Ind & Trade, INMETRO, Minist Sci & Technol, CNPq, FINEP, Minist Educ DE absolute distance interferometry; diode laser; laser interferometry; wavelength sweeping ID WAVELENGTH AB In this paper we describe the status of our research on the use of diode lasers for absolute distance interferometry, and we discuss the major sources of uncertainty that limit the accuracy of this technique for distance measurement. We have primarily employed a 670 nm external cavity diode laser as the tunable source for our interferometer, but currently we are developing a system based on an 850 nm distributed Bragg reflector laser. These two lasers have very different strengths and weaknesses; the primary sources of uncertainty in length measurement depend on which laser is employed. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Stone, JA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4127-9 J9 PROC SPIE PY 2001 VL 4420 BP 1 EP 9 DI 10.1117/12.439197 PG 9 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA BT41P UT WOS:000172924300001 ER PT S AU Callicoatt, BE Schlager, JB Silverman, KL Hickernell, RK Mirin, RP Sanford, NA Hayden, JS Conzone, S Simpson, R AF Callicoatt, BE Schlager, JB Silverman, KL Hickernell, RK Mirin, RP Sanford, NA Hayden, JS Conzone, S Simpson, R GP IEEE IEEE TI Single-frequency and mode-locked Er/Yb co-doped waveguide lasers SO LEOS 2001: 14TH ANNUAL MEETING OF THE IEEE LASERS & ELECTRO-OPTICS SOCIETY, VOLS 1 AND 2, PROCEEDINGS SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 14th Annual Meeting of the IEEE Lasers-and-Electro-Optics-Society CY NOV 11-15, 2001 CL SAN DIEGO, CA SP IEEE, IEE Lasers and Electro Opt Soc C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Callicoatt, BE (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80305 USA. OI Mirin, Richard/0000-0002-4472-4655 NR 7 TC 0 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8081 BN 0-7803-7105-4 J9 IEEE LEOS ANN MTG PY 2001 BP 576 EP 577 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Condensed Matter SC Engineering; Optics; Physics GA BU32T UT WOS:000175700800289 ER PT S AU Cundiff, ST Ye, J Hall, JL AF Cundiff, ST Ye, J Hall, JL GP IEEE IEEE TI Time meets frequency: Phase stabilization of ultrafast pulses and optical frequency metrology with modelocked lasers SO LEOS 2001: 14TH ANNUAL MEETING OF THE IEEE LASERS & ELECTRO-OPTICS SOCIETY, VOLS 1 AND 2, PROCEEDINGS SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 14th Annual Meeting of the IEEE Lasers-and-Electro-Optics-Society CY NOV 11-15, 2001 CL SAN DIEGO, CA SP IEEE, IEE Lasers and Electro Opt Soc C1 Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. RP Cundiff, ST (reprint author), Natl Inst Stand & Technol, JILA, 325 Broadway, Boulder, CO 80309 USA. RI Cundiff, Steven/B-4974-2009 OI Cundiff, Steven/0000-0002-7119-5197 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8081 BN 0-7803-7105-4 J9 IEEE LEOS ANN MTG PY 2001 BP 903 EP 903 PG 1 WC Engineering, Electrical & Electronic; Optics; Physics, Condensed Matter SC Engineering; Optics; Physics GA BU32T UT WOS:000175700800451 ER PT J AU Yin, L Ives, LK Jahanmir, S Rekow, ED Romberg, E AF Yin, L Ives, LK Jahanmir, S Rekow, ED Romberg, E TI Abrasive machining of glass-infiltrated alumina with diamond burs SO MACHINING SCIENCE AND TECHNOLOGY LA English DT Article DE glass-infiltrated alumina; dental ceramics; abrasive machining; diamond burs; dental handpiece; chipping damage; surface integrity ID FRACTURE-TOUGHNESS; CUTTING EFFICIENCY; FLEXURAL STRENGTH; DENTAL CERAMICS; DAMAGE; MICROSTRUCTURE; HANDPIECE; CROWNS AB The abrasive machining characteristics of a glass-infiltrated alumina used for fabrication of all-ceramic dental crowns were investigated using a high-speed dental handpiece and diamond burs with different grit sizes. The material removal rate, surface roughness, and extent of edge chipping were measured as a function of grit size. The removal rate decreased substantially with decreasing bur grit size from supercoarse (180 mum) to fine (40 mum) and ultrafine (10 I-lm) The removal rate with the supercoarse burs was approximately twice that achieved with the fine burs and four times the removal rate with the ultrafine burs. Both surface roughness and edge chipping damage were sensitive to diamond grit size. Chipping damage was severe and the surface roughness substantial with the supercoarse burs, while negligible edge chipping and smooth surfaces were obtained with the ultrafine burs. The removal rate also decreased with continued machining for all grit sizes. The observed reduction in removal rate was found to be primarily due to wear of the diamond grit and accumulation of debris on the bur (i.e., bur loading). After prolonged use, a significant loss of diamond grit was observed that led to a substantial loss of cutting efficiency. It is concluded that, with respect to material removal rate and surface integrity, diamond machining is a feasible machining process for glass-infiltrated alumina in the final infiltrated state. However, caution should be exercised in the use of diamond grit larger than 40 mum. Such burs may result in excessively rough surfaces, chipped edges, and strength limiting surface and subsurface microcracks. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Med & Dent New Jersey, Newark, NJ 07103 USA. Univ Maryland, Baltimore, MD 21201 USA. RP Yin, L (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 23 TC 37 Z9 37 U1 0 U2 2 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1091-0344 J9 MACH SCI TECHNOL JI Mach. Sci. Technol. PY 2001 VL 5 IS 1 BP 43 EP 61 DI 10.1081/MST-100103177 PG 19 WC Engineering, Manufacturing; Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 453PX UT WOS:000169926000003 ER PT J AU Medicus, KM Davies, MA Dutterer, BS Evans, CJ Fielder, RS AF Medicus, KM Davies, MA Dutterer, BS Evans, CJ Fielder, RS TI Tool wear and surface finish in high speed milling of aluminum bronze SO MACHINING SCIENCE AND TECHNOLOGY LA English DT Article AB Aluminum bronze C95800 is used extensively for the manufacture of propellers because of its mechanical strength and corrosion resistance. Typically these components are machined from large castings and then hand ground and polished. In this work, we demonstrate the possibility of using high speed machining with tungsten carbide tooling to significantly reduce machining times and minimize or eliminate hand polishing/grinding. Tool wear rates for the high speed machining of aluminum bronze are assessed using three metrics: mean force, flank wear depth, and surface finish. Workpiece surface finish and tool flank wear depth are assessed using a new replica block technique. Wear rates in carbide tools remained low over a wide range of surface speeds such that material removal rates in aluminum bronze were increased more than tenfold over current machining practices. Our findings support the idea that high speed machining to produce fine surface finishes through ball end milling with very closely spaced tool paths will be cost effective. C1 NIST, Gaithersburg, MD 20899 USA. USN, Ctr Surface Warfare, Carderock, MD USA. RP Medicus, KM (reprint author), NIST, 100 Bur Dr,Stop 3460, Gaithersburg, MD 20899 USA. NR 20 TC 6 Z9 7 U1 0 U2 3 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1091-0344 J9 MACH SCI TECHNOL JI Mach. Sci. Technol. PY 2001 VL 5 IS 2 BP 255 EP 268 DI 10.1081/MST-100107846 PG 14 WC Engineering, Manufacturing; Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 494RE UT WOS:000172299000007 ER PT J AU Heide-Jorgensen, MP Lockyer, C AF Heide-Jorgensen, MP Lockyer, C TI Age and sex distributions in the catches of belugas, Delphinapterus leucas, in West Greenland and in western Russia SO MAMMALIAN BIOLOGY LA English DT Article DE Delphinapterus leucas; age structure; Greenland; Russian Arctic ID REPRODUCTION; POPULATION; GROWTH AB Age and sex were determined for belugas or white whales, Delphinapterus leucas, harvested in West Greenland in 1985-86 and 1989-1997. There was a clear segregation of whales in the drive fishery conducted during autumn in Qaanaaq and Upernavik. Primarily immature whales of both sexes together with mature females were taken. Age was estimated from Growth Layer Groups (GLGs) in sectioned teeth, assuming the currently accepted criteria of 2 GLGs forming annually. The mean and median ages were increasing slightly in both sexes from Upernavik from 1985 through 1994. Both immature and mature whales were taken on the wintering grounds from Disko Bay and south. Estimation of survival was confounded by the large number of whales where only a minimum age could be assigned because of tooth wear at the crown (i. e. no neonatal Line in the dentine). The apparent survival rates for belugas from West Greenland were estimated as 0.81 and 0.79 for females and males, respectively. Correction of these estimates for an observed population decline of 4.7% per year revealed true survival rates of 0.85 and 0.82 for females and males, respectively. The estimates of true survival rates are less than those determined for beluga populations in the White and Kara seas and in Alaska for comparable age truncations. Since the exploitation levels are much Lower in these areas the low apparent survival rate from West Greenland strongly supports the evidence of a population decline. Colour change from grey to white occurs at mean ages of 8.5 yr and 9.1 yr and median lengths of 367 cm and 445 cm in females and males, respectively. C1 Greenland Inst Nat Resoures, Nauk, Greenland. Danish Inst Fisheries Res, Charlottenlund, Denmark. RP Heide-Jorgensen, MP (reprint author), Natl Marine Mammal Lab, 7600 Sant Point Way NE, Seattle, WA 98115 USA. NR 15 TC 5 Z9 6 U1 1 U2 11 PU URBAN & FISCHER VERLAG PI JENA PA BRANCH OFFICE JENA, P O BOX 100537, D-07705 JENA, GERMANY SN 1616-5047 J9 MAMM BIOL JI Mamm. Biol. PY 2001 VL 66 IS 4 BP 215 EP 227 PG 13 WC Zoology SC Zoology GA 464MT UT WOS:000170536900003 ER PT J AU Yeung, C Jones, DL Criales, MM Jackson, TL Richards, WJ AF Yeung, C Jones, DL Criales, MM Jackson, TL Richards, WJ TI Influence of coastal eddies and counter-currents on the influx of spiny lobster, Panulirus argus, postlarvae into Florida Bay SO MARINE AND FRESHWATER RESEARCH LA English DT Article; Proceedings Paper CT 6th International Conference and Workshop on Lobster Biology and Management CY SEP 10-15, 2000 CL KEY WEST, FLORIDA SP Darden Environm Trust, Fl Sea Grant Program, Nat Conservancy, Fl Keys Natl Marine Sanctuary, Natl Marine Fisheries Serv, Florida Fish & Wildlife Conservat Commiss, VA Inst Marine Sci, Old Dominion Univ, Florida State Univ ID WESTERN ROCK LOBSTER; SEASONAL VARIABILITY; LARVAL RECRUITMENT; SOUTHERN STRAITS; LEEUWIN CURRENT; CORAL-REEFS; KEYS; TRANSPORT; CONNECTIVITY; TEMPERATURE AB Postlarvae of the spiny lobster Panulirus argus migrate from offshore in the Florida Keys into their juvenile habitat in Florida Bay through interisland channels. The influx of postlarvae was monitored monthly over the new-moon period at Long Key and Whale Harbor channels (July 1997 June 1999). Although the channels were only 30 km apart, their influx patterns differed. At Long Key, influx peaked every 2 3 months, whereas at Whale Harbor the peaks were in winter and of higher magnitudes. The influx pattern at Long Key was highly correlated with the strength of coastal counter-current flow in the two-week period prior to sampling. Countercurrent flow was correlated with alongshore (upstream) wind stress, but the latter was not a significant predictor of postlarval influx. Coastal counter-current flow is hypothesized to indicate the presence of a cyclonic, mesoscale eddy offshore. Satellite imagery confirmed the presence of these eddies offshore of the Middle Florida Keys often when positive postlarval influx and counter-current anomalies were observed. These eddies can facilitate onshore larval transport, and their variable temporal and spatial properties can cause transport variability over a scale of several tens of kilometres along the Keys. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Cooperat Inst Marine & Atmospher Studies, Miami, FL 33149 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Marine Biol & Fisheries, Miami, FL 33149 USA. NOAA Fisheries, SE Fisheries Ctr, Miami, FL 33149 USA. RP Yeung, C (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Cooperat Inst Marine & Atmospher Studies, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. NR 43 TC 24 Z9 25 U1 0 U2 2 PU C S I R O PUBLISHING PI COLLINGWOOD PA 150 OXFORD ST, PO BOX 1139, COLLINGWOOD, VICTORIA 3066, AUSTRALIA SN 1323-1650 J9 MAR FRESHWATER RES JI Mar. Freshw. Res. PY 2001 VL 52 IS 8 BP 1217 EP 1232 DI 10.1071/MF01110 PG 16 WC Fisheries; Limnology; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 516RT UT WOS:000173571100020 ER PT J AU Castro, KM Cobb, JS Wahle, RA Catena, J AF Castro, KM Cobb, JS Wahle, RA Catena, J TI Habitat addition and stock enhancement for American lobsters, Homarus americanus SO MARINE AND FRESHWATER RESEARCH LA English DT Article; Proceedings Paper CT 6th International Conference and Workshop on Lobster Biology and Management CY SEP 10-15, 2000 CL KEY WEST, FLORIDA SP Darden Environm Trust, Fl Sea Grant Program, Nat Conservancy, Fl Keys Natl Marine Sanctuary, Natl Marine Fisheries Serv, Florida Fish & Wildlife Conservat Commiss, VA Inst Marine Sci, Old Dominion Univ, Florida State Univ DE artificial reef; production; attraction ID RECRUITMENT PROCESSES; JUVENILE LOBSTER; POPULATIONS; POSTLARVAL; CRUSTACEA; BEHAVIOR; REEFS; LIFE AB Six experimental artificial reefs for lobsters were established in Narragansett Bay, Rhode Island, in February 1997. These have been monitored according to a before-after-control-impact design since placement by means of visual surveys, traps, tag-recapture, photoquadrats, and airlift sampling. Juvenile and adult lobster density at the reef increased from near zero to >1 lobster m(-2), significantly higher than the two control areas. Settlement of young-of-year lobsters has significantly increased. We used microwire tags to mark hatchery-reared lobsters and released over 2000 marked 5th-6th-stage lobsters in each of two years. The density of young-of-year lobsters on enhanced reefs was not different from that on the control reefs. Despite intensive sampling, we have recovered only one of the hatchery-reared animals. Field observations indicate possible behaviour differences in the hatchery-reared lobsters that might make them more susceptible to predation. C1 Univ Rhode Isl, Kingston, RI 02881 USA. Bigelow Lab Ocean Sci, Boothbay Harbor, ME 04575 USA. Natl Marine Fisheries Serv, Restorat Ctr, Gloucester, MA 01930 USA. RP Castro, KM (reprint author), Univ Rhode Isl, Kingston, RI 02881 USA. NR 38 TC 28 Z9 28 U1 0 U2 7 PU C S I R O PUBLISHING PI COLLINGWOOD PA 150 OXFORD ST, PO BOX 1139, COLLINGWOOD, VICTORIA 3066, AUSTRALIA SN 1323-1650 J9 MAR FRESHWATER RES JI Mar. Freshw. Res. PY 2001 VL 52 IS 8 BP 1253 EP 1261 DI 10.1071/MF01095 PG 9 WC Fisheries; Limnology; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 516RT UT WOS:000173571100023 ER PT J AU Buonaccorsi, VP Starkey, E Graves, JE AF Buonaccorsi, VP Starkey, E Graves, JE TI Mitochondrial and nuclear DNA analysis of population subdivision among young-of-the-year Spanish mackerel (Scomberomorus maculatus) from the western Atlantic and Gulf of Mexico SO MARINE BIOLOGY LA English DT Article ID GENETIC-DIVERGENCE; RESTRICTION DATA; UNITED-STATES; DIFFERENTIATION; PATTERNS; MARKERS; SAMPLES; BIGHT; BASS; KING AB The degree of population subdivision among collections of young-of-the-year (YOY) Spanish mackerel Scomberomorus maculatus sampled from along the Atlantic coast of the United States (Atlantic) and Gulf of Mexico (Gulf) was examined. Young-of-thr-year were collected from spawning areas to minimize possible mixing among putative spawning stocks that may occur at later life history stages along migratory pathways or at over-wintering grounds. Restriction fragment length polymorphism (RFLP) analysis of the mitochondrial DNA (mtDNA) ND4 region and a nuclear actin intron was conducted. Collections in each of two years were analyzed to minimize bias associated with sampling at a single point in space or time. Substantial variation was detected at ND4 (haplotype diversity = 0.81) and at the actin intron locus (gene diversity = 0.31). Significant differences in gene diversity or allele frequencies were not detected among temporal samples at any of three locations. A homogeneous distribution of genetic variance among samples from widely spaced geographic regions was consistent with the hypothesis that Spanish mackerel comprise a single intermingling genetic stock. Power analysis showed that the mitochondrial analysis from this study was much more likely to detect population subdivision than analysis of the nuclear actin locus, despite lower mtDNA sample size. C1 Virginia Inst Marine Sci, Coll William & Mary, Sch Marine Sci, Gloucester Point, VA 23062 USA. RP Buonaccorsi, VP (reprint author), SW Fisheries Sci Ctr, 8604 La Jolla Shores Dr, La Jolla, CA 92037 USA. NR 52 TC 25 Z9 27 U1 0 U2 5 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD JAN PY 2001 VL 138 IS 1 BP 37 EP 45 DI 10.1007/s002270000439 PG 9 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 398CT UT WOS:000166738900004 ER PT J AU Chute, AS Turner, JT AF Chute, AS Turner, JT TI Plankton studies in Buzzards Bay, Massachusetts, USA. V. Ichthyoplankton, 1987 to 1993 SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE ichthyoplankton; composition; abundance; Buzzards Bay ID LOWER CHESAPEAKE BAY; NEARSHORE ICHTHYOPLANKTON; NORTH-ATLANTIC; ABUNDANCE; ESTUARY; WESTERN; ANCHOVY AB Monthly sampling for ichthyoplankton was conducted at 8 stations in Buzzards Bay, Massachusetts, from October 1987 to September 1993 using a 48 cm diameter plankton net with 0.102 mm mesh. From October 1992 to September 1993, an additional 75 cm diameter net with 0.202 mm mesh was also towed to compare mesh selectivity. Stations included two with heavy anthropogenic impact, the urbanized inner harbor of New Bedford, Massachusetts, and over New Bedford's offshore sewage outfall, as well as other nearshore shallow and offshore deep stations in comparatively pristine areas of the bay. Fish larvae from 32 genera were identified. Fish eggs were counted but not identified. There was a pronounced summer peak in larval abundance dominated by cunner Tautogolabrus adspersus, anchovy Anchoa sp. and tautog Tautoga onitis. A smaller winter/early spring peak was dominated by sand lance Ammodytes sp. This pattern was evident for all 6 years of the study. The assemblage of fish larvae found in Buzzards Bay differed from that in Cape Cod Bay, lending support to the concept of Cape Cod as a faunal boundary. The 2 differently sized nets used during the last year of the study did not catch significantly different numbers of fish larvae per ml, but length frequency distributions of 4 abundant species of larvae revealed that the smaller mesh net caught significantly smaller Anchoa sp. The larger mesh net collected significantly more species of fish larvae. A comparison of annual mean catches of 4 species did not reveal significant changes in abundance over 6 yr. C1 Univ Massachusetts, Dept Biol, N Dartmouth, MA 02747 USA. NE Fisheries Sci Ctr, Natl Marine Fisheries Serv, Natl Ocean & Atmospher Adm, Woods Hole, MA 02543 USA. RP Turner, JT (reprint author), Univ Massachusetts, Dept Biol, 285 Old Westport Rd, N Dartmouth, MA 02747 USA. EM jturner@umassd.edu NR 38 TC 11 Z9 12 U1 1 U2 3 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 224 BP 45 EP 54 PG 10 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 518TL UT WOS:000173683900004 ER PT J AU Natunewicz, CC Epifanio, CE Garvine, RW AF Natunewicz, CC Epifanio, CE Garvine, RW TI Transport of crab larval patches in the coastal ocean SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE Delaware Bay; Callinectes sapidus; drifters; zoeae; transport; patches ID CALLINECTES-SAPIDUS RATHBUN; DELAWARE BAY; BLUE-CRAB; INNER-SHELF; DRIFT; RECRUITMENT; SURVIVAL; DYNAMICS; BUOYANCY; ESTUARY AB We assessed the role of wind and buoyancy forcing on the transport of newly hatched blue crab larvae Callinectes sapidus near the mouth of Delaware Bay, USA, Eight patches of larvae were tagged with satellite-tracked drifters and followed for periods of 1 to 11 d. We conducted daily plankton tows within a 3.2 km(2) area circumscribing each drifter. This allowed us to verify that each drifter remained within a patch, Trajectories of the patches were assessed in relation to physical data (salinity, temperature, winds, and river discharge) and compared to trajectories predicted by a 2-dimensional mathematical model. Analysis of CTD data indicated that 3 patches were-initially tagged in the coastal plume emanating from Delaware Bay, while 5 patches were initially tagged in shelf water adjacent to the plume. Patches occurring in plume waters traveled farther down-shelf (southward) than those in adjacent shelf waters. Winds modified this along-shelf transport. Specifically, upwelling-favorable (northward) winds mixed larvae offshore and out of the coastal plume. Downwelling-favorable (southward) winds drove patches of larvae across the continental shelf and toward the coast. Trajectories were simulated well by the mathematical model. As river discharge diminished in the late summer, the effect of winds (relative to buoyancy forcing) on larval transport increased. This shift in the dominant forcing mechanism was demonstrated both by the trajectories of the tagged larval patches and by predictions from the mathematical model. C1 NOAA, NMFS, Beaufort, NC 28516 USA. Univ Delaware, Grad Coll Marine Studies, Lewes, DE 19958 USA. Univ Delaware, Grad Coll Marine Studies, Newark, DE 19706 USA. RP Natunewicz, CC (reprint author), NOAA, NMFS, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. EM cecily.natunewicz@noaa.gov RI Steppe, Cecily/K-3388-2012 OI Steppe, Cecily/0000-0002-5448-3533 NR 23 TC 27 Z9 27 U1 0 U2 3 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 222 BP 143 EP 154 DI 10.3354/meps222143 PG 12 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 498NA UT WOS:000172516300012 ER PT J AU Pan, YL Parsons, ML Busman, M Moeller, PDR Dortch, Q Powell, CL Doucette, GJ AF Pan, YL Parsons, ML Busman, M Moeller, PDR Dortch, Q Powell, CL Doucette, GJ TI Pseudo-nitzschia sp cf. pseudodelicatissima - a confirmed producer of domoic acid from the northern Gulf of Mexico SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE Pseudo nitzschia; domoic acid; harmful algal blooms; receptor-binding assay; Gulf of Mexico ID ACHNANTHES-LONGIPES BACILLARIOPHYTA; SEXUAL-BEHAVIOR; SHELLFISH; MULTISERIES; PUNGENS; CULTURE; LIMITATION; CALIFORNIA; MORTALITY; CANADA AB Domoic acid (DA), a potent neurotoxin, is synthesized by certain members of the ubiquitous marine diatom genus Pseudo-nitzschia. We recently detected elevated concentrations of DA in phytoplankton field samples from the northern Gulf of Mexico. In searching for a possible source of the toxin, we used a receptor-binding assay to detect DA activity in cultures of R sp, cf. pseudodelicatissima (Hasle) isolated from this region and confirmed its presence in 2 of 7 clones using liquid chromatography coupled with tandem mass-spectrometric detection (LC-MS/MS). Unlike other toxic Pseudo-nitzschia species examined previously (e,g., P. multiseries, P. australis), cellular levels and net production of DA in these clones were highest in the early exponential phase, while the population growth rate was high and cell concentration was low. There was a negative correlation between cellular DA and cell concentration. The maximum cellular DA activity in cultures was 36 fg DA equiv. cell(-1). No net toxin production was evident in the stationary phase,. yet extracellular DA levels increased markedly during this period to as much as 88% of the total DA in the cultures. Interestingly, these 2 toxic clones were able to enlarge their cell size after the apical axes declined to 15 to 25 mum, and these larger cells had considerably higher levels of DA than the original small cells. This study unequivocally establishes P. sp. cf. pseudodelicatissima as a source of DA in the northern Gulf of Mexico. Moreover, our work suggests that rapidly growing, rather than nutrient-limited, populations of this diatom should yield maximum net DA production rates and DA cell quotas. Thus, the presence of P. sp, cf. pseudodelicatissima cells, even at the low levels of early, rapidly growing bloom stages, can potentially lead to toxic events. C1 NOAA, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Marine Biotoxins Program, Charleston, SC 29412 USA. Med Univ S Carolina, Charleston, SC 29412 USA. Louisiana Univ Marine Consortium, Chauvin, LA 70344 USA. RP Doucette, GJ (reprint author), NOAA, Natl Ocean Serv, Ctr Coastal Environm Hlth & Biomol Res, Marine Biotoxins Program, 219 Fort Johnson Rd, Charleston, SC 29412 USA. EM greg.doucette@noaa.gov RI Doucette, Gregory/M-3283-2013 NR 38 TC 64 Z9 65 U1 2 U2 9 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 220 BP 83 EP 92 DI 10.3354/meps220083 PG 10 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 489HV UT WOS:000171986700008 ER PT J AU De Robertis, A Eiane, K Rau, GH AF De Robertis, A Eiane, K Rau, GH TI Eat and run: anoxic feeding and subsequent aerobic recovery by Orchomene obtusus in Saanich Inlet, British Columbia, Canada SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE Orchomene obtusus; amphipoda; anoxia; benthic-pelagic coupling; vertical migration; C-13; N-15 ID EUPHAUSIA-PACIFICA; AMPHIPODS; MARINE; CARBON; ZOOPLANKTON; NITROGEN; HYPOXIA; FRACTIONATION; CONSUMPTION; PATTERNS AB The lysianassid amphipod Orchomene obtusus (Sars) is known as an epibenthic scavenger, but it is abundant in the water column of Saanich Inlet, British Columbia, a temperate fjord with poorly oxygenated deep water, Sampling with vertically-stratified nets and baited traps indicates that O. obtusus is abundant within the oxycline at 100 to 140 m, is present in anoxic deep waters at low abundances, and is also abundant in the anoxic benthic environment. Shipboard incubations revealed that O. obtusus can survive between 10 and 33 h of anoxia at in situ conditions. Stable isotope and gut fluorescence measurements suggest that these amphipods feed on material produced in surface waters, and not on the isotopically dissimilar suspended detrital material present in the vicinity of the oxycline. The amphipods do not enter surface waters, and it appears that O. obtusus has adapted to oxygen gradients in this environment by feeding on surf ace-water-derived material in the food-rich and predator-poor anoxic benthos and subsequently migrating into the water column to conduct aerobic respiration, These vertical excursions are probably a modification of the swimming behavior exhibited by hyperbenthic amphipods in well-oxygenated environments, and may constitute an important mechanism for benthic-pelagic coupling. C1 Scripps Inst Oceanog, La Jolla, CA 92037 USA. Univ Courses Svalbard, N-9171 Longyearbyen, Norway. Univ Calif Santa Cruz, Inst Marine Sci, Santa Cruz, CA 95064 USA. RP De Robertis, A (reprint author), Oregon State Univ, Hatfield Marine Sci Ctr, NWFSC, NMFS, 2030 S Marine Sci Dr, Newport, OR 97365 USA. EM aderobertis@ucsd.edu RI Eiane, Ketil/G-5510-2010; Eiane, Ketil/B-2073-2012 NR 38 TC 19 Z9 19 U1 0 U2 13 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 219 BP 221 EP 227 DI 10.3354/meps219221 PG 7 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 480AY UT WOS:000171439300018 ER PT J AU Spear, LB Ballance, LT Ainley, DG AF Spear, LB Ballance, LT Ainley, DG TI Response of seabirds to thermal boundaries in the tropical Pacific: the thermocline versus the Equatorial Front SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE seabird; planktivore; piscivore; equatorial front; thermocline; tropical pacific; southern oscillation ID TUNA THUNNUS-ALBACARES; BERING SEA; EL-NINO; MARINE BIRDS; ECOLOGY; ISLANDS; OCEAN; DISTRIBUTIONS; PRODUCTIVITY; VARIABILITY AB Our 10 yr study is the first to associate seabirds with oceanic boundaries, or fronts, in tropical oceans. It addresses the semi-permanent Equatorial Front, hereafter 'front', a vertical boundary lying between the South Equatorial Current (SEC) and North Equatorial Countercurrent (NECC) in the eastern tropical Pacific (ETP). We also consider the subsurface, horizontal thermal boundary created by the thermocline, Our study area included the front and the north and south boundaries of the SEC and NECC respectively, between 100 and 145 degreesW. Our data were based on 45 north-south crossings of this area. The intensity of the front differed with season and phase of the El Nino Southern Oscillation (ENSO). Densities of planktivorous seabirds, higher at the front than in the SEC or NECC, increased with front intensity (i.e., during autumn/La Nina). Densities of piscivorous seabirds were unaffected by the front, but were related to depth and intensity of the thermocline, Piscivore densities were highest in the NECC, and higher during spring than autumn. Furthermore, they were higher in the western part of the study area, i.e., when and where the thermocline was deepest and most stratified, We suggest that the difference in patterns observed for the tropical planktivorous versus piscivorous seabirds reflects processes that affect the distribution and availability of their respective prey. Zooplankton are concentrated in the surface layer by physical processes that structure the front. Prey fish, on the other hand, are made available by foraging tuna, which drive them to the ocean surface. As a result, the distribution of the piscivorous seabirds is closely tied to that of schooling surface-feeding tunas, that are most abundant in the NECC. Other studies have shown that tunas spend most of their time near the thermocline. We suggest that this, along with the patterns observed among the piscivorous seabirds, indicate that the tuna's prey aggregate near the thermocline. Specifically, most tropical squid and small fishes perform vertical movements to the surface at night. A deeper thermocline, such as that of the NECC, is likely to be attractive to these animals for hiding during the day (when the tuna and birds forage) because of the lack of light at depth, and because of the enriched O-2 content of the cold-water layer lying immediately below the warmer surface layer. Hence, by searching on a horizontal plane near the boundary created by a deep, well stratified thermal structure, schooling tuna, and thus piscivorous seabirds, are likely to find concentrations of prey more readily than equally abundant prey dispersed throughout a less stratified water column. C1 HT Harvey & Associates, San Jose, CA 95118 USA. NOAA, Natl Marine Fisheries Serv, Ecol Program, SW Fisheries Sci Ctr, La Jolla, CA 92037 USA. RP HT Harvey & Associates, 3150 Almaden Expressway,Suite 145, San Jose, CA 95118 USA. EM spearlarry@yahoo.com NR 63 TC 64 Z9 69 U1 1 U2 14 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 EI 1616-1599 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 219 BP 275 EP 289 DI 10.3354/meps219275 PG 15 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 480AY UT WOS:000171439300023 ER PT J AU Rooker, JR Secor, DH Zdanowicz, VS Itoh, T AF Rooker, JR Secor, DH Zdanowicz, VS Itoh, T TI Discrimination of northern bluefin tuna from nursery areas in the Pacific Ocean using otolith chemistry SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE otolith chemistry; Pacific bluefin tuna; North Pacific Ocean ID EAST-CHINA-SEA; SHAD ALOSA-SAPIDISSIMA; FISH OTOLITHS; STRONTIUM; MICROCHEMISTRY; TEMPERATURE; SEDIMENTS; ELEMENTS; CALCIUM; STOCKS AB Otolith chemistry of juvenile Pacific bluefin tuna Thunnus orientalis was measured to assess differences in composition among 3 nursery areas in the North Pacific Ocean: East China Sea, Sea of Japan and the Pacific Ocean off Shikoku. Six elements (Li, Mg, Ca, Mn, Sr and Ba) were measured in whole otoliths using solution-based inductively coupled plasma mass spectrometry, Univariate contrasts of T. orientalis otoliths collected in 1994 and 1995 indicated that concentrations of 5 elements (Li, Mg, Ca, Mn, Sr) differed among nurseries. Concentrations of Ca and Sr were significantly higher in the Pacific Ocean than in either marginal sea (East China Sea or Sea of Japan) nursery, while concentrations of Li, Mg and Mn were higher in fishes inhabiting marginal seas. Discriminant analysis showed clear separation of elemental fingerprints between Pacific Ocean and marginal sea nurseries, and to a lesser degree separation between the 2 marginal sea groups, Temporal stability of the elemental fingerprint was examined over a 3 yr period (1995 to 1997) in the East China Sea, Significant interannual trends were observed for 3 elements (Mg, Mn and Ba); however, elemental fingerprints of T orientalis from the Pacific Ocean nursery were markedly different from all year classes in the East China Sea. C1 Texas A&M Univ, Dept Marine Biol, Galveston, TX 77551 USA. Univ Maryland, Chesapeake Biol Lab, Ctr Environm Sci, Solomons, MD 20688 USA. Natl Marine Fisheries Serv, Natl Ocean & Atmospher Adm, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. Natl Res Inst Far Seas Fisheries, Shimizu, Shizuoka 424, Japan. RP Rooker, JR (reprint author), Texas A&M Univ, Dept Marine Biol, 5007 Ave U, Galveston, TX 77551 USA. EM rookerj@tamug.tamu.edu RI Secor, D/D-4367-2012; Rooker, Jay/M-3197-2013 OI Secor, D/0000-0001-6007-4827; Rooker, Jay/0000-0002-5934-7688 NR 41 TC 74 Z9 78 U1 1 U2 11 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 EI 1616-1599 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 218 BP 275 EP 282 DI 10.3354/meps218275 PG 8 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 474XN UT WOS:000171132300023 ER PT J AU Benoit-Bird, KJ Au, WWL Brainard, RE Lammers, MO AF Benoit-Bird, KJ Au, WWL Brainard, RE Lammers, MO TI Diel horizontal migration of the Hawaiian mesopelagic boundary community observed acoustically SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE mesopelagic boundary community; diel horizontal migration; diel vertical migration; acoustic sampling; Hawaiian Islands AB The mesopelagic boundary community off the leeward coasts of 2 Hawaiian Islands, Oahu and Hawaii, was investigated with an echosounder modified to read directly into a laptop computer, Acoustic sampling was conducted over a total distance of 12.6 km off the Waianae coast of Oahu and 46.3 km off the Kona coast of Hawaii. The density of organisms was determined using echo energy integration, and relative abundance was determined in a way analogous to catch-per-unit-effort, The vertical range of mesopelagic organisms expanded as the mesopelagic layer rose and then compressed as it descended. The vertical range of the layer off the Kona coast was larger than that off the Waianae coast, possibly because of the greater bottom depth off Kona. Near midnight, the boundary community 3 km from the shoreline was split into 2 distinct layers, one beginning approximately 25 m from the surface and one beginning approximately 90 m from the surface. The density and the relative abundance of mesopelagic organisms were consistently higher off the Waianae coast than the Kona coast. However, the density of organisms observed in both locations was high, reaching a maximum of 1800 organisms m(-3) off Waianae and 700 organisms m(-3) off Kona. The maximum relative abundance off Waianae neared 100%, while off Kona it never exceeded 70%. In both locations, organisms were found within 1 km of shore, in waters much shallower than their assumed daytime habitat. The temporal patterns of relative abundance and density of organisms in waters closest to the shores of each island resembled a bell curve, with a peak in relative abundance and density around midnight. In waters further from shore, the temporal patterns in relative abundance and density had a bimodal distribution, with peaks around both 21:00 and 03:00 h. These patterns in relative abundance and density are significantly affected by the distance of the sampling location from the shoreline, but not by the depth of the sampling site. The data suggest that the organisms of the mesopelagic boundary community undergo a diel horizontal migration that is reciprocal, 1.8 km in 2 h toward shore and then the same distance in approximately the same amount of time away from shore, in addition to their well-established vertical migration. The temporal patterns of the horizontal component of the migration are predictable and are conserved between days, phases of the moon, seasons, and islands. C1 Univ Hawaii, Hawaii Inst Marine Biol, Kailua, HI 96734 USA. Univ Hawaii, Dept Zool, Kailua, HI 96734 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. RP Benoit-Bird, KJ (reprint author), Univ Hawaii, Hawaii Inst Marine Biol, POB 1106, Kailua, HI 96734 USA. EM benoit@hawaii.edu NR 44 TC 43 Z9 44 U1 1 U2 15 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 217 BP 1 EP 14 DI 10.3354/meps217001 PG 14 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 469AL UT WOS:000170790300001 ER PT J AU Sogard, SM Olla, BL AF Sogard, SM Olla, BL TI Growth and behavioral responses to elevated temperatures by juvenile sablefish Anoplopoma fimbria and the interactive role of food availability SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE growth efficiency; temperature selection; ration; activity ID VERTICAL-DISTRIBUTION; SALVELINUS-ALPINUS; THERMAL-GRADIENT; BODY-COMPOSITION; RAINBOW-TROUT; LIFE-HISTORY; ARCTIC CHARR; RATION SIZE; MARINE FISH; ENERGY AB Larval and age-0 sablefish Anoplopoma fimbria reside in neustonic waters of the North Pacific during spring and summer. We estimated the potential impacts of elevated surface temperatures on ecological processes of growth, conversion efficiency, and behavior in early juvenile sablefish. Growth experiments tested a wide range of temperatures from 6 to 24(degrees)C, with fish receiving ad libitum or low (3 % body weight d(-1)) rations. With unlimited food, growth increased rapidly as temperature increased to 14(degrees)C, then displayed a more gradual rise to 22 degreesC. Growth rates at the warmer temperatures were among the highest recorded for teleosts, attaining a maximum of 3.3 nun d(-1) in length and a specific growth in weight of 11.8 %. A similar response to temperature was observed at low rations, although at lower overall growth rates. At 24 degreesC, there was a severe decline in growth for both ration levels, and few fish survived the 3 wk experiments. Gross growth efficiency, measured at temperatures of 6 to 22 degreesC, displayed an interactive effect of temperature with ration level consistent with bioenergetic relationship, Conversion peaked at 16 to 20 degreesC for fish receiving ad libitum rations, and at 10 degreesC for fish on restricted rations. Conversion rates of sablefish were comparable to those calculated for a diverse array of fish species, suggesting that the rapid growth rates are driven by high consumption rather than unusually efficient energy transfer. Experiments analyzing sablefish behavior in thermally stratified water columns demonstrated increasing movement into colder water as ration level decreased, in agreement with an energy conserving strategy. Average monthly temperatures within the major nursery areas of neustonic juveniles (north of 40 degreesN) did not exceed 19 degreesC during the last 19 yr. These results suggest that juvenile sablefish are capable of tolerating and thriving at increased temperatures, with the critical caveat that sufficient food resources must be available. Thus, impacts on early life stages exerted by El Nino conditions, oceanographic regime shifts, or climate changes induced by current global warming scenarios are likely to be a consequence of indirect effects on circulation and productivity patterns rather than direct effects of warmer temperatures. However, because the upper thermal limit for growth nearly coincides with the upper limit for survival, exhibiting a sharp demarcation between favorable growth conditions and intolerable temperatures, juvenile sablefish at the southern Limit of their distribution may suffer the direct effects of elevated temperature; recruitment of juveniles to southern populations may become more sporadic if the frequency of warming events increases with climate change. C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. RP Sogard, SM (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. EM susan.sogard@noaa.gov NR 53 TC 26 Z9 26 U1 5 U2 21 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 217 BP 121 EP 134 DI 10.3354/meps217121 PG 14 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 469AL UT WOS:000170790300011 ER PT J AU Begg, GA Weidman, CR AF Begg, GA Weidman, CR TI Stable delta C-13 and delta O-18 isotopes in otoliths of haddock Melanogrammus aeglefinus from the northwest Atlantic Ocean SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE otolith isotopic composition; carbon; oxygen; Georges Bank; retrospective environmental regimes; stock identification; fisheries management ID COD GADUS-MORHUA; GEORGES BANK; FISH OTOLITHS; WESTERN-AUSTRALIA; CONTINENTAL-SHELF; STOCK STRUCTURE; RATIO ANALYSIS; FOOD WEB; CARBON; OXYGEN AB Analyzing stable isotopes deposited in fish otoliths can provide insights into the environmental variation that individual fish experience throughout their life history which, in turn, can indicate their home range, movements, and underlying stock structure, We investigated the use of stable delta C-13 and delta O-18 isotopes in haddock Melanogrammus aeglefinus otoliths as indicators of environmental variation and stock structure in the northwest Atlantic Ocean. Samples were collected between 1995 and 1998 from individual spawning components on Georges Bank, the Gulf of Maine, and along the Scotian Shelf. Samples from 1 yr- and 4 yr-old haddock were analyzed from an integrated and chronological life history perspective, respectively. Annual, seasonal, and ontogenetic variation in otolith isotopes indicated that haddock undergo shifts in distribution throughout their life history, possibly as a means of compensating for variable environmental conditions; this underlines the difficulty of temperature reconstructions from mobile organisms with optimal temperature ranges. C1 NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP Begg, GA (reprint author), James Cook Univ N Queensland, CRC Reef Res Ctr, Townsville, Qld 4811, Australia. EM cweidman@whoi.edu NR 50 TC 22 Z9 23 U1 0 U2 11 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 216 BP 223 EP 233 DI 10.3354/meps216223 PG 11 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 462AF UT WOS:000170395500019 ER PT J AU Friedland, KD Walker, RV Davis, ND Myers, KW Boehlert, GW Urawa, S Ueno, Y AF Friedland, KD Walker, RV Davis, ND Myers, KW Boehlert, GW Urawa, S Ueno, Y TI Open-ocean orientation and return migration routes of chum salmon based on temperature data from data storage tags SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE chum salmon; data storage tag; orientation; migration ID RIVER SOCKEYE-SALMON; PACIFIC SALMON; VERTICAL MOVEMENTS; ONCORHYNCHUS-NERKA; ATLANTIC SALMON; COMPUTER-SIMULATIONS; MAGNETIC ORIENTATION; COMPASS ORIENTATION; BRITISH-COLUMBIA; RAINBOW-TROUT AB Temperature data storage tags were applied to maturing chum salmon Oncorhynchus keta in the Bering Sea during summer 1998, 5 of which were recovered in the coastal waters around Japan. These tags recorded water temperatures experienced by the fish for periods of 62 to 118 d at resolutions of 15 to 30 min, We considered fine-scale aspects of the data by analyzing diel temperature patterns in regard to the migration behavior and orientation of the fish. During the night, temperatures experienced by the fish changed little, and were among the highest temperatures experienced whereas daytime temperatures often showed dramatic changes as the fish changed depth. We analyzed a time series of temperature differences between sunrise and sunset as an indication of progress made by the fish against horizontal thermal gradients, which was assumed to represent changes in latitudinal position. Daytime differences were positive when the fish were migrating to warmer waters, whereas night-time differences were zero or slightly negative, This suggests that the fish made more progress migrating during the day than at night. We also considered large-scale aspects by examining oceanographic data in relation to the temperatures recorded by the tags. Analysis of possible migration routes based on large-scale patterns of sea surface temperature distributions suggests that zonal (east-west) routes are preferred. These data support the hypothesis that chum salmon utilize orientation cues associated with the sun during open ocean migration. However, whether salmon also utilize additional orientation or navigation mechanisms remains to be determined. C1 Univ Massachusetts, NOAA, CMER Program, Amherst, MA 01003 USA. Univ Washington, Sch Aquat & Fishery Sci, Seattle, WA 98195 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Pacific Fisheries Environm Lab, Pacific Grove, CA 93950 USA. Natl Salmon Resources Ctr, Sapporo, Hokkaido 0620922, Japan. Fisheries Agcy Japan, Tohoku Natl Fisheries Inst, Hachinohe Branch, Hachinohe 0310841, Japan. RP Friedland, KD (reprint author), Univ Massachusetts, NOAA, CMER Program, Blaisdell House, Amherst, MA 01003 USA. EM friedlandk@forwild.umass.edu NR 55 TC 30 Z9 32 U1 1 U2 10 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 EI 1616-1599 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 216 BP 235 EP 252 DI 10.3354/meps216235 PG 18 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 462AF UT WOS:000170395500020 ER PT J AU Stone, RP O'Clair, CE AF Stone, RP O'Clair, CE TI Seasonal movements and distribution of Dungeness crabs Cancer magister in a glacial southeastern Alaska estuary SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE dungeness crab; biotelemetry; essential habitat; migration ID TEMPERATURE; BRACHYURA; CANCRIDAE; DECAPODA; RANGE AB The movements of 10 female and 8 male adult Dungeness crabs, Cancer magister (Dana, 1852), were monitored biweekly to monthly with ultrasonic biotelemetry for periods ranging from 73 to 555 d. Female and male crabs had different seasonal patterns of habitat use, depth distribution, and activity. The general pattern for female crabs was: (1) a relatively inactive period between November and mid-April at depths below 20 m; ovigerous crabs were typically buried during this period in a dense aggregation; (2) abrupt movement into shallow water (<8 m) in late April and residence there until early June; this movement was coincident with the spring phytoplankton bloom and initiation of larval hatching; (3) increased activity beginning in July with movement back to deeper water, presumably to forage. Females that molted prior to oviposition did so in June and July. Male crabs occupied deep water (> 40 m) from November to April, then concentrated in shallow water (< 25 m), segregated from females, until late July. Males were most active in late summer and moved into deeper water (> 30 m) near the mouth of the cove in fall. The range of depths were -0.5 to -61.3 m for females and +0.1 to -89.0 m for males. Female crabs showed fidelity to the head of the cove and typically ranged only 1.5 km from there. Male crabs, however, moved. up to 7.2 km from the head of the cove, but did not move close to the nearest established population of Dungeness crabs 9.6 km distant. The discrete population of adult Dungeness crabs in Fritz Cove may be representative of most Dungeness crab populations inhabiting shallow embayments of the coastal fjord system of southeastern Alaska. C1 NOAA, Auke Bay Lab, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Juneau, AK 99801 USA. RP Stone, RP (reprint author), NOAA, Auke Bay Lab, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, 11305 Glacier Highway, Juneau, AK 99801 USA. EM bob.stone@noaa.gov NR 29 TC 23 Z9 23 U1 4 U2 8 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 214 BP 167 EP 176 DI 10.3354/meps214167 PG 10 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 437DG UT WOS:000168974500016 ER PT J AU Stoner, AW Manderson, JP Pessutti, JP AF Stoner, AW Manderson, JP Pessutti, JP TI Spatially explicit analysis of estuarine habitat for juvenile winter flounder: combining generalized additive models and geographic information systems SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE habitat; nursery; spatial analysis; generalized additive model; estuary; flounder ID PLAICE PLEURONECTES-PLATESSA; DUTCH WADDEN SEA; PSEUDOPLEURONECTES-AMERICANUS; NURSERY AREAS; ENVIRONMENTAL-FACTORS; SEDIMENT PREFERENCE; SALINITY GRADIENTS; FIELD OBSERVATIONS; ABIOTIC FACTORS; 0-GROUP PLAICE AB Quasisynoptic seasonal beam trawl surveys for age-0 winter flounder Pseudopleuronectes americanus were conducted in the Navesink River/Sandy Hook Bay estuarine system (NSHES), New Jersey, from 1996 to 1998, to develop spatially explicit models of habitat association. Relationships between environmental parameters and fish distribution were distinctly nonlinear and multivariate. Logistic generalized additive models (GAMs) revealed that the distribution of newly settled flounder (< 25 mm total length) in spring collections was associated with low temperature and high sediment organic content, placing them in deep, depositional environments. Fish 25 to 55 mm total length were associated with high sediment organics, shallow depth (<3 m), and salinity near 20 ppt. The largest age-0 fish (56 to 138 mm) were associated with shallow depths (< 2 m), temperature near 22 degreesC, and presence of macroalgae. Abundance of prey organisms contributed significantly to the GAM for fish 25 to 55 mm total length, but not for fish > 55 mm. Independent test collections and environmental measurements made at 12 new sites in NSHES during 1999 showed that the GAMs had good predictive capability for juvenile flounder, and new GAMs developed for the test set demonstrated the robustness of the original models. Maps for the probability of capturing fish of particular sizes were produced by integrating GAMs with maps of environmental data in a geographic information system (GIS). These plots revealed 2 important centers of settlement in the system, probably related to hydrographic conditions, and the fact that nursery locations shift rapidly with fish size during the first year of life. It was also apparent that nursery habitats are dynamic-expanding, contracting, and shifting position with changes in key environmental variables. C1 NE Fisheries Sci Ctr, Behav Ecol Branch, Natl Marine Fisheries Serv, Highlands, NJ 07732 USA. RP Stoner, AW (reprint author), NOAA, NMFS, Fisheries Behav Ecol Program, Alaska Fieheries Sci Ctr, 2030 S Marine Sci Dr, Newport, OR 97365 USA. EM al.stoner@noaa.gov NR 81 TC 114 Z9 118 U1 1 U2 20 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 213 BP 253 EP 271 DI 10.3354/meps213253 PG 19 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 432PP UT WOS:000168704100020 ER PT J AU Oedekoven, CS Ainley, DG Spear, LB AF Oedekoven, CS Ainley, DG Spear, LB TI Variable responses of seabirds to change in marine climate: California Current, 1985-1994 SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE aleutian low pressure system; Cassin's auklet; climate change; common murre; El Nino; La Nina; sooty shearwater; upwelling ID EL-NINO; ROCKFISH SEBASTES; SOOTY SHEARWATERS; PUFFINUS-GRISEUS; DIVING DEPTHS; PACIFIC-OCEAN; PATTERNS; EVENTS; DECLINES; DIET AB We conducted annual ship-board surveys to determine the density and distribution of seabirds off central California in relation to marine climate, from 1985 to 1994. Summarized here are results for the sooty shearwater Puffinus griseus, the common murre Uria aalge, and Cassin's auklet Ptychoramphus aleuticus, the 3 most abundant seabirds in the central part of the California Current (91% of seabird abundance and biomass). During the study, sea-surface temperature, wind speed and thermocline depth all increased, salinity decreased and thermocline intensity (slope) showed no consistent trend. Periods of cool water and warm water, as well as offshore and inshore excursions of the shelfbreak front, alternated and were mediated by the Southern Oscillation and upwelling intensity. The responses to climate variation by the 3 seabird species were in accord with their respective morphologies and natural history patterns. All moved closer to shore and away from the shelf-break front (which also weakened). Abundance of the shallow-diving shearwater and auklet decreased dramatically, but those of the deeper-diving murre did not. The shearwater, which nests in the southern hemisphere and is the most mobile of the 3 seabirds, likely changed its migration routes and reduced its association with the California Current. The auklet, which breeds within the study area and lacks mobility, declined in number, most likely due to reduced breeding success and subsequent reduced population size. Remaining auklets moved away from the shelfbreak, but not as far inshore as the shearwater. The murre, which also breeds locally, is the most adaptable owing to its deeper-diving capabilities. It shifted distribution within the study area to feed on alternative prey found throughout the water column. C1 HT Harvey & Associates, San Jose, CA 95118 USA. RP Oedekoven, CS (reprint author), SW Fisheries Sci Ctr, La Jolla, CA 92037 USA. EM coedekoven@yahoo.com NR 63 TC 63 Z9 72 U1 2 U2 20 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 212 BP 265 EP 281 DI 10.3354/meps212265 PG 17 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 420RH UT WOS:000168017600022 ER PT J AU Secor, DH Rooker, JR Zlokovitz, E Zdanowicz, VS AF Secor, DH Rooker, JR Zlokovitz, E Zdanowicz, VS TI Identification of riverine, estuarine, and coastal contingents of Hudson River striped bass based upon otolith elemental fingerprints SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE Hudson River; striped bass; anadromy; migration; otolith microchemistry; strontium; elemental fingerprint ID LASER-ABLATION ICPMS; COD GADUS-MORHUA; CHESAPEAKE BAY; FISH OTOLITHS; STOCK IDENTIFICATION; ATLANTIC CROAKER; MORONE-SAXATILIS; MICROCHEMISTRY; MIGRATIONS; WATERS AB Elemental fingerprints of otoliths from Hudson River striped bass Morone saxatilis were used to define resident, estuarine, and ocean migratory contingents, which had previously been determined by otolith microprobe analysis of Sr:Ca. Using solution-based inductively coupled plasma mass-spectrometry, 7 metals were quantified in whole otoliths. Discriminant analysis of elements showed a high degree of separation among the 3 migratory contingents. Barium was significantly higher in otoliths from the freshwater resident group, while Sr and Na were significantly lower in comparison to mesohaline and ocean contingents. Identification of contingents by the bulk chemistry method indicated that divergent migratory patterns persist over lifetimes for Hudson River striped bass. C1 Univ Maryland, Ctr Environm Sci, Chesapeake Biol Lab, Solomons, MD 20688 USA. Texas A&M Univ, Dept Marine Biol, Galveston, TX 77553 USA. Maryland Dept Nat Resources, Stevensville, MD 21666 USA. NOAA, Natl Marine Fisheries Serv, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. RP Secor, DH (reprint author), Univ Maryland, Ctr Environm Sci, Chesapeake Biol Lab, POB 38, Solomons, MD 20688 USA. EM secor@cbl.umces.edu RI Secor, D/D-4367-2012; Rooker, Jay/M-3197-2013; Mason, Robert/A-6829-2011 OI Secor, D/0000-0001-6007-4827; Rooker, Jay/0000-0002-5934-7688; NR 44 TC 107 Z9 116 U1 0 U2 14 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 211 BP 245 EP 253 DI 10.3354/meps211245 PG 9 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 412NM UT WOS:000167561300021 ER PT J AU Purcell, JE Sturdevant, MV AF Purcell, JE Sturdevant, MV TI Prey selection and dietary overlap among zooplanktivorous jellyfish and juvenile fishes in Prince William Sound, Alaska SO MARINE ECOLOGY PROGRESS SERIES LA English DT Review DE Aurelia; competition; ctenophore; Cyanea; herring; pollock; salmon; sandlance; zooplankton ID GULF-OF-ALASKA; HERRING CLUPEA-HARENGUS; AGE-0 WALLEYE POLLOCK; CTENOPHORE MNEMIOPSIS-LEIDYI; BRITISH-COLUMBIA; THERAGRA-CHALCOGRAMMA; SAND LANCE; CHRYSAORA-QUINQUECIRRHA; COMMUNITY COMPOSITION; SOUTHEASTERN ALASKA AB The potential for competition for food among zooplanktivorous species of gelatinous zooplankton and fishes has been the subject of much speculation. Here, we evaluate the dietary overlaps among 2 scyphomedusan species, Aurelia labiata and Cyanea capillata, 1 ctenophore species, Pleurobrachia bachei, 1 hydromedusan species, Aequorea aequorea var. albida, and juveniles (Age-0) of 4 forage fish species, walleye pollock Theragra chalcogramma, Pacific sandlance Ammodytes hexapterus, Pacific herring Clupea pallasi, and pink salmon Oncorhynchus gorbuscha. Zooplankton samples collected in July-August 1995 to 1998 showed great similarity among years (86 to 96 %), which allowed valid dietary comparisons between pelagic coelenterates and fishes collected in different years during that period. The predators fell into 2 groups, one that ate primarily crustacean prey (A. labiata, P, bachei, juvenile walleye pollock, sandlance, and herring), and another that ate mostly larvaceans (C, capillata, A. aequorea, and juvenile pink salmon). Species within the first group showed significant positive selection for crustacean prey and 1significant negative selection for larvaceans. The opposite trends were observed in the second group. Dietary overlaps were higher among crustacean-eating species (63 +/- 13 %) and larvacean-eating species (66 +/- 10 %) than when comparing crustacean- with larvacean-eating species (24 +/- 14 %). Dietary overlaps among pelagic coelenterate species (41 +/- 21 %) and among fish species (42 +/- 25 %) were similar, while overlaps between pelagic coelenterate and fish species averaged 50 +/- 21 %. These pelagic coelenterate and fish species were collected together in 45 purse seine sets taken in Prince William Sound in July 1999. We conclude that the diets of pelagic coelenterate and forage fish species overlap substantially, and that the species co-occur spatially and temporally. Therefore, the potential for competition for prey exists for these zooplanktivores in Prince William Sound. C1 Univ Maryland, Horn Point Lab, Ctr Environm Sci, Cambridge, MD 21613 USA. NOAA, NMFS, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. RP Purcell, JE (reprint author), Shannan Point Marine Ctr, 1900 Shannon Point Rd, Anacortes, WA 98221 USA. EM purcell@hpl.umces.edu RI Purcell, Jennifer/E-9991-2011 NR 106 TC 85 Z9 96 U1 3 U2 31 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 210 BP 67 EP 83 DI 10.3354/meps210067 PG 17 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 405TE UT WOS:000167175000006 ER PT J AU Meyer, DL Johnson, JM Gill, JW AF Meyer, DL Johnson, JM Gill, JW TI Comparison of nekton use of Phragmites australis and Spartina alterniflora marshes in the Chesapeake Bay, USA SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE Phragmites; Spartina; nekton; fish; shrimp; fauna; alteration; invasion; disruption; utilization; restoration; marsh; Fundulus; Palaemonetes ID FUNDULUS-HETEROCLITUS LINNAEUS; PREDATOR-PREY INTERACTIONS; SALT-MARSH; NORTH-CAROLINA; TIDAL MARSHES; MACROFAUNAL CRUSTACEANS; DECAPOD CRUSTACEANS; NATANT MACROFAUNA; FISH; HABITAT AB Throughout the eastern USA many Spartina alterniflora salt-marsh systems are being altered through the invasion of Phragmites australis. As a result, substantial declines in the areal distribution of S. alterniflora-dominated habitat have occurred in contrast to increases in P. australis dominated habitat. While information is scarce on nekton use of P. australis marsh, increases in the areal distribution of this species have concerned resource managers. Managers typically view the shift of S. alterniflora to P. australis marsh as a shift from a biologically diverse and productive marsh to one less biologically diverse and productive. We examined nekton use of P, australis marsh relative to S, alterniflora marsh with similar geographic location and physical conditions. We found no significant differences (p > 0.05) in the utilization of P. australis and S, alterniflora marsh by nekton in terms of abundance or biomass. Further, no significant difference (p > 0.05) in the total number of nekton species was evident between P. australis and S. alterniflora marsh. We postulate that under similar environmental and physical conditions these marsh types are equivalent in terms of nekton use. It may be necessary to reevaluate current wetland management practices which involve the elimination of P, australis in favor of S, alterniflora marsh in order to increase nekton use. C1 NOAA, Ctr Coastal Fisheries & Habitat Res, Beaufort, NC 28516 USA. USFWS, Annapolis, MD 21401 USA. RP Meyer, DL (reprint author), NOAA, Ctr Coastal Fisheries & Habitat Res, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. EM dave.meyer@noaa.gov NR 66 TC 42 Z9 42 U1 2 U2 8 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2001 VL 209 BP 71 EP 84 DI 10.3354/meps209071 PG 14 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 399VR UT WOS:000166834500006 ER PT J AU Dziak, RP Fox, CG Bobbitt, AM Goldfinger, C AF Dziak, RP Fox, CG Bobbitt, AM Goldfinger, C TI Bathymetric map of the gorda plate: Structural and geomorphological processes inferred from multibeam surveys SO MARINE GEOPHYSICAL RESEARCHES LA English DT Article DE Gorda Plate; bathymetric maps; structural deformation; submarine canyons ID EAST PACIFIC RISE; MENDOCINO TRIPLE JUNCTION; DE-FUCA PLATE; SEA BEAM; DEFORMATION; EARTHQUAKE; FLANKS; TECTONICS; CASCADIA; STRESS AB Full-coverage multibeam bathymetric maps of the southern section of the Juan de Fuca Plate, also known as the Gorda Plate, are presented. The bathymetric maps represent the compilation of multibeam surveys conducted by the National Oceanic and Atmospheric Administration during the last 20 yrs, and illustrate the complex tectonic, volcanic, and geomorphologic features as well as the intense deformation occurring within this region. The bathymetric data have revealed several major, previously unmapped midplate faults. A series of gently curving faults are apparent in the Gorda Plate, with numerous faults offsetting the Gorda Plate seafloor. The multibeam surveys have also provided a detailed view of the intense deformation occurring within the Gorda Plate. A preliminary deformation model estimated from basement structure is discussed, where the southern part of the plate (south of similar to42degrees30' N) seems to be deforming through a series of left-lateral strike-slip faults, while the northern section appears to be moving passively with the rest of the Juan de Fuca Plate. The bathymetry also demonstrates the Mendocino and Eel Canyons are prominent morphologic features in the northern California margin. These canyons are active depositional features with a large sediment fan present at the mouths of both the Mendocino and Eel canyons. The depositional lobes of these fan(s) are evident in the bathymetry, as are the turbidite channels that have deposited sediment along the fans over time. The Trinidad Canyon is readily evident in the margin morphology as well, with a large (similar to10 km) plunge pool formed at the mouth of the canyon as it enters the Gorda Plate sediments. C1 Oregon State Univ, Hatfield Marine Sci Ctr, Cooperat Inst Marine Resources Studies, Newport, OR 97365 USA. NOAA, Pacific Marine Environm Lab, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. RP Dziak, RP (reprint author), Oregon State Univ, Hatfield Marine Sci Ctr, Cooperat Inst Marine Resources Studies, Newport, OR 97365 USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 36 TC 11 Z9 11 U1 0 U2 12 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0025-3235 J9 MAR GEOPHYS RES JI Mar. Geophys. Res. PY 2001 VL 22 IS 4 BP 235 EP 250 DI 10.1023/A:1014606407111 PG 16 WC Geochemistry & Geophysics; Oceanography SC Geochemistry & Geophysics; Oceanography GA 532NN UT WOS:000174482100001 ER PT J AU Marks, KM Stock, JM AF Marks, KM Stock, JM TI Evolution of the Malvinas Plate South of Africa SO MARINE GEOPHYSICAL RESEARCHES LA English DT Article DE Agulhas Basin; gravity anomalies; Late Cretaceous; Malvinas Plate; plate tectonics; reconstruction; South Atlantic Ocean ID AGULHAS BASIN; ATLANTIC; RECONSTRUCTIONS; KINEMATICS; ANOMALIES; HISTORY; RIDGE AB We confirm that a Malvinas Plate is required in the Agulhas Basin during the Late Cretaceous because: (1) oblique Mercator plots of marine gravity show that fracture zones generated on the Agulhas rift, as well as the Agulhas Fracture Zone, do not lie on small circles about the 33o-28y South America-Africa stage pole and were therefore not formed by South America-Africa spreading, (2) the 33o-28y South America-Africa stage rotation does not bring 33o magnetic anomalies on the Malvinas Plate into alignment with their conjugates on the African Plate, and (3) errors in the 33o-28y South America-Africa stage rotation cannot account for the misalignment. We present improved Malvinas-Africa finite rotations determined by interpreting magnetic anomaly data in light of fracture zones and extinct spreading rift segments (the Agulhas rift) that are clearly revealed in satellite-derived marine gravity fields covering the Agulhas Basin. The tectonic history of the Malvinas Plate is chronicled through gravity field reconstructions that use the improved Malvinas-Africa finite rotations and more recent South America-Africa and Antarctica-Africa finite rotations. Newly-mapped triple junction traces on the Antarctic, South American, Malvinas, and African Plates, combined with geometric and magnetic constraints observed in the reconstructions, enable us to investigate the locations of the elusive western and southern boundaries of the Malvinas Plate. C1 NOAA, Lab Satellite Alimetry, Silver Spring, MD 20910 USA. CALTECH, Seismol Lab, Pasadena, CA 91125 USA. RP Marks, KM (reprint author), NOAA, Lab Satellite Alimetry, Silver Spring, MD 20910 USA. RI Marks, Karen/F-5610-2010; OI Marks, Karen/0000-0001-6524-1495; Stock, Joann Miriam/0000-0003-4816-7865 NR 30 TC 14 Z9 16 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0025-3235 J9 MAR GEOPHYS RES JI Mar. Geophys. Res. PY 2001 VL 22 IS 4 BP 289 EP 302 DI 10.1023/A:1014638325616 PG 14 WC Geochemistry & Geophysics; Oceanography SC Geochemistry & Geophysics; Oceanography GA 532NN UT WOS:000174482100004 ER PT J AU Snyder, GM Pitcher, KW Perryman, WL Lynn, MS AF Snyder, GM Pitcher, KW Perryman, WL Lynn, MS TI Counting Steller sea lion pups in Alaska: An evaluation of medium-format, color aerial photography SO MARINE MAMMAL SCIENCE LA English DT Article DE Steller sea lion; Eumetopias jubatus; census; pup counts; aerial photography ID EUMETOPIAS-JUBATUS; VARIABILITY; CALIFORNIA AB Estimates of Steller sea lion (Eumetopias jubatus) pup production are valuable for estimating population trend and size. Currently in Alaska, pups are counted by visiting rookeries, driving older animals into the water, then walking through the rookeries and counting the pups, a highly disruptive procedure. At smaller rookeries, with good vantage points, pups are occasionally counted from the periphery of rookeries without disturbing the sea lions. We evaluated counts made from medium-format, color, aerial photographs as an alternative to drive counts and peripheral counts. Neither the peripheral counts nor the aerial photographic counts disturbed animals on the rookeries. There were strong 1:1 linear relationships between photographic counts and drive counts (r(2) = 0.966, P < 0.001) and between photographic counts and peripheral counts (r(2) = 0.999, P < 0.001). Precision was similar for all three methods of counting. We suggest that medium-format, color, aerial photography is appropriate for routine surveys of Steller sea lion pups in Alaska because it is not disruptive to the hauled-out sea lions and provides comparable estimates with similar precision to drive and peripheral counts. Large areas can be rapidly surveyed during periods of good weather with a minimum of manpower. C1 Alaska Dept Fish & Game, Div Wildlife Conservat, Anchorage, AK 99518 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Snyder, GM (reprint author), Alaska Dept Fish & Game, Div Wildlife Conservat, 333 Raspberry Rd, Anchorage, AK 99518 USA. NR 22 TC 5 Z9 5 U1 0 U2 3 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD JAN PY 2001 VL 17 IS 1 BP 136 EP 146 DI 10.1111/j.1748-7692.2001.tb00984.x PG 11 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 383ML UT WOS:000165886400006 ER PT J AU Holland, DS Ginter, JJC AF Holland, DS Ginter, JJC TI Common property institutions in the Alaskan groundfish fisheries SO MARINE POLICY LA English DT Article DE common property; fisheries; cooperatives; institutions ID MANAGEMENT; RESOURCES AB This paper describes the process by which the groundfish resources off Alaska are being transformed from essentially open access to more manageable common property resources. Selected common property institutions that were created or developed in these fisheries are described in terms of the problems they were designed to solve, their success or lack of success in doing so, and the factors that influenced both emergence and success of these institutions. The institutions discussed include the North Pacific Fishery Management Council, the Community Development Quota system, the Pollock Conservation Cooperative, and the cooperative bycatch control system known as Sea State used by the factory trawler fleets. Conclusions applicable to other fisheries and other common property resources are then drawn from the analysis of these common property institutions in the Alaskan groundfish fisheries. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Univ Massachusetts, Sch Marine Sci & Technol, New Bedford, MA 02744 USA. Natl Marine Fisheries Serv, Alaska Reg, Juneau, AK 99802 USA. RP Holland, DS (reprint author), Univ Massachusetts, Sch Marine Sci & Technol, 706 S Rodney French Blvd, New Bedford, MA 02744 USA. OI Holland, Daniel/0000-0002-4493-859X NR 21 TC 24 Z9 24 U1 1 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0308-597X J9 MAR POLICY JI Mar. Pol. PD JAN PY 2001 VL 25 IS 1 BP 33 EP 42 DI 10.1016/S0308-597X(00)00033-6 PG 10 WC Environmental Studies; International Relations SC Environmental Sciences & Ecology; International Relations GA 406EN UT WOS:000167202100004 ER PT B AU Stutzman, PE AF Stutzman, PE BE Skalny, J Gebauer, J Odler, I TI Scanning electron microscopy in concrete petroghraphy SO MATERIALS SCIENCE OF CONCRETE: SPECIAL VOLUME: CALCIUM HYDROXIDE IN CONCRETE SE MATERIALS SCIENCE OF CONCRETE SERIES LA English DT Proceedings Paper CT Workshop on the Role of Calcium Hydroxide in Concrete CY NOV 01-03, 2000 CL HOLMES BEACH, FL SP Calif Portland Cement Co, Essroc Italce Grp, Grace Construct Products, Holderbank Manage & Consult, Lafarge, Mat Serv Life, Natl Inst Standard & Technol, Natl Res Council, Portland Cement Assoc, R J Lee Grp, S E M AB Scanning electron microscopy has distinct advantages for characterization of concrete, cement, and aggregate microstructure, and in the interpretation of causes for concrete deterioration. Scanning electron microscope imaging facilitates identification of hardened cement paste constituents with greater contrast, and greater spatial resolution than for optical methods and provides ancillary capability for element analysis and imaging. Quantitative information may be extracted from these data, such as composition, phase abundance and distribution. Sample preparation and demonstration of some of the common imaging techniques and extraction of data using image processing and analysis are presented. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Stutzman, PE (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8621, Gaithersburg, MD 20899 USA. NR 6 TC 10 Z9 10 U1 0 U2 4 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA BN 1-57498-128-5 J9 MAT SCI SERIES PY 2001 BP 59 EP 72 PG 14 WC Materials Science, Composites SC Materials Science GA BS88P UT WOS:000171316000004 ER PT J AU Robertson, DS AF Robertson, DS TI Using absolute gravimeter data to determine vertical gravity gradients SO METROLOGIA LA English DT Article AB The position versus time data from a free-fall absolute gravimeter can be used to estimate the vertical gravity gradient in addition to the gravity value itself. Hipkin has reported success in estimating the vertical gradient value using a data set of unusually good quality. This paper explores techniques that may,be applicable to a broader class of data that may be contaminated with "system response" errors of larger magnitude than were evident in the data used by Hipkin. This system response function is usually modelled as a sum of exponentially decaying sinusoidal components. The technique employed here involves combining the x(0), nu (0) and g parameters from all the drops made during a site occupation into a single least-squares solution, and including the value of the vertical gradient and the coefficients of system response function in the same solution. The resulting non-linear equations must be solved iteratively and convergence presents some difficulties. Sparse matrix techniques are used to make the least-squares problem computationally tractable. C1 Univ Colorado, NOAA, NOS, Natl Geodet Survey, Boulder, CO 80309 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. RP Robertson, DS (reprint author), Univ Colorado, NOAA, NOS, Natl Geodet Survey, Campus Box 216, Boulder, CO 80309 USA. NR 6 TC 8 Z9 9 U1 1 U2 1 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 2001 VL 38 IS 2 BP 147 EP 153 DI 10.1088/0026-1394/38/2/6 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 460DF UT WOS:000170290000006 ER PT J AU Mills, IM Taylor, BN Thor, AJ AF Mills, IM Taylor, BN Thor, AJ TI Definitions of the units radian, neper, bel and decibel SO METROLOGIA LA English DT Article AB The definition of coherent derived units in the International System of Units (SI) is reviewed, and the important role of the equations defining physical quantities is emphasized in obtaining coherent derived units. In the case of the dimensionless quantity plane angle, the choice between alternative definitions is considered, leading to a corresponding choice between alternative definitions of the coherent derived unit-the radian, degree or revolution. In this case the General Conference on Weights and Measures (CGPM) has chosen to adopt the definition that leads to the radian as the coherent derived unit in the SI. In the case of the quantity logarithmic decay (or gain), also sometimes called decrement, and sometimes called level, a similar choice of defining equation exists, leading to a corresponding choice for the coherent derived unit-the neper or the bel. In this case the CGPM has not yet made a choice. We argue that for the quantity logarithmic decay the most logical choice of defining equation is linked to that of the radian, and is that which leads to the neper as the corresponding coherent derived unit. This should not prevent us from using the bel and decibel as units of logarithmic decay. However, it is an important part of the SI to establish in a formal sense the equations defining physical quantities, and the corresponding coherent derived units. C1 Univ Reading, Dept Chem, Reading RG6 6AD, Berks, England. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Swedish Stand Inst, SE-10044 Stockholm, Sweden. Royal Inst Technol, SE-10044 Stockholm, Sweden. RP Mills, IM (reprint author), Univ Reading, Dept Chem, Reading RG6 6AD, Berks, England. NR 5 TC 8 Z9 8 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0026-1394 J9 METROLOGIA JI Metrologia PY 2001 VL 38 IS 4 BP 353 EP 361 DI 10.1088/0026-1394/38/4/8 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 508WE UT WOS:000173112100008 ER PT J AU Suarez-Romero, JG Tepichin-Rodriguez, E Mielenz, KD AF Suarez-Romero, JG Tepichin-Rodriguez, E Mielenz, KD TI Cross-spectral density propagated through a circular aperture SO METROLOGIA LA English DT Article ID DIFFRACTION AB A method is presented for evaluating the cross-spectral density diffracted by a circular aperture in the Fresnel approximation. Our proposal is a generalization to partially coherent illumination of the classical solution to the problem of near-field diffraction due to a circular aperture. We show that our generalization covers particular cases already reported in the literature and present numerical and experimental results that verify our proposal. This work is a contribution to the treatment of diffraction by multiple apertures. C1 CENAM, Ctr Nacl Metrol, Queretaro, Mexico. Inst Nacl Astrofis Opt & Elect, Puebla, Mexico. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Suarez-Romero, JG (reprint author), CENAM, Ctr Nacl Metrol, Km 4-5 Carretera Cues, Queretaro, Mexico. NR 17 TC 12 Z9 12 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 2001 VL 38 IS 5 BP 379 EP 384 DI 10.1088/0026-1394/38/5/2 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 524PT UT WOS:000174022600002 ER PT J AU Shirley, JH Lee, WD Drullinger, RE AF Shirley, JH Lee, WD Drullinger, RE TI Accuracy evaluation of the primary frequency standard NIST-7 SO METROLOGIA LA English DT Article ID PUMPED CESIUM BEAM; VELOCITY DISTRIBUTIONS; SCHRODINGER EQUATION; MAGNETIC-RESONANCE; SHIFTS; STABILITY; CAVITY; CLOCK; UNCERTAINTY; TRANSITIONS AB We develop a comprehensive approach to the evaluation of the uncertainty of a primary frequency standard. Indirect, model-dependent means are employed for the evaluation of all known biases. This approach leads to a lower combined standard uncertainty (CSU) and leaves frequency measurements under altered conditions as a powerful search technique for unknown biases. We report the results of this evaluation technique applied to NIST-7, one of the United States' primary frequency standards. The best CSU value we have reported to the Bureau International des Poids et Mesures (BIPM) is 5 x 10(-15), while a rigorous application of this evaluation process would suggest that a limiting Type B uncertainty of 3.5 x 10(-15) is possible. We discuss this difference and the implications of reporting optimistic values. We also discuss the history of reported evaluations of NIST-7 including those made before the full implementation of the techniques presented here. C1 Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. RP Shirley, JH (reprint author), Natl Inst Stand & Technol, Div Time & Frequency, Boulder, CO 80303 USA. NR 63 TC 42 Z9 43 U1 3 U2 12 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0026-1394 J9 METROLOGIA JI Metrologia PY 2001 VL 38 IS 5 BP 427 EP 458 DI 10.1088/0026-1394/38/5/7 PG 32 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 524PT UT WOS:000174022600007 ER PT J AU Allen, JW Ascroft, J Mellouet, B Perepelkin, V AF Allen, JW Ascroft, J Mellouet, B Perepelkin, V TI Effective efficiency in waveguide R-400 (WR-22) SO METROLOGIA LA English DT Article AB The national metrology institutes of the United Kingdom (NPL), France (LCIE), the United States (NIST), and the Russian Federation (VNIIFTRI) have completed an international comparison of radio frequency (rf) power measurement capability in rectangular waveguide R-400 (WR-22). Each laboratory measured the effective efficiency and reflection coefficient of the same bolometric power sensors in the frequency range from 33 GHz to 50 GHz in 1 GHz steps. This paper summarizes the results of this comparison. C1 Natl Inst Stand & Technol, Boulder, CO 80303 USA. Natl Phys Lab, Teddington TW11 0LW, Middx, England. Bur Natl Metrol, Lab Cent Ind Elect, Fontenay Aux Roses, France. Gosstandart Russia, Inst Phys Tech & Radiotech Measurements, Mendekeevo, Moscow Region, Russia. RP Allen, JW (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80303 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 2001 VL 38 IS 5 BP 463 EP 470 DI 10.1088/0026-1394/38/5/9 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 524PT UT WOS:000174022600009 ER PT J AU Nelson, RA McCarthy, DD Malys, S Levine, J Guinot, B Fliegel, HF Beard, RL Bartholomew, TR AF Nelson, RA McCarthy, DD Malys, S Levine, J Guinot, B Fliegel, HF Beard, RL Bartholomew, TR TI The leap second: its history and possible future SO METROLOGIA LA English DT Review ID GLOBAL POSITIONING SYSTEM; TIME SCALES; ROTATION; DEFINITION; EARTH AB This paper reviews the theoretical motivation for the leap second in the context of the historical evolution of time measurement. The periodic insertion of a leap second step into the scale of Coordinated Universal Time (UTC) necessitates frequent changes in complex timekeeping systems and is currently the subject of discussion in working group of various international scientific organizations. UTC is an atomic time scale that agrees in rate with International Atomic Time (TAI), but differs by an integral number of seconds, and is the basis of civil time. In contrast, Universal Time (UT1) is an astronomical time scale defined by the Earth's rotation and is used in celestial navigation. UTC is presently maintained to within 0.9 s of UTI. As the needs of celestial navigation that depend on UTI can now be met by satellite systems, such as the Global Positioning System (GPS), options for revising the definition of UTC and the possible role of leap seconds in the future are considered. C1 USN Observ, Washington, DC 20392 USA. Natl Imagery & Mapping Agcy, Res Tech Off, Bethesda, MD 20816 USA. Natl Inst Stand & Technol, Dept Commerce, Boulder, CO 80303 USA. Observ Paris, Dept Astron Fondamentale, F-75014 Paris, France. Aerosp Corp, El Segundo, CA 90245 USA. USN, Res Lab, Washington, DC 20375 USA. Litton TASC Inc, Annapolis, MD 20701 USA. Satellite Engn Res Corp, Bethesda, MD 20814 USA. RP Nelson, RA (reprint author), Satellite Engn Res Corp, 7701 Woodmont Ave,Suite 208, Bethesda, MD 20814 USA. NR 142 TC 39 Z9 40 U1 0 U2 3 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 2001 VL 38 IS 6 BP 509 EP 529 DI 10.1088/0026-1394/38/6/6 PG 21 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 531QA UT WOS:000174425700005 ER PT J AU Shreiner, RH Fuko, J Jensen, HD Wandel, M Sorensen, J AF Shreiner, RH Fuko, J Jensen, HD Wandel, M Sorensen, J TI International comparison of electrolytic conductivity between the DFM (Denmark), the NIST (USA) and the OMH (Hungary) SO METROLOGIA LA English DT Article AB Electrolytic conductivity measurements at the Danish Institute of Fundamental Metrology (DFM), the United States National Institute of Standards and Technology (NIST), and the Hungarian National Office of Measures (OMH) were compared using solutions of potassium chloride in water with nominal conductivities of 10 mS/m, 100 mS/m, and 1 S/m at 25 degreesC. Each participant determined the conductivities of the solutions by the method of their choice and reported uncertainties that were calculated according to the Guide to the Expression Of Uncertainty in Measurement of the International Organization for Standardization (ISO). Secondary methods were used. The values determined by each institute for all three solutions agree within the stated uncertainties reported by the participants. C1 NIST, Gaithersburg, MD 20899 USA. OMH, Kemiai Meresek Osztalya, H-1124 Budapest, Hungary. Danish Inst Fundamental Metrol, DK-2800 Lyngby, Denmark. RP Shreiner, RH (reprint author), NIST, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 8 TC 2 Z9 2 U1 1 U2 2 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 2001 VL 38 IS 6 BP 549 EP 554 DI 10.1088/0026-1394/38/6/10 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 531QA UT WOS:000174425700009 ER PT S AU Dagata, JA Chien, FSS Gwo, S Morimoto, K Inoue, T Itoh, J Yokoyama, H AF Dagata, JA Chien, FSS Gwo, S Morimoto, K Inoue, T Itoh, J Yokoyama, H BE Sullivan, NT TI Electric force microscopy with a single carbon nanotube tip SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XV CY FEB 26-MAR 01, 2001 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Int SEMATECH DE scanned probe microscopy; lithography; electric force microscopy; carbon nanotube; silicon-on-insulator ID SCANNED PROBE OXIDATION; RESOLUTION; SILICON AB Carbon nanotube tips offer a significant improvement over standard scanned probe microscope (SPM) tips for electrical characterization of nanodevice structures. Carbon nanotube tips are compatible with requirements for integrated SPM-probe station instruments in which SPM-based lithography, topography, electric force microscopy, and traditional current-voltage measurements are performed simultaneously or sequentially. As device dimensions shrink, traditional diagnostics will be unable to probe nanometer-scale phenomena that affect device performance and reliability. At the same time, the introduction of novel materials such as silicon-on-insulator into standard processing will require methods that can rapidly identify defects and their local behavior. Electric force microscopy with carbon nanotube tips offers unique capabilities for satisfying these needs. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Dagata, JA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI Gwo, Shangjr/A-9946-2008 NR 18 TC 7 Z9 7 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4030-2 J9 P SOC PHOTO-OPT INS PY 2001 VL 4344 BP 58 EP 71 DI 10.1117/12.436728 PG 14 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BT28K UT WOS:000172533300008 ER PT S AU Potzick, J AF Potzick, J BE Sullivan, NT TI The problem with submicrometer linewidth standards, and a proposed solution SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XV CY FEB 26-MAR 01, 2001 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Int SEMATECH DE linewidth; metrology; imaging; error; measurement uncertainty; traceability; tolerance; standards AB Traceable linewidth measurements of tiny features on photomasks and wafers present interesting challenges. Usually technical solutions exist for the problems encountered, but traceability can be costly in time and labor. A measurement is useful only if its value exceeds its cost. One such problem is that an optical or electron microscope forms a scaled image of the linewidth object, which is measured instead of the object itself. Interpreting this image to identify the object's edges in it can be difficult, because the image depends on instrument and object parameters (such as topography and materials) not directly related to the linewidth. Use of a linewidth standard can provide a traceable measurement if the relevant object parameters are known to match those of the standard. In the majority of cases, however, the object being measured and the linewidth standard will differ in topography and/or materials. Then the instrument images of object and standard will also differ, leading to possible measurement errors. Traceability requires that these measurement errors be quantified - a costly prospect. One can calculate the measurement error resulting from object/standard parameter differences. Then a measurement error tolerance can be chosen, and parameter tolerances can be found corresponding to a "parametric measurement uncertainty" that is consistent with it. These parameter tolerances define "islands of tolerance" in parameter space over which the parametric uncertainty will be tolerated. The larger the islands, the greater the measurement uncertainty, but the greater the number of different objects whose parameter differences fall on the island. While the calculations for the islands of tolerance may be complex, a single island can apply to a whole group of different objects, reducing the cost of measuring the parameters and calculating their effects. This is a way to obtain traceable linewidth measurements while balancing measurement cost and measurement uncertainty. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Potzick, J (reprint author), Natl Inst Stand & Technol, Metrol Bldg A 117, Gaithersburg, MD 20899 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4030-2 J9 P SOC PHOTO-OPT INS PY 2001 VL 4344 BP 139 EP 146 DI 10.1117/12.436737 PG 8 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BT28K UT WOS:000172533300016 ER PT S AU Villarrubia, JS Vladar, AE Lowney, JR Postek, MT AF Villarrubia, JS Vladar, AE Lowney, JR Postek, MT BE Sullivan, NT TI Edge determination for polycrystalline silicon lines on gate oxide SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XV CY FEB 26-MAR 01, 2001 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Int SEMATECH DE critical dimension (CD); independent-edges approximation; library-based metrology; linewidth metrology; line shape; scanning electron microscopy (SEM) ID METROLOGY AB In a scanning electron microscope (SEM) top-down secondary electron image, areas within a few tens of nanometers of the line edges are characteristically brighter than the rest of the image. In general, the shape of the secondary electron signal within such edge regions depends upon the energy and spatial distribution of the electron beam and the sample composition, and it is sensitive to small variations in sample geometry. Assigning edge shape and position is done by finding a model sample that is calculated, on the basis of a mathematical model of the instrument-sample interaction, to produce an image equal to the one actually observed. Edge locations, and consequently line widths, are then assigned based upon this model sample. In previous years we have applied this strategy to lines with geometry constrained by preferential etching of single crystal silicon. With this study we test the procedure on polycrystalline silicon lines. Polycrystalline silicon lines fabricated according to usual industrial processes represent a commercially interesting albeit technically more challenging application of this method. With the sample geometry less constrained a priori, a larger set of possible sample geometries must be modeled and tested for a match to the observed line scan, and the possibility of encountering multiple acceptable matches is increased. For this study we have implemented a data analysis procedure that matches measured image line scans to a precomputed library of sample shapes and their corresponding line scans. Linewidth test patterns containing both isolated and dense lines separated from the underlying silicon substrate by a thin gate oxide have been fabricated. Line scans from test pattern images have been fitted to the library of modeled shapes. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Villarrubia, JS (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 9 TC 36 Z9 36 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4030-2 J9 P SOC PHOTO-OPT INS PY 2001 VL 4344 BP 147 EP 156 DI 10.1117/12.436738 PG 10 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BT28K UT WOS:000172533300017 ER PT S AU Dixson, R Orji, NG Fu, J Tsai, V Williams, ED Kacker, R Vorburger, T Edwards, H Cook, D West, P Nyffenegger, R AF Dixson, R Orji, NG Fu, J Tsai, V Williams, ED Kacker, R Vorburger, T Edwards, H Cook, D West, P Nyffenegger, R BE Sullivan, NT TI Silicon single atom steps as AFM height standards SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XV SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XV CY FEB 26-MAR 01, 2001 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Int SEMATECH DE AFM; metrology; step height; atomic steps ID FORCE MICROSCOPE; DIMENSIONAL METROLOGY; PHASE-SEPARATION; VICINAL SI(111) AB Atomic force microscopes (AFMs) are used in the semiconductor industry for a variety of metrology purposes. Step height measurements at the nanometer level and roughness measurements at sub-manometer levels are often of interest. To perform accurate measurements, the scales of an AFM must be calibrated. We have been exploring the use of silicon single atomic steps as height standards for AFMs in the sub-manometer regime. We have also designed and developed the calibrated AFM (C-AFM) to calibrate standards for other AFMs. Previously, we measured the step height of silicon single atomic steps on Si (111) (with native oxide) using the C-AFM. The value we obtained was 304 +/- 8 pm (k=2). From three independent measurement techniques, including our C-AFM result, we estimate an "accepted" value for the silicon step height of 312 pm +/- 12 pin (k=2), which corresponds to an expanded uncertainty of about 4 %. We have also completed a NIST led comparison of AFM measurements of silicon step samples to further evaluate their suitability as standards in industrial applications. If the reproducibility of the participants' measurements is sufficient, the accepted value could be used to calibrate the scale of the measuring tools in this sub-manometer regime. The participants sent the data to NIST for analysis. This was done so that all of the data would be analyzed in a uniform manner. The results of our analysis indicate that these samples can be used effectively as standards. The average standard deviation of all of the participants results was 6 pm. Hence, it should be possible to use these specimens as sub-manometer z-axis calibration standards with an expanded uncertainty of about 6 %. C1 NIST, Gaithersburg, MD 20899 USA. RP Dixson, R (reprint author), NIST, Gaithersburg, MD 20899 USA. EM ronald.dixson@nist.gov NR 15 TC 12 Z9 12 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4030-2 J9 PROC SPIE PY 2001 VL 4344 BP 157 EP 168 DI 10.1117/12.436739 PG 12 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BT28K UT WOS:000172533300018 ER PT S AU Lin, EK Wu, WL Lin, QH Angelopoulos, M AF Lin, EK Wu, WL Lin, QH Angelopoulos, M BE Sullivan, NT TI Feature-shape and line-edge roughness measurement of deep sub-micron lithographic structures using small-angle neutron scattering SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XV SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XV CY FEB 26-MAR 01, 2001 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Int SEMATECH ID ATOMIC-FORCE MICROSCOPY; X-RAY-LITHOGRAPHY; OPTICAL SCATTEROMETRY; SIDEWALL ROUGHNESS; GRATINGS; DIFFRACTION; METROLOGY; FILMS AB We demonstrate the application of small angle neutron scattering (SANS) measurements for the quick, nondestructive, and quantitative measurement of the feature shape and size and line-edge roughness of lithographically prepared structures using a model photoresist pattern consisting of a periodic grating of 0.15 mum lines. The measurements are performed directly on structures as fabricated on a silicon wafer with no other sample preparation. For well-defined patterns placed normal to the neutron beam, we easily observe up to six orders of diffraction peaks. Analytic expressions from standard small angle scattering formalism are used to extract the average line structure, spacing, and line-edge roughness from the peak positions and intensities. Additional structural information is obtained by tilting the pattern relative to the incident beam. Changes in the observed scattering data as a function of the tilting angle are related to characteristics such as the height of the structures and the symmetry of the line shape. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. RP Lin, EK (reprint author), Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. NR 14 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4030-2 J9 PROC SPIE PY 2001 VL 4344 BP 414 EP 422 DI 10.1117/12.436767 PG 9 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BT28K UT WOS:000172533300044 ER PT S AU Silver, RM Jun, J Kornegay, E Morton, R AF Silver, RM Jun, J Kornegay, E Morton, R BE Sullivan, NT TI Comparison of edge detection methods using a prototype overlay calibration artifact SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XV CY FEB 26-MAR 01, 2001 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Int SEMATECH ID ACCURACY; TOOL AB Accurate overlay measurements rely on robust, repeatable, and accurate feature position determination. In our effort to develop traceable overlay standards we have examined a number of edge detection methods and the parameters which affect those measurements. The samples used in this study are a comprehensive set of prototype overlay wafer standards. The methods for determining the position of a feature generally rely on some determination of edges, and the resulting feature centerline can be significantly affected by the method of choice. We have compared cross-correlation, centroid, and edge-threshold methods as well as an integrated least squares method. This paper is focused on empirical results obtained through the measurement of relevant overlay targets and pitch specimens. The data presented in this paper was acquired using charge coupled device (CCD)-based arrays. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Silver, RM (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 11 TC 7 Z9 7 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4030-2 J9 P SOC PHOTO-OPT INS PY 2001 VL 4344 BP 515 EP 529 DI 10.1117/12.436777 PG 15 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BT28K UT WOS:000172533300054 ER PT S AU Damazo, BN Vladar, AE Ling, AV Donmez, MA Postek, MT Jayewardene, EC AF Damazo, BN Vladar, AE Ling, AV Donmez, MA Postek, MT Jayewardene, EC BE Sullivan, NT TI SEM sentinel - SEM performance measurement system SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XV CY FEB 26-MAR 01, 2001 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Int SEMATECH DE SEM; performance; monitoring; automatic; computer control AB This paper describes the design and implementation of a system for monitoring the performance of several major subsystems of a critical dimension measurement scanning electron microscope (CD-SEM). Experiments were performed for tests involving diagnosis of the vacuum system and column stability by monitoring of the following subsystems and associated functional parameters. These include: 1) Vacuum system with pressure as a function of time being recorded for the electron-optical column (gun chamber), the specimen chamber, and the sample-loading unit. 2) The action of several components of the wafer handling system can be timed. 3) The electron gun emission currents and other signals to monitor the characteristics of the condenser and objective lenses may be used to correlate with image quality. 4) Image sharpness, electron beam current, signal-to-noise ratio, etc. can be evaluated. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Damazo, BN (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8220, Gaithersburg, MD 20899 USA. NR 3 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4030-2 J9 P SOC PHOTO-OPT INS PY 2001 VL 4344 BP 773 EP 782 DI 10.1117/12.436805 PG 10 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BT28K UT WOS:000172533300082 ER PT S AU Vladar, AE Postek, MT Zhang, NF Larrabee, RD Jones, SN Hajdaj, RE AF Vladar, AE Postek, MT Zhang, NF Larrabee, RD Jones, SN Hajdaj, RE BE Sullivan, NT TI Reference Material 8091: New scanning electron microscope sharpness standard SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XV CY FEB 26-MAR 01, 2001 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Int SEMATECH DE scanning electron microscope; CD; SEM; performance; measurement; CD-SEM; metrology; standard; reference material AB All scanning electron microscope-based inspection instruments, whether they are in a laboratory or on the production line, slowly lose their performance and then are no longer capable of providing as good quality, sharp images as before. Loss in image quality also means loss in measurement quality. Loss of performance is related to changes in the electron source, in the alignment of the electron-optical column, astigmatism, and sample and electron optical column contamination. Detecting a loss in image sharpness easily reveals this decrease of performance. Reference Material (RM) 8091 is intended primarily for routinely checking the performance of scanning electron microscopes. RM 8091 is designed for use in conjunction with Fourier analysis software such as the NIST/SPECTEL2 SEM Monitor Program, the NIST Kurtosis program, or the University of Tennessee SMART program. This RM is supplied as a small, approximately 2 mm x 2 mm diced semiconductor chip. RM 8091 is designed to be mounted onto a so-called drop-in wafer for specialized wafer inspection or dimensional metrology scanning electron microscopes or put on a specimen stub for insertion into laboratory scanning electron microscopes. This Reference Material is fully compatible with state-of-the-art integrated circuit technology. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Vladar, AE (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 10 TC 1 Z9 1 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4030-2 J9 P SOC PHOTO-OPT INS PY 2001 VL 4344 BP 827 EP 834 DI 10.1117/12.436723 PG 8 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BT28K UT WOS:000172533300087 ER PT S AU Vladar, AE Postek, MT Vane, R AF Vladar, AE Postek, MT Vane, R BE Sullivan, NT TI Active monitoring and control of electron beam induced contamination SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XV CY FEB 26-MAR 01, 2001 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Int SEMATECH DE scanning electron microscope; CD; SEM; contamination; measurement; CD-SEM; lithography; metrology; accuracy; linewidth ID MICROSCOPE AB The vacuum systems of all scanning electron microscopes (SEMs), even in the so-called "clean" instruments, have certain hydrocarbon residues that the vacuum pumps do not effectively remove. The cleanliness of the vacuum and the amount and nature of these residual molecules depends on the type of the pumps and also on the samples moved through the system. Many times, the vacuum readings are quite good but the electron beam still leaves disturbing contamination marks on the sample. This means that in a critical dimension (CD) SEM, repeated measurements cannot be done without extra, sometimes unacceptably high measurement errors resulting from "carry-over." During the time necessary for even one measurement, the sample dimension can change, and the extent of this change remains unknown unless a suitable contamination deposition measurement technique is found and regular monitoring is implemented. This paper assesses the problem of contamination of carbonatious materials in the SEM, shows a possible method for its measurement and presents a promising solution to the contamination deposition problem. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Vladar, AE (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 3 TC 26 Z9 26 U1 2 U2 7 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4030-2 J9 P SOC PHOTO-OPT INS PY 2001 VL 4344 BP 835 EP 843 DI 10.1117/12.436724 PG 9 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BT28K UT WOS:000172533300088 ER PT S AU Evans, CJ Parks, RE Shao, LZ Schmitz, T Davies, A AF Evans, CJ Parks, RE Shao, LZ Schmitz, T Davies, A BE Sullivan, NT TI Interferometric testing of photomask substrate flatness SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XV CY FEB 26-MAR 01, 2001 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Int SEMATECH DE photomasks; interferometry; flatness; Ritchey-Common test ID FIZEAU INTERFEROMETER; TRANSPARENT AB Conventional interferometric testing of the flatness of photomask substrates($) is rendered difficult by the long coherence length of the HeNe laser sources typically used in commercially available phase measuring interferometers appropriate for flatness testing. The Ritchey-Common configuration allows testing of flats in a spherical wavefront; this paper shows that, under appropriate conditions, high resolution surface flatness maps of photomask substrates may be obtained using instrumentation currently available in many optical shops. C1 Natl Inst Stand & Technol, Mfg Metrol Div, Gaithersburg, MD 20899 USA. RP Evans, CJ (reprint author), Natl Inst Stand & Technol, Mfg Metrol Div, Stop 8220, Gaithersburg, MD 20899 USA. NR 15 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4030-2 J9 P SOC PHOTO-OPT INS PY 2001 VL 4344 BP 844 EP 851 DI 10.1117/12.436725 PG 8 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BT28K UT WOS:000172533300089 ER PT S AU Stieren, DC AF Stieren, DC BE Choset, HM Gage, DW Stein, MR TI Telepresence applications in manufacturing research and measurement services at NIST SO MOBILE ROBOTS XV AND TELEMANIPULATOR AND TELEPRESENCE TECHNOLOGIES VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Mobile Robots XV and Telemanipulator and Telepresence Technologies VII CY NOV 05-06, 2000 CL BOSTON, MA SP SPIE DE ATM; collaboratory; information technology; metrology; NAMT; telepresence AB This paper describes applications of and infrastructural technologies for telepresence capabilities within the context of the Information-Based Manufacturing Program at the National Institute of Standards and Technology (NIST). The Information-Based Manufacturing Program is supported by the National Advanced Manufacturing Testbed (NAMT), which enables collaborative research among scientists and engineers at NIST, remote industry locations, and government and university laboratories. The research environment of the NAMT operates as a collaboratory, or a "research center without walls," using computing and networking technology to improve the performance of manufacturing research and the delivery of NIST measurement services. Telepresence is one of the critical technical capabilities upon which the operation of the NAMT collaboratory is based. C1 NIST, Mat Engn Lab, Gaithersburg, MD 20899 USA. RP Stieren, DC (reprint author), NIST, Mat Engn Lab, Gaithersburg, MD 20899 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3860-X J9 P SOC PHOTO-OPT INS PY 2001 VL 4195 BP 240 EP 251 DI 10.1117/12.417307 PG 12 WC Automation & Control Systems; Robotics; Optics SC Automation & Control Systems; Robotics; Optics GA BS25T UT WOS:000169199700024 ER PT J AU Kim, E Suh, HR Kim, H Char, K Hong, J Lee, SH Satija, SK Ivkov, R AF Kim, E Suh, HR Kim, H Char, K Hong, J Lee, SH Satija, SK Ivkov, R TI Neutron reflectivity from the monolayer of SAN random copolymer SO MOLECULAR CRYSTALS AND LIQUID CRYSTALS LA English DT Article; Proceedings Paper CT 3rd Asian Symposium on Organized Molecular Films for Electronics and Photonics (ASOMF 3) CY JUL 09-12, 2000 CL HANYANG UNIV, SEOUL, SOUTH KOREA SP Korea Sci & Engn Fdn, Polymer Soc Korea, Molec Electr Div, Samsung Adv Inst Technol, LC Electr Inst Technol, Natl Program Tera Level Nanodevices, Sogang Univ, Pohang Univ Sci & Technol, Inje Univ, Study Grp Properties Photon & Microelectr Polymers Molec Design HO HANYANG UNIV DE neutron reflectivity; segment density profiling; Langmuir monolayer; SAN random copolymer AB The detailed structural aspects of the monolayer of SAN random copolymer with 22.6 wt% AN content at the air/water interface were investigated using neutron reflectivity(NR) technique. NR data at various surface pressures were analyzed to obtain the thickness, the density, and the concentration distribution. Well defined double-layered structure could fit the data. C1 Hongik Univ, Dept Appl Sci, Seoul, South Korea. Kyung Hee Univ, Dept Chem, Yongin, Kyungki Do, South Korea. Seoul Natl Univ, Dept Chem Engn, Seoul, South Korea. Natl Inst Stand & Technol, Div Reactor Radiat, Gaithersburg, MD USA. RP Kim, E (reprint author), Hongik Univ, Dept Appl Sci, Seoul, South Korea. RI Ivkov, Robert/A-3902-2015 OI Ivkov, Robert/0000-0002-2930-5276 NR 5 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1542-1406 J9 MOL CRYST LIQ CRYST JI Mol. Cryst. Liquid Cryst. PY 2001 VL 371 BP 211 EP 214 DI 10.1080/10587250108024724 PG 4 WC Crystallography SC Crystallography GA 503TK UT WOS:000172816400053 ER PT J AU Trapp, RJ Schultz, DM Ryzhkov, AV Holle, RL AF Trapp, RJ Schultz, DM Ryzhkov, AV Holle, RL TI Multiscale structure and evolution of an Oklahoma winter precipitation event SO MONTHLY WEATHER REVIEW LA English DT Article ID 3-DIMENSIONAL AGEOSTROPHIC CIRCULATIONS; MULTIPARAMETER RADAR MEASUREMENTS; COLORADO CONVECTIVE STORMS; POLARIMETRIC RADAR; FRONTAL SURFACES; POSITIVE CAPE; MELTING SNOW; THUNDERSTORMS; BAND; RAIN AB A significant winter precipitation event occurred on 8-9 March 1994 in Oklahoma. Snow accumulations greater than 30 cm (12 in.) were measured within a narrow corridor in northern Oklahoma. On the synoptic scale and mesoscale, a correspondence between large snow accumulations and 600-hPa frontogenesis was revealed; the precipitation was formed above the cold frontal surface, owing to midtropospheric ascent associated with the cross-frontal circulation in a region of elevated conditional instability. The location of such a narrow corridor of large accumulations was not, however, disclosed by any patterns in the radar reflectivity data. Indeed, during this event, an elongated maximum of snow accumulation was not associated with a persistent "band'' of enhanced reflectivity and vice versa. Dual-polarization and dual-Doppler radar data allowed for a novel analysis of winter precipitation processes and structures, within the context of the larger-scale diagnosis. It was possible to identify, in order of distance southward toward the surface cold front: (i) an elevated convective element, which was classified as an elevated thunderstorm and may have functioned as an ice crystal "generator'' cell, embedded within a broad region of generally stratiform precipitation; (ii) a reflectivity band and associated rain-snow transition zone, the evolution and structure of which apparently were coupled to the effects of melting precipitation and strong vertical wind shear; and (iii) a mixed-phase precipitation-generating, prolific lightning-producing, nonelevated thunderstorm cell that was sustained in the postfrontal air in part by virtue of its rotational dynamics. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. RP Trapp, RJ (reprint author), Natl Ctr Atmospher Res, MMM, POB 3000, Boulder, CO 80307 USA. RI Schultz, David M./A-3091-2010 OI Schultz, David M./0000-0003-1558-6975 NR 50 TC 21 Z9 22 U1 0 U2 5 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. PY 2001 VL 129 IS 3 BP 486 EP 501 DI 10.1175/1520-0493(2001)129<0486:MSAEOA>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 408MB UT WOS:000167329000008 ER PT J AU Xu, M Bao, JW Warner, TT Stensrud, DJ AF Xu, M Bao, JW Warner, TT Stensrud, DJ TI Effect of time step size in MM5 simulations of a mesoscale convective system SO MONTHLY WEATHER REVIEW LA English DT Article ID LARGE-SCALE ENVIRONMENTS; MODEL; PARAMETERIZATION; COMPLEXES; CYCLONE; SCHEMES; TESTS AB Results from simulations of a mesoscale convective system (MCS) that occurred in a weakly forced large-scale environment show significant sensitivity to the time step size chosen for model integration. As the time step is decreased, the movement and longevity of the simulated MCS depart further from the observations. It is found that the time step-dependent formulation of the numerical diffusivity is responsible for a major part of this sensitivity in the simulated MCS. The changes contributed by truncation errors may or may not be negligible, depending on the physics schemes used in the simulations. This suggests that the choice of a specific linearly stable model time step, in combination with the definition of the numerical diffusivity, may at times be as important as the choice of the basic model configuration. C1 Natl Ctr Atmospher Res, Res Applicat Program, Boulder, CO 80307 USA. Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Environm Technol Lab, Boulder, CO USA. NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Xu, M (reprint author), Natl Ctr Atmospher Res, Res Applicat Program, POB 3000, Boulder, CO 80307 USA. NR 26 TC 5 Z9 6 U1 0 U2 0 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. PY 2001 VL 129 IS 3 BP 502 EP 516 DI 10.1175/1520-0493(2001)129<0502:EOTSSI>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 408MB UT WOS:000167329000009 ER PT J AU Elmore, KL Richman, MB AF Elmore, KL Richman, MB TI Euclidean distance as a similarity metric for principal component analysis SO MONTHLY WEATHER REVIEW LA English DT Article ID PATTERNS; ROTATION AB Eigentechniques, in particular principal component analysis (PCA), have been widely used in meteorological analyses since the early 1950s. Traditionally, choices for the parent similarity matrix, which are diagonalized, have been limited to correlation, covariance, or, rarely, cross products. Whereas each matrix has unique characteristic benefits, all essentially identify parameters that vary together. Depending on what underlying structure the analyst wishes to reveal, similarity matrices can be employed, other than the aforementioned, to yield different results. In this work, a similarity matrix based upon Euclidean distance, commonly used in cluster analysis, is developed as a viable alternative. For PCA, Euclidean distance is converted into Euclidean similarity. Unlike the variance-based similarity matrices, a PCA performed using Euclidean similarity identifies parameters that are close to each other in a Euclidean distance sense. Rather than identifying parameters that change together, the resulting Euclidean similarity-based PCA identifies parameters that are close to each other, thereby providing a new similarity matrix choice. The concept used to create Euclidean similarity extends the utility of PCA by opening a wide range of similarity measures available to investigators, to be chosen based on what characteristic they wish to identify. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. RP Elmore, KL (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 27 TC 23 Z9 23 U1 1 U2 4 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. PY 2001 VL 129 IS 3 BP 540 EP 549 DI 10.1175/1520-0493(2001)129<0540:EDAASM>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 408MB UT WOS:000167329000012 ER PT J AU Hamill, TM AF Hamill, TM TI Interpretation of rank histograms for verifying ensemble forecasts SO MONTHLY WEATHER REVIEW LA English DT Article ID PROBABILISTIC FORECASTS; PRECIPITATION FORECASTS; PREDICTION SYSTEM; MODEL; PREDICTABILITY; PERTURBATIONS; VALIDATION; FLOW AB Rank histograms are a tool for evaluating ensemble forecasts. They are useful for determining the reliability of ensemble forecasts and for diagnosing errors in its mean and spread. Rank histograms are generated by repeatedly tallying the rank of the verification (usually an observation) relative to values from an ensemble sorted from lowest to highest. However, an uncritical use of the rank histogram can lead to misinterpretations of the qualities of that ensemble. For example, a flat rank histogram, usually taken as a sign of reliability, can still be generated from unreliable ensembles. Similarly, a U-shaped rank histogram, commonly understood as indicating a lack of variability in the ensemble, can also be a sign of conditional bias. It is also shown that flat rank histograms can be generated for some model variables if the variance of the ensemble is correctly specified, yet if covariances between model grid points are improperly specified, rank histograms for combinations of model variables may not be flat. Further, if imperfect observations are used for verification, the observational errors should be accounted for, otherwise the shape of the rank histogram may mislead the user about the characteristics of the ensemble. If a statistical hypothesis test is to be performed to determine whether the differences from uniformity of rank are statistically significant, then samples used to populate the rank histogram must be located far enough away from each other in time and space to be considered independent. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Hamill, TM (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Climate Diagnost Ctr,RCDCI, 325 Broadway, Boulder, CO 80309 USA. EM hamill@cdc.noaa.gov NR 36 TC 315 Z9 323 U1 1 U2 28 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. PY 2001 VL 129 IS 3 BP 550 EP 560 DI 10.1175/1520-0493(2001)129<0550:IORHFV>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 408MB UT WOS:000167329000013 ER PT J AU Rogers, RF Fritsch, JM AF Rogers, RF Fritsch, JM TI Surface cyclogenesis from convectively driven amplification of midlevel mesoscale convective vortices SO MONTHLY WEATHER REVIEW LA English DT Article ID WARM-CORE VORTEX; 1977 JOHNSTOWN FLOOD; BETA-SCALE STRUCTURE; SQUALL-LINE; CUMULUS PARAMETERIZATION; EXTRATROPICAL CYCLONES; NUMERICAL-SIMULATION; HURRICANE-GUILLERMO; TROPICAL CYCLONE; MODEL AB Mesoscale convective vortices (MCVs) are midtropospheric warm-core cyclonic circulations that often develop in the stratiform region of mesoscale convective systems. Typically, divergent, anticyclonically circulating, mesoscale cold anomalies appear both above and below the MCV. The upper-level cold anomaly is usually found near the tropopause while the low-level anomaly is surface based and exhibits locally higher pressure. One aspect of MCVs that has received much attention recently is the role that they may play in tropical cyclogenesis. Of special interest is how an MCV amplifies when deep convection redevelops within the borders of its midlevel cyclonic circulation and how the amplified MCV transforms the divergent surface-based cold pool with anomalously high surface pressure into a convergent cyclonic circulation with anomalously low pressure. The Pennsylvania State University-National Center for Atmospheric Research fifth-generation Mesoscale Model is used to simulate an MCV that was instrumental in initiating, within the borders of the midlevel vortex's circulation, several successive cycles of convective development and decay over a 2-day period. After each cycle of convection, both the horizontal size of the cyclonic circulation and the magnitude of the potential vorticity associated with the vortex were observed to increase. The simulation reproduces the development and evolution of the MCV and associated convective cycles. Mesoscale features responsible for the initiation of convection within the circulation of the vortex and the impact of this convection on the structure and evolution of the vortex are investigated. A conceptual model is presented to explain how convective redevelopment within the MCV causes low-level heights to fall and cyclonic vorticity to grow downward to the surface. Applying this conceptual model to a tropical marine environment is also considered. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Div Hurricane Res, Miami, FL 33149 USA. RP Rogers, RF (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Div Hurricane Res, 4301 Rickenbacker Causeway, Miami, FL 33149 USA. RI Rogers, Robert/I-4428-2013 NR 69 TC 41 Z9 44 U1 1 U2 5 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. PY 2001 VL 129 IS 4 BP 605 EP 637 DI 10.1175/1520-0493(2001)129<0605:SCFCDA>2.0.CO;2 PG 33 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 424VD UT WOS:000168253900003 ER PT J AU Wandishin, MS Mullen, SL Stensrud, DJ Brooks, HE AF Wandishin, MS Mullen, SL Stensrud, DJ Brooks, HE TI Evaluation of a short-range multimodel ensemble system SO MONTHLY WEATHER REVIEW LA English DT Article ID NUMERICAL WEATHER PREDICTION; LIMITED-AREA MODEL; PRECIPITATION FORECASTS; QUANTITATIVE PRECIPITATION; PREDICTABILITY EXPERIMENTS; SKILL; TESTS; NMC; PARAMETERIZATIONS; REPRESENTATION AB Forecasts from the National Centers for Environmental Prediction's experimental short-range ensemble system are examined and compared with a single run from a higher-resolution model using similar computational resources. The ensemble consists of five members from the Regional Spectral Model and 10 members from the 80-km Eta Model, with both in-house analyses and bred perturbations used as initial conditions. This configuration allows for a comparison of the two models and the two perturbation strategies, as well as a preliminary investigation of the relative merits of mixed-model, mixed-perturbation ensemble systems. The ensemble is also used to estimate the short-range predictability limits of forecasts of precipitation and fields relevant to the forecast of precipitation. Whereas error growth curves for the ensemble and its subgroups are in relative agreement with previous work for large-scale fields such as 500-mb heights, little or no error growth is found for fields of mesoscale interest, such as convective indices and precipitation. The difference in growth rates among the ensemble subgroups illustrates the role of both initial perturbation strategy and model formulation in creating ensemble dispersion. However, increase spread per se is not necessarily beneficial, as is indicated by the fact that the ensemble subgroup with the greatest spread is less skillful than the subgroup with the least spread. Further examination into the skill of the ensemble system for forecasts of precipitation shows the advantage gained from a mixed-model strategy, such that even the inclusion of the less skillful Regional Spectral Model members improves ensemble performance. For some aspects of forecast performance, even ensemble configurations with as few as five members are shown to significantly outperform the 29-km Meso-Eta Model. C1 NOAA, Environm Res Lab, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Arizona, Inst Atmospher Phys, Tucson, AZ 85721 USA. RP NOAA, Environm Res Lab, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. EM mwand@vicksburg.nssl.noaa.gov NR 67 TC 78 Z9 86 U1 2 U2 11 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PY 2001 VL 129 IS 4 BP 729 EP 747 DI 10.1175/1520-0493(2001)129<0729:EOASRM>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 424VD UT WOS:000168253900008 ER PT J AU Otte, TL Seaman, NL Stauffer, DR AF Otte, TL Seaman, NL Stauffer, DR TI A heuristic study on the importance of anisotropic error distributions in data assimilation SO MONTHLY WEATHER REVIEW LA English DT Article ID 4-DIMENSIONAL DATA-ASSIMILATION; NUMERICAL WEATHER PREDICTION; RETROSPECTIVE DATA ASSIMILATION; FIELD-COHERENCE TECHNIQUE; PLANETARY BOUNDARY-LAYER; ENSEMBLE KALMAN FILTER; AREA MESOSCALE MODEL; SAN-JOAQUIN VALLEY; ANALYSIS SYSTEM; AIR-QUALITY AB A challenging problem in numerical weather prediction is to optimize the use of meteorological observations in data assimilation. Even assimilation techniques considered "optimal'' in the "least squares'' sense usually involve a set of assumptions that prescribes the horizontal and vertical distributions of analysis increments used to update the background analysis. These assumptions may impose limitations on the use of the data that can adversely affect the data assimilation and any subsequent forecast. Virtually all widely used operational analysis and dynamic-initialization techniques assume, at some level, that the errors are isotropic and so the data can be applied within circular regions of influence around measurement sites. Whether implied or used directly, circular isotropic regions of influence are indiscriminate toward thermal and wind gradients that may reflect changes of air mass. That is, the analytic process may ignore key flow-dependent information available about the physical error structures of an individual case. Although this simplification is widely recognized, many data assimilation schemes currently offer no practical remedy. To explore the potential value of case-adaptive, noncircular weighting in a computationally efficient manner, an approach for structure-dependent weighting of observations (SWOBS) is investigated in a continuous data assimilation scheme. In this study, SWOBS is used to dynamically initialize the PSU-NCAR Mesoscale Model using temperature and wind data in a series of observing-system simulation experiments. Results of this heuristic study suggest that improvements in analysis and forecast skill are possible with case-specific, flow-dependent, anisotropic weighting of observations. C1 NOAA, Div Atmospher Sci Modeling, Air Resources Lab, Res Triangle Pk, NC USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. RP Otte, TL (reprint author), US EPA, NERL, AMD, MD-80, Res Triangle Pk, NC 27711 USA. OI Spero, Tanya/0000-0002-1600-0422 NR 72 TC 6 Z9 6 U1 0 U2 1 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. PY 2001 VL 129 IS 4 BP 766 EP 783 DI 10.1175/1520-0493(2001)129<0766:AHSOTI>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 424VD UT WOS:000168253900010 ER PT J AU Mo, KC AF Mo, KC TI Adaptive filtering and prediction of intraseasonal oscillations SO MONTHLY WEATHER REVIEW LA English DT Article ID MADDEN-JULIAN OSCILLATION; RANGE FORECASTS; CIRCULATION; MODEL; PRECIPITATION; CONVECTION; EPISODES; TROPICS; ERRORS; SKILL AB A statistical model based on the combination of singular spectrum analysis (SSA) and the maximum entropy method (MEM) is applied to monitor and forecast outgoing longwave radiation anomalies (OLRAs) in the intraseasonal band over the Indian-Pacific sector and in the pan-American region. SSA is related to empirical orthogonal function analysis (EOF) but is applied to time series. The leading SSA modes (T-EOFs) are orthogonal and they are determined from the training period before filtering. The OLRA time series can be projected onto T-EOFs to obtain the principal components (T-PCs). To obtain fluctuations in any frequency band, one can partially sum up a chosen subset of T-EOFs and the related T-PCs in that band. The filter based on the SSA modes is data adaptive and there is no loss of end points. It is well suited for real-time monitoring of intraseasonal oscillations. In the Pacific and the pan-American region, there are three leading modes (T-EOFs) of oscillations with periods near 40, 22, and 18 days. The T-PCs associated with these modes are quasiperiodic and they can be modeled by an autoregressive process. To perform forecasts, the MEM is used to determine the autoregressive coefficients from the training period. These coefficients are used to advance T-PCs. The summation of T-EOFs and T-PCs related to three preferred modes gives the predicted OLRAs. For 5-day mean OLRAs, the averaged correlation between the predicted and the observed anomalies is 0.65 at the lead times of four pentads (20 days). The SSA-MEM method is effective for any time series containing large oscillatory components. The deficiency of this method is that the forecasted magnitudes of anomalies are usually weaker than observations. C1 NOAA, NWS, NCEP, Climate Predict Ctr, Camp Springs, MD 20746 USA. RP Mo, KC (reprint author), NOAA, NWS, NCEP, Climate Predict Ctr, 5200 Auth Rd, Camp Springs, MD 20746 USA. EM kmo@ncep.noaa.gov NR 28 TC 35 Z9 43 U1 0 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. PY 2001 VL 129 IS 4 BP 802 EP 817 DI 10.1175/1520-0493(2001)129<0802:AFAPOI>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 424VD UT WOS:000168253900012 ER PT J AU Soden, BJ Velden, CS Tuleya, RE AF Soden, BJ Velden, CS Tuleya, RE TI The impact of satellite winds on experimental GFDL hurricane model forecasts SO MONTHLY WEATHER REVIEW LA English DT Article ID TROPICAL CYCLONE MOTION; TRACK FORECASTS; DROPWINDSONDE OBSERVATIONS; INTENSITY FORECASTS; PREDICTION SYSTEM; INITIALIZATION; IMPROVEMENTS; ASSIMILATION; ATLANTIC; MOVEMENT AB A series of experimental forecasts are performed to evaluate the impact of enhanced satellite-derived winds on numerical hurricane track predictions. The winds are derived from Geostationary Operational Environmental Satellite-8 (GOES-8) multispectral radiance observations by tracking cloud and water vapor patterns from successive satellite images. A three-dimensional optimum interpolation method is developed to assimilate the satellite winds directly into the Geophysical Fluid Dynamics Laboratory (GFDL) hurricane prediction system. A series of parallel forecasts are then performed, both with and without the assimilation of GOES winds. Except for the assimilation of the satellite winds, the model integrations are identical in all other respects. A strength of this study is the large number of experiments performed. Over 100 cases are examined from 11 different storms covering three seasons (1996-98), enabling the authors to account for and examine the case-to-case variability in the forecast results when performing the assessment. On average, assimilation of the GOES winds leads to statistically significant improvements for all forecast periods, with the relative reductions in track error ranging from similar to5% at 12 h to similar to 12% at 36 h. The percentage of improved forecasts increases following the assimilation of the satellite winds, with roughly three improved forecasts for every two degraded ones. Inclusion of the satellite winds also dramatically reduces the westward bias that has been a persistent feature of the GFDL model forecasts, implying that much of this bias may be related to errors in the initial conditions rather than a deficiency in the model itself. Finally, a composite analysis of the deep-layer flow fields suggests that the reduction in track error may be associated with the ability of the GOES winds to more accurately depict the strength of vorticity gyres in the environmental flow. These results offer compelling evidence that the assimilation of satellite winds can significantly improve the accuracy of hurricane track forecasts. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI USA. RP Soden, BJ (reprint author), NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. NR 33 TC 49 Z9 56 U1 0 U2 1 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. PY 2001 VL 129 IS 4 BP 835 EP 852 DI 10.1175/1520-0493(2001)129<0835:TIOSWO>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 424VD UT WOS:000168253900014 ER PT J AU Marzban, C Schaefer, JT AF Marzban, C Schaefer, JT TI The correlation between US tornadoes and Pacific Sea surface temperatures SO MONTHLY WEATHER REVIEW LA English DT Article ID SOUTHERN OSCILLATION; EL-NINO AB The correlation between tornadic activity in several regions of the United States and the monthly mean sea surface temperature over four zones in the tropical Pacific Ocean is examined. Tornadic activity is gauged with two mostly independent measures: the number of tornadoes per month, and the number of tornadic days per month. Within the assumptions set forth for the analysis, it is found that there appears to exist a statistically significant but very weak correlation between sea surface temperature in the Pacific Ocean and tornadic activity in the United States, with the strength and significance of the correlation depending on the coordinates at which the sea surface temperatures are assessed and the geographic region of the United States. The strongest evidence found is for the correlation between the number of days with strong and violent (F2 and greater) tornadoes in an area that runs from Illinois to the Atlantic Coast, and Kentucky to Canada and a cool sea surface temperature in the central tropical Pacific. However, there is only about a 53% chance of this relationship occurring in a specific month. C1 Univ Oklahoma, Cooperat Inst Mesoscale & Meteorol Studies, Natl Severe Storms Lab, Norman, OK 73019 USA. Univ Oklahoma, Dept Phys, Norman, OK 73019 USA. Storm Predict Ctr, Norman, OK USA. RP Marzban, C (reprint author), Univ Washington, NRCSE, Box 354323, Seattle, WA 98195 USA. NR 24 TC 14 Z9 14 U1 0 U2 4 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. PY 2001 VL 129 IS 4 BP 884 EP 895 DI 10.1175/1520-0493(2001)129<0884:TCBUST>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 424VD UT WOS:000168253900017 ER PT J AU Koch, SE Zhang, FQ Kaplan, ML Lin, YL Weglarz, R Trexler, CM AF Koch, SE Zhang, FQ Kaplan, ML Lin, YL Weglarz, R Trexler, CM TI Numerical simulations of a gravity wave event over CCOPE. Part III: The role of a mountain-plains solenoid in the generation of the second wave episode SO MONTHLY WEATHER REVIEW LA English DT Article ID MESOSCALE CONVECTIVE SYSTEM; BOUNDARY-LAYER; EVOLUTION; MODEL; SHEAR; BORE; FLOW; ENVIRONMENT; ATMOSPHERE; DYNAMICS AB Mesoscale model simulations have been performed of the second episode of gravity waves observed in great detail in previous studies on 11-12 July 1981 during the Cooperative Convective Precipitation Experiment. The dominant wave simulated by the model was mechanically forced by the strong updraft associated with a mountain-plains solenoid (MPS). As this updraft impinged upon a stratified shear layer above the deep, well-mixed boundary layer that developed due to strong sensible heating over the Absaroka Mountains, the gravity wave was created. This wave rapidly weakened as it propagated eastward. However, explosive convection developed directly over the remnant gravity wave as an eastward-propagating density current produced by a rainband generated within the MPS leeside convergence zone merged with a westward-propagating density current in eastern Montana. The greatly strengthened cool pool resulting from this new convection then generated a bore wave that appeared to be continuous with the movement of the incipient gravity wave as it propagated across Montana and the Dakotas. The nonlinear balance equation and Rossby number were computed to explore the role of geostrophic adjustment in the forecast gravity wave generation, as suggested in previous studies of this wave event. These fields did indicate flow imbalance, but this was merely the manifestation of the MPS-forced gravity wave. Thus, the imbalance indicator fields provided no lead time for predicting wave occurrence. Several sensitivity tests were performed to study the role of diabatic processes and topography in the initiation of the flow imbalance and the propagating gravity waves. When diabatic effects owing to precipitation were prevented, a strong gravity wave still was generated in the upper troposphere within the region of imbalance over the mountains. However, it did not have a significant impact because moist convection was necessary to maintain wave energy in the absence of an efficient wave duct. No gravity waves were present in either a simulation that disallowed surface sensible heating, or the "flat terrain'' simulation, because the requisite MPS forcing could not occur. This study highlights difficulties encountered in attempting to model the generation of observed gravity waves over complex terrain in the presence of strong diabatic effects. The complex interactions that occurred between the sensible heating over complex terrain, the incipient gravity wave, and convection highlight the need for much more detailed observations between wave generation regions over mountains and the plains downstream of such regions. C1 NOAA, Forecast Syst Lab, OAR, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Raleigh, NC 27695 USA. RP Koch, SE (reprint author), NOAA, Forecast Syst Lab, OAR, R-FS1,325 Broadway, Boulder, CO 80303 USA. EM koch@fsl.noaa.gov RI Zhang, Fuqing/E-6522-2010 OI Zhang, Fuqing/0000-0003-4860-9985 NR 40 TC 31 Z9 32 U1 2 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. PY 2001 VL 129 IS 5 BP 909 EP 933 DI 10.1175/1520-0493(2001)129<0909:NSOAGW>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 429HN UT WOS:000168510700001 ER PT J AU Chien, FC Mass, CF Neiman, PJ AF Chien, FC Mass, CF Neiman, PJ TI An observational and numerical study of an intense landfalling cold front along the northwest coast of the United States during COAST IOP 2 SO MONTHLY WEATHER REVIEW LA English DT Article ID MID-LATITUDE CYCLONES; DOPPLER OBSERVATIONS; MICROSCALE STRUCTURE; MESOSCALE OROGRAPHY; PACIFIC-NORTHWEST; OLYMPIC MOUNTAINS; COMPLEX TERRAIN; WIND PROFILERS; CATALINA EDDY; KELVIN WAVES AB This paper presents an observational and numerical study of an intense wintertime cold front that made landfall along the northwest coast of the United States during IOP 2 (3-4 Dec 1993) of the Coastal Observation and Simulation with Topography experiment. Observations suggest that the offshore frontal zone was associated with two transitions: the first characterized by a substantial temperature gradient, a nearly vertically oriented wind shift from southwesterly ahead to westerly behind, and a convective rainband, while the second transition had a slantwise wind shift zone from westerly ahead to northwesterly behind. The frontal zone was quite narrow (similar to5 km wide) and nearly vertical below 850 mb, and its width increased by 1-2 orders of magnitude above 850 mb. Well before the frontal landfall, low-level flow to the west of the Olympics was associated with geostrophic balance in the cross-shore direction and downgradient acceleration in the alongshore direction, which contributed to the formation of strong coastal southerlies roughly within similar to 130 km off the coast. The front started weakening approximately 80 km upstream from the coast. As the front moved closer to the coast, the westerly wind component decreased toward the coastline, which was contributed by both an offshore-directed pressure gradient force and friction as suggested by the force balance result. During landfall, the thermal evolution indicated that the low-level front was delayed by the Olympics, while it could advance farther inland to the north and to the south. Over the water of the Strait of Juan de Fuca the front maintained its integrity at low levels and its thermal gradient even increased as a result of tilting effect, in contrast to the distinct weakening over land. After the frontal landfall, strong northwesterly flow behind the front was greatly modified by the mountains: winds over the ocean were forced to turn into more westerly, and winds over the barrier were substantially disturbed. C1 Natl Taiwan Normal Univ, Dept Earth Sci, Taipei 116, Taiwan. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. NOAA, ERL, Environm Technol Lab, Boulder, CO USA. RP Chien, FC (reprint author), Natl Taiwan Normal Univ, Dept Earth Sci, 88,Sect 4,Ting Chou Rd, Taipei 116, Taiwan. NR 55 TC 13 Z9 14 U1 0 U2 0 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. PY 2001 VL 129 IS 5 BP 934 EP 955 DI 10.1175/1520-0493(2001)129<0934:AOANSO>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 429HN UT WOS:000168510700002 ER PT J AU Griffies, SM Pacanowski, RC Schmidt, M Balaji, V AF Griffies, SM Pacanowski, RC Schmidt, M Balaji, V TI Tracer conservation with an explicit free surface method for z-coordinate ocean models SO MONTHLY WEATHER REVIEW LA English DT Article ID GENERAL-CIRCULATION MODELS; FLUX; EQUILIBRIUM; COMPUTERS; STABILITY; MOMENTUM; WATER AB This paper details a free surface method using an explicit time stepping scheme for use in z-coordinate ocean models. One key property that makes the method especially suitable for climate simulations is its very stable numerical time stepping scheme, which allows for the use of a long density time step, as commonly employed with coarse-resolution rigid-lid models. Additionally, the effects of the undulating free surface height are directly incorporated into the baroclinic momentum and tracer equations. The novel issues related to local and global tracer conservation when allowing for the top cell to undulate are the focus of this work. The method presented here is quasi-conservative locally and globally of tracer when the baroclinic and tracer time steps are equal. Important issues relevant for using this method in regional as well as large-scale climate models are discussed and illustrated, and examples of scaling achieved on parallel computers provided. C1 NOAA, Geophys Fluid Dynam Lab, Cray SGI, Princeton, NJ 08542 USA. Baltic Sea Res Inst Warnemunde, Rostock, Germany. RP Griffies, SM (reprint author), NOAA, Geophys Fluid Dynam Lab, Cray SGI, POB 308,Forrestal Campus, Princeton, NJ 08542 USA. EM smg@gfdl.gov NR 48 TC 65 Z9 67 U1 0 U2 5 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. PY 2001 VL 129 IS 5 BP 1081 EP 1098 DI 10.1175/1520-0493(2001)129<1081:TCWAEF>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 429HN UT WOS:000168510700009 ER PT J AU Yu, CK Jou, BJD Jorgensen, DP AF Yu, CK Jou, BJD Jorgensen, DP TI Retrieved thermodynamic structure of a subtropical, orographically influenced, quasi-stationary convective line SO MONTHLY WEATHER REVIEW LA English DT Article ID DUAL-DOPPLER DATA; MIDLATITUDE SQUALL LINE; KINEMATIC STRUCTURE; PERTURBATION PRESSURE; RADAR DATA; MESOSCALE; TAMEX; SIMULATION; EVOLUTION; COPT-81 AB Airborne Doppler radar and flight-level measurements were used to document the three-dimensional thermodynamic structure of a convective line that developed off the southeastern coast of Taiwan on 16 June 1987 during the Taiwan Area Mesoscale Experiment. During the period of aircraft observation the convective line appeared to be quasi-stationary in a region similar to 90 km away from the coast. Calculations of perturbation pressure and buoyancy retrieved from the Doppler-radar-derived wind fields show that a high pressure perturbation associated with negative buoyancy existed in the region of heavy precipitation in the lowest level. In low levels, an elongated zone of low pressure was documented along the line, which was closely related to the distributions of buoyancy. These retrieved features are basically consistent with those calculated from in situ observations. In mid- to upper levels, the high (low) pressure perturbation lay around the updraft cores on the upshear (downshear) of environmental shear. The quantitative diagnosis for the perturbation pressure indicates that the positive buoyancy associated with the in-cloud latent heat release as well as evaporative cooling occurring near cloud base and subcloud regions is crucial to determine the low-level perturbation pressure distributions. However, dynamic forcing contributing to the pressure perturbation cannot be ignored in middle levels, because of updraft-shear interaction due to the presence of pronounced cross-line wind shear and corresponding updrafts reaching maximum values near midtroposphere. In distinct contrast to squall lines, which are rapidly moving, the near-surface temperature gradient across this quasi-stationary line was very weak, and at low levels no gust front, rear inflow, or dynamically induced high pressure was evident near the leading edge of the line. Analyses presented here suggest that the persistent, stationary convergence, in association with the deceleration of low-level southeasterly flow as it approached the nearshore blocked flow, played an important role in maintaining and organizing the deep convection in this case. C1 Natl Taiwan Univ, Dept Atmospher Sci, Taipei, Taiwan. NOAA, Natl Severe Storms Lab, Mesoscale Res Div, Boulder, CO USA. RP Jou, BJD (reprint author), Natl Taiwan Univ, Dept Atmospher Sci, 61 Ln 144,Sec 4 Keelung Rd, Taipei, Taiwan. RI Yu, Cheng-Ku/C-3066-2011; OI JOU, BEN JONG DAO/0000-0001-5715-042X; Yu, Cheng-Ku/0000-0002-5522-4998 NR 42 TC 5 Z9 5 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. PY 2001 VL 129 IS 5 BP 1099 EP 1116 DI 10.1175/1520-0493(2001)129<1099:RTSOAS>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 429HN UT WOS:000168510700010 ER PT J AU Janjic, ZI Gerrity, JP Nickovic, S AF Janjic, ZI Gerrity, JP Nickovic, S TI An alternative approach to nonhydrostatic modeling SO MONTHLY WEATHER REVIEW LA English DT Article ID STEP-MOUNTAIN COORDINATE; HYDROSTATIC-PRESSURE; INTEGRATION; EQUATIONS; SCHEMES AB An alternative approach to the design of nonhydrostatic numerical weather prediction (NWP) models is presented. Instead of extending mesoscale nonhydrostatic modeling concepts to the synoptic scales and beyond, a hydrostatic NWP model using the mass-based sigma vertical coordinate has been extended to include the nonhydrostatic motions, preserving the favorable features of the hydrostatic formulation. In order to do so, the system of nonhydrostatic equations was split into two parts: (a) the part that corresponds to the hydrostatic system, except for higher-order corrections due to the vertical acceleration, and (b) the system of equations that allows computation of the corrections appearing in the first system due to the vertical acceleration. This procedure does not require any linearization or approximation. With this approach, the nonhydrostatic dynamics has been introduced through an add-on nonhydrostatic module. The separation of the nonhydrostatic contributions shows in a transparent way where, how, and to what extent relaxing the hydrostatic approximation affects the hydrostatic equations. The nonhydrostatic module can be turned on and off depending on resolution, so that the model can be run in the hydrostatic mode at lower resolutions with no extra cost. This also allows easy comparison of hydrostatic and nonhydrostatic solutions obtained using otherwise identical model. The nonhydrostatic model developed appears to be computationally robust at all resolutions and efficient in NWP applications. With the current coding, the extra computational effort needed due to the nonhydrostatic extension is of the order of 20% of that required by the hydrostatic dynamics, both in terms of computer time and memory. Compared to the hydrostatic version of the model, no additional computational boundary conditions are needed in real data runs. At lower resolutions, in the hydrostatic limit, the forecasts of traditional meteorological parameters obtained using the hydrostatic and the nonhydrostatic modes are almost indistinguishable. The model also demonstrated the presence of important two-dimensional nonhydrostatic effects at very high horizontal resolutions. At these scales, the nonhydrostatic model was generally more robust than the hydrostatic one and produced smoother solutions. The impact of the nonhydrostatic dynamics appears to be weak at the horizontal resolutions of about 8 km. However, a visible effect on the orographic precipitation was detected. In addition to that, the nonhydrostatic deviation of pressure made a significant small-scale contribution to the pressure gradient force at places. The proposed approach appears well suited for models designed for a wide range of horizontal resolutions, and in particular for unified global and regional forecasting systems. Being developed from an existing model, the new model requires only minimal changes to the existing preprocessing and postprocessing infrastructure. C1 NCEP, EMC, Camp Springs, MD 20746 USA. Univ Malta, ICoD, Valetta, Malta. RP Janjic, ZI (reprint author), NCEP, WWB, Rm 207,5200 Auth Rd, Camp Springs, MD 20746 USA. NR 24 TC 122 Z9 123 U1 1 U2 10 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. PY 2001 VL 129 IS 5 BP 1164 EP 1178 DI 10.1175/1520-0493(2001)129<1164:AAATNM>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 429HN UT WOS:000168510700014 ER PT J AU Vickers, D Mahrt, L Sun, JL Crawford, T AF Vickers, D Mahrt, L Sun, JL Crawford, T TI Structure of offshore flow SO MONTHLY WEATHER REVIEW LA English DT Article ID CONVECTIVE TURBULENCE; FLUX; LAYER; DECAY AB The horizontal and vertical structure of the mean flow and turbulent fluxes are examined using aircraft observations taken near a barrier island on the east coast of the United States during offshore flow periods. The spatial structure is strongly influenced by the surface roughness and surface temperature discontinuities at the coast. With offshore flow of warm air over cool water, the sea surface momentum flux is large near the coast and decreases rapidly with increasing offshore distance or travel time. The decrease is attributed to advection and decay of turbulence from land. The rate of decrease is dependent on the characteristic timescale of the eddies in the upstream land-based boundary layer that are advected over the ocean. As a consequence, the air-sea momentum exchange near the coast is influenced by upstream conditions and similarity theory is not adequate to predict the flux. The vertical structure reveals an elevated layer of downward momentum flux and turbulence energy maxima over the ocean. This increase in the momentum flux with height contributes to acceleration of the low-level mean wind. In the momentum budget, the vertical advection term, vertical flux divergence term, and the horizontal pressure gradient term are all of comparable magnitude and all act to balance large horizontal advection. An interpolation technique is applied to the aircraft data to develop fetch-height cross sections of the mean flow and momentum flux that are suitable for future verification of numerical models. C1 Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NOAA, FRD, Idaho Falls, ID USA. RP Vickers, D (reprint author), Oregon State Univ, Coll Ocean & Atmospher Sci, Oceanog Adm Bldg 104, Corvallis, OR 97331 USA. RI Sun, Jielun/H-6576-2015 OI Sun, Jielun/0000-0003-3271-7914 NR 17 TC 26 Z9 26 U1 0 U2 5 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. PY 2001 VL 129 IS 5 BP 1251 EP 1258 DI 10.1175/1520-0493(2001)129<1251:SOOF>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 429HN UT WOS:000168510700021 ER PT J AU Steenburgh, WJA Onton, DJ AF Steenburgh, WJA Onton, DJ TI Multiscale analysis of the 7 December 1998 Great Salt Lake-effect snowstorm SO MONTHLY WEATHER REVIEW LA English DT Article ID EFFECT SNOW; DATA ASSIMILATION; MESOSCALE MODELS; HORIZONTAL-ROLL; BOUNDARY-LAYER; MICHIGAN; FLOW; SIMULATION; CONVECTION; SCHEME AB The large-scale and mesoscale structure of the Great Salt Lake-effect snowstorm of 7 December 1998 is examined using radar analyses, high-density surface observations, conventional meteorological data, and a simulation by the Pennsylvania State University-National Center for Atmospheric Research fifth generation Mesoscale Model (MM5). Environmental conditions during the event were characterized by a lake-700-hPa temperature difference of up to 22.5 degreesC, a lake-land temperature difference as large as 10 degreesC, and conditionally unstable low-level lapse rates. The primary snowband of the event formed along a land-breeze front near the west shoreline of the Great Salt Lake. The snowband then migrated eastward and merged with a weaker snowband as the land-breeze front moved eastward, offshore flow developed from the eastern shoreline, and low-level convergence developed near the midlake axis. Snowfall accumulations reached 36 cm and were heaviest in a narrow, 10-km-wide band that extended downstream from the southern shore of the Great Salt Lake. Thus, although the Great Salt Lake is relatively small in scale compared to the Great Lakes, it is capable of inducing thermally driven circulations and banded precipitation structures similar to those observed in lake-effect regions of the eastern United States and Canada. C1 Univ Utah, Dept Meteorol, Salt Lake City, UT 84112 USA. Univ Utah, NOAA, Cooperat Inst Reg Predict, Salt Lake City, UT 84112 USA. RP Steenburgh, WJA (reprint author), Univ Utah, Dept Meteorol, 135 S 1460 E Room 819, Salt Lake City, UT 84112 USA. NR 42 TC 27 Z9 31 U1 0 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. PY 2001 VL 129 IS 6 BP 1296 EP 1317 DI 10.1175/1520-0493(2001)129<1296:MAOTDG>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 434FT UT WOS:000168805000002 ER PT J AU Onton, DJ Steenburgh, WJA AF Onton, DJ Steenburgh, WJA TI Diagnostic and sensitivity studies of the 7 December 1998 Great Salt Lake-effect snowstorm SO MONTHLY WEATHER REVIEW LA English DT Article ID BOUNDARY-LAYER; EFFECT SNOW; AIR-FLOW; MICHIGAN; MODEL; STORMS AB The processes responsible for the Great Salt Lake-effect snowstorm of 7 December 1998 are examined using a series of mesoscale model simulations. Localized surface sensible and latent heating are shown to destabilize the boundary layer over the Great Salt Lake (GSL) and to produce mesoscale pressure troughing, land-breeze circulations, and low-level convergence that lead to the development of the primary band of convective clouds and precipitation. Model diagnostics and sensitivity studies further illustrate that . moisture fluxes from the lake surface were necessary to fully develop the snowband; . the hypersaline composition of the GSL did, however, decrease moisture fluxes compared to a body of freshwater, resulting in a 17% reduction of snowfall; . latent heat release within the cloud and precipitation band intensified overlake pressure troughing, convergence, and precipitation; . orographic effects were not responsible for snowband generation, but they did affect the distribution and intensity of precipitation in regions where the snowband interacted with downstream terrain; and . surface roughness contrasts across the GSL shoreline did not play a primary role in forming the snowband. Simulations in which lake-surface temperature and upstream moisture were modified are used to illustrate how small errors in the specification of these quantities can impact quantitative precipitation forecasts, potentially limiting the utility of high-resolution mesoscale model guidance. Results are compared to those from studies of lake-effect precipitation over the Great Lakes, and the implications for operational forecasting and numerical weather prediction are discussed. C1 Univ Utah, Dept Meteorol, Salt Lake City, UT 84112 USA. Univ Utah, NOAA, Cooperat Inst Reg Predict, Salt Lake City, UT 84112 USA. RP Onton, DJ (reprint author), Univ Utah, Dept Meteorol, 135 S 1460 E Room 819, Salt Lake City, UT 84112 USA. NR 33 TC 30 Z9 36 U1 1 U2 4 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. PY 2001 VL 129 IS 6 BP 1318 EP 1338 DI 10.1175/1520-0493(2001)129<1318:DASSOT>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 434FT UT WOS:000168805000003 ER PT J AU Ziegler, CL Rasmussen, EN Shepherd, TR Watson, AI Straka, JM AF Ziegler, CL Rasmussen, EN Shepherd, TR Watson, AI Straka, JM TI The evolution of low-level rotation in the 29 May 1994 Newcastle-Graham, Texas, storm complex during VORTEX SO MONTHLY WEATHER REVIEW LA English DT Article ID DUAL-DOPPLER RADAR; TORNADIC THUNDERSTORMS; SINGLE-DOPPLER; VORTICITY; DRYLINE; ORIGINS AB This paper reports the results of an analysis of airflow evolution in the tornadic Newcastle-Graham, Texas, storm complex of 29 May 1994. A series of seven pseudo-dual-Doppler analyses from 2242 to 2315 are performed from tail radar observations by the National Oceanic and Atmospheric Administration P-3 aircraft. Subjective analyses of quasi-horizontal single-Doppler radar observations provide a detailed look at structure and evolution of the hook echo and the low-level Newcastle mesocyclone. Special emphasis is placed on the evolution of low-level [i.e., below 1 km above ground level (AGL)] rotation of the parent mesoscale circulation of the Newcastle tornado and the origins of mesoscale rotation preceding tornadogenesis. The structure and evolution of the Newcastle and Graham mesocyclones are compared and contrasted. The airborne Doppler analyses reveal that the tornadic Newcastle cell had supercell characteristics and that the Newcastle storm circulation could be classified as a mesocyclone based on commonly accepted criteria of circulation amplitude, spatial scale, and persistence. The Newcastle mesocyclone initially developed downward from midlevels (i.e., 2-5 km AGL), then transitioned into a subsequent period of rapid low-level stretching intensification and upward growth just prior to the development of an F3 tornado. Single-radar analysis reveals the stretching contraction and intensification of the Newcastle mesocyclone and an embedded tornado cyclone prior to and after tornadogenesis. In contrast, the nontornadic Graham mesocyclone ultimately became rain-filled and transitioned from moderate stretching growth to negative stretching after the development of a central downdraft in low levels, possibly contributing to tornadogenesis failure. Using a hybrid, two-supercell schematic diagram to depict the Newcastle-Graham storm complex, it was concluded that the Newcastle tornado occurred at the traditionally accepted location of a supercell tornado at the point of the warm sector occlusion in the westernmost cell. Computed trajectories based on a Lagrangian solution of the vertical vorticity equation suggested that the midlevel Newcastle mesocyclone was formed by a sequence of tilting of ambient horizontal vorticity followed by stretching intensification in the rotating updrafts. The air parcels that entered the low-level Newcastle mesocyclone initially possessed vertical vorticity of order 10(-3) s(-1), which was subsequently concentrated by stretching upon entering the Newcastle updraft to form the low-level mesocyclone. Though the vorticity dynamical origin of the weak ambient rotation could not be identified, the spatial origins of low-level trajectories that entered the Newcastle mesocyclone were determined to be from a broad area of low-level rainy easterly outflow from the Graham storm. The present findings were compared and contrasted with results of an earlier study of the Newcastle storm. C1 NOAA, Natl Severe Storms Lab, Mesoscale Res Applicat Div, Norman, OK 73069 USA. NOAA, Natl Weather Serv, Tallahassee, FL USA. Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. RP Ziegler, CL (reprint author), NOAA, Natl Severe Storms Lab, Mesoscale Res Applicat Div, 1313 Halley Circle, Norman, OK 73069 USA. NR 43 TC 26 Z9 30 U1 1 U2 1 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. PY 2001 VL 129 IS 6 BP 1339 EP 1368 DI 10.1175/1520-0493(2001)129<1339:TEOLLR>2.0.CO;2 PG 30 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 434FT UT WOS:000168805000004 ER PT J AU Xu, M Stensrud, DJ Bao, JW Warner, TT AF Xu, M Stensrud, DJ Bao, JW Warner, TT TI Applications of the adjoint technique to short-range ensemble forecasting of mesoscale convective systems SO MONTHLY WEATHER REVIEW LA English DT Article ID ATMOSPHERIC PREDICTION SYSTEM; SINGULAR VECTORS; GRAVITY-WAVES; TARGETED OBSERVATIONS; NUMERICAL-SIMULATION; INITIAL CONDITIONS; ETA-MODEL; ASSIMILATION; SENSITIVITY; TESTS AB The feasibility of applying a mesoscale adjoint model to the creation of an ensemble for short-range simulations of mesoscale convective systems (MCSs) is explored. Because past studies show that forecasters routinely improve upon numerical guidance and can identify mesoscale-sized areas of forecast concern with a high level of skill, it is clear that forecasters have insights into the daily weather forecast problems that exceed what can be provided by a numerical weather prediction model. Using an adjoint model, one could develop a system in which a forecaster identifies the area of forecast concern and then designs a set of rapidly produced sensitivity experiments that evaluate the influence of key atmospheric parameters on the model forecast. The output from these sensitivity experiments is then used to create ensemble members for a short-range operational ensemble forecast, which is specifically designed to investigate the forecast concern of the day. This adjoint ensemble approach is tested for the 48-h period beginning 1200 UTC 27 May 1985, in which a long-lived MCS developed underneath a large-scale ridge. A mesoscale adjoint model is used to define the alterations to the model initial conditions necessary to evaluate the influences of key mesoscale structures, which the authors believe have a large influence on later convective development in the model. Results indicate that the adjoint technique is effective in creating the proper directional response in the model simulation. When compared to initial condition and model physics ensembles of this event, the adjoint ensemble produces more variance than the initial condition ensemble and almost as much variance as the model physics ensemble. However, the values of the equitable threat score and the ranked probability score are better for the adjoint ensemble between 6 and 24 h than for either of the other two ensembles. These results suggest that further exploration of ensembles that incorporate the experience and expertise possessed by forecasters is warranted. C1 Natl Ctr Atmospher Res, Res Applicat Program, Boulder, CO 80307 USA. Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Environm Technol Lab, Boulder, CO USA. RP Xu, M (reprint author), Natl Ctr Atmospher Res, Res Applicat Program, POB 3000, Boulder, CO 80307 USA. NR 81 TC 11 Z9 15 U1 0 U2 0 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. PY 2001 VL 129 IS 6 BP 1395 EP 1418 DI 10.1175/1520-0493(2001)129<1395:AOTATT>2.0.CO;2 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 434FT UT WOS:000168805000006 ER PT J AU Coniglio, MC Stensrud, DJ AF Coniglio, MC Stensrud, DJ TI Simulation of a progressive derecho using composite initial conditions SO MONTHLY WEATHER REVIEW LA English DT Article ID MESOSCALE CONVECTIVE SYSTEMS; MIDLATITUDE SQUALL LINE; DENSITY CURRENTS; BOW-ECHO; DOPPLER RADAR; MID-LATITUDE; REAR-INFLOW; PART I; MODEL; SHEAR AB This study focuses on the progressive derecho, a widespread, convectively induced windstorm produced by a mesoscale convective system that often occurs within a relatively benign synoptic-scale environment. Sounding data from 12 progressive derechos, which occurred in weakly forced large-scale environments, are composited in order to examine important large-scale features in the preconvective environment. This analysis captures many features that are common in warm season derecho environments, such as an upper-level wind maximum, a relatively dry midtroposphere, and low-level warm advection. Initial and boundary conditions for the Pennsylvania State University-National Center for Atmospheric Research fifth-generation Mesoscale Model (MM5) are created using this analysis. A three-dimensional, horizontally nonhomogeneous, explicitly resolved simulation of a progressive derecho is produced and compared to previous, more idealized simulations of similar convective systems that have been used to explain the strength and structure of observed long-lived squall lines and bow echoes. A subset of previous squall line simulations produced within horizontally homogeneous environments without wind shear above 5 km suggests that a balance between the positive vorticity associated with the environmental low-level shear (Deltau) and the negative vorticity created baroclinically at the leading edge of the cold pool (C) is the essential ingredient that determines the strength and time-dependent structure of long-lived squall lines (local balance theory). In the simulation presented here, which occurs in an environment with deep-tropospheric shear but relatively weak low-level shear, the model develops a realistic, rapidly moving squall line with embedded bow echoes that maintains its strength for much longer than the squall lines within previous idealized simulations that develop and evolve within similar less than optimal balance conditions (C/Deltau > 2). Previous simulations of squall lines under similar less than optimal conditions contain updrafts that progressively weaken and become more upshear tilted with time as the cold pool surges ahead of the updrafts within 1-3 h after the system develops. However, the simulated squall line used here contains convective updrafts that remain almost directly above the gust front, maintains a nearly constant upshear tilt for several hours, and produces severe, near-surface winds for over 8 h. Examination of the maximum grid-resolved vertical velocity indicates that the cells are not weakening with time relative to their thermodynamic potential, which contrasts the behavior of the cells within the less than optimal squall lines of the previous, idealized simulations. These results support the idea that local balance theory, which attempts to explain both the strength and longevity of squall lines, may be incomplete within environments that often favor warm season progressive derechos. In particular, tests with a simple two-dimensional cloud-scale model indicate that both significant upper-tropospheric shear above 5 km (which is found in the composite analysis and in the MM5 solution) and low-level shear play significant roles in maintaining the strength of squall lines over long periods and need to be considered in order to fully understand and forecast these events. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. RP Coniglio, MC (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 68 TC 45 Z9 47 U1 2 U2 6 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. PY 2001 VL 129 IS 7 BP 1593 EP 1616 DI 10.1175/1520-0493(2001)129<1593:SOAPDU>2.0.CO;2 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 445AQ UT WOS:000169435300001 ER PT J AU Camp, JP Montgomery, MT AF Camp, JP Montgomery, MT TI Hurricane maximum intensity: Past and present SO MONTHLY WEATHER REVIEW LA English DT Article ID SEA INTERACTION THEORY; VORTEX ROSSBY-WAVES; TROPICAL CYCLONES; SPIRAL BANDS; MODEL; CYCLOGENESIS; ENERGETICS; DYNAMICS AB Hurricane intensity forecasting has lagged far behind the forecasting of hurricane track. In an effort to improve the understanding of the hurricane intensity dilemma, several attempts have been made to compute an upper bound on the intensity of tropical cyclones. This paper investigates the strides made into determining the maximum intensity of hurricanes. Concentrating on the most recent attempts to understand the maximum intensity problem, the theories of Holland and Emanuel are reviewed with the objective of assessing their validity in real tropical cyclones. Each theory is then tested using both observations and the axisymmetric hurricane numerical models of Ooyama and Emanuel. It is found that ambient convective instability plays a minor role in the determination of the maximum intensity and that the Emanuel model is the closest to providing a useful calculation of maximum intensity. Several shortcomings are revealed in Emanuel's theory, however, showing the need for more basic research on the axisymmetric and asymmetric dynamics of hurricanes. As an illustration of the importance of asymmetric vorticity dynamics in the determination of a hurricane's maximum intensity it is shown, using Ooyama's hurricane model, that the maximum intensity of a tropical cyclone may be diminished by convectively generated vorticity anomolies excited outside the primary eyewall. The vorticity anomolies are parameterized by adding a concentric ring of vorticity outside the primary eyewall that acts to cut off its supply of angular momentum and moist enthalpy. It is suggested that the generation of vorticity rings (or bands) outside the primary eyewall is a major reason why tropical cyclones fail to attain their maximum intensity even in an otherwise favorable environment. The upshot of this work points to the need for obtaining a more complete understanding of asymmetric vorticity processes in hurricanes and their coupling to the boundary layer and convection. C1 Natl Weather Serv, Sterling, VA 20166 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RP Camp, JP (reprint author), Natl Weather Serv, 44087 Weather Serv Rd, Sterling, VA 20166 USA. NR 38 TC 50 Z9 51 U1 0 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. PY 2001 VL 129 IS 7 BP 1704 EP 1717 DI 10.1175/1520-0493(2001)129<1704:HMIPAP>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 445AQ UT WOS:000169435300007 ER PT J AU Penland, C Matrosova, L AF Penland, C Matrosova, L TI Expected and actual errors of linear inverse model forecasts SO MONTHLY WEATHER REVIEW LA English DT Article ID EL-NINO; OSCILLATION AB The authors discuss forecast uncertainty, which should be employed for the purpose of judging prediction model performance, and actual forecast errors, which can be employed by users to judge the reliability of the forecasts. Realistic a priori estimates of forecast uncertainty for linear inverse modeling sea surface temperature predictions are presented and compared with the actual forecast errors occurring during the course of real-time predictions. The a priori estimates are of size similar to the actual errors except during the warmest phase of observed El Nino events. C1 NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO 80305 USA. RP Penland, C (reprint author), NOAA, CIRES, Climate Diagnost Ctr, R-CDC1,325 Broadway, Boulder, CO 80305 USA. NR 12 TC 10 Z9 10 U1 0 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. PY 2001 VL 129 IS 7 BP 1740 EP 1745 DI 10.1175/1520-0493(2001)129<1740:EAAEOL>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 445AQ UT WOS:000169435300010 ER PT J AU Lehmiller, GS Bluestein, HB Neiman, PJ Ralph, FM Feltz, WF AF Lehmiller, GS Bluestein, HB Neiman, PJ Ralph, FM Feltz, WF TI Wind structure in a supercell thunderstorm as measured by a UHF wind profiler SO MONTHLY WEATHER REVIEW LA English DT Article ID DOPPLER RADAR OBSERVATIONS; SPECTRAL MOMENT DATA; GRAVITY-WAVES; PRECIPITATION; STORM; CLOUD; HAIL; CLASSIFICATION; MESOCYCLONES; OKLAHOMA AB A mesocyclone associated with a tornadic supercell passed almost directly over the Lamont, Oklahoma, 404-MHz wind profiler on 24 May 1998. The archived spectral moment data, including 6-min resolution radial velocity measurements from the vertical and two oblique beams of the profiler, provided a rare opportunity to construct a detailed time-height section of the three-dimensional wind structure of a severe convective storm near and in its mesocyclone. Supplemental information used to create this cross section was provided by nearby operational Next Generation Weather Radar/Weather Surveillance Radar (NEXRAD/WSR-88D) radars, as well as visual and surface observations. The most difficult challenge in analyzing the profiler data was the removal of hydrometeor fall-speed contamination in order to determine the true air motions. Since the profiler beams saturate under heavy precipitation conditions, the use of the returned signal power in the profiler beams to estimate precipitation fall speeds was not reliable. To overcome this difficulty, radar reflectivity data from four surrounding NEXRAD/WSR-88D radars were objectively analyzed for the region scanned by the profiler. The components of vertical velocity due to precipitation were then estimated by developing empirical statistical models between the objectively analyzed reflectivity factors and profiler-measured vertical velocities located well outside the storm updraft. This technique was successful in that it removed fully 80% of the explainable variance associated with the precipitation fall speeds; the corresponding estimated expected error, on the order of 1 m s(-1), was fully one magnitude smaller than the scale of the measured vertical velocities within the updraft. Although the recovery of the horizontal winds was less successful than the recovery of the vertical velocities, horizontal winds were recoverable in regions where the horizontal vertical velocity gradient was reduced, and where corroborated by observations from nearby operational NEXRAD radars. The resulting time-height cross section of wind exhibited a region of strong updraft near and in the mesocyclone and downdraft flanking it. Weak downdrafts were also present at low levels surrounding the region of strongest updraft. The updraft peak velocity of 50 m s(-1) represents one of the largest vertical velocities ever measured in a convective storm. Evidence is presented of significant modification of the horizontal wind structure away from the updraft and of storm-generated buoyancy waves in the surrounding environment. C1 Univ Oklahoma, Sch Meteorol, Norman, OK 73019 USA. NOAA, ERL, Environm Technol Lab, Boulder, CO 80303 USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI USA. RP Bluestein, HB (reprint author), Univ Oklahoma, Sch Meteorol, 100 E Boyd,Room 1310, Norman, OK 73019 USA. NR 45 TC 8 Z9 9 U1 0 U2 5 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. PY 2001 VL 129 IS 8 BP 1968 EP 1986 DI 10.1175/1520-0493(2001)129<1968:WSIAST>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 454XF UT WOS:000169996500010 ER PT J AU Gudgel, RG Rosati, A Gordon, CT AF Gudgel, RG Rosati, A Gordon, CT TI The sensitivity of a coupled atmospheric-oceanic GCM to prescribed low-level clouds over the ocean and tropical landmasses SO MONTHLY WEATHER REVIEW LA English DT Article ID GENERAL-CIRCULATION MODELS; PACIFIC; PARAMETERIZATION; CLIMATOLOGIES; SYSTEM AB The sensitivity of a coupled general circulation model (CGCM) to tropical marine stratocumulus (MSc) clouds and low-level clouds over the tropical land is examined. The hypothesis that low-level clouds play an important role in determining the strength and position of the Walker circulation and also on the strength and phase of the El Nino-Southern Oscillation (ENSO) is studied using a Geophysical Fluid Dynamics Laboratory (GFDL) experimental prediction CGCM. In the Tropics, a GFDL experimental prediction CGCM exhibits a strong bias in the western Pacific where an eastward shift in the ascending branch of the Walker circulation diminishes the strength and expanse of the sea surface temperature (SST) warm pool, thereby reducing the east-west SST gradient, and effectively weakening the trade winds. These model features are evidence of a poorly simulated Walker circulation, one that mirrors a "perpetual El Nino" state. One possible factor contributing to this bias is a poor simulation of MSc clouds in the eastern equatorial Pacific (which are essential to a proper SST annual cycle). Another possible contributing factor might be radiative heating biases over the land in the Tropics, which could, in turn, have a significant impact on the preferred locations of maximum convection in the Tropics. As a means of studying the sensitivity of a CGCM to both MSc clouds and to varied radiative forcing over the land in the Tropics, low-level clouds obtained from the International Satellite Cloud Climatology Project (ISCCP) are prescribed. The experiment sets consist of one where clouds are fully predicted, another where ISCCP low-level clouds are prescribed over the oceans alone, and a third where ISCCP low-level clouds are prescribed both over the global oceans and over the tropical landmasses. A set of ten 12-month hindcasts is performed for each experiment. The results show that the combined prescription of interannually varying global ocean and climatological tropical land low-level clouds into the CGCM results in a much improved simulation of the Walker circulation over the Pacific Ocean. The improvement to the tropical circulation was also notable over the Indian and Atlantic basins as well. These improvements in circulation led to a considerable increase in ENSO hindcast skill in the first year by the CGCM. These enhancements were a function of both the presence of MSc clouds over the tropical oceans and were also due to the more realistic positioning of the regions of maximum convection in the Tropics. This latter model feature was essentially a response to the change in radiative forcing over tropical landmasses associated with a reduction in low cloud fraction and optical depth when ISCCP low-level clouds were prescribed there. These results not only underscore the importance of a reasonable representation of MSc clouds but also point out the considerable impact that radiative forcing over the tropical landmasses has on the simulated position of the Walker circulation and also on ENSO forecasting. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08543 USA. RP Gudgel, RG (reprint author), NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08543 USA. NR 25 TC 8 Z9 9 U1 0 U2 1 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. PY 2001 VL 129 IS 8 BP 2103 EP 2115 DI 10.1175/1520-0493(2001)129<2103:TSOACA>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 454XF UT WOS:000169996500018 ER PT J AU Xu, Q Wei, L Van Tuyl, A Barker, EH AF Xu, Q Wei, L Van Tuyl, A Barker, EH TI Estimation of three-dimensional error covariances. Part I: Analysis of height innovation vectors SO MONTHLY WEATHER REVIEW LA English DT Article ID INTERPOLATION ANALYSIS SYSTEM; RANGE FORECAST ERRORS; STATISTICAL-INTERPOLATION; PREDICTION SYSTEMS; RADIOSONDE DATA AB The statistical analysis of innovation (observation minus forecast) vectors is one of the most commonly used techniques for estimating observation and forecast error covariances in large-scale data assimilation. Building on the work of Hollingsworth and Lonnberg, the height innovation data over North America from the Navy Operational Global Atmospheric Prediction System (NOGAPS) are analyzed. The major products of the analysis include (i) observation error variances and vertical correlation functions, (ii) forecast error autocovariances as functions of height and horizontal distance, (iii) their spectra as functions of height and horizontal wavenumber. Applying a multilevel least squares fitting method, which is simpler and more rigorously constrained than that of Hollingsworth and Lonnberg, a full-space covariance function was determined. It was found that removal of the large-scale horizontal component, which has only small variation in the vertical, reduces the nonseparability. The results were compared with those of Hollingsworth and Lonnberg, and show a 20% overall reduction in forecast errors and a 10% overall reduction in observation errors for the NOGAPS data in comparison with the ECMWF global model data 16 yr ago. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. USN, Res Lab, Monterey, CA USA. RP Xu, Q (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 17 TC 18 Z9 32 U1 0 U2 1 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. PY 2001 VL 129 IS 8 BP 2126 EP 2135 DI 10.1175/1520-0493(2001)129<2126:EOTDEC>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 454XF UT WOS:000169996500020 ER PT J AU Romero, R Doswell, CA Riosalido, R AF Romero, R Doswell, CA Riosalido, R TI Observations and fine-grid simulations of a convective outbreak in northeastern Spain: Importance of diurnal forcing and convective cold pools SO MONTHLY WEATHER REVIEW LA English DT Article ID LARGE-SCALE ENVIRONMENTS; NUMERICAL-SIMULATION; ADJUSTMENT SCHEME; SQUALL LINES; MODEL; SYSTEMS; RESOLUTION; TESTS; PARAMETERIZATION; VERIFICATION AB The life cycle and interactions of a series of convective systems that developed in northeastern Spain during the afternoon of 7 August 1996 are examined based on remote sensing products, surface observations, and numerical simulations. Most of the convection was organized in two mesoscale convective systems (MCSs) and a line of storms attached to the Pyrenees Mountains. One of these storms produced rainfalls in excess of 200 mm in 3 h and severe flash floods in the Biescas area. The end of the convection in the Biescas area occurred after merger of the storm with one of the MCSs that approached from the southwest. A high-resolution (4-km grid length) simulation of the event reproduces the observed timing and interactions of the convective systems, as well as the general rainfall pattern. The highly localized rainfall core at Biescas is well located, although the peak rainfall amount is underestimated. The success of the model at triggering the convection at the proper locations and time results from a reasonably accurate prediction of mesoscale features of the low-level flow pattern, such as a thermal mesolow in the Ebro valley, deformation zone, upslope wind systems, and the pushing of a cold front in the upper portion of the valley. After the onset of the initial convection, the role of the convectively induced cold pools and outflows for the propagation of the convective systems is shown to be very important. In particular, the MCS interacting with the Biescas convection was driven by strong mesoscale ascent established between the convectively induced outflows, the upvalley southeasterly winds sustained by the mesolow, and the downvalley northwesterly winds associated with the cold front. After the interaction, the convection in Biescas ceased because of the interruption of the southerly upslope flow caused by the convective cold pools. Finally, the explosive character of convection after noon and its initial focusing in uplands and slopes suggest that diurnal forcing could have played a decisive role. This idea is validated by means of simulations. C1 NOAA, Natl Severe Storms Lab, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK USA. Inst Nacl Meteorol, Madrid, Spain. RP Romero, R (reprint author), Univ Illes Balears, Dept Fis, E-07071 Palma de Mallorca, Spain. RI Doswell III, Charles/E-7662-2010 NR 38 TC 26 Z9 30 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. PY 2001 VL 129 IS 9 BP 2157 EP 2182 DI 10.1175/1520-0493(2001)129<2157:OAFGSO>2.0.CO;2 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 465XN UT WOS:000170615400001 ER PT J AU Hane, CE Baldwin, ME Bluestein, HB Crawford, TM Rabin, RM AF Hane, CE Baldwin, ME Bluestein, HB Crawford, TM Rabin, RM TI A case study of severe storm development along a dryline within a synoptically active environment. Part I: Dryline motion and an Eta Model forecast SO MONTHLY WEATHER REVIEW LA English DT Article ID MOBILE SOUNDING OBSERVATIONS; HORIZONTAL CONVECTIVE ROLLS; BOUNDARY-LAYER; FINESCALE STRUCTURE; TEXAS STORM; COPS-91; COORDINATE; DYNAMICS; SCHEME; BOMEX AB Through a case study approach the motion of a dryline (on 16 May 1991) within a synoptically active environment in the southern plains, along which severe storms ultimately developed, is examined in detail. Observations from research aircraft, surface mesonetwork stations, mobile ballooning vehicles, radar, wind profilers, and operational surface and upper air networks are examined and combined. Additionally, output from the operational mesoscale Eta Model is examined to compare predictions of dryline motion with observations and to aid in interpretation of observations. The dryline on this day advanced rapidly eastward and included formation of a bulge; additionally, in at least two instances it exhibited redevelopment (loss of definition at one location and gain at another). Aircraft observations revealed that an eastward redevelopment occurred in the early afternoon and was characterized by a series of four "steps'' along the western edge of the boundary layer moisture. The westernmost and easternmost steps coincide with the locations of the dryline before and after redevelopment, respectively. The retreat of the dryline in the central and southern portion of the analysis domain in the late afternoon included both continuous motion and redevelopment toward the west-northwest. This dual-mode retreat of the dryline was accompanied by gradual backing of the winds and moistening in low levels. The Eta Model forecast initialized at 1200 UTC produced dryline features that were qualitatively similar to observed fields. The eastward motion of a broad area of enhanced moisture gradient agreed well with observations following an initial spinup period. A north-south moisture convergence axis preceded the rapid eastward motion of the dryline by several hours. Lack of subsidence in the air behind the modeled dryline leads to the conclusion that processes other than downward transfer of horizontal momentum by larger-scale motions (that would support eastward advection) produced the rapid dryline motion and observed eastward dryline bulge. Results of diagnosing physical processes affecting model dryline motion point toward boundary layer vertical mixing coupled with advection of dry air aloft as vital components in rapid advance of the dryline eastward in this synoptically active case. C1 NOAA, Natl Severe Storms Lab, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73069 USA. NOAA, NWS, Storm Predict Ctr, Norman, OK USA. Univ Oklahoma, Sch Meteorol, Norman, OK USA. RP Hane, CE (reprint author), NOAA, Natl Severe Storms Lab, Cooperat Inst Mesoscale Meteorol Studies, 1313 Halley Circle, Norman, OK 73069 USA. NR 42 TC 21 Z9 21 U1 0 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. PY 2001 VL 129 IS 9 BP 2183 EP 2204 DI 10.1175/1520-0493(2001)129<2183:ACSOSS>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 465XN UT WOS:000170615400002 ER PT J AU Schultz, DM AF Schultz, DM TI Reexamining the cold conveyor belt SO MONTHLY WEATHER REVIEW LA English DT Article ID LAGRANGIAN-BASED ANALYSIS; PRESIDENTS DAY CYCLONE; FRONTAL CYCLONE; EXTRATROPICAL CYCLONES; MIDLATITUDE CYCLONE; POTENTIAL VORTICITY; ROCKY-MOUNTAINS; MARINE CYCLONE; SEVERE WEATHER; AIR-FLOW AB Despite the popularity of the conveyor-belt model for portraying the airflow through midlatitude cyclones, questions arise as to the path of the cold conveyor belt, the lower-tropospheric airflow poleward of and underneath the warm front. Some studies, beginning with Carlson's analysis of the eastern U.S. cyclone of 5 December 1977, depict the cold conveyor belt moving westward, reaching the northwest quadrant of the storm, turning abruptly anticyclonically, rising to jet level, and departing the cyclone downstream (hereafter, the anticyclonic path). Other studies depict the cold conveyor belt reaching the northwest quadrant, turning cyclonically around the low center, and remaining in the lower troposphere (the cyclonic path). To clarify the path of the cold conveyor belt, the present study reexamines Carlson's analysis of the cold conveyor belt using an observational and mesoscale numerical modeling study of the 5 December 1977 cyclone. This reexamination raises several previously unappreciated and underappreciated issues. First, airflow in the vicinity of the warm front is shown to be composed of three different airstreams: air-parcel trajectories belonging to the ascending warm conveyor belt, air-parcel trajectories belonging to the cyclonic path of the cold conveyor belt that originate from the lower troposphere, and air-parcel trajectories belonging to the anticyclonic path of the cold conveyor belt that originate within the midtroposphere. Thus, the 5 December 1977 storm consists of a cold conveyor belt with both cyclonic and anticyclonic paths. Second, the anticyclonic path represents a transition between the warm conveyor belt and the cyclonic path of the cold conveyor belt, which widens with height. Third, the anticyclonic path of the cold conveyor belt is related to the depth of the closed circulation associated with the cyclone, which increases as the cyclone deepens and evolves. When the closed circulation is strong and deep, the anticyclonic path of the cold conveyor belt is not apparent and the cyclonic path of the cold conveyor belt dominates. Fourth, Carlson's analysis of the anticyclonic path of the cold conveyor belt was fortuitous because his selection of isentropic surface occurred within the transition zone, whereas, if a slightly colder isentropic surface were selected, the much broader lower-tropospheric cyclonic path would have been evident in his analysis instead. Finally, whereas Carlson concludes that the clouds and precipitation in the cloud head were associated with the anticyclonic path of the cold conveyor belt, results from the model simulation suggest that the clouds and precipitation originated within the ascending warm conveyor belt. As a consequence of the reexamination of the 5 December 1977 storm using air-parcel trajectories, this paper clarifies the structure of and terminology associated with the cold conveyor belt. It is speculated that cyclones with well-defined warm fronts will have a sharp demarcation between the cyclonic and anticyclonic paths of the cold conveyor belt. In contrast, cyclones with weaker warm fronts will have a broad transition zone between the two paths. Finally, the implications of this research for forecasting warm-frontal precipitation amount and type are discussed. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. RP Schultz, DM (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. RI Schultz, David M./A-3091-2010 OI Schultz, David M./0000-0003-1558-6975 NR 93 TC 51 Z9 52 U1 1 U2 9 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. PY 2001 VL 129 IS 9 BP 2205 EP 2225 DI 10.1175/1520-0493(2001)129<2205:RTCCB>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 465XN UT WOS:000170615400003 ER PT J AU Revell, MJ Kidson, JW Kiladis, GN AF Revell, MJ Kidson, JW Kiladis, GN TI Interpreting low-frequency modes of Southern Hemisphere atmospheric variability as the rotational response to divergent forcing SO MONTHLY WEATHER REVIEW LA English DT Article ID ROSSBY-WAVE PROPAGATION; EXTRATROPICAL CIRCULATION; BAROCLINIC ATMOSPHERE; PERSISTENT ANOMALIES; TROPICAL CONVECTION; FLOW; TELECONNECTIONS; DYNAMICS; PACIFIC; TOGA AB The principal modes of Southern Hemisphere low-frequency variability have recently been calculated using a 39-yr record of 300-hPa streamfunction fields from the NCEP-NCAR reanalysis dataset. The authors attempt to interpret these modes as the rotational response to some divergent forcing. For a range of mean states the linearized barotropic vorticity equation (BVE) is used to solve for the divergent wind that would generate (or at least be consistent with) the observed vorticity modes. Several of these low-frequency modes can be generated by forcing the BVE with fairly simple divergent wind fields that could easily be interpreted as resulting from anomalous tropical convection. In particular this is found to be true for streamfunction anomalies with El Nino-Southern Oscillation (ENSO), high-latitude mode, South Pacific wave, and Madden-Julian oscillation structure. The authors speculate that it may be possible to relate these calculated divergent wind fields to recently observed OLR fields and hence explain some of the variance of the next month's 300-hPa streamfunction by solving the inverse problem. These results are further evidence that linear Rossby wave propagation provides an important link between anomalous convection in the Tropics and the occurrence of circulation anomalies in higher latitudes. C1 Natl Inst Water & Atmospher Res, Wellington, New Zealand. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Natl Inst Water & Atmospher Res, POB 14901, Wellington, New Zealand. EM m.revell@niwa.cri.nz NR 29 TC 15 Z9 16 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PY 2001 VL 129 IS 9 BP 2416 EP 2425 DI 10.1175/1520-0493(2001)129<2416:ILFMOS>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 465XN UT WOS:000170615400015 ER PT J AU Hart, RE Grumm, RH AF Hart, RE Grumm, RH TI Using normalized climatological anomalies to rank synoptic-scale events objectively SO MONTHLY WEATHER REVIEW LA English DT Article ID QE-II STORM; DEEPENING EXTRATROPICAL CYCLONE; MARCH 1993 SUPERSTORM; CYCLOGENESIS; EVOLUTION; AGNES; TRANSFORMATION; VORTICITY; LAND AB A method for ranking synoptic-scale events objectively is presented. NCEP 12-h reanalysis fields from 1948 to 2000 are compared to a 30-yr (1961-90) reanalysis climatology. The rarity of an event is the number of standard deviations 1000-200-hPa height, temperature, wind, and moisture fields depart from this climatology. The top 20 synoptic-scale events from 1948 to 2000 for the eastern United States, southeast Canada, and adjacent coastal waters are presented. These events include the "The Great Atlantic Low'' of 1956 (ranked 1st), the "superstorm'' of 1993 (ranked 3d), the historic New England/Quebec ice storm of 1998 (ranked 5th), extratropical storm Hazel of 1954 (ranked 9th), a catastrophic Florida freeze and snow in 1977 (ranked 11th), and the great Northeast snowmelt and flood of 1996 (ranked 12th). During the 53-yr analysis period, only 33 events had a total normalized anomaly (M-TOTAL) of 4 standard deviations or more. An M-TOTAL of 5 or more standard deviations has not been observed during the 53-yr period. An M-TOTAL of 3 or more was observed, on average, once or twice a month. October through January are the months when a rare anomaly (M-TOTAL greater than or equal to 4 standard deviations) is most likely, with April through September the least likely period. The 1960s and 1970s observed the fewest number of monthly top 10 events, with the 1950s, 1980s, and 1990s having the greatest number. A comparison of the evolution of M-TOTAL to various climate indices reveals that only 5% of the observed variance of M-TOTAL can be explained by ENSO, North Atlantic oscillations, or Pacific-North American indices. Therefore, extreme synoptic-scale departures from climatology occur regardless of the magnitude of conventional climate indices, a consequence of a necessary mismatch of temporal and spatial scale representation between the M-TOTAL and climate index measurements. C1 Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Natl Weather Serv, State Coll, PA USA. RP Hart, RE (reprint author), Penn State Univ, Dept Meteorol, 503 Walker Bldg, University Pk, PA 16802 USA. NR 43 TC 53 Z9 56 U1 0 U2 4 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. PY 2001 VL 129 IS 9 BP 2426 EP 2442 DI 10.1175/1520-0493(2001)129<2426:UNCATR>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 465XN UT WOS:000170615400016 ER PT J AU Neiman, PJ Ralph, FM Weber, RL Uttal, T Nance, LB Levinson, DH AF Neiman, PJ Ralph, FM Weber, RL Uttal, T Nance, LB Levinson, DH TI Observations of nonclassical frontal propagation and frontally forced gravity waves adjacent to steep topography SO MONTHLY WEATHER REVIEW LA English DT Article ID WIND-PROFILER OBSERVATIONS; MOUNTAIN LEE WAVES; ROCKY-MOUNTAINS; WEATHER SYSTEMS; STORMS PROJECT; COLD SURGES; RADAR; MESOSCALE; SIMULATIONS; TEMPERATURE AB Through the integrated analysis of remote sensing and in situ data taken along the Front Range of Colorado, this study describes the interactions that occurred between a leeside arctic front and topographically modulated flows. These interactions resulted in nonclassical frontal behavior and structure across northeastern Colorado. The shallow arctic front initially advanced southwestward toward the Front Range foothills, before retreating eastward. Then, a secondary surge of arctic air migrated westward into the foothills. During its initial southwestward advance, the front exhibited obstacle-like, density-current characteristics. Its initial advance was interrupted by strong downslope northwesterly flow associated with a high-amplitude mountain wave downstream of the Continental Divide, and by a temporal decrease in the density contrast across the front due to diurnal heating in the cold air and weak cold advection in the warm air. The direction and depth of flow within the arctic air also influenced the frontal propagation. The shallow, obstacle-like front actively generated both vertically propagating and vertically trapped gravity waves as it advanced into the downslope northwesterly flow, resulting in midtropospheric lenticular wave clouds aloft that tracked with the front. Because the front entered a region where strong downslope winds and mountain waves extended downstream over the high plains, the wave field in northeastern Colorado included both frontally forced and true mountain-forced gravity waves. A sequence of Scorer parameter profiles calculated from hourly observations reveals a sharp contrast between the prefrontal and postfrontal wave environments. Consequently, analytic resonant wave mode calculations based on the Scorer parameter profiles reveal that the waves supported in the postfrontal regime differed markedly from those supported in the prefrontal environment. This result is consistent with wind profiler observations that showed the amplitude of vertical motions decreasing substantially through 16 km above mean sea level (MSL) after the shallow frontal passage. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. US Dept Interior, BLM, Missoula, MT USA. RP Neiman, PJ (reprint author), NOAA, Environm Technol Lab, Mail Code R-E-ET7,325 Broadway, Boulder, CO 80303 USA. NR 64 TC 12 Z9 13 U1 0 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. PY 2001 VL 129 IS 11 BP 2633 EP 2659 DI 10.1175/1520-0493(2001)129<2633:OONFPA>2.0.CO;2 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 480XL UT WOS:000171488500001 ER PT J AU Wheeler, M Weickmann, KM AF Wheeler, M Weickmann, KM TI Real-time monitoring and prediction of modes of coherent synoptic to intraseasonal tropical variability SO MONTHLY WEATHER REVIEW LA English DT Article ID MADDEN-JULIAN OSCILLATION; COUPLED EQUATORIAL WAVES; EXTRATROPICAL INTERACTION; FORECAST SKILL; PRECIPITATION; CLIMATOLOGIES; TEMPERATURE; EPISODES; PACIFIC; CLOUDS AB A technique of near-real-time monitoring and prediction of various modes of coherent synoptic to intraseasonal zonally propagating tropical variability is developed. It involves Fourier filtering of a daily updated global dataset for the specific zonal wavenumbers and frequencies of each of the phenomena of interest. The filtered fields obtained for times before the end of the dataset may be used for monitoring, while the filtered fields obtained for times after the end point may be used as a forecast. Tests of the technique, using satellite-observed outgoing longwave radiation (OLR) data, reveal its skill for monitoring. For prediction, it demonstrates good skill for the Madden-Julian oscillation (MJO), and detectable skill for other convectively coupled equatorial modes, although the decaying amplitude of the predictions with time is a characteristic that users need to be aware of. The skill for the MJO OLR field appears to be equally as good as that obtained by the recent empirical MJO forecast methods developed by Waliser et al., and Lo and Hendon, with a useful forecast out to about 15-20 days. Unlike the previously developed methods, however, the current monitoring and prediction technique is extended to other defined modes of large-scale coherent zonally propagating tropical variability. These other modes are those that appear as equatorial wavelike oscillations in the OLR. For them, the skill shown by this empirical technique, although considerably less than that obtained for the MJO, is still deemed to be high enough for the technique to be sometimes useful, especially when compared to that of a medium-range global numerical weather prediction (NWP) model. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO USA. RP Wheeler, M (reprint author), Bur Meteorol, Res Ctr, POB 1289K, Melbourne, Vic 3001, Australia. RI Wheeler, Matthew/C-9038-2011 OI Wheeler, Matthew/0000-0002-9769-1973 NR 31 TC 114 Z9 126 U1 0 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. PY 2001 VL 129 IS 11 BP 2677 EP 2694 DI 10.1175/1520-0493(2001)129<2677:RTMAPO>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 480XL UT WOS:000171488500003 ER PT J AU Angevine, WM Mitchell, K AF Angevine, WM Mitchell, K TI Evaluation of the NCEP mesoscale Eta Model convective boundary layer for air quality applications SO MONTHLY WEATHER REVIEW LA English DT Article ID STEP-MOUNTAIN ETA; WIND PROFILER; LAND-SURFACE; COORDINATE; ACCURACY; IMPACT AB Atmospheric models are a basic tool for understanding the processes that produce poor air quality, for predicting air quality problems, and for evaluating proposed solutions. At the base of many air quality models is a mesoscale meteorological model. The National Centers for Environmental Prediction (NCEP) is now using a model with spatial resolution better than that used for many previous air quality studies. Mixing depth and wind and temperature profiles in the convective boundary layer are the key parameters that must be predicted correctly by a meteorological model for air quality applications. This paper describes an evaluation of the Eta Model predictions of these parameters based on comparisons to measurements made by boundary layer wind profilers at sites in Illinois and Tennessee. The results indicate that the Eta Model is quite usable as a meteorological driver for air quality modeling under reasonably simple terrain and weather conditions. The model estimates of mixing depth, boundary layer winds, and temperature profiles are reasonably accurate. This performance stems from a combination of recent Eta Model advancements in PBL and surface layer physics, land surface physics, 4D data assimilation, and vertical and horizontal resolution. C1 NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. NCEP, Environm Modeling Ctr, Camp Springs, MD USA. RP Angevine, WM (reprint author), NOAA, Aeron Lab, R-AL3,325 Broadway, Boulder, CO 80303 USA. RI Angevine, Wayne/H-9849-2013 OI Angevine, Wayne/0000-0002-8021-7116 NR 33 TC 14 Z9 16 U1 0 U2 0 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. PY 2001 VL 129 IS 11 BP 2761 EP 2775 DI 10.1175/1520-0493(2001)129<2761:EOTNME>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 480XL UT WOS:000171488500008 ER PT J AU Hamill, TM Whitaker, JS Snyder, C AF Hamill, TM Whitaker, JS Snyder, C TI Distance-dependent filtering of background error covariance estimates in an ensemble Kalman filter SO MONTHLY WEATHER REVIEW LA English DT Article ID QUASI-GEOSTROPHIC MODEL; DATA ASSIMILATION; ANALYSIS SCHEME; PREDICTION; FORECASTS; SYSTEM AB The usefulness of a distance-dependent reduction of background error covariance estimates in an ensemble Kalman filter is demonstrated. Covariances are reduced by performing an element-wise multiplication of the background error covariance matrix with a correlation function with local support. This reduces noisiness and results in an improved background error covariance estimate, which generates a reduced-error ensemble of model initial conditions. The benefits of applying the correlation function can be understood in part from examining the characteristics of simple 2 x 2 covariance matrices generated from random sample vectors with known variances and covariance. These show that noisiness in covariance estimates tends to overwhelm the signal when the ensemble size is small and/or the true covariance between the sample elements is small. Since the true covariance of forecast errors is generally related to the distance between grid points, covariance estimates generally have a higher ratio of noise to signal with increasing distance between grid points. This property is also demonstrated using a two-layer hemispheric primitive equation model and comparing covariance estimates generated by small and large ensembles. Covariances from the large ensemble are assumed to be accurate and are used a reference for measuring errors from covariances estimated from a small ensemble. The benefits of including distance-dependent reduction of covariance estimates are demonstrated with an ensemble Kalman filter data assimilation scheme. The optimal correlation length scale of the filter function depends on ensemble size; larger correlation lengths are preferable for larger ensembles. The effects of inflating background error covariance estimates are examined as a way of stabilizing the filter. It was found that more inflation was necessary for smaller ensembles than for larger ensembles. C1 NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO 80303 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Hamill, TM (reprint author), NOAA, CIRES, Climate Diagnost Ctr, R-CDC1,325 Broadway, Boulder, CO 80303 USA. NR 32 TC 486 Z9 505 U1 3 U2 25 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. PY 2001 VL 129 IS 11 BP 2776 EP 2790 DI 10.1175/1520-0493(2001)129<2776:DDFOBE>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 480XL UT WOS:000171488500009 ER PT J AU Zhang, S Zou, X Ahlquist, JE AF Zhang, S Zou, X Ahlquist, JE TI Examination of numerical results from tangent linear and adjoint of discontinuous nonlinear models SO MONTHLY WEATHER REVIEW LA English DT Article ID VARIATIONAL DATA ASSIMILATION; PARAMETERIZED DISCONTINUITIES; GENERALIZED ADJOINT; PHYSICAL PROCESSES; METEOROLOGICAL OBSERVATIONS; PRECIPITABLE WATER; SPECTRAL MODEL; MINIMIZATION AB The forward model solution and its functional (e.g., the cost function in 4DVAR) are discontinuous with respect to the model's control variables if the model contains discontinuous physical processes that occur during the assimilation window. In such a case, the tangent linear model (the first-order approximation of a finite perturbation) is unable to represent the sharp jumps of the nonlinear model solution. Also, the first-order approximation provided by the adjoint model is unable to represent a finite perturbation of the cost function when the introduced perturbation in the control variables crosses discontinuous points. Using an idealized simple model and the Arakawa-Schubert cumulus parameterization scheme, the authors examined the behavior of a cost function and its gradient obtained by the adjoint model with discontinuous model physics. Numerical results show that a cost function involving discontinuous physical processes is zeroth-order discontinuous, but piecewise differentiable. The maximum possible number of involved discontinuity points of a cost function increases exponentially as 2(kn), where k is the total number of thresholds associated with on-off switches, and n is the total number of time steps in the assimilation window. A backward adjoint model integration with the proper forcings added at various time steps, similar to the backward adjoint model integration that provides the gradient of the cost function at a continuous point, produces a one-sided gradient (called a subgradient and denoted as del (s)J) at a discontinuous point. An accuracy check of the gradient shows that the adjoint-calculated gradient is computed exactly on either side of a discontinuous surface. While a cost function evaluated using a small interval in the control variable space oscillates, the distribution of the gradient calculated at the same resolution not only shows a rather smooth variation, but also is consistent with the general convexity of the original cost function. The gradients of discontinuous cost functions are observed roughly smooth since the adjoint integration correctly computes the one-sided gradient at either side of discontinuous surface. This implies that, although (del (s)J)(T)deltax may not approximate deltaJ = J(x + dx) - J(x) well near the discontinuous surface, the subgradient calculated by the adjoint of discontinuous physics may still provide useful information for finding the search directions in a minimization procedure. While not eliminating the possible need for the use of a nondifferentiable optimization algorithm for 4DVAR with discontinuous physics, consistency between the computed gradient by adjoints and the convexity of the cost function may explain why a differentiable limited-memory quasi-Newton algorithm still worked well in many 4DVAR experiments that use a diabatic assimilation model with discontinuous physics. C1 Princeton Univ, NOAA, GFDL, Princeton, NJ 08542 USA. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. RP Zhang, S (reprint author), Princeton Univ, NOAA, GFDL, Princeton, NJ 08542 USA. NR 34 TC 11 Z9 14 U1 0 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. PY 2001 VL 129 IS 11 BP 2791 EP 2804 DI 10.1175/1520-0493(2001)129<2791:EONRFT>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 480XL UT WOS:000171488500010 ER PT J AU Monteverdi, JP Blier, W Stumpf, G Pi, W Anderson, K AF Monteverdi, JP Blier, W Stumpf, G Pi, W Anderson, K TI First WSR-88D documentation of an anticyclonic supercell with anticyclonic tornadoes: The Sunnyvale-Los Altos, California, tornadoes of 4 May 1998 SO MONTHLY WEATHER REVIEW LA English DT Article ID NORTHERN AB On 4 May 1998, a pair of tornadoes occurred in the San Francisco Bay Area in the cities of Sunnyvale (F2 on the Fujita scale) and Los Altos (F1). The parent thunderstorm was anticyclonically rotating and produced tornadoes that were documented photographically to be anticyclonic as well, making for an extremely rare event. The tornadic thunderstorm was one of several "pulse type'' thunderstorms that developed on outflow boundaries on the left flank of an earlier-occurring thunderstorm east of San Jose. Satellite imagery showed that the tomadic storm moved northwestward along a sea-breeze boundary and ahead of the outflow boundary associated with the prior thunderstorms. The shear environment into which the storm propagated was characterized by a straight hodograph with some cyclonic curvature, and by shear and buoyancy profiles that were favorable for anticyclonically rotating updrafts. Mesoanticyclones were detected in the Monterey (KMUX) radar data in association with each tornado by the National Severe Storm Laboratory's (NSSL) new Mesocyclone Detection Algorithm (MDA) making this the only documented case of a tornadic mesoanticyclone in the United States that has been captured with WSR-88D level-II data. Analysis of the radar data indicates that the initial (Sunnyvale) tornado was not associated with a mesoanticyclone. The satellite evidence suggests that this tornado may have occurred as the storm ingested, tilted, and stretched solenoidally induced vorticity associated with a sea-breeze boundary, giving the initial tornado nonsupercellular characteristics, even though the parent thunderstorm itself was an anticyclonic supercell. The radar-depicted evolution of the second (Los Altos) tornado suggests that it was associated with a mesoanticyclone, although the role of the sea-breeze boundary in the tornadogenesis cannot be discounted. C1 San Francisco State Univ, Dept Geosci, San Francisco, CA 94132 USA. Natl Weather Serv, Forecast Off, Monterey, CA USA. Univ Oklahoma, Natl Severe Storms Lab, Norman, OK 73019 USA. Univ Oklahoma, Cooperat Inst Mesoscale Meteorol Studies, Norman, OK 73019 USA. Second Nat, Sunnyvale, CA USA. RP Monteverdi, JP (reprint author), San Francisco State Univ, Dept Geosci, 1600 Holloway Ave, San Francisco, CA 94132 USA. NR 15 TC 11 Z9 11 U1 0 U2 0 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. PY 2001 VL 129 IS 11 BP 2805 EP 2814 DI 10.1175/1520-0493(2001)129<2805:FWDOAA>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 480XL UT WOS:000171488500011 ER PT J AU Xue, Y Zeng, FJ Mitchell, KE Janjic, Z Rogers, E AF Xue, Y Zeng, FJ Mitchell, KE Janjic, Z Rogers, E TI The impact of land surface processes on simulations of the US hydrological cycle: A case study of the 1993 flood using the SSiB land surface model in the NCEP Eta regional model SO MONTHLY WEATHER REVIEW LA English DT Article ID CENTRAL UNITED-STATES; GENERAL-CIRCULATION MODELS; SIMPLE BIOSPHERE MODEL; CONVECTIVE ADJUSTMENT SCHEME; STEP-MOUNTAIN COORDINATE; PARAMETERIZATION SCHEMES; SOIL-MOISTURE; WEATHER PREDICTION; CLIMATE MODEL; SUMMER FLOODS AB This paper describes a methodology for coupling the Simplified Simple Biosphere Model (SSiB) to the regional Eta Model of the National Centers for Environmental Prediction (NCEP), and presents the application of the coupled system in regional simulation studies. The coupled Eta-SSiB model is used to study the impact of land surface processes and land surface initialization on the regional water and energy cycle in an extreme climate event, by comparing the results from the Eta-SSiB with those from the Eta-bucket model. Simulations from both models spanned 3 months via a succession of 48-hr simulations over June, July, and August 1993, a summer of heavy flooding in the United States. The monthly and seasonal means from the simulations in both model runs are compared. The Eta-SSiB model produces more realistic monthly mean precipitation over the United States and the flood areas. The improvements are mainly manifested in the intensity of the heavy rainfall and its spatial distribution. The results demonstrate that even with a short-term simulation, a more realistic representation of land surface processes and land surface initialization improves the monthly and seasonal means of the simulated regional precipitation for the summer of 1993. In addition to precipitation, the simulations of surface air temperature are also evaluated and they show that the Eta-SSiB model produces reasonable results over most of the United States, with the exception of a cold bias at night in the mountainous western region of the United States. To understand the mechanisms of land surface-atmosphere interactions and the causes for the differences in the Eta-SSiB and the Eta-bucket simulations, the water cycle in the atmosphere-land system and the energy balance at the land surface are analyzed. The changes in (a) spatial distribution and diurnal cycle of surface latent and sensible heat, and (b) low-level moisture flux convergence (MFC) in response to these changes in surface heating are the primary factors for the improvement in the precipitation simulation. That is, the different surface models of SSiB and bucket, and their different soil moisture initializations, produce different energy partitioning in the surface heat fluxes of the Eta Model. The changes in both the daily mean and the diurnal variation at the land surface lead to different boundary layer evolutions and atmospheric stability conditions. In response to these differences, the Eta-SSiB model and the Eta-bucket model produce different low-level MFC in the heavy rainfall area. Strong and persistent MFC was one of the major forces that produced the heavy rainfall in the summer of 1993. In the above experiments, the Eta-SSiB model used the global reanalysis of the NCEP-NCAR (National Center for Atmospheric Research) 40-year Reanalysis Project (NNRP) for its initial soil moisture, whereas the Eta-bucket model used a tuned annual-mean fixed field of initial soil moisture as employed in the then-operational Eta Model. Because of this important initialization difference, a further set of simulations was performed in which the Eta-bucket was initialized with the NNRP reanalysis soil moisture employed in the Eta-SSiB. Results show that with similarly derived initial soil moisture states, the differences between the Eta-SSiB and the Eta-bucket are reduced but still evident, suggesting that improved representation of vegetation in the SSiB is at least partially responsible for the overall improvements in the simulations. Given that the NCEP-NCAR reanalysis is used for initial conditions and lateral and lower boundary conditions in these experiments, this study shows that a coupled atmosphere-biosphere regional model imbedded in a global reanalysis has the potential to provide a more realistic simulation of precipitation in extreme climate events. C1 Univ Calif Los Angeles, Dept Geog, Los Angeles, CA 90095 USA. Ctr Ocean Land Atmosphere Studies, Calverton, MD USA. NOAA, Natl Ctr Environm Predict, Camp Springs, MD USA. RP Xue, Y (reprint author), Univ Calif Los Angeles, Dept Geog, 1255 Bunche Hall,405 Hilgard Ave, Los Angeles, CA 90095 USA. EM yxue@geog.ucla.edu NR 85 TC 56 Z9 61 U1 2 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PY 2001 VL 129 IS 12 BP 2833 EP 2860 DI 10.1175/1520-0493(2001)129<2833:TIOLSP>2.0.CO;2 PG 28 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 490HG UT WOS:000172045700001 ER PT J AU Anderson, JL AF Anderson, JL TI An ensemble adjustment Kalman filter for data assimilation SO MONTHLY WEATHER REVIEW LA English DT Article ID QUASI-GEOSTROPHIC MODEL; PRIMITIVE-EQUATION MODEL; MEDIUM-RANGE ENSEMBLES; FORECAST ERROR; ADAPTIVE OBSERVATIONS; WEATHER OBSERVATIONS; PREDICTION SYSTEM; SINGULAR VECTORS; SIMULATION; VALIDATION AB A theory for estimating the probability distribution of the state of a model given a set of observations exists. This nonlinear filtering theory unifies the data assimilation and ensemble generation problem that have been key foci of prediction and predictability research for numerical weather and ocean prediction applications. A new algorithm, referred to as an ensemble adjustment Kalman filter, and the more traditional implementation of the ensemble Kalman filter in which "perturbed observations'' are used, are derived as Monte Carlo approximations to the nonlinear filter. Both ensemble Kalman filter methods produce assimilations with small ensemble mean errors while providing reasonable measures of uncertainty in the assimilated variables. The ensemble methods can assimilate observations with a nonlinear relation to model state variables and can also use observations to estimate the value of imprecisely known model parameters. These ensemble filter methods are shown to have significant advantages over four-dimensional variational assimilation in low-order models and scale easily to much larger applications. Heuristic modifications to the filtering algorithms allow them to be applied efficiently to very large models by sequentially processing observations and computing the impact of each observation on each state variable in an independent calculation. The ensemble adjustment Kalman filter is applied to a nondivergent barotropic model on the sphere to demonstrate the capabilities of the filters in models with state spaces that are much larger than the ensemble size. When observations are assimilated in the traditional ensemble Kalman filter, the resulting updated ensemble has a mean that is consistent with the value given by filtering theory, but only the expected value of the covariance of the updated ensemble is consistent with the theory. The ensemble adjustment Kalman filter computes a linear operator that is applied to the prior ensemble estimate of the state, resulting in an updated ensemble whose mean and also covariance are consistent with the theory. In the cases compared here, the ensemble adjustment Kalman filter performs significantly better than the traditional ensemble Kalman filter, apparently because noise introduced into the assimilated ensemble through perturbed observations in the traditional filter limits its relative performance. This superior performance may not occur for all problems and is expected to be most notable for small ensembles. Still, the results suggest that careful study of the capabilities of different varieties of ensemble Kalman filters is appropriate when exploring new applications. C1 Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. RP Anderson, JL (reprint author), Princeton Univ, NOAA, Geophys Fluid Dynam Lab, POB 308, Princeton, NJ 08542 USA. NR 58 TC 702 Z9 738 U1 8 U2 82 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. PY 2001 VL 129 IS 12 BP 2884 EP 2903 DI 10.1175/1520-0493(2001)129<2884:AEAKFF>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 490HG UT WOS:000172045700003 ER PT J AU Juang, HMH Hong, SY AF Juang, HMH Hong, SY TI Sensitivity of the NCEP regional spectral model to domain size and nesting strategy SO MONTHLY WEATHER REVIEW LA English DT Article ID LIMITED-AREA MODEL; LATERAL BOUNDARY-CONDITIONS; CLIMATE MODEL; WEATHER PREDICTION; FORECAST SYSTEM; RESOLUTION; SIMULATION; GCM AB This paper evaluates the performance of the National Centers for Environmental Prediction (NCEP) Regional Spectral Model (RSM) based on the sensitivities of different model domain sizes and horizontal resolutions. The perturbation method and the spectral computation in the NCEP RSM construct the nesting strategy as a "domain nesting'' in physical space as well as a "spectral nesting'' in spectral space, instead of the conventional "lateral boundary nesting'' as used in most regional models. The NCEP RSM has the same model structure, dynamics, and physics as its outer coarse-resolution global model, and it also has a terrain blending along the lateral boundary at the initial time. Both together result in a smooth lateral boundary behavior through one-way nesting. An optimal lateral boundary relaxation reduces the influence of lateral boundary error and generates more areas with small-scale features. The treatment of numerical stabilities, such as a semi-implicit time scheme, time filter, and horizontal diffusion, are applied in perturbation without recomputing or disturbing the large-scale waves. The combination of the aforementioned methods is the uniqueness of the NCEP RSM, which demonstrates the capabilities to conserve the large-scale waves, resolve the mesoscale features, and minimize the lateral boundary errors. A case of winter cyclogenesis with propagation of the synoptic-scale disturbances through the lateral boundaries was selected to investigate the sensitivities of the NCEP RSM based on different nesting strategies. The results from the experiment over a quarter-sphere domain with similar resolutions between RSM and T126 global model demonstrated that the domain nesting was a success, because the lateral boundary error and perturbation were negligibly small. The experiments in a 48-km resolution with different sizes of the model domain had mixed results. The continental domain had the best performance but inclined to generate erroneous large-scale waves that degraded its performance after 60 h. The results of the regional and subregional domains were proximity to their base field, T126, in terms of root-mean-square differences. They had similar mesoscale features in a 48-km horizontal resolution regardless of the different model domain sizes. The results from the experiments with nesting in different coarse grids over the radar-range domain imply that it can use either a T126 or subregional domain as its base field for similar performances. Nevertheless, more mesoscale features were obtained by the experiment with the base field at higher resolution. The results from the experiments, with 30-day integration, reveal that the performance of the experiment in the subregional domain was much closer to its base field than that in the continental domain. It indicates that the predictability of the global model is the predictability of the NCEP RSM in the regional domain; however, the regional domain could generate higher-resolution features than its base field. This successful long-range integration with the regional domain is because the lateral boundary errors are relatively small and the large-scale waves are preserved through the domain and spectral nesting. C1 NOAA, NWS, NCEP, CPC,W NP5 Natl Sci Ctr, Camp Springs, MD 20746 USA. Yonsei Univ, Dept Atmospher Sci, Lab Atmospher Modeling Res, Seoul, South Korea. NCEP, Environm Modeling Ctr, Washington, DC USA. RP Juang, HMH (reprint author), NOAA, NWS, NCEP, CPC,W NP5 Natl Sci Ctr, Room 806,5200 Auth Rd, Camp Springs, MD 20746 USA. RI Hong, Song-You/I-3824-2012 NR 40 TC 34 Z9 34 U1 0 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. PY 2001 VL 129 IS 12 BP 2904 EP 2922 DI 10.1175/1520-0493(2001)129<2904:SOTNRS>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 490HG UT WOS:000172045700004 ER PT J AU Xu, Q Wei, L AF Xu, Q Wei, L TI Estimation of three-dimensional error covariances. Part II: Analysis of wind innovation vectors SO MONTHLY WEATHER REVIEW LA English DT Article ID MAXIMUM-LIKELIHOOD-ESTIMATION; RANGE FORECAST ERRORS; BAROCLINIC EADY WAVE; STATISTICAL-INTERPOLATION; DATA ASSIMILATION; RADIOSONDE DATA; SYSTEM; PARAMETERS; FRONTS AB The method of statistical analysis of wind innovation (observation minus forecast) vectors is refined upon the work of Hollingsworth and Lonnberg (HL). The new refinements include (i) improved spectral representations of wind forecast error covariance functions, and (ii) simplified and yet more rigorously constrained formulations for multilevel analysis. The method is applied to wind innovation data over North America from the Navy Operational Global Atmospheric Prediction System (NOGAPS). The major products of the analysis include (i) wind observation error variance and vertical correlation, (ii) wind forecast error covariances as functions of height and horizontal distance, (iii) their spectra as functions of height and horizontal wavenumber, and (iv) partitioned vector wind error variances and correlation structures for the large-scale and synoptic-scale components and for the rotational and divergent components of synoptic scale. The results are compared with HL, showing a 20% overall reduction in wind forecast errors and a slight reduction in wind observation errors for the NOGAPS data in comparison with the European Centre for Medium-Range Weather Forecasts (ECMWF) global model data 16 years ago. The spatial structures of the estimated observation and forecast error correlation functions are found to be roughly comparable to those in HL. C1 NOAA, Natl Severe Storms Lab, Norman, OK 73069 USA. Univ Oklahoma, Cooperat Inst Mesocale Meteorol Studies, Norman, OK 73019 USA. RP Xu, Q (reprint author), NOAA, Natl Severe Storms Lab, 1313 Halley Circle, Norman, OK 73069 USA. NR 22 TC 24 Z9 33 U1 0 U2 1 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. PY 2001 VL 129 IS 12 BP 2939 EP 2954 DI 10.1175/1520-0493(2001)129<2939:EOTDEC>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 490HG UT WOS:000172045700006 ER PT J AU Lawrence, MB Avila, LA Beven, JL Franklin, JL Pasch, RJ Stewart, SR AF Lawrence, MB Avila, LA Beven, JL Franklin, JL Pasch, RJ Stewart, SR TI Eastern North Pacific hurricane season of 2000 SO MONTHLY WEATHER REVIEW LA English DT Article AB There were 11 tropical storms, 6 hurricanes, and 2 tropical depressions during the 2000 eastern North Pacific hurricane season. Two tropical storms made landfall in Mexico. C1 NOAA, NWS, NCEP, Trop Predict Ctr,Natl Hurricane Ctr, Miami, FL 33165 USA. RP Lawrence, MB (reprint author), NOAA, NWS, NCEP, Trop Predict Ctr,Natl Hurricane Ctr, 11691 SW 17 St, Miami, FL 33165 USA. NR 4 TC 4 Z9 4 U1 0 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. PY 2001 VL 129 IS 12 BP 3004 EP 3014 DI 10.1175/1520-0493(2001)129<3004:ENPHSO>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 490HG UT WOS:000172045700011 ER PT J AU Franklin, JL Avila, LA Beven, JL Lawrence, MB Pasch, RJ Stewart, SR AF Franklin, JL Avila, LA Beven, JL Lawrence, MB Pasch, RJ Stewart, SR TI Atlantic hurricane season of 2000 SO MONTHLY WEATHER REVIEW LA English DT Article ID GPS DROPWINDSONDE; TRACK; BASIN AB The 2000 Atlantic hurricane season is summarized and the year's tropical and subtropical cyclones are described. While overall activity was very high compared to climatology, with 15 cyclones attaining tropical (or subtropical) storm intensity, much of this activity occurred outside of the deep Tropics, over open waters north of 25 degreesN. The season's tropical cyclones were responsible for 54 fatalities, with most of these occurring in Central America in association with Hurricanes Gordon and Keith. C1 NOAA, NWS, Trop Predict Ctr, Natl Hurricane Ctr, Miami, FL 33165 USA. RP Franklin, JL (reprint author), NOAA, NWS, Trop Predict Ctr, Natl Hurricane Ctr, 11691 SW 17th St, Miami, FL 33165 USA. NR 17 TC 18 Z9 18 U1 0 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. PY 2001 VL 129 IS 12 BP 3037 EP 3056 DI 10.1175/1520-0493(2001)129<3037:AHSO>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 490HG UT WOS:000172045700013 ER PT J AU Lawrence, MB Avila, LA Beven, JL Franklin, JL Guiney, JL Pasch, RJ AF Lawrence, MB Avila, LA Beven, JL Franklin, JL Guiney, JL Pasch, RJ TI Atlantic hurricane season of 1999 SO MONTHLY WEATHER REVIEW LA English DT Article AB The 1999 Atlantic basin hurricane season produced 4 tropical storms and 8 hurricanes for a total of 12 named tropical cyclones. Seven of these affected land. Hurricane Floyd-the deadliest U.S. hurricane since Agnes in 1972-caused a disastrous flood event over the U.S. mid-Atlantic and northeastern coastal states, resulting in 56 U.S. deaths and 1 death in the Bahamas. Heavy rain from a tropical depression contributed to some 400 inland flood deaths in Mexico. C1 NOAA, NWS, Natl Hurricane Ctr, Trop Predict Ctr, Miami, FL 33165 USA. RP Lawrence, MB (reprint author), NOAA, NWS, Natl Hurricane Ctr, Trop Predict Ctr, 11619 SW 17th St, Miami, FL 33165 USA. NR 7 TC 37 Z9 37 U1 0 U2 4 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. PY 2001 VL 129 IS 12 BP 3057 EP 3084 DI 10.1175/1520-0493(2001)129<3057:AHSO>2.0.CO;2 PG 28 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 490HG UT WOS:000172045700014 ER PT J AU Pasch, RJ Avila, LA Guiney, JL AF Pasch, RJ Avila, LA Guiney, JL TI Atlantic hurricane season of 1998 SO MONTHLY WEATHER REVIEW LA English DT Article ID TROPICAL SYSTEMS AB The 1998 hurricane season in the Atlantic basin is summarized, and the individual tropical storms and hurricanes are described. It was an active season with a large number of landfalls. There was a near-record number of tropical cyclone-related deaths, due almost entirely to Hurricane Mitch in Central America. Brief summaries of forecast verification and tropical wave activity during 1998 are also presented. C1 NOAA, NWS, Trop Predict Ctr, Natl Hurricane Ctr, Miami, FL 33165 USA. RP Pasch, RJ (reprint author), NOAA, NWS, Trop Predict Ctr, Natl Hurricane Ctr, 11691 SW 17th St, Miami, FL 33165 USA. NR 17 TC 34 Z9 35 U1 0 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. PY 2001 VL 129 IS 12 BP 3085 EP 3123 DI 10.1175/1520-0493(2001)129<3085:AHSO>2.0.CO;2 PG 39 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 490HG UT WOS:000172045700015 ER PT B AU Black, PE Okun, V Yesha, Y AF Black, PE Okun, V Yesha, Y BE Wong, WE TI Mutation of model checker specifications for test generation and evaluation SO MUTATION TESTING FOR THE NEW CENTURY SE KLUWER INTERNATIONAL SERIES ON ADVANCES IN DATABASE SYSTEMS LA English DT Proceedings Paper CT Symposium on Mutation Testing for the New Century (Mutation 2000) CY OCT 06-07, 2000 CL SAN JOSE, CA SP IEEE Reliabil Soc, Telcordia Technologies, Software Engn Res Ctr DE specification mutation; mutation operators; test generation; model checking AB Mutation analysis on model checking specifications Is, a recent development. This approach mutates a specification, then applies a model checker to compare the mutants with the original specification to automatically generate tests or evaluate coverage. The properties of specification mutation operators have not been explored in depth. We report our work on theoretical and empirical comparison of these operators. Our future plans, include studying how the form of a specification influences the results, finding relations between different operators, and validating the method against independent metrics. C1 NIST, Gaithersburg, MD 20899 USA. RP NIST, Gaithersburg, MD 20899 USA. EM paul.black@nist.gov; vokun1@cs.umbc.edu; yayesha@cs.umbc.edu NR 28 TC 7 Z9 7 U1 0 U2 0 PU KLUWER ACADEMIC PUBLISHERS PI NORWELL PA 101 PHILIP DRIVE, ASSINIPPI PARK, NORWELL, MA 02061 USA BN 0-7923-7323-5 J9 KLUW INT S ADV DATA PY 2001 VL 24 BP 14 EP 20 PG 7 WC Computer Science, Software Engineering SC Computer Science GA BS57Z UT WOS:000170428800002 ER PT S AU Phillips, WD AF Phillips, WD BE Allegrini, M Garcia, N Marti, O TI Optical manipulation of atoms at the nanoscale SO NANOMETER SCALE SCIENCE AND TECHNOLOGY SE Proceedings of the International School of Physics Enrico Fermi LA English DT Proceedings Paper CT International-School-of-Physics-Enrico-Fermi on Nanometer Scale Science and Technology CY JUN 27-JUL 07, 2000 CL VARENNA, ITALY SP Int Sch Phys Enrico Fermi ID SELF-ASSEMBLED MONOLAYERS; NANOSTRUCTURE FABRICATION; DOPPLER LIMIT; NEUTRAL ATOMS; STANDING-WAVE; LIGHT FORCES; LITHOGRAPHY; LOCALIZATION; LATTICES; DEPOSITION C1 Natl Inst Stand & Technol, Phys Lab, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Phys Lab, Atom Phys Div, Gaithersburg, MD 20899 USA. EM wphillips@nist.gov NR 41 TC 0 Z9 0 U1 0 U2 0 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 0074-784X BN 1-58603-165-1 J9 P INT SCH PHYS PY 2001 VL 144 BP 247 EP 254 PG 8 WC Chemistry, Physical; Physics, Multidisciplinary; Physics, Particles & Fields SC Chemistry; Physics GA BU49N UT WOS:000176146800012 ER PT S AU Marbukh, V AF Marbukh, V BE Lorenze, P TI Minimum regret approach to network management under uncertainty with application to connection admission control and routing SO NETWORKING - ICN 2001, PART II, PROCEEDINGS SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 1st International Conference on Networking CY JUL 09-13, 2001 CL COLMAR, FRANCE SP Assoc Colmar Liberty, GdR CNRS ARP, Minist Rech, Univ Haute Alsace, France Telecom, IEEE, IEE, IST, WSES ID ATM NETWORKS AB This paper proposes a framework for network management intended to balance network performance under normal steady operational conditions with robustness under non-steady, and/or adverse conditions. Working in conjunction with anomaly and/or intrusion detection, the proposed framework allows the network to develop a set of measured responses to possible anomalies and external threats by minimizing the average maximum network losses, i.e., regrets or risks, due to uncertainty, Loss maximization guards against uncertainty within each scenario. Averaging of the maximum losses reflects an available information on the likelihood of different scenarios. The proposed framework includes Bayesian and minimax approaches as particular cases. The paper demonstrates how the proposed framework can alleviate high sensitivity of a cost-based admission and routing scheme to uncertain resource costs and possible presence of excessive and/or adversarial traffic. Specific examples include competitive and minimum interference admission and routing schemes. C1 NIST, Gaithersburg, MD 20899 USA. RP NIST, 100 Bureau Dr,Stop 8920, Gaithersburg, MD 20899 USA. EM marbukh@nist.gov NR 13 TC 0 Z9 0 U1 0 U2 3 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-42303-6 J9 LECT NOTES COMPUT SC PY 2001 VL 2094 BP 309 EP 318 PG 10 WC Computer Science, Software Engineering; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BT88U UT WOS:000174347900031 ER PT B AU Jelenkovic, BM Bollinger, JJ Newbury, AB Mitchell, TB Itano, WM AF Jelenkovic, BM Bollinger, JJ Newbury, AB Mitchell, TB Itano, WM BE Surko, CM Gianturco, FA TI A laser-cooled positron plasma SO NEW DIRECTIONS IN ANTIMATTER CHEMISTRY AND PHYSICS LA English DT Proceedings Paper CT Workshop on New Directions in Antimatter Chemistry and Physics CY OCT, 2000 CL INST THEORET ATOM & MOLEC PHYS, CAMBRIDGE, MA HO INST THEORET ATOM & MOLEC PHYS ID NONNEUTRAL ION PLASMA; PURE ELECTRON-PLASMA; PENNING TRAP; ANTIHYDROGEN PRODUCTION; FIELD; SIMULATION; SEPARATION; TRANSPORT; ROTATION; CLOUDS AB We present results on trapping and cooling of positrons in a Penning trap. Positrons from a 2 mCi Na-22 source travel along the axis of a 6 T magnet and through the trap after which they strike a Cu reflection moderator crystal. Up to a few thousand positrons are trapped and lose energy through Coulomb collisions (sympathetic cooling) with laser-cooled Be-9(+). By imaging the Be-9(+) laser-induced fluorescence, we observe centrifugal separation of the Be-9(+) ions and positrons, with the positrons coalescing into a column along the trap axis. This indicates the positrons have the same rotation frequency and comparable density (4 x 10(9) cm(-3)) as the Be-9(+) ions, and places an upper limit of approximately 5 K on the positron temperature of motion parallel to the magnetic field. We estimate the number of trapped positrons from the volume of this column and from the annihilation radiation when the positrons are ejected from the trap. The measured positron lifetime is > 8 days in our room temperature vacuum of 10(-8) Pa. C1 NIST, Div Time & Frequency, Boulder, CO USA. RP Jelenkovic, BM (reprint author), NIST, Div Time & Frequency, Boulder, CO USA. NR 36 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-7152-6 PY 2001 BP 1 EP 20 PG 20 WC Physics, Atomic, Molecular & Chemical SC Physics GA BU78G UT WOS:000177000000001 ER PT S AU Kotochigova, S Tiesinga, E Tupitsyn, I AF Kotochigova, S Tiesinga, E Tupitsyn, I BE Maruani, J Minot, C McWeeny, R Smeyers, YG Wilson, S TI Relativistic valence bond theory and its application to metastable XE2 SO NEW TRENDS IN QUANTUM SYSTEMS IN CHEMISTRY AND PHYSICS, VOL 1: BASIC PROBLEMS AND MODEL SYSTEMS SE Progress in Theoretical Chemistry and Physics LA English DT Proceedings Paper CT 4th European Workshop on Quantum Systems in Chemistry and Physics (QSCP-IV) CY APR 22-27, 1999 CL MARLY LE ROI, FRANCE SP European Commiss, CNRS, Univ Pierre & Marie Curie AB We present a new version of the relativistic configuration interaction valence bond (RCIVB) method. It is designed to perform an ab initio all-electron relativistic electronic structure calculation for diatomic molecules. A nonorthogonal basis set is constructed from numerical Dirac-Fock atomic orbitals as well as relativistic Sturmian functions. A symmetric reexpansion of atomic orbitals from one atomic center to another is introduced to simplify the calculation of many-center integrals. The electronic structure of the metastable (5p(5)6s + 5p(5)6s) Xenon molecule is calculated and the influence of different configurations on the formation of the molecule is analyzed. C1 NIST, Gaithersburg, MD 20899 USA. RP NIST, Gaithersburg, MD 20899 USA. NR 30 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1567-7354 BN 0-7923-6708-1 J9 PROG THEOR CHEM PHYS PY 2001 VL 6 BP 219 EP 242 PG 24 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA BR78U UT WOS:000167522900012 ER PT J AU Larsen, DA Beckman, BR Dickhoff, WW AF Larsen, DA Beckman, BR Dickhoff, WW TI The effect of low temperature and fasting during the winter on growth and smoltification of coho salmon SO NORTH AMERICAN JOURNAL OF AQUACULTURE LA English DT Article ID SPRING CHINOOK SALMON; ONCORHYNCHUS-TSHAWYTSCHA; ATLANTIC SALMON; GAIRDNERI RICHARDSON; SEAWARD MIGRATION; RAINBOW-TROUT; PARR; WILD; KISUTCH; STARVATION AB This study examined the effect of winter feeding and fasting, under both warm (10 degreesC) and cold (2.5 degreesC) water temperatures, on smoltification of juvenile coho salmon Oncorhynchus kisutch. Treatments were warm-fed, warm-not fed, cold-fed, and cold-not fed during the winter (January-February) before smoltification in March-May. All groups were fed and maintained at 10 degreesC during the smoltification period. The following variables were measured: fork length, weight, condition factor, smelt-associated appearance, whole-body lipid levels, and gill Na+,K+-ATPase activity. Warm-fed fish grew continuously throughout the winter and were larger than fish from the other treatments. Fish from the other groups showed little or no growth during January and February. Although condition factors decreased significantly in the winter-fasted groups under bo th warm and cold temperatures, winter whole-body lipid levels and smoltification-associated gill Na+,K+-ATPase activities were not different among groups. These data suggest that winter fasting, even under relatively warm winter water temperatures, may not impair the condition or smoltification of hatchery-cultured coho salmon. C1 NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Integrat Fish Biol Program, Seattle, WA 98112 USA. Univ Washington, Sch Aquat & Fishery Sci, Seattle, WA 98195 USA. RP Larsen, DA (reprint author), NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Integrat Fish Biol Program, 2725 Montlake Blvd E, Seattle, WA 98112 USA. NR 36 TC 19 Z9 19 U1 1 U2 11 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 1522-2055 J9 N AM J AQUACULT JI N. Am. J. Aqualcult. PD JAN PY 2001 VL 63 IS 1 BP 1 EP 10 DI 10.1577/1548-8454(2001)063<0001:TEOLTA>2.0.CO;2 PG 10 WC Fisheries SC Fisheries GA 419JC UT WOS:000167944700001 ER PT J AU Beland, KF Kocik, JF VandeSande, J Sheehan, TF AF Beland, KF Kocik, JF VandeSande, J Sheehan, TF TI Striped bass predation upon atlantic salmon smolts in maine SO NORTHEASTERN NATURALIST LA English DT Article ID PENOBSCOT RIVER AB We documented estuarine predation by an immature striped bass (Morone saxatilis) upon an Atlantic salmon smolt (Salmo salar) that had previously been tagged with an ultrasonic transmitter on the Narraguagus River, Maine. That observation revealed the potential confounding effects that fish predation can have upon a telemetry study if the behavior of predatory fish cannot be distinguished from that of the target species. To investigate this effect, we also tracked the movements of immature striped bass in the same river system. We found that the striped bass alternately moved upstream and downstream of the release site, independent of tidal flows and light conditions, whereas salmon movements were generally passive and in the direction of tidal flows. These differences can be incorporated into our data analysis to better recognize and explain anomalous behavior of tagged smolts. Salmon abundance in Maine rivers has steadily declined since the mid-1980s, whereas Atlantic coast striped bass stocks have been increasing in abundance. Although the potential exists for significant smolt predation by striped bass in any one year, striped bass abundance in eastern Maine rivers is highly variable between years, suggesting that striped bass predation is not the proximate cause of the persistent decline in salmon populations. C1 Maine Atlantic Salmon Commiss, Bangor, ME 04401 USA. Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA. RP Beland, KF (reprint author), Maine Atlantic Salmon Commiss, 650 State St, Bangor, ME 04401 USA. NR 22 TC 8 Z9 8 U1 2 U2 8 PU HUMBOLDT FIELD RESEARCH INST PI STEUBEN PA PO BOX 9, STEUBEN, ME 04680-0009 USA SN 1092-6194 J9 NORTHEAST NAT JI Northeast. Nat PY 2001 VL 8 IS 3 BP 267 EP 274 PG 8 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 528JJ UT WOS:000174240400002 ER PT J AU Bhat, TN Bourne, P Feng, ZK Gilliland, G Jain, S Ravichandran, V Schneider, B Schneider, K Thanki, N Weissig, H Westbrook, J Berman, HM AF Bhat, TN Bourne, P Feng, ZK Gilliland, G Jain, S Ravichandran, V Schneider, B Schneider, K Thanki, N Weissig, H Westbrook, J Berman, HM TI The PDB data uniformity project SO NUCLEIC ACIDS RESEARCH LA English DT Article ID FILE AB The Protein Data Bank (PDB; http://www.rcsb.org/pdb/) is the single worldwide archive of structural data of biological macromolecules. This paper describes the data uniformity project that is underway to address the inconsistency in PDB data. C1 Rutgers State Univ, Dept Chem, Piscataway, NJ 08854 USA. Univ Calif San Diego, Dept Pharmacol, La Jolla, CA 92093 USA. Univ Calif San Diego, San diego Supercomp Ctr, La Jolla, CA 92093 USA. Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Berman, HM (reprint author), Rutgers State Univ, Dept Chem, 610 Taylor Rd, Piscataway, NJ 08854 USA. RI Bourne, Philip/C-2073-2008; Schneider, Bohdan/D-2565-2009 OI Schneider, Bohdan/0000-0001-7855-3690 NR 9 TC 74 Z9 78 U1 0 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD JAN 1 PY 2001 VL 29 IS 1 BP 214 EP 218 DI 10.1093/nar/29.1.214 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 391MT UT WOS:000166360300059 PM 11125095 ER PT J AU Ruitberg, CM Reeder, DJ Butler, JM AF Ruitberg, CM Reeder, DJ Butler, JM TI STRBase: a short tandem repeat DNA database for the human identity testing community SO NUCLEIC ACIDS RESEARCH LA English DT Article AB The National Institute of Standards and Technology (NIST) has compiled and maintained a Short Tandem Repeat DNA Internet Database (http://www.cstl.nist.gov/ biotech/strbase/) since 1997 commonly referred to as STRBase. This database is an Information resource for the forensic DNA typing community with details on commonly used short tandem repeat (STR) DNA markers. STRBase consolidates and organizes the abundant literature on this subject to facilitate on-going efforts in DNA typing. Observed alleles and annotated sequence for each STR locus are described along with a review of STR analysis technologies. Additionally, commercially available STR multiplex kits are described, published polymerase chain reaction (PCR) primer sequences are reported, and validation studies conducted by a number of forensic laboratories are listed. To supplement the technical information, addresses for scientists and hyperlinks to organizations working in this area are available, along with the comprehensive reference list of over 1300 publications on STRs used for DNA typing purposes. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. RP Butler, JM (reprint author), Natl Inst Stand & Technol, Div Biotechnol, 100 Bur Dr,Mail Stop 8311, Gaithersburg, MD 20899 USA. RI Butler, John/C-7812-2011 NR 5 TC 118 Z9 125 U1 0 U2 16 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD JAN 1 PY 2001 VL 29 IS 1 BP 320 EP 322 DI 10.1093/nar/29.1.320 PG 3 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 391MT UT WOS:000166360300089 PM 11125125 ER PT J AU Schittone, J AF Schittone, J TI Tourism vs. commercial fishers: development and changing use of Key West and Stock Island, Florida SO OCEAN & COASTAL MANAGEMENT LA English DT Article AB For more than 200 years, commercial fishing was the most important economic activity in Key West, Florida. Over the last 20 years however, this way of life has been squeezed off the island, until there is no longer a commercial las opposed to charter) fishing industry present on the Key. The "squeeze" is attributable to space competition from businesses associated with the explosive growth of the tourism sector in recent years. This paper relates a bit of the historical background of both the commercial fishing and the tourism industries. It goes on to examine some of the economic factors that converged to displace fishing activity to a nearby Key (Stock Island). This case study considers some of the implications for Key West of placing almost total economic reliance on the tourism segment. Published by Elsevier Science Ltd. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Marine Affairs & Policy, Miami, FL 33149 USA. RP Schittone, J (reprint author), NOAA, NOS, Natl Marine Sanctuary Program, 1305 East West Hwy, Silver Spring, MD 20910 USA. NR 55 TC 6 Z9 9 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0964-5691 J9 OCEAN COAST MANAGE JI Ocean Coastal Manage. PY 2001 VL 44 IS 1-2 BP 15 EP 37 DI 10.1016/S0964-5691(00)00078-8 PG 23 WC Oceanography; Water Resources SC Oceanography; Water Resources GA 413LQ UT WOS:000167614000002 ER PT B AU Naughton, J Jokiel, PL AF Naughton, J Jokiel, PL GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI Coral reef mitigation and restoration techniques employed in the Pacific Islands: I. Overview SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc ID KANEOHE BAY; HAWAII AB In the past two decades numerous reef mitigation and restoration projects have been undertaken throughout the world. This article summarizes our experience with a wide range of projects in Hawaii and the U. S. - affiliated Pacific Islands. The terms "mitigation" and "restoration" are often taken to mean reef repair, coral transplantation or construction of additional habitat (e.g. artificial reefs). However, other options are available and should be considered. In some situations removal of the anthropogenic factor causing the damage while allowing natural processes of recovery to occur is the best approach. Natural rates of reef recovery can be very rapid In such situations and direct human intervention on the reefs is unnecessary. In some instances a negotiated environmental settlement or financial penalties can be used to establish trust funds to offset environmental losses. Review of past attempts to mitigate reef damage and restore reefs suggests that managers must have a broad strategic plan and incorporate a wide range of approaches designed to fit each situation on a case by case basis. Although protection of the reefs must always be the top priority, there will inevitably be situations where damage will occur. In these situations restoration and mitigation measures will have to be considered. C1 Natl Marine Fisheries Serv, Pacific Isl Area Off, Honolulu, HI 96814 USA. RP Naughton, J (reprint author), Natl Marine Fisheries Serv, Pacific Isl Area Off, 1601 Kapiolani Blvd,Suite 1110, Honolulu, HI 96814 USA. NR 47 TC 1 Z9 1 U1 1 U2 9 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 306 EP 312 PG 7 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800047 ER PT B AU Burgess, JP Jones, EI AF Burgess, JP Jones, EI GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI NOAA Restoration Center: Restoring living marine resource habitats SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc AB The NOAA Restoration Center is the focal point for coastal and estuarine habitat restoration within NOAA. Its missions are to: Restore fish habitat and other natural resources that have been injured by human activities; Advance the science and technology of coastal habitat restoration; and Transfer restoration technology to the public, the private sector, and other governmental agencies. The Restoration Center serves NOAA, other federal agencies, and state and local governments. In addition, the center works with non-governmental organizations, schools and private industry. The Restoration Center is a part of NOAA's Damage Assessment and Restoration Program (DARP). Through DARP, NOAA claims damages for injuries to marine resources resulting from oil spills, hazardous releases, or other human-induced environmental disturbances. Monetary awards from polluters and other responsible parties are used to "restore, replace, or acquire the equivalent of" the Injured resources. To-date, this program has initiated restoration activities at over 25 sites around the country. The Restoration Center is also working to stem the tide of wetland loss in Louisiana, which is beset by the highest rate of coastal wetland loss in the nation. Under the Coastal Wetland Planning, Protection, and Restoration Act, NOAA and the State of Louisiana are engaged in a partnership to restore salt marshes lost to erosion, subsidence and hydrological alterations. As part of this program, the Restoration Center has been awarded 14 projects to be carried out over a period of 20 years. When completed, these restorations will benefit over 80,000 acres of coastal wetlands. The Restoration Center administers grants programs to foster community-based habitat restoration projects and to fund research on habitat restoration. Over the past few years, over 50 community-based and 20 research grants have been awarded. The community-based grants seek to promote stewardship and a conservation ethic among coastal communities, while the research grants work to advance the science and technology of coastal habitat restoration. The Restoration Center has demonstrated the effectiveness of habitat restoration for countering human impacts on the marine environment. As with any emerging technology, much remains to be done. The Center is committed to continued development of the science and technology of coastal environmental restoration. These efforts will be greatly enhanced by the Administration's FY2000 Lands Legacy Initiative and complement other investments seeking to restore the Nation's valuable ocean and coastal resources. C1 NOAA, NMFS, FHC3, SSMC3, Silver Spring, MD 20910 USA. RP Burgess, JP (reprint author), NOAA, NMFS, FHC3, SSMC3, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 317 EP 320 PG 4 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800049 ER PT B AU Bellmer, RJ AF Bellmer, RJ GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI Restoration success criteria SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc AB The prosperity of living marine resources is essential to the survival of human populations throughout the Nation. Dr. Cairns (1998) noted that, "...Alarmingly, the amount of ecosystem services per capita is declining precipitously as the natural systems providing these services are destroyed while the human population simultaneously increases. The only way to counteract this trend is to use ecological restoration to repair natural systems." To date although awareness of the diminishing availability of undisturbed marine coastal habitats is widespread, methods for evaluating the functional status of marine habitats have not been fully developed. A more detailed understanding of their structure and function Is needed to improve our success in restoring their health. Restoration failures may occur for several reasons. One reason is that, restoration projects may be carelessly implemented, as when a contractor disregards, or unachieves engineering or biological specifications. The failure in this case is not a consequence of ecological science or engineering knowledge, but of implementation. Another reason a restoration project may fail is when design criteria are scrupulously followed but the project designer's knowledge proves inadequate to produce a functional restoration design. A third reason failure may occur is when objectives and criteria are not established prior to the project undertaking. Such a project lacks milestones to judge progress, and in the absence of assessment criteria for use in monitoring, it is impossible to obtain early warnings that the restoration is not "on track." A decision must be made concerning which criteria to measure when designing an assessment program to evaluate the success of a restoration project. Each evaluation must be tailored to habitat type and site-specific conditions. At the same time, all, however, evaluations should share common criteria that allow a degree of comparability. The criteria should (1) enable a determination of the degree to which the restoration reestablishes the ecosystem structure and functions, disturbance regime, and abiotic services of the reference ecosystem; (2) Criteria need to be quantifiable such that the variance or uncertainty surrounding their measurement can be determined; (3) Criteria should be diagnostic in their ability to assist in the determination whether a habitat Is restored; (4) Criteria also need to be responsive to any change in resource availability and/or habitat conditions; Finally, (5) Criteria should adequately identify the transitional stages that a healthy marine habitat goes through as it suffers impairment and as a system recovers from an impaired state. achieve success. Evaluation of a completed restoration project is vital to learning whether the regulatory permit requirements of a mandatory restoration project have been met. It is also essential for people conducting a "discretionary" restoration projects to determine how effective their efforts have been. Preproject evaluation can help a decision-maker identify the project most likely to provide the greatest ecological benefits at the lowest cost, an especially important consideration in an era of budgetary constraints and enormous restoration challenges. The general approach to evaluating the success of a restoration project is either to determine how effective the restoration attempt was In replicating the target habitat or to select from among competing restoration projects that one most likely to achieve success. Evaluation of a completed restoration project is vital to learning whether the regulatory permit requirements of a mandatory restoration project have been met. It is also essential for people conducting a "discretionary" restoration projects to determine how effective their efforts have been. Pre-project evaluation can help a decision-maker identify the project most likely to provide the greatest ecological benefits at the lowest cost, an especially important consideration in an era of budgetary constraints and enormous restoration challenges. C1 NOAA, SSMC3, FHC3, Silver Spring, MD 20910 USA. RP Bellmer, RJ (reprint author), NOAA, SSMC3, FHC3, 1315 East West Highway, Silver Spring, MD 20910 USA. NR 0 TC 0 Z9 0 U1 3 U2 8 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 327 EP 330 PG 4 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800051 ER PT B AU Malahoff, A Wiltshire, JC Crook, KAW Kelley, CD Smith, JR AF Malahoff, A Wiltshire, JC Crook, KAW Kelley, CD Smith, JR GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI New research directions and enhanced potential at the Hawaii Undersea Research Laboratory SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc AB The Hawaii Undersea Research Laboratory, NOAA's National Undersea Research Center for Hawaii and the Western Pacific (HURL/NURC-HWP) at the University of Hawaii at Manoa, has been in the process of upgrading its deep submergence system to better address the marine research challenges of the twenty-first century. The recent acquisition of Pisces IV, as a safety backup, will allow a greater range of dive targets to be selected, moving further from Hawaii into the Western Pacific and coral reefs of the Northwest Hawaiian Islands. Substantial upgrades have also taken place on the ROV system, the Pisces V scientific sampling package and the power and propulsion system on the mothership R/Y Kaimikai-o-Kanaloa. The number of research submersibles worldwide operating at 2,000 m and below is on the order of 10, including HURL's two Pisces subs. The number of easily transportable systems able to rescue these vehicles is also very small. For this reason, It was the recommendation of the International Submersible Safety Symposium that each of the deep submergence operating groups be able to provide its own rescue capability. HURL has just accomplished this with the addition of Pisces IV. C1 Univ Hawaii Manoa, NOAA, Natl Undersea Res Ctr, Hawaii Undersea Res Lab, Honolulu, HI 96822 USA. RP Malahoff, A (reprint author), Univ Hawaii Manoa, NOAA, Natl Undersea Res Ctr, Hawaii Undersea Res Lab, Honolulu, HI 96822 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 807 EP 811 PG 5 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800128 ER PT B AU Kelley, CD AF Kelley, CD GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI Mapping submersible observations of deepwater snappers on 3-D multibeam images of a bottomfish habitat in Hawaii SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc ID LUTJANID AB Two species of deepwater snappers in the bottomfish fishery in Hawaii have been depleted in the main Hawaiian Islands. The depth at which these fish live has impeded the collection of data necessary to design effective management strategies to restore their populations. However, recent multibeam surveys in Hawaii combined with in situ submersible and ROV observations and GIS provide a means to obtain that data. This paper presents the recent application of this method on a bottomfish habitat site and the types of information that can be acquired. C1 NOAA, Natl Undersea Res Ctr, Hawaii Undersea Res Lab, Honolulu, HI 96822 USA. RP Kelley, CD (reprint author), NOAA, Natl Undersea Res Ctr, Hawaii Undersea Res Lab, Honolulu, HI 96822 USA. NR 13 TC 0 Z9 0 U1 0 U2 1 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 876 EP 879 PG 4 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800137 ER PT B AU Welch, JM AF Welch, JM GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI National Ocean Service Real-Time Monitoring Infrastructure SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc AB The National Ocean Service (NOS) Center for Operational Oceanographic Products and Services (CO-OPS) manages the NOS Real-Time Monitoring Infrastructure. CO-OPS provides the National infrastructure, science, and technical expertise to monitor, assess, and disseminate coastal oceanographic products and services necessary to support NOAA's dual mission of environmental stewardship and environmental assessment and prediction. CO-OPS strengthens core capabilities through additional partnership links with outside groups including private organizations. A CO-OPS operating principle is to focus the core workforce capability on the establishment and maintenance of NOS program and technical standards, validation and certification of data and information products, research and development, and quality control/assurance (QA/QC) of data and information products. Validation, certification, and QA/QC all link to the liability associated with CO-OPS data, information products, and services. C1 NOAA, US Dept Commerce, Natl Ocean Serv, Ctr Operat Oceanog Prod & Serv, Silver Spring, MD 20910 USA. RP Welch, JM (reprint author), NOAA, US Dept Commerce, Natl Ocean Serv, Ctr Operat Oceanog Prod & Serv, 1305 East West Highway,Room 6544, Silver Spring, MD 20910 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 1171 EP 1174 PG 4 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800184 ER PT B AU Seki, MP Bidigare, RR Lumpkin, R Polovina, JJ Kobayashi, DR Flament, P Foley, DG AF Seki, MP Bidigare, RR Lumpkin, R Polovina, JJ Kobayashi, DR Flament, P Foley, DG GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI Mesoscale cyclonic eddies and pelagic fisheries in Hawaiian waters SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc ID EDDY; PACIFIC; IMAGERY; SEA AB The combination of prevailing northeasterly tradewinds and island topography result 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 islands of Maui and the Big Island of Hawaii. Like other open-ocean eddies, their biological impact can be significant, although Hawaii's open-ocean, wind driven features dynamically contrast the well-studied cold core current-generated eddies such as those that spin off the Gulf Stream or the Kuroshio. These latter features characteristically trap or isolate an adjacent water mass retaining its developed floristic composition. Cyclonic eddies in subtropical waters such as around Hawaii vertically displace the underlying nutricline into the overlying, nutrient-deplete euphotic zone creating localized biologically enhanced patches. Recent direct high-resolution horizontal and vertical observations of these vortices made from satellite and shipboard platforms provide new perspectives on biological enhancement within open-ocean cyclonic eddies and are presented here. These localized regions of high productivity may lead to aggregation and development of a forage base for higher trophic levels. How eddies may directly influence pelagic fish distribution are examined from recreational and commercial fish catch data coinciding with the presence of eddies. We highlight the 1995 Hawaii International Billfish Tournament in which a cyclonic eddy dominated the ocean conditions during the weeklong event and appeared to be the principle factor influencing fish availability. On the tournament 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 direct (e.g., physiological limitations) and/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. RP Seki, MP (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, 2570 Dole St, Honolulu, HI 96822 USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 1590 EP 1594 PG 5 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800247 ER PT B AU Kobayashi, DR Polovina, JJ AF Kobayashi, DR Polovina, JJ GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI Evaluation of mitigation measures for sea turtle take reduction in the Hawaii-based longline fishery SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc AB Computer simulation was used to evaluate mitigation measures for sea turtle take reduction In the Hawaii-based longline fishery. Federal logbook and observer data were merged with high-resolution environmental data to produce generalized additive models of sea turtle take. Various types of seasonal and spatial closures were evaluated as well as possible fishing gear modifications. These results led to the formal adoption of a multifaceted management policy consisting of a seasonal spatial closure of the fishery south of 15degreesN during April and May, combined with a gear restriction to prohibit swordfish style fishing in the upper surface layers for the entire fishery. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. RP Kobayashi, DR (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, 2570 Dole St, Honolulu, HI 96822 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 1595 EP 1595 PG 1 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800248 ER PT B AU Parrish, FA Pyle, RL AF Parrish, FA Pyle, RL GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI Surface logistics and consumables for open-circuit and closed-circuit deep mixed-gas diving operations SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc AB A series of eight dives, four with open-circuit scuba and four with closed-circuit rebreathers were made to compare the two diving methodologies. Two criteria were considered: time requirements for topside equipment preparation, and consumption of expendables. The open-circuit divers required four times as much topside equipment preparation as the rebreather divers, consumed 17 times as much gas, and cost seven times more in expendables. These findings indicate significantly less time and an infrastructure are needed to support closed-circuit rebreather diving rather than conventional open circuit modes for deep mixed-gas work. C1 Natl Marine Fisheries Serv, Honolulu Lab, Honolulu, HI 96822 USA. RP Parrish, FA (reprint author), Natl Marine Fisheries Serv, Honolulu Lab, 2750 Dole St, Honolulu, HI 96822 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 1735 EP 1737 PG 3 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800273 ER PT B AU Ruberg, SA Vanderploeg, HA Cavaletto, JF Lang, GA Liebig, JR Miller, TC Agy, M AF Ruberg, SA Vanderploeg, HA Cavaletto, JF Lang, GA Liebig, JR Miller, TC Agy, M GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI Plankton Survey System SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc ID CALIBRATION; COUNTER AB The Plankton Survey System (PSS), developed at the National Oceanic and Atmospheric Administration's (NOAA) Great Lakes Environmental Research Laboratory (GLERL), has been designed to collect high temporal and spatial resolution marine environmental data in three dimensions. The system has proven effective in providing valuable survey information before, during and after sediment re-suspension events in Lake Michigan in support of GLERL's NOAA/NSF funded Episodic Events Great Lakes Experiment (EEGLE) program. The PSS is a towed multi-sensor platform capable of measuring turbidity, chlorophyll a, photosynthetically active radiation (PAR), conductivity, temperature, and zooplankton spatial distributions. All sensors are integrated using a serial data interface. All data are geo-referenced and registered with time, depth, and vehicle pitch, roll, and speed information. A deck unit supplies power for the underwater vehicle components and provides interfaces for data collection and system monitoring. System software provides real-time display of all marine environmental measurements and vehicle status. Zooplankton spatial and individual size distributions are measured using an optical plankton counter (OPC). The OPC measures particle size distributions (0.25 - 14mm) using an LED array and a photodiode receiver. Deflections caused by particles crossing the LED generated light beam (4x20x100 mm) are detected by the receiver and digitized. Present work is focused on moving the OPC beyond use as merely a survey tool to calibrating the instrument using laboratory and field measurements. Laboratory calibration plans include the use of specified particles to establish a reference and subsequent investigations using live zooplankton samples. A range of issues involving the implications of variations in zooplankton body characteristics on OPC detection threshold, turbidity on OPC signal-to-noise ratio, tow vehicle orientation and vehicle and OPC channel turbulence will also be investigated. C1 NOAA, Great Lakes Environm Res Lab, Ann Arbor, MI 48105 USA. RP Ruberg, SA (reprint author), NOAA, Great Lakes Environm Res Lab, 2205 Commonwealth Blvd, Ann Arbor, MI 48105 USA. OI Ruberg, Steven/0000-0001-8809-5689; Liebig, James/0000-0002-0433-9066; Vanderploeg, Henry/0000-0003-1358-8475 NR 6 TC 2 Z9 2 U1 0 U2 0 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 1899 EP 1903 PG 5 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800300 ER PT B AU Soreide, NN Sun, CL Kilonsky, BJ Denbo, DW Zhu, WH Osborne, JR AF Soreide, NN Sun, CL Kilonsky, BJ Denbo, DW Zhu, WH Osborne, JR GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI A Climate Data Portal SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc C1 NOAA, Pacific Marine Environm Lab, OD, Seattle, WA 98115 USA. RP Soreide, NN (reprint author), NOAA, Pacific Marine Environm Lab, OD, 7600 Sand Point Way Ne,Route R PMEL, Seattle, WA 98115 USA. NR 12 TC 0 Z9 0 U1 0 U2 1 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 2315 EP 2317 PG 3 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800369 ER PT B AU Hemsley, JM AF Hemsley, JM GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI The long-term marine data set collected by the National Data Buoy Center SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc AB According to the authors of "Long Time Series Measurements in the Coastal Ocean: A Workshop" (C.L. Vincent, T.C. Royer, and KH., Brink Woods Hole Oceanographic Institution, November, 1993), "Long time series measurements (in excess of 10 years duration) in the coastal ocean are important to science and society. They provide a measure of the health of the coastal ocean and are essential to distinguish long-term trends, caused by anthropogenic effects or climate change for example, from natural variability. They provide a basis for a new hypothesis about processes operating in the coastal ocean and a range of conditions for testing predictive capabilities. In addition, they document rare and/or catastrophic events that may play a critical role in coastal processes." When that report was written, 8 years ago, The National Data Buoy Center (NDBC) had 55 stations in the 10 to 100 years of data category. NDBC buoys and Coastal-Marine Automated Network (C-MAN) stations, because of their continued importance to the National Weather Service (NWS), can be assumed to be long-term. That means that the manager engaged in maritime commerce, scientist involved in marine research, commercial fisherman, and recreational boater can depend on NDBC data when making decisions. The value of these data is validated by the three million hits on NDBC's Web site in an average month. NDBC has a history of providing high-quality data in a timely manner to the users of its data. That group, originally comprised primarily of forecasters, has expanded many times over as a result of the Internet. It has been a challenge to meet the needs of such a diverse group of real-time users, but NDBC has accepted that challenge and continues to respond to the needs of those who rely on the data. This paper will review the quantity and quality of NDBC data. It will discuss how and where the data are collected, and it will explain how it can be obtained. It will also evaluate how successful NDBC has been in collecting quality data and discuss what is being done to maintain, even improve, the quantity of data made available to those who depend on it. C1 Natl Data Buoy Ctr, Engn Branch, Stennis Space Ctr, MS 39529 USA. RP Hemsley, JM (reprint author), Natl Data Buoy Ctr, Engn Branch, Bldg 1100, Stennis Space Ctr, MS 39529 USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 2328 EP 2335 PG 8 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800372 ER PT B AU Perugini, NE Kenny, MR Bailey, JW AF Perugini, NE Kenny, MR Bailey, JW GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI NOAA's integrated suite of navigational products and services SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc AB The National Oceanic and Atmospheric Administration (NOAA) maintains the United States' suite of nautical charts, the coastal water level observation system, and the geodetic positioning reference system. NOAA charts are developed from NOAA's hydrographic and shoreline surveys, tide and current measurements, and national geographic positioning data, as well as information from other sources. NOAA's integrated suite of surveying, charting, water level, and positioning services is capable of increasing the efficient movement of goods while significantly reducing the risk of marine accidents and resulting environmental damage. NOAA is creating a database of digital vector chart data for the production of Electronic Navigational Charts (ENC). ENCs are being produced in the International Hydrographic Organization (IHO) format as defined in Edition 3.1 of Publication S-57: IHO Transfer Standard for Digital Hydrographic Data. ENCs are being compiled from original source materials where appropriate to provide the most accurate data available. The ENC database will be kept in continual maintenance (i.e., up-to-date on a weekly basis), allowing ENC users to obtain vector data sets that contain the most up-to-date and accurate information. NOAA is also offering the Physical Oceanographic Real-Time System (PORTS) in many major U.S. ports. PORTS is a program that supports safe and cost-efficient navigation by providing ship masters and pilots with accurate real-time information. PORTS includes centralized data acquisition and dissemination systems that provide real-time water levels, currents, and other oceanographic and meteorological data from bays and harbors to the maritime user community in a variety of user friendly formats, including telephone voice response and Internet. Also, some PORTS will provide forecasts (predictions) of water levels and currents with the use of numerical circulation models. Access to accurate real-time water level information allows U.S.. fort authorities and maritime shippers to make sound decisions regarding maximizing tonnage (based on available bottom clearance), and limiting passage times, without compromising safety. One of NOAA's missions is to survey coastal regions and to provide the Nation with an accurate, consistent, up-to-date national shoreline. NOAA is exploring the use of new remote sensing technologies and new methodologies to map the shoreline. These technologies include Interferometric Synthetic Aperture Radar (SAR), Light Detection And Ranging (LIDAR), and hyperspectral imaging. C1 NOAA, Natl Ocean Serv, Silver Spring, MD 20910 USA. RP Perugini, NE (reprint author), NOAA, Natl Ocean Serv, 1315 EW Highway, Silver Spring, MD 20910 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 2336 EP 2341 PG 6 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800373 ER PT B AU Stinus, J Klein, F Sheridan, A AF Stinus, J Klein, F Sheridan, A GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI The new National Coastal Data Development Center SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc AB This paper provides an update on the NCDDC development, its technologies, and the pilot projects it Is conducting. A Coastal Risk Atlas, support to Harmful Algal Bloom efforts, a Coast Watch Hypoxia warning capability, and a coral reef data pilot project will continue into FY2002. Certification as a FGDC node will be achieved in late FY2001 and the center is expected to open at the end of March 2002. C1 NOAA, Natl Coastal Data Dev Ctr, Stennis Space Ctr, MS 39529 USA. RP Stinus, J (reprint author), NOAA, Natl Coastal Data Dev Ctr, Bldg 1100,Room 101, Stennis Space Ctr, MS 39529 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 2445 EP 2448 PG 4 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800390 ER PT B AU Soreide, NN Woody, CE Holt, SM AF Soreide, NN Woody, CE Holt, SM GP MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY MARINE TECHNOLOGY SOCIETY TI Overview of ocean based buoys and drifters: Present applications and future needs SO OCEANS 2001 MTS/IEEE: AN OCEAN ODYSSEY, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Annual Conference of the Marine-Technology-Society CY NOV 05-08, 2001 CL HONOLULU, HI SP Marine Technol Soc, IEEE, OES, Minerals, Met & Mat Soc, Soc Explorat Geophysicists, Amer Geophys Union, Womens Aquat Network, Coasts, Oceans, Ports & Rivers Inst, Amer Meteorol Soc, Oceanog Soc AB Starting with an overview of the historical legacy of buoy technology from ancient times to the present, this paper will present a discussion of several topics related to buoy technology, its present applications, and future needs. Technologies for meteorological and oceanographic applications will be discussed in relation to buoys, buoy arrays, and drifters. Scientific and technical issues related to these systems are addressed in three topic areas. The first topic will address buoy, buoy arrays, and drifter programs presently employed. The second will address data acquisition, signal processing, product generation, and information distribution techniques. The third and final topic concerns the buoy user needs and future scientific and technical requirements. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. RP NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way Ne, Seattle, WA 98115 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW,SUITE 906, WASHINGTON, DC 20035 USA BN 0-933957-28-9 PY 2001 BP 2470 EP 2472 PG 3 WC Engineering, Marine; Engineering, Ocean; Engineering, Electrical & Electronic; Geosciences, Multidisciplinary; Oceanography SC Engineering; Geology; Oceanography GA BV22H UT WOS:000178200800395 ER PT J AU Kurle, CM Worthy, GAJ AF Kurle, CM Worthy, GAJ TI Stable isotope assessment of temporal and geographic differences in feeding ecology of northern fur seals (Callorhinus ursinus) and their prey SO OECOLOGIA LA English DT Article DE stable isotopes; northern fur seals; feeding ecology; foraging; migration ID FOOD-WEB STRUCTURE; LOW-PROTEIN RATION; TROPHIC RELATIONSHIPS; NATURAL ABUNDANCE; CARBON ISOTOPES; BERING SEA; MAMMALIAN REPRODUCTION; ZALOPHUS-CALIFORNIANUS; BALAENA-MYSTICETUS; NITROGEN ISOTOPES AB We investigated the feeding ecology and foraging location of migrating and nursing northern fur seal (Callorhinus ursinus) adult females and migrating juvenile males from the Pribilof Islands, Alaska, using carbon (delta C-13) and nitrogen (delta N-15) isotope analysis of fur seal skin and whole potential prey. Post-parturient and lactating females had mean delta N-15 values significantly (0.8%) higher than pregnant, migratory females, and delta C-13 values that were not significantly different. Two opportunistically collected, migrating, nulliparous females had mean delta C-13 values 1.1% lower than migrating, pregnant females, and delta N-15 values that were not different. Pregnant, migratory females had mean delta C-13 values significantly (similar to1.5%) higher than migratory juvenile males, and mean delta N-15 values significantly (similar to0.6-1.6%) higher than migratory juvenile males. The exception was one group of juvenile males from St. Paul Island with mean delta N-15 values that were not significantly different from migrating females. The mean delta N-15 values of pregnant females indicate they were feeding at a higher trophic level than juvenile males during migration. The higher mean delta C-13 values for pregnant females suggest they were feeding coastally during the spring migration, while juvenile males and nulliparous females were feeding offshore. The higher delta N-15 values for post-parturient, lactating females over migrating, pregnant females point to either a trophic shift in diet over time, or a more likely N-15-enrichment due to negative nitrogen balance caused by the nutritional stress of lactation and the feeding/fasting regime experienced by females. Similar mean delta C-13 values for migrating and breeding-season females indicate that both groups were feeding in coastal, on-shelf domains during their respective time periods. Similar mean delta N-15 values for nulliparous and pregnant females indicate they were feeding at similar trophic levels despite indications of feeding in separate ecosystems during migration. Using a delta N-15 shift of 2-3% per trophic level, we made general inferences about the trophic levels at which northern fur seals were feeding. The interpretation of our delta N-15 data indicates that migrating pregnant females, lactating females and the majority of migrating juvenile males consumed prey with mean delta N-15 values between 14.2% and 15.2%, 15.1% and 16.1%, and 13.6% and 14.6%, respectively. Probable fur seal prey was analyzed as well. Walleye pollock showed progressive N-15 and C-13-enrichments with age. Mean delta N-15 and delta C-13 values of 3- to 4-year-old fish were similar to6.0% and 1.1% higher, respectively, than values for 0-age pollock. Atka mackerel also showed isotopic enrichment with age. The delta N-15 and delta C-13 values of large fish were 0.8% and 0.3% higher, respectively, than values for smaller fish. C1 NOAA, Natl Marine Fisheries Serv, Natl Marine Mammal Lab, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. Texas A&M Univ, Physiol Ecol & Bioenerget Lab, Galveston, TX 77551 USA. RP Kurle, CM (reprint author), NOAA, Natl Marine Fisheries Serv, Natl Marine Mammal Lab, Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98115 USA. EM Carolyn.Kurle@NOAA.gov NR 97 TC 78 Z9 78 U1 3 U2 25 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0029-8549 EI 1432-1939 J9 OECOLOGIA JI Oecologia PD JAN PY 2001 VL 126 IS 2 BP 254 EP 265 DI 10.1007/s004420000518 PG 12 WC Ecology SC Environmental Sciences & Ecology GA 393XK UT WOS:000166494800014 ER PT S AU Tang, X Zheng, J AF Tang, X Zheng, J BE Hurst, T Kobayashi, S TI Reflectance calibration standard for optical discs SO OPTICAL DATA STORAGE 2001 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 17th Topical Meeting on Optical Data Storage (ODS2001) CY APR 22-25, 2001 CL SANTA FE, NM SP SPIE, Opt Soc Amer, IEEE Lasers & Electro Opt Soc DE testing method; reflectance; calibration standard; optical disc AB An accurate method for the determination of reflectance of primary reference discs has been developed at National Institute of Standards and Technology (NIST). The reference discs can be used as a traceable industry standard in the calibration of optical disc testing equipments and in the manufacturing of secondary calibration discs. C1 Natl Inst Stand & Technol, Informat Technol Lab, Gaithersburg, MD 20899 USA. RP Tang, X (reprint author), Natl Inst Stand & Technol, Informat Technol Lab, 100 Bur Dr,Stop 8951, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4028-0 J9 P SOC PHOTO-OPT INS PY 2001 VL 4342 BP 511 EP 514 AR UNSP 4342-50 PG 4 WC Computer Science, Hardware & Architecture; Optics; Physics, Applied SC Computer Science; Optics; Physics GA BU10D UT WOS:000175013500061 ER PT S AU White, GS Braun, LM AF White, GS Braun, LM BE Matthewson, MJ TI Difficulties making reliability predictions for Si, GaAs, and InP SO OPTICAL FIBER AND FIBER COMPONENT MECHANICAL RELIABILITY AND TESTING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Fiber and Fiber Component Mechanical Reliability and Testing CY NOV 06-07, 2000 CL BOSTON, MA SP SPIE DE crack growth; failure mechanism; GaAs; InP; lifetime; reliability; semiconductor; Si ID CRACK-GROWTH; INDIUM(III) PHOSPHIDE; FRACTURE-MECHANICS; FATIGUE; WINDOWS; FLAWS AB The lifetime prediction model that has been developed for brittle materials implicitly assumes an initial flaw population from which, under the influence of an applied or residual stress, cracks grow to failure. The relationship between crack growth rate and stress intensity factor is assumed to be a power law expression. While the tests used to predict lifetimes, i.e., Weibull distribution, inert strength, and dynamic fatigue, can all be applied to semiconductors without apparent discrepancies, analysis of the crack growth behavior in Si, GaAs, and InP shows that assumptions in the lifetime model are violated for these materials. Consequently, lifetime predictions based upon this model will be wrong. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP White, GS (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3880-4 J9 P SOC PHOTO-OPT INS PY 2001 VL 4215 BP 81 EP 89 DI 10.1117/12.424363 PG 9 WC Engineering, Mechanical; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BS26A UT WOS:000169262400009 ER PT S AU Schmitz, TL Davies, AD Evans, CJ AF Schmitz, TL Davies, AD Evans, CJ BE Stahl, HP TI Uncertainties in interferometric measurements of radius of curvature SO OPTICAL MANUFACTURING AND TESTING IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Optical Manufacturing and Testing IV Conference CY JUL 31-AUG 02, 2001 CL SAN DIEGO, CA SP SPIE DE radius of curvature; interferometry; uncertainty analysis; diffraction ID AIR AB The radius of curvature of spherical surfaces may be determined using the well-known radius, or optical, bench. In this method, a figure measuring interferometer is employed to identify the null positions at the center of curvature (confocal) and surface (cat's eye) of the test optic. A linear slide provides motion between these positions and one or more displacement transducers is used to record the displacement between the cat's eye and confocal positions and, hence, the radius of curvature. Measurements of a polished Zerodur sphere have been completed on the X-ray Optics Calibration Interferometer (XCALIBIR) using both Twyman-Green and Fizeau configurations. Mechanical measurements of the spherical artifact have also been completed using a coordinate measuring machine (CMM). Recorded disagreement between the individual transmission sphere measurements and CMM measurements under well-controlled environmental conditions is larger than the limits predicted from a traditional uncertainty analysis based on a geometric measurement model. Additional uncertainty sources for the geometric model, as well as a physical optics model of the propagation of light, are therefore suggested. The expanded uncertainty analysis is described. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Schmitz, TL (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,MS 8223, Gaithersburg, MD 20899 USA. NR 16 TC 32 Z9 33 U1 0 U2 5 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4165-1 J9 P SOC PHOTO-OPT INS PY 2001 VL 4451 BP 432 EP 447 DI 10.1117/12.453641 PG 16 WC Optics SC Optics GA BT91N UT WOS:000174430600049 ER PT S AU Kim, JH Ehrman, SH Mulholland, GW Germer, TA AF Kim, JH Ehrman, SH Mulholland, GW Germer, TA BE Duparre, A Singh, B TI Polarized light scattering from metallic particles on silicon wafers SO OPTICAL METROLOGY ROADMAP FOR THE SEMICONDUCTOR, OPTICAL, AND DATA STORAGE INDUSTRIES II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Optical Metrology Roadmap for the Semiconductor, Optical, and Data Storage Industries II Conference CY AUG 02-03, 2001 CL SAN DIEGO, CA SP SPIE DE copper; gold; inspection; metal; particles; polarization; scattering; spheres ID OUT-OF-PLANE; SUBSURFACE DEFECTS; MU-M; SPHERES; SURFACES; INSTRUMENT; SUBSTRATE; FEATURES AB Polarized light scattering by monodisperse copper and gold spheres, having diameters ranging from 96 nm to 205 nm, deposited on silicon substrates were measured using visible light. The results are compared to an exact theory for scattering by a sphere on a surface, originally developed by Bobbert and Vlieger. The results show that accurate calculation of the scattering of light by a metal sphere requires that the near-field interaction between the sphere and its image be included in a complete manner, that the normal incidence approximation does not suffice for this interaction, and that the existence of any thin oxide layer on the substrate must be included. The polarization of light scattered by these spheres on silicon substrates can be used to determine the size of those spheres. However, uncertainties in the thickness of the substrate oxide layer, roughness of the particles, and uncertainties in the optical properties of the particles may prevent them from being used as standard scatterers. The implementation of the theory, which requires special care when the spheres are metallic and the substrate is highly reflecting, is described in detail. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kim, JH (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 28 TC 7 Z9 7 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4163-5 J9 P SOC PHOTO-OPT INS PY 2001 VL 4449 BP 281 EP 290 DI 10.1117/12.450105 PG 4 WC Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Optics; Physics, Applied SC Materials Science; Optics; Physics GA BT90N UT WOS:000174395800031 ER PT S AU Burke, JP Chu, ST Bryant, GW Williams, CJ Julienne, PS AF Burke, JP Chu, ST Bryant, GW Williams, CJ Julienne, PS BE Band, YB TI Trapping atoms with evanescent light fields from integrated optical waveguides SO OPTICAL PULSE AND BEAM PROPAGATION III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Pulse and Beam Propagation III CY JAN 24-25, 2001 CL SAN JOSE, CA SP SPIE DE waveguides; atom optics; atom traps; dipole traps; integrated optics ID NEUTRAL ATOMS; TRAPS AB We theoretically investigate three approaches to trapping atoms above linear integrated optical waveguides. A two-color scheme balances the decaying evanescent fields of red- and blue-detuned light to produce a potential minimum above the guide. A one-color surface trap proposal uses blue-detuned Light and the attractive surface interaction to provide a potential minimum. A third proposal uses blue-detuned light in two guides positioned above and below one another. The atoms are confined to the "dark" spot in the vacuum gap between the guides. We find that all three approaches can be used in principle to trap atoms in two- or three-dimensions with a few 10's of mW of laser power. Of these three methods, we show that the dark spot guide is the most robust to power fluctuations and provides the most viable design approach to constructing integrated optical circuits that could transport and manipulate atoms in a controlled manner. C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Burke, JP (reprint author), Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Williams, Carl/B-5877-2009; Chu, Sai /D-3312-2014; Julienne, Paul/E-9378-2012; OI Julienne, Paul/0000-0002-5494-1442; CHU, Sai Tak /0000-0001-8263-8507 NR 12 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3949-5 J9 P SOC PHOTO-OPT INS PY 2001 VL 4271 BP 52 EP 61 PG 10 WC Optics; Physics, Applied SC Optics; Physics GA BS26G UT WOS:000169263400005 ER PT S AU Grossman, EN Nolen, S Paulter, NG Reintsema, CD AF Grossman, EN Nolen, S Paulter, NG Reintsema, CD BE Smith, RM Appleby, R TI Concealed weapons detection system using uncooled, pulsed, imaging arrays of millimeter-wave bolometers SO PASSIVE MILLIMETER-WAVE IMAGING TECHNOLOGY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Passive Millimeter-Wave Imaging Technology V CY APR 19, 2001 CL ORLANDO, FL SP SPIE DE bolometer; array; millimeter-wave; concealed weapons; imaging ID INTEGRATED-CIRCUIT ANTENNAS; ANNULAR-SLOT ANTENNA AB We describe a system for detection of concealed weapons based on imaging the millimeter-wave reflectance contrast between the weapon and the human body. An architecture based upon pulsed illumination and gated integration has a large advantage in sensitivity over chopped CW illumination and synchronous detection. A simple sensitivity estimate based on an assumed range of 8 m, a 30 Hz frame rate, a primary collection area of 30 cm diameter, and an overall optical efficiency of 50 %, yields a noise-equivalent reflectance difference of 0.66 % in a single frame. The uncooled niobium microbolometers provide a (measured) noise-equivalent power of 100 pW/Hz(1/2) and a time constant of 175 ns, well matched to the source pulse width and the system sensitivity requirements. Optical coupling is provided by resonant slot-ring antennas, distributed in a focal plane array covering a single 75 mm diameter wafer. The optical and electrical systems used for coupling signals into and out of the focal plane array are also described. C1 Natl Inst Stand & Technol, Electromagnet Technol Div, Boulder, CO USA. RP Grossman, EN (reprint author), Natl Inst Stand & Technol, Electromagnet Technol Div, 325 Broadway, Boulder, CO USA. NR 14 TC 7 Z9 7 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4068-X J9 P SOC PHOTO-OPT INS PY 2001 VL 4373 BP 7 EP 15 DI 10.1117/12.438138 PG 9 WC Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology; Telecommunications SC Engineering; Remote Sensing; Imaging Science & Photographic Technology; Telecommunications GA BT20R UT WOS:000172264600002 ER PT S AU Nolen, S Harvey, TE Reintsema, CD Grossman, EN AF Nolen, S Harvey, TE Reintsema, CD Grossman, EN BE Smith, RM Appleby, R TI Properties of cavity-backed slot-ring antennas at 95 GHz SO PASSIVE MILLIMETER-WAVE IMAGING TECHNOLOGY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Passive Millimeter-Wave Imaging Technology V CY APR 19, 2001 CL ORLANDO, FL SP SPIE DE slot-ring; annular slot; ring-slot; millimeter wave ID DIELECTRIC HALF-SPACE; MILLIMETER-WAVE; ANNULAR SLOT AB Slot-ring antennas with planar backshorts designed for operation at 95 GHz have been fabricated and their properties measured. Using optical lithography, we fabricated the slot-ring antennas, along with integrated niobium thin-film bolometers, on dielectrically thin (50 mum) silicon substrates. We have performed a theoretical analysis of the slot-ring antennas with planar backshorts and compared the theoretical results with our measured beam patterns. The measured antenna patterns have highly circular main beams with full -3 dB beamwidths of 21 degrees. The patterns have low sidelobe levels of about -15 dB in the H-plane and below -25 dB in the E-plane and a directivity of 17 dB. We are investigating a focal-plane array of slot-ring antenna-coupled bolometers for use in a concealed-weapons imaging system. C1 Natl Inst Stand & Technol, Boulder, CO USA. RP Nolen, S (reprint author), Natl Inst Stand & Technol, 325 Broadway, Boulder, CO USA. NR 18 TC 4 Z9 4 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4068-X J9 P SOC PHOTO-OPT INS PY 2001 VL 4373 BP 49 EP 57 DI 10.1117/12.438144 PG 9 WC Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology; Telecommunications SC Engineering; Remote Sensing; Imaging Science & Photographic Technology; Telecommunications GA BT20R UT WOS:000172264600007 ER PT S AU Paulter, NG Grossman, EN Stenbakken, GN Waltrip, BC Nolen, S Reintsema, CD AF Paulter, NG Grossman, EN Stenbakken, GN Waltrip, BC Nolen, S Reintsema, CD BE Smith, RM Appleby, R TI Design of an active mm-wave concealed object imaging system SO PASSIVE MILLIMETER-WAVE IMAGING TECHNOLOGY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Passive Millimeter-Wave Imaging Technology V CY APR 19, 2001 CL ORLANDO, FL SP SPIE DE active imaging system; concealed object imaging; microbolometers; millimeter-wave ID WEAPONS AB The research and design of an active millimeter-wave concealed object imaging system is described. Several illumination and detection methods were analyzed via computer simulation to assess the effects of system parameters on the signal-to-noise ratio of the detected signal. The results of many of these simulations were experimentally verified using either a 10 MHz or a 100 GHz measurement system. Based on this assessment, two designs using pulsed illumination with gated detection were selected for development. Pulsed illumination is provided using a pulsed broadband noise source. For detecting the reflected noise pulse, two methods were examined, one using microbolometers and the other using electrooptics. Based on imaging system considerations, such as cost of manufacture, ruggedness, etc., and technical parameters, microbolometer arrays were selected for further development. The electronics interface, including image display capability, was developed. We examined the absorption of some common clothing materials at 100 GHz and compared this to results previously reported. C1 Natl Inst Stand & Technol, Div Elect, Gaithersburg, MD 20899 USA. RP Paulter, NG (reprint author), Natl Inst Stand & Technol, Div Elect, 100 Bur Dr, Gaithersburg, MD 20899 USA. NR 15 TC 4 Z9 4 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4068-X J9 P SOC PHOTO-OPT INS PY 2001 VL 4373 BP 64 EP 71 DI 10.1117/12.438145 PG 8 WC Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology; Telecommunications SC Engineering; Remote Sensing; Imaging Science & Photographic Technology; Telecommunications GA BT20R UT WOS:000172264600009 ER PT J AU Moon, H Phillips, PJ AF Moon, H Phillips, PJ TI Computational and performance aspects of PCA-based face-recognition algorithms SO PERCEPTION LA English DT Article ID FERET EVALUATION METHODOLOGY; REPRESENTATION; EIGENFACES AB Algorithms based on principal component analysis (PCA) form the basis of numerous studies in the psychological and algorithmic face-recognition literature. PCA is a statistical technique and its incorporation into a face-recognition algorithm requires numerous design decisions. We explicitly state the design decisions by introducing a generic modular PCA-algorithm. This allows us to investigate these decisions, including those not documented in the literature. We experimented with different implementations of each module, and evaluated the different implementations using the September 1996 FERET evaluation protocol (the de facto standard for evaluating face-recognition algorithms). We experimented with (i) changing the illumination normalization procedure; (ii) studying effects on algorithm performance of compressing images with JPEG and wavelet compression algorithms; (iii) varying the number of eigenvectors in the representation: and (iv) changing the similarity measure in the classification process. We performed two experiments. In the first experiment, we obtained performance results on the standard September 1996 FERET large-gallery image sets. In the second experiment, we examined the variability in algorithm performance on different sets of facial images. The study was performed on 100 randomly generated image sets (galleries) of the same size. Our two most significant results are (i) changing the similarity measure produced the greatest change in performance, and (ii) that difference in performance of +/- 10% is needed to distinguish between algorithms. C1 SUNY Buffalo, Dept Elect & Comp Engn, Amherst, NY 14260 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Moon, H (reprint author), SUNY Buffalo, Dept Elect & Comp Engn, Amherst, NY 14260 USA. NR 38 TC 162 Z9 169 U1 0 U2 11 PU PION LTD PI LONDON PA 207 BRONDESBURY PARK, LONDON NW2 5JN, ENGLAND SN 0301-0066 J9 PERCEPTION JI Perception PY 2001 VL 30 IS 3 BP 303 EP 321 DI 10.1068/p2896 PG 19 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA 431TF UT WOS:000168646100004 PM 11374202 ER PT J AU Minniti, R Ratliff, LP Gillaspy, JD AF Minniti, R Ratliff, LP Gillaspy, JD TI In-situ observation of surface modification induced by highly charged ion bombardment SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 10th International Conference on the Physics of Highly Charged Ions (HCI 2000) CY JUL 30-AUG 03, 2000 CL CLARK KERR CAMPUS, BERKELEY, CALIFORNIA SP Amer Vacuum Soc, Lawrence Livermore Natl Lab HO CLARK KERR CAMPUS ID SCANNING-TUNNELING-MICROSCOPY; ELECTRONIC EXCITATION; SLOW; GRAPHITE; ENERGY; SOLIDS; NEUTRALIZATION; SILICON; IMPACTS; TRAP AB Nanoscale dots created on the surface of a highly oriented pyrolitic graphite sample by individual highly charged xenon projectile ions were observed using an in-situ scanning tunneling microscope. This is the first time that such features have been created and imaged without exposure to air. The dots vary in size with the charge state of the ion, up to a diameter of 6.6 nm for Xe44+. The results are discussed in terms of the energy density deposited in the near surface region. C1 NIST, Gaithersburg, MD 20899 USA. RP Minniti, R (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 45 TC 25 Z9 25 U1 0 U2 3 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0031-8949 J9 PHYS SCRIPTA JI Phys. Scr. PY 2001 VL T92 BP 22 EP 26 DI 10.1238/Physica.Topical.092a00022 PG 5 WC Physics, Multidisciplinary SC Physics GA 460CK UT WOS:000170288100003 ER PT J AU Suominen, KA Machholm, M Julienne, PS AF Suominen, KA Machholm, M Julienne, PS TI Cold collisions between laser-cooled magnesium atoms SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 32nd Annual Conference of the European-Group-for-Atmoic-Spectroscopy (EGAS) CY JUL 04-07, 2000 CL VILNIUS, LITHUANIA SP European Grp Atomic Spectroscopy ID LIGHT FIELDS; QUANTUM AB Light-assisted inelastic cold collisions are the main loss process for neutral atoms trapped and laser cooled in magneto-optical traps. Alkaline earth atoms do not have hyperfine structure, which is expected to make the comparison between theoretical predictions and experimental results much easier, compared to the case of alkali-metal atoms. We present here a numerical calculation for the loss rates in a weak laser field for cold magnesium atoms. C1 Univ Turku, Dept Appl Phys, FIN-20014 Turun Yliopisto, Finland. Helsinki Inst Phys, FIN-00014 Helsinki, Finland. Univ Copenhagen, Orsted Lab, DK-2100 Copenhagen, Denmark. Natl Univ Singapore, Dept Computat Sci, Singapore 119260, Singapore. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Suominen, KA (reprint author), Univ Turku, Dept Appl Phys, FIN-20014 Turun Yliopisto, Finland. RI Suominen, Kalle-Antti/H-9076-2012; Julienne, Paul/E-9378-2012 OI Suominen, Kalle-Antti/0000-0002-1091-2893; Julienne, Paul/0000-0002-5494-1442 NR 12 TC 1 Z9 1 U1 0 U2 0 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PY 2001 VL T95 BP 58 EP 61 DI 10.1238/Physica.Topical.095a00058 PG 4 WC Physics, Multidisciplinary SC Physics GA 496EE UT WOS:000172382600009 ER PT J AU Bohm, S Schippers, S Shi, W Muller, A Djuric, N Dunn, GH Zong, W Jelencovic, B Eklow, N Glans, P Schuch, R Danared, H Badnell, NR AF Bohm, S Schippers, S Shi, W Muller, A Djuric, N Dunn, GH Zong, W Jelencovic, B Eklow, N Glans, P Schuch, R Danared, H Badnell, NR TI Influence of electromagnetic fields on the dielectronic recombination of Ne7+ and O5+ ions SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 10th International Conference on the Physics of Highly Charged Ions (HCI 2000) CY JUL 30-AUG 03, 2000 CL CLARK KERR CAMPUS, BERKELEY, CALIFORNIA SP Amer Vacuum Soc, Lawrence Livermore Natl Lab HO CLARK KERR CAMPUS ID MAGNETIC-FIELDS AB Within a series of measurements of the dielectronic recombination (DR) of lithium-like ions we have determined the enhancement of the recombination rate in the presence of crossed electric and magnetic fields for Ne7+ and O5+ ions. In both cases the electron energy range covers a DR resonances attached to 2s --> 2p(1/2) and 2s --> 2p(3/2) Deltan = 0 core excitations. For increasing field the enhancement factor first increases linearly with the electric field and then saturates. In order to investigate the field effect on high-n Rydberg states the ion energy in the O5+-experiment was changed from 9.4 MeV/u to 5 MeV/u and 3.26 MeV/u. With the variation of the ion energy the field ionization of Rydberg states in the analyzing magnet is influenced. This enabled us to study the field enhancement for a narrow bandwidth of n-states. C1 Univ Giessen, Inst Kernphys, D-35392 Giessen, Germany. JILA, Boulder, CO USA. Natl Inst Stand & Technol, Boulder, CO USA. Stockholm Univ, S-10691 Stockholm, Sweden. Manne Siegbahn Lab, Stockholm, Sweden. Univ Strathclyde, Glasgow G4 0NG, Lanark, Scotland. RP Bohm, S (reprint author), Univ Giessen, Inst Kernphys, D-35392 Giessen, Germany. RI Schippers, Stefan/A-7786-2008; Muller, Alfred/A-3548-2009 OI Schippers, Stefan/0000-0002-6166-7138; Muller, Alfred/0000-0002-0030-6929 NR 7 TC 2 Z9 2 U1 0 U2 0 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0031-8949 J9 PHYS SCRIPTA JI Phys. Scr. PY 2001 VL T92 BP 395 EP 397 PG 3 WC Physics, Multidisciplinary SC Physics GA 460CK UT WOS:000170288100114 ER PT J AU Kink, I Laming, JM Takacs, E Porto, JV Gillaspy, JD Silver, E Schnopper, H Bandler, SR Barbera, M Brickhouse, N Murray, S Madden, N Landis, D Beeman, J Haller, EE AF Kink, I Laming, JM Takacs, E Porto, JV Gillaspy, JD Silver, E Schnopper, H Bandler, SR Barbera, M Brickhouse, N Murray, S Madden, N Landis, D Beeman, J Haller, EE TI Microcalorimeter/EBIT measurements of X-ray spectra of highly charged ions SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 10th International Conference on the Physics of Highly Charged Ions (HCI 2000) CY JUL 30-AUG 03, 2000 CL CLARK KERR CAMPUS, BERKELEY, CALIFORNIA SP Amer Vacuum Soc, Lawrence Livermore Natl Lab HO CLARK KERR CAMPUS ID FE-XVII; PLASMAS AB Spectra of highly charged At, Kr, Xe and Fe ions, produced in an Electron Beam Ion Trap (EBIT), have been recorded in a broad X-ray energy band (0.2 keV to 10 keV) with a microcalorimeter detector. The first analysis of the Kr spectra has been completed and most of the spectral lines have been identified as transitions of B- to Al-like Kr. Line intensity ratios of Fe XVII have been measured and compared with theoretical models. C1 NIST, Gaithersburg, MD 20899 USA. USN, Res Lab, Washington, DC 20375 USA. MIT, Cambridge, MA 02139 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osservatorio Astron GS Vaiana, Palermo, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kink, I (reprint author), NIST, Gaithersburg, MD 20899 USA. RI Bandler, Simon/A-6258-2010; OI Bandler, Simon/0000-0002-5112-8106; Brickhouse, Nancy/0000-0002-8704-4473; Barbera, Marco/0000-0002-3188-7420 NR 13 TC 5 Z9 6 U1 0 U2 1 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0031-8949 J9 PHYS SCRIPTA JI Phys. Scr. PY 2001 VL T92 BP 454 EP 456 DI 10.1238/Physica.Topical.092a00454 PG 3 WC Physics, Multidisciplinary SC Physics GA 460CK UT WOS:000170288100131 ER PT J AU Herndon, SC Gierczak, T Talukdar, RK Ravishankara, AR AF Herndon, SC Gierczak, T Talukdar, RK Ravishankara, AR TI Kinetics of the reactions of OH with several alkyl halides SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID LASER-INDUCED FLUORESCENCE; RATE CONSTANTS; RADICALS; CH3CL; 1-BROMOPROPANE; TEMPERATURE; LIFETIMES; METHANES; CH2CL2; CHCL3 AB The rate coefficients for the reactions of OH with methyl chloride (k(1)), ethyl chloride (k(2)), methylene chloride (k(3)), ethyl bromide (k(4)), n-propyl bromide (k(5)) and isopropyl bromide (k(6)) were measured over the temperature range, 220-380 K, using pulsed photolysis-pulsed laser induced fluorescence (PP-PLIF). The measured rate coefficients, k(1-6), (cm(3) molecule(-1) s(-1)) are : k(1) = 1.3 x 10(-13) T-0.5 exp[-(1238)/T]; k(2) = 1.5 x 10(-13) T-0.5 exp[-637/T]; k(3) = 6.6 x 10(-14) T-0.5 exp[-721/T]; k(4) = 1.7 x 10(-13) T-0.5 exp[-641/T]; k(5) = 9.1 x 10(-14) T-0.5 exp[-157/T]; k(6) = 7.0 x 10(-14) T-0.50 exp[-145/T]. These rate constants are compared with those from previous studies. Some trends in the reactivities are also noted. The globally averaged atmospheric lifetime for methyl chloride, CH3Cl, with respect to loss by reaction with OH, derived from the rate constant data performed in this study is 1.3 years. The rate constants for the reaction of OH with the other compounds presented in this study are large enough to make these reactions their dominant atmospheric loss pathway. 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 Warsaw, Dept Chem, PL-02089 Warsaw, Poland. RP Ravishankara, AR (reprint author), NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80305 USA. RI TALUKDAR, RANAJIT/G-4530-2013; Ravishankara, Akkihebbal/A-2914-2011 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; NR 23 TC 20 Z9 20 U1 0 U2 5 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 J9 PHYS CHEM CHEM PHYS JI Phys. Chem. Chem. Phys. PY 2001 VL 3 IS 20 BP 4529 EP 4535 DI 10.1039/b105188c PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 484VZ UT WOS:000171711400009 ER PT J AU Donaldson, DJ Tuck, AF Vaida, V AF Donaldson, DJ Tuck, AF Vaida, V TI Spontaneous fission of atmospheric aerosol particles SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID WATER; INTERFACE; MEMBRANES; ACIDS; MODEL AB We show that spontaneous division of atmospheric aerosol particles is thermodynamically possible, in spite of the corresponding increase in surface area, when there is a highly compressed organic surfactant coating on the particle. This class of atmospheric aerosol is thought to be present (and potentially important) in both marine and urban atmospheres. Fully-coated particles have been suggested to have played a role in the origin of cell-based life. The possibility of their spontaneous division has important implications for atmospheric chemistry, radiative transfer and the evolution of life on Earth. C1 Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Toronto, Dept Chem, Toronto, ON M5S 1A1, Canada. NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Donaldson, DJ (reprint author), Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RI Tuck, Adrian/F-6024-2011; Vaida, Veronica/N-6069-2014; Donaldson, James/G-7120-2012 OI Tuck, Adrian/0000-0002-2074-0538; Vaida, Veronica/0000-0001-5863-8056; Donaldson, James/0000-0002-5090-3318 NR 31 TC 19 Z9 19 U1 2 U2 7 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 J9 PHYS CHEM CHEM PHYS JI Phys. Chem. Chem. Phys. PY 2001 VL 3 IS 23 BP 5270 EP 5273 DI 10.1039/b105215m PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 496UB UT WOS:000172414400030 ER PT J AU Durr, S Miller, KW Wieman, CE AF Durr, S Miller, KW Wieman, CE TI Improved loading of an optical dipole trap by suppression of radiative escape SO PHYSICAL REVIEW A LA English DT Article ID ULTRACOLD COLLISIONS; COLD AB We investigate two-body loss in an optical dipole trap for Rb-87 atoms. In the presence of additional near-resonant light, such as from a magneto-optical trap during the trap loading, the two-body loss is strongly enhanced by long-range radiative escape. We suppressed this loss by a factor of 15 by adding a sideband to the optical dipole trap laser. This allows more atoms to be loaded into the optical dipole trap. C1 JILA, Boulder, CO 80309 USA. NIST, Boulder, CO 80309 USA. Univ Colorado, Boulder, CO 80309 USA. RP Durr, S (reprint author), JILA, Boulder, CO 80309 USA. RI Durr, Stephan/C-3760-2017 OI Durr, Stephan/0000-0003-0811-6211 NR 10 TC 0 Z9 0 U1 0 U2 1 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 JAN PY 2001 VL 63 IS 1 AR 011401 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 391YC UT WOS:000166383000006 ER PT J AU Kotochigova, S Tiesinga, E Julienne, PS AF Kotochigova, S Tiesinga, E Julienne, PS TI Relativistic ab initio treatment of the second-order spin-orbit splitting of the a (3)Sigma(+)(u) potential of rubidium and cesium dimers SO PHYSICAL REVIEW A LA English DT Article ID DISPERSION COEFFICIENTS; RELAXATION RATES; ATOMS; COLLISIONS AB We have calculated the splitting between the 0(u)(-) and 1(u) components of the a (3)Sigma (+)(u) state of Rb-2 and CS2 using a relativistic ab initio configuration-interaction valence bond method. This so-called second-order spin-orbit splitting is entirely due to relativistic correlations within the molecule. Our nb initio nonperturbative splitting is 5 and 3 times larger than perturbative splittings at the inner turning point of the a (3)Sigma (+)(u) potential for Rb-2 and Cs-2, respectively. In addition, close-coupled nuclear dynamics calculations that estimate the effect of this splitting on experimentally accessible quantities are presented. The splitting affects the collisional loss rate of magnetically trapped ultracold Rb and Cs atoms and the spectroscopic determination of the vibrational structure of Rb-2 and Cs-2 dimers. Agreement with the experimental collisional loss rates of Ca is found. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Kotochigova, S (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8401, Gaithersburg, MD 20899 USA. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 22 TC 3 Z9 3 U1 1 U2 2 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 JAN PY 2001 VL 63 IS 1 AR 012517 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 391YC UT WOS:000166383000050 ER PT J AU Samuelis, C Tiesinga, E Laue, T Elbs, M Knockel, H Tiemann, E AF Samuelis, C Tiesinga, E Laue, T Elbs, M Knockel, H Tiemann, E TI Cold atomic collisions studied by molecular spectroscopy SO PHYSICAL REVIEW A LA English DT Article ID GROUND-STATE ASYMPTOTE; LONG-RANGE POTENTIALS; ALKALI-METAL DIMERS; DISSOCIATION-ENERGY; HYPERFINE-STRUCTURE; SCATTERING LENGTHS; VIBRATIONAL LEVELS; BOUND LEVELS; NA-2; NA2 AB We observe bound states just below the dissociation limit and shape and Feshbach resonances between the ground state hyperfine asymptotes by Raman spectroscopy on a molecular beam of sodium dimers. The rotational selectivity of a two-photon transition gives access to specific states of nuclear motion and thus to cold collision properties of two colliding atoms. Modeling of the collisional resonance structures requires a multichannel treatment of the nuclear dynamics that uses highly accurate X (1)Sigma (+)(g) and a (3)Sigma (+)(u) potentials. These potentials are constructed from bound levels just below the ground state asymptote measured in this experiment and bound state information available in the literature. We also present simulations of the spectrum between the ground state hyperfine asymptotes. The good agreement shows that accurate potentials obtained from bound state information are able to reproduce scattering properties of two colliding sodium atoms. From this analysis we find for the scattering lengths a(f = 2) = a(1. - t) = 52.98(40)a(0), a(singlet) = 19.20(30)a(0), and a(triplet) = 62.51(50)a(0), where 1a(0) = 0.052 917 7 nm. C1 Univ Hannover, Inst Quantenopt, D-30167 Hannover, Germany. Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Samuelis, C (reprint author), Univ Hannover, Inst Quantenopt, D-30167 Hannover, Germany. NR 27 TC 57 Z9 57 U1 0 U2 5 PU AMER 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 JAN PY 2001 VL 63 IS 1 AR 012710 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 391YC UT WOS:000166383000063 ER PT J AU Walser, R Cooper, J Holland, M AF Walser, R Cooper, J Holland, M TI Reversible and irreversible evolution of a condensed bosonic gas SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; COLLECTIVE EXCITATIONS; FINITE TEMPERATURES; TRAPPED GASES; DYNAMICS; DILUTE; ENERGY; ATOMS AB We have formulated a kinetic theory for a condensed atomic gas in a trap, i.e., a generalized Gross-Pitaevskii equation, as well as a quantum-Boltzmann equation for the normal and anomalous fluctuations [R. Walser et al., Phys. Rev. A 59, 3878 (1999)]. In this paper, the theory is applied to the case of an isotropic configuration and we present numerical and analytical results for the reversible real-time propagation. as well as irreversible evolution towards equilibrium. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Boulder, CO 80309 USA. RP Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 51 TC 6 Z9 6 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 JAN PY 2001 VL 63 IS 1 AR 013607 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 391YC UT WOS:000166383000095 ER PT J AU Yoon, TH Marian, A Hall, JL Ye, J AF Yoon, TH Marian, A Hall, JL Ye, J TI Phase-coherent multilevel two-photon transitions in cold Rb atoms: Ultrahigh-resolution spectroscopy via frequency-stabilized femtosecond laser SO PHYSICAL REVIEW A LA English DT Article ID MODE-LOCKED LASER; 2-PHOTON ABSORPTION; SODIUM VAPOR AB A two-photon transition in cold Rb atoms will be probed with a phase-coherent wide bandwidth femtosecond laser comb. Frequency domain analysis yields a high-resolution picture where phase coherence among various transition pathways through different intermediate states produces interference effects on the resonantly enhanced transition probability. This result is supported by the time domain Ramsey interference effect. The two-photon transition spectrum is analyzed in terms of the pulse repetition rate and carrier frequency offset, leading to a cold-atom-based frequency stabilization scheme for both degrees of freedom of the femtosecond laser. C1 Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. Univ Colorado, Boulder, CO 80309 USA. KRISS, Taejon 305600, South Korea. RP Yoon, TH (reprint author), Natl Inst Stand & Technol, JILA, 325 Broadway, Boulder, CO 80309 USA. EM Ye@jila.colorado.edu RI Ye, Jun/C-3312-2011 NR 19 TC 11 Z9 11 U1 2 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 JAN PY 2001 VL 63 IS 1 AR 011402 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 391YC UT WOS:000166383000007 ER PT J AU Dimeo, RM Neumann, DA AF Dimeo, RM Neumann, DA TI Low-temperature dynamics of confined methyl iodide SO PHYSICAL REVIEW B LA English DT Article ID ROTATIONAL EXCITATIONS; NEUTRON-SCATTERING; METHANE MOLECULES; GLASSY-POLYMERS; SILICA GLASSES; SPECTROSCOPY; CH4; MIXTURES; KR AB The rotational tunneling and librational excitations of the one-dimensional quantum rotor, methyl iodide, confined in porous glass monoliths (mean pore diameter of 58 Angstrom) have been investigated using incoherent inelastic neutron scattering. When the pores are completely filled with the solid at low temperatures (5 K 50 degreesN) part of the basin. The winter-to-winter autocorrelation of SSS anomalies exceed those of SST, since only the latter are strongly damped by surface fluxes. The re-emergence mechanism also has a modest influence on MLD through changes in the vertical stratification in the seasonal thermocline. Published by Elsevier Science Ltd. C1 NOAA, CIRES, Climate Diagnost Ctr, Boulder, CO USA. RP Alexander, MA (reprint author), R CDC1, 325 Broadway, Boulder, CO 80305 USA. RI Alexander, Michael/A-7097-2013 OI Alexander, Michael/0000-0001-9646-6427 NR 66 TC 33 Z9 33 U1 3 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6611 J9 PROG OCEANOGR JI Prog. Oceanogr. PY 2001 VL 49 IS 1-4 SI SI BP 41 EP 61 DI 10.1016/S0079-6611(01)00015-5 PG 21 WC Oceanography SC Oceanography GA 477AU UT WOS:000171261600004 ER PT J AU Leonard, CL Bidigare, RR Seki, MP Polovina, JJ AF Leonard, CL Bidigare, RR Seki, MP Polovina, JJ TI Interannual mesoscale physical and biological variability in the North Pacific Central Gyre SO PROGRESS IN OCEANOGRAPHY LA English DT Article; Proceedings Paper CT Conference on Beyond El Nino CY MAR, 2000 CL LA JOLLA, CA ID TEMPORAL VARIABILITY; SATELLITE ALTIMETRY; COMMUNITY STRUCTURE; EQUATORIAL PACIFIC; EL-NINO; OCEAN; PHYTOPLANKTON; CHLOROPHYLL; DISTRIBUTIONS AB Springtime composites of surface chlorophyll a (chi) from the SeaWiFS instrument show a sharp increase in chi standing stock (from similar to0.1 to 0.3 mg m(-3)) occurring between 30 degrees and 40 degreesN in the eastern North Pacific Ocean. To investigate the spatial and interannual variability of this springtime feature, multi-platform surveys (23 degrees -33 degreesN, 158 degreesW), including shipboard and satellite measurements, were conducted in April 1998 and 1999 to characterize the hydrographic conditions associated with the large chi gradient. Irradiance and chi data collected during the cruise periods were used in an optical model to compute depth-integrated rates of primary production. The southern portion of both transects resembled the climatological conditions at the Hawai'i Ocean Time-series (HOT) study site, Station ALOHA (22.75 degreesN, 158 degreesW), with two major physical and biological frontal features encountered: 1) the South Subtropical Front (SSTF) in 1998 at 27 degrees -28 degreesN and in 1999 at 32.5 degreesN; and 2) the Subtropical Front (STF) in 1998 at 32 degreesN, which in 1999 had migrated northward out of our study area to similar to 34 degreesN. Integrated chi and primary production both increased at the frontal locations in both years. Increases in surface chi from SeaWiFS and shipboard measurements were not apparent at the SSTF, yet the subsurface chi maximum both shallowed and doubled at this front. In addition, primary production modeled from the satellite chi data did not reflect the smaller mesoscale variability of the SSTF. The increase in surface chi at the STF, however, was clearly recorded in both the satellite and shipboard chi measurements. HPLC pigment analysis was performed for select samples collected during the 1998 cruise and revealed a change in phytoplankton composition at all frontal locations. Specifically, there were distinct increases in the dinoflagellate marker, peridinin, and the diatom marker, fucoxanthin, at the SSTF. The same patterns at the SSTF were observed during both cruises, except all gradients were shifted to the north, as a result of changes in the large-scale circulation of the gyre in 1999. While the eastern equatorial Pacific experienced a dramatic decrease in chi concentrations during El Nino events, the subtropical Pacific appeared to be more 'green' with a southward shift of the circulatory and high surface chl fronts. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Dept Oceanog, Honolulu, HI 96822 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI USA. RP Leonard, CL (reprint author), Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Dept Oceanog, 1000 Pope Rd, Honolulu, HI 96822 USA. EM carrie@soest.hawaii.edu NR 36 TC 14 Z9 16 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6611 J9 PROG OCEANOGR JI Prog. Oceanogr. PY 2001 VL 49 IS 1-4 SI SI BP 227 EP 244 DI 10.1016/S0079-6611(01)00024-6 PG 18 WC Oceanography SC Oceanography GA 477AU UT WOS:000171261600013 ER PT J AU Hollowed, AB Hare, SR Wooster, WS AF Hollowed, AB Hare, SR Wooster, WS TI Pacific Basin climate variability and patterns of Northeast Pacific marine fish production SO PROGRESS IN OCEANOGRAPHY LA English DT Article; Proceedings Paper CT Conference on Beyond El Nino CY MAR, 2000 CL LA JOLLA, CALIFORNIA ID GULF-OF-ALASKA; ZOOPLANKTON BIOMASS; ECOSYSTEM RESPONSE; REGIME SHIFTS; EL-NINO; RECRUITMENT; STOCKS; SALMON; SEA; ENVIRONMENT AB A review of oceanographic and climate data from the North Pacific and Bering Sea has revealed climate events that occur on two principal time scales: a) 2-7 years (i.e. El Nino Southern Oscillation, ENSO), and b) inter-decadal (i.e. Pacific Decadal Oscillation, PDO). The timing of ENSO events and of related oceanic changes at higher latitudes were examined. The frequency of ENSO was high in the 1980s. Evidence of ENSO forcing on ocean conditions in the North Pacific (Nino North conditions) showed ENSO events were more frequently observed along the West Coast than in the western Gulf of Alaska (GOA) and Eastern Bering Sea (EBS). Time series of catches for 30 region/species groups of salmon, and recruitment data for 29 groundfish and 5 non-salmonid pelagic species, were: examined for evidence of a statistical relationship with any of the time scales associated with Nino North conditions or the PDO. Some flatfish stocks exhibited high autocorrelation in recruitment coupled with a significant step in recruitment in 1977 suggesting a relationship between PDO forcing and recruitment success. Five of the dominant gadid stocks (EBS and GOA Pacific cod, Pacific hake and EBS and GOA walleye pollock) exhibited low autocorrelation in recruitment. Of these, Pacific hake, GOA walleye pollock and GOA Pacific cod exhibited significantly higher incidence of strong year classes in years associated with Nino North conditions. These findings suggest that the PDO and ENSO may play an important role in governing year-class strength of several Northeast Pacific marine fish stocks. (C) 2001 Published by Elsevier Science Ltd. C1 Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. Int Pacific Halibut Commiss, Seattle, WA 98145 USA. Univ Washington, Sch Marine Affairs, Seattle, WA 98105 USA. Univ Washington, Sch Marine Affairs, Seattle, WA 98105 USA. RP Hollowed, AB (reprint author), Alaska Fisheries Sci Ctr, 7600 Sand Point Way NE, Seattle, WA 98115 USA. NR 75 TC 137 Z9 139 U1 2 U2 28 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6611 J9 PROG OCEANOGR JI Prog. Oceanogr. PY 2001 VL 49 IS 1-4 SI SI BP 257 EP 282 DI 10.1016/S0079-6611(01)00026-X PG 26 WC Oceanography SC Oceanography GA 477AU UT WOS:000171261600015 ER PT J AU Logerwell, EA Lavaniegos, B Smith, PE AF Logerwell, EA Lavaniegos, B Smith, PE TI Spatially-explicit bioenergetics of Pacific sardine in the Southern California Bight: are mesoscale eddies areas of exceptional prerecruit production? SO PROGRESS IN OCEANOGRAPHY LA English DT Article; Proceedings Paper CT Conference on Beyond El Nino CY MAR, 2000 CL LA JOLLA, CALIFORNIA ID CURRENT SYSTEM; ENGRAULIS-MORDAX; SHELIKOF-STRAIT; OFFSHORE EDDY; THERAGRA-CHALCOGRAMMA; NORTHERN ANCHOVY; GROWTH; LARVAE; VARIABILITY; ALASKA AB Previous research shows that offshore mesoscale eddies in the Southern California Bight region are areas where sardine larval abundance is significantly increased relative to inshore, slope and surrounding offshore waters. In order for mesoscale eddies to be a mechanism linking climate and sardine population variability they must be areas of exceptional prerecruit production. Temperature and prey data from various Southern California Bight (SCB) habitats, including offshore eddies, were applied to a spatially-explicit bioenergetic model which predicts sardine prerecruit growth potential. Growth potential was similar in inshore, slope, and eddy regions (11% and 12% day(-1)), and was lower in the offshore region, 9% day(-1). To estimate production in eddy and non-eddy habitats, growth potential was multiplied by habitat-specific estimates of sardine larval biomass from at-sea surveys. A production index, a measure of potential production resulting from individual growth rate potential and local abundance, was greater in the model cyclonic eddy than in all other regions by more than an order of magnitude. In fact, the production index in the eddy was four times greater than in all other regions combined. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Univ Washington, Sch Aquat & Fishery Sci, Seattle, WA 98195 USA. Univ Calif San Diego, Scripps Inst Oceanog, Marine Life Res Grp, La Jolla, CA 92093 USA. Ctr Invest Cient & Educ Super Ensenada, Dept Ecol, Ensenada 22800, Baja California, Mexico. SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Logerwell, EA (reprint author), Alaska Fisheries Sci Ctr, F-AKC3,POB 15700, Seattle, WA 98115 USA. NR 64 TC 29 Z9 30 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6611 J9 PROG OCEANOGR JI Prog. Oceanogr. PY 2001 VL 49 IS 1-4 SI SI BP 391 EP 406 DI 10.1016/S0079-6611(01)00032-5 PG 16 WC Oceanography SC Oceanography GA 477AU UT WOS:000171261600021 ER PT J AU Beamish, RJ Mahnken, C AF Beamish, RJ Mahnken, C TI A critical size and period hypothesis to explain natural regulation of salmon abundance and the linkage to climate and climate change SO PROGRESS IN OCEANOGRAPHY LA English DT Article; Proceedings Paper CT Conference on Beyond El Nino CY MAR, 2000 CL LA JOLLA, CALIFORNIA ID GROWTH-FACTOR-I; ONCORHYNCHUS-KISUTCH; COHO SALMON; THERAGRA-CHALCOGRAMMA; WALLEYE POLLOCK; PACIFIC SALMON; RAINBOW-TROUT; PLASMA; EXPRESSION; SURVIVAL AB We hypothesise that salmon year class strength is determined in two stages during the first year in the ocean. There is an early natural mortality that is mostly related to predation, which is followed by a physiologically-based mortality. Juvenile salmon that fail to reach a critical size by the end of their first marine summer do not survive the following winter. In this study we describe our initial tests of this critical size and critical period hypothesis using data from ocean surveys of juvenile salmon and from experimental feeding studies on coho. Conservative swept volume abundance estimates for juvenile coho, and possibly chinook, indicate that there is high mortality in fall and winter during their first year in the sea. Studies of otolith weight show that the length and otolith-weight relationship for young coho changes in the early fall of their first ocean year. Studies of growth and associated hormone levels in feeding studies show that slow growing juvenile coho are stunted and deficient in an insulin-like growth factor-I (IGF-I). Juvenile coho sampled in September had low IGF-I values, indicative of poor growth. The results of these studies provide evidence for the general hypothesis that growth-related mortality occurs late in the first marine year and may be important in determining the strength of the year class (brood year). The link between total mortality and climate could be operating via the availability of nutrients regulating the food supply and hence competition for food (i.e. bottom-up regulation). (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Pacific Biol Stn, Nanaimo, BC V9R 5K6, Canada. Natl Marine Fisheries Serv, Port Orchard, WA 98366 USA. RP Beamish, RJ (reprint author), Pacific Biol Stn, 3190 Hammond Bay Rd, Nanaimo, BC V9R 5K6, Canada. NR 29 TC 203 Z9 212 U1 2 U2 41 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6611 J9 PROG OCEANOGR JI Prog. Oceanogr. PY 2001 VL 49 IS 1-4 SI SI BP 423 EP 437 DI 10.1016/S0079-6611(01)00034-9 PG 15 WC Oceanography SC Oceanography GA 477AU UT WOS:000171261600023 ER PT J AU Polovina, JJ Howell, E Kobayashi, DR Seki, MP AF Polovina, JJ Howell, E Kobayashi, DR Seki, MP TI The transition zone chlorophyll front, a dynamic global feature defining migration and forage habitat for marine resources SO PROGRESS IN OCEANOGRAPHY LA English DT Article; Proceedings Paper CT Conference on Beyond El Nino CY MAR, 2000 CL LA JOLLA, CALIFORNIA ID OCEAN COLOR; PACIFIC AB Pelagic ecosystem dynamics on all temporal scales may be driven by the dynamics of very specialized oceanic habitats. One such habitat is the basin-wide chlorophyll front located at the boundary between the low chlorophyll subtropical gyres and the high chlorophyll subarctic gyres. Global satellite maps of surface chlorophyll clearly show this feature in all oceans. In the North Pacific, the front is over 8000 km long and seasonally migrates north and south about 1000 km. In the winter this front is located at about 30-35 degreesN latitude and in the summer at about 40-45 degreesN. It is a zone of surface convergence where cool, vertically mixed, high chlorophyll, surface water on the north side sinks beneath warm, stratified, low chlorophyll water on the south side. Satellite telemetry data on movements of loggerhead turtles and detailed fisheries data for albacore tuna show that both apex predators travel along this front as they migrate across the North Pacific. The front is easily monitored with ocean color satellite remote sensing. A change in the position of the TZCF between 1997 and 1998 appears Lo have altered the spatial distribution of loggerhead turtles. The position and dynamics of the front varied substantially between the 1998 El Nino and the 1999 La Nina. For example, from May to July 1999 the transition zone chlorophyll front (TZCF) remained between about 35 degreesN and 40 degreesN latitude showing very little meandering, whereas in 1998, during the same period, the TZCF exhibited considerable meandering and greater monthly latitudinal movement. Catch rates for albacore were considerably higher in 1998 than in 1999, and we hypothesize that a meandering TZCF creates regions of convergence, which enhances the foraging habitat for apex predators along the front. Published by Elsevier Science Ltd. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. Univ Hawaii, Joint Inst Marine & Atmospher Res, Honolulu, HI 96822 USA. RP Polovina, JJ (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, 2570 Dole St, Honolulu, HI 96822 USA. OI Howell, Evan/0000-0001-9904-4633 NR 11 TC 237 Z9 256 U1 2 U2 42 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6611 J9 PROG OCEANOGR JI Prog. Oceanogr. PY 2001 VL 49 IS 1-4 SI SI BP 469 EP 483 DI 10.1016/S0079-6611(01)00036-2 PG 15 WC Oceanography SC Oceanography GA 477AU UT WOS:000171261600025 ER PT B AU Charron, E Tiesinga, E Mies, F Williams, C AF Charron, E Tiesinga, E Mies, F Williams, C BE Tombesi, P Hirota, O TI Quantum gates using motional states in an optical lattice SO QUANTUM COMMUNICATION, COMPUTING, AND MEASUREMENT 3 LA English DT Proceedings Paper CT 5th International Conference on Quantum Communication, Measurement, and Computing CY JUL 03-08, 2000 CL CAPRI, ITALY SP Tamagawa Univ, Univ Camerino, NEC, SCAT, MagiQ Technologies, Elsag Informat, Yamaha Motor Europe, Telecom Italia, Ist Nazl Fis Nucl, CNR Gruppo Nazl Struttura Mat, Ist Nazl Fis Mat DE universal quantum gate; cold atoms; optical lattice; motional states ID NEUTRAL ATOMS AB We study an implementation of a two-qubit universal quantum gate with neutral (87)Rb atoms trapped in a far-detuned two-color optical lattice. The qubit states \0> and \1> represent the ground and first excited motional states of an atom in a laser induced potential well. By varying the ratio of the laser intensities of the two colors, the barrier between two neighboring atoms is lowered, creating two-particle entanglement. We predict the duration of operation of a conditional pi-phase gate with a time-dependent configuration interaction model. C1 Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RP Charron, E (reprint author), Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. RI Williams, Carl/B-5877-2009; Charron, Eric/A-9017-2011 OI Charron, Eric/0000-0003-1660-6368 NR 9 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA BN 0-306-46609-0 PY 2001 BP 227 EP 230 PG 4 WC Computer Science, Information Systems; Optics; Physics, Multidisciplinary; Physics, Mathematical SC Computer Science; Optics; Physics GA BT93H UT WOS:000174471100035 ER PT J AU Manabe, S Knutson, TR Stouffer, RJ Delworth, TL AF Manabe, S Knutson, TR Stouffer, RJ Delworth, TL TI Exploring natural and anthropogenic variation of climate SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE climate change; climate modelling; low-frequency variability ID SEA-SURFACE TEMPERATURE; OCEAN-ATMOSPHERE MODEL; THERMOHALINE CIRCULATION; INTERDECADAL VARIATIONS; AIR-TEMPERATURE; COUPLED MODEL; VARIABILITY; CO2; WINTER; FIELD AB This lecture discusses the low-frequency variability of surface temperature using a coupled ocean-atmosphere-land-surface model developed at the Geophysical Fluid Dynamics Laboratory/NOAA, Despite the highly. idealized parametrization of various physical processes, the coupled model simulates reasonably well the variability of local and global mean surface temperature. The first half of the lecture explores the basic physical mechanisms responsible for the variability. The second half examines the trends of local surface temperature during the last half century in the context of decadal variability simulated by the coupled model. C1 Frontier Res Syst Global Change, Minato Ku, Tokyo 1056791, Japan. NOAA, Geophys Fluid Dynam Lab, Silver Spring, MD 20910 USA. RP Manabe, S (reprint author), Frontier Res Syst Global Change, Minato Ku, 9f Seavans N Bldg,1-2-1 Shibaura, Tokyo 1056791, Japan. EM sm@frontier.esto.or.jp RI Delworth, Thomas/C-5191-2014 NR 40 TC 9 Z9 9 U1 0 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD JAN PY 2001 VL 127 IS 571 BP 1 EP 24 PN A PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 400JG UT WOS:000166868000001 ER PT J AU Vitart, F Anderson, JL Sirutis, J Tuleya, RE AF Vitart, F Anderson, JL Sirutis, J Tuleya, RE TI Sensitivity of tropical storms simulated by a general circulation model to changes in cumulus parametrization SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE cumulus convection; general circulation models; tropical-storm frequency; tropical storm intensity ID HURRICANE PREDICTION SYSTEM; GCM INTEGRATIONS; PARAMETERIZATION; ATMOSPHERE; INTENSITY; ENSEMBLE; CYCLONES; SCHEME; FORECASTS; FREQUENCY AB A number of recent studies have examined the statistics of tropical storms simulated by general circulation models (GCMs) forced by observed sea surface temperatures. Many GCMs have demonstrated an ability to simulate some aspects of the observed interannual variability of tropical storms, in particular, variability in storm frequency. This has led to nascent attempts to use GCMs as part of programs to produce operational seasonal forecasts of tropical-storm numbers. In this study, the sensitivity of the statistics of GCM-simulated tropical storms to changes in the model's physical parametrizations is examined. After preliminary results indicated that these statistics were most sensitive to details of the convective parametrization, GCM simulations with identical dynamical cores but different convective parametrizations were created. The parametrizations examined included moist convective adjustment, two variants of the Arakawa-Schubert scheme, and several variants of the relaxed Arakawa-Schubert (RAS) scheme; the impact of including a shallow-convection parametrization was also examined. The simulated tropical-storm frequency, intensity, structure, and interannual variability were all found to exhibit significant sensitivities to changes in convective parametrization. A particularly large sensitivity was found when:he RAS and Arakawa-Schubert parametrizations were modified to place restrictions on the production of deep convection. Climatologies of the GCM tropical atmosphere and composites of tropical storms were examined to address the question of whether the tropical-storm statistics were directly impacted on by changes in convection associated with tropical storms, or if they were indirectly affected by parametrization-induced changes in the tropical mean atmosphere. A number of results point to the latter being the primary cause. A regional hurricane model, initialized with mean states from the GCM simulation climatologies, is used to further investigate this point. Particularly compelling is the fact that versions of the RAS scheme that produce significantly less realistic simulations of tropic;ll storms nevertheless produce a much more realistic interannual variability of storms, apparently due to an improved tropical mean climate. A careful analysis of the background convective available potential energy (CAPE) is used to suggest that this quantity is particularly relevant to the occurrence of tropical storms in the low-resolution GCMs, although this may not be the case with observations. If the tropical CAFE is too low, tropical storms in the low-resolution GCMs cannot form with realistic frequency. C1 Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. Princeton Univ, NOAA, GFDL, Princeton, NJ 08544 USA. RP Vitart, F (reprint author), European Ctr Medium Range Weather Forecasts, Shinfield Pk, Reading RG2 9AX, Berks, England. NR 41 TC 18 Z9 18 U1 0 U2 0 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 JAN PY 2001 VL 127 IS 571 BP 25 EP 51 DI 10.1256/smsqj.57102 PN A PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 400JG UT WOS:000166868000002 ER PT J AU Shapiro, MA Wernli, H Bond, NA Langland, R AF Shapiro, MA Wernli, H Bond, NA Langland, R TI The influence of the 1997-99 El Nino Southern Oscillation on extratropical baroclinic life cycles over the eastern North Pacific SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE baroclinic waves; El Nino; potential vorticity ID CIRCULATION; CONVECTION; FLOW AB The El Ni (n) over tildeo Southern Oscillation (ENSO) strongly influences the interannual and seasonal atmospheric circulation over the North Pacific. The present study shows that the meridional displacement of the time-mean upper-level jet associated with ENSO modulates the time-mean barotropic (meridional) wind shear over the central and eastern North Pacific storm track. Earlier theoretical and observational studies established the influence of barotropic wind shear on the life cycles of extratropical cyclones and their upper-level potential vorticity (PV) waves. The present study suggests that differences in the time-mean flow associated with the 1997-99 ENSO cycle had a similar impact on tropopause PV structure, meridional eddy fluxes of momentum and temperature, and predictability. C1 NOAA, Silver Spring, MD USA. USN, Washington, DC 20350 USA. RP Shapiro, MA (reprint author), Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. EM mshapiro@ncar.ucar.edu NR 21 TC 51 Z9 52 U1 3 U2 9 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD JAN PY 2001 VL 127 IS 572 BP 331 EP 342 DI 10.1002/qj.49712757205 PN B PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 416FV UT WOS:000167770400004 ER PT J AU Muschinski, A Chilson, PB Palmer, RD Hooper, DA Schmidt, G Steinhagen, H AF Muschinski, A Chilson, PB Palmer, RD Hooper, DA Schmidt, G Steinhagen, H TI Boundary-layer convection and diurnal variation of vertical-velocity characteristics in the free troposphere SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE convection; gravity waves; vertical-wind spectra; VHF radars ID FREQUENCY-DOMAIN INTERFEROMETRY; INTERNAL GRAVITY-WAVES; MOUNTAIN WAVES; ATMOSPHERIC-TURBULENCE; NUMERICAL EXPERIMENTS; RADAR MEASUREMENTS; MST RADAR; LEE WAVES; WIND; SPECTRA AB During the field experiment SOMARE-99 (Sounding System Multifrequency Atmospheric Radar Experiment 1999), the troposphere above the Hart Mountains in Northern Germany was observed with the SOUSY VHF radar, with four microbarographs, and with 26 radiosondes launched every 3 h from nearby the radar site. This paper examines the 72 h period between 0000 UTC 25 May and 0000 UTC 25 May. Time series, root-mean-square values, and power spectra of radar-observed vertical-wind, w, fluctuations in the free troposphere and of pressure, p, fluctuations at the surface are presented and discussed. A pronounced diurnal cycle was observed: standard deviations (from 1 h periods) were about 10 cm s(-1) (w) and 2 Pa (p) at night and up to 60 cm s(-1) and 6 Pa during daytime. This is seen as evidence for the relevance of boundary-layer convection for short-period gravity waves in the free troposphere. Frequency spectra of w show a power-law drop-off beyond the Brunt-Vaisala frequency with logarithmic slopes close to -5/3 at moderate and strong wind speeds and down to -3 or -4 at weak winds (smaller than 5 m s(-1)), supporting earlier work on the effects of Doppler shift on Eulerian gravity-wave spectra. The w spectra, which have been calculated from 8 h long w time series (sampling period 1 min), have a noise floor of 10(-3) m(2)s(-2)Hz(-1) or less. This corresponds to an uncorrelated noise with a standard deviation of 3 mm s(-1) for the 1 min samples. The concept of gravity-wave intermittency is introduced, in analogy to a well-established concept in turbulence physics. It is demonstrated how this concept can be used to distinguish turbulence from gravity waves empirically. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80305 USA. NOAA, Environm Technol Lab, Silver Spring, MD USA. Univ Nebraska, Lincoln, NE 68583 USA. RP Muschinski, A (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, 325 Broadway,R-ET2, Boulder, CO 80305 USA. NR 67 TC 12 Z9 12 U1 0 U2 4 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 JAN PY 2001 VL 127 IS 572 BP 423 EP 443 DI 10.1256/smsqj.57209 PN B PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 416FV UT WOS:000167770400009 ER PT J AU Desroisiers, MF Nagy, VY Slepchonok, OF AF Desroisiers, MF Nagy, VY Slepchonok, OF TI Reply to letter to the editor by E.B. Hayes (vol 59, pg 445, 2000) SO RADIATION PHYSICS AND CHEMISTRY LA English DT Correction C1 NIST, Ionizing Radiat Div, Gaithersburg, MD 20899 USA. RP Desroisiers, MF (reprint author), NIST, Ionizing Radiat Div, Room C229,Bldg 245, Gaithersburg, MD 20899 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 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD JAN PY 2001 VL 60 IS 1-2 BP 149 EP 149 DI 10.1016/S0969-806X(00)00427-8 PG 1 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 396ZP UT WOS:000166668500024 ER PT J AU Seltzer, SM Romanyukha, AA Nagy, V AF Seltzer, SM Romanyukha, AA Nagy, V TI Monte Carlo calculations of the dose distribution in teeth due to internal exposure from Sr-90: Application to EPR tooth dosimetry SO RADIATION PROTECTION DOSIMETRY LA English DT Article ID ELECTRON-SPIN-RESONANCE; ESR DOSIMETRY; NUCLEAR WORKERS; TECHA RIVER; ENAMEL; RECONSTRUCTION; POPULATION; CYLINDERS AB This paper addresses issues in the application of the electron paramagnetic resonance (EPR) retrospective dosimetry with dental tissues exposed by radionuclides accumulated in the dentin. A simple dosimetric model of a tooth incorporating Sr-90 is presented. The tooth is modelled as two concentric cylinders: the inner cylinder composed of dentin, and the outer cylindrical shell of enamel. Extensive Monte Carlo calculations were done to obtain I:he distributions of absorbed dose in dentin and enamel for teeth of different sizes. The results were used to calculate the mean absorbed doses in enamel that are directly measurable by EPR. A relationship between such measured doses and the specific activity of 90Sr in dentin was derived based on a simple model of 90Sr accumulation. The roles of different tooth tissues as dose detectors are analysed, and the importance of dentin as a dosimetric material for internal exposure is pointed out. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Seltzer, SM (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 43 TC 10 Z9 10 U1 1 U2 1 PU NUCLEAR TECHNOLOGY PUBL PI ASHFORD PA PO BOX 7, ASHFORD TN23 1YW, KENT, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PY 2001 VL 93 IS 3 BP 245 EP 260 PG 16 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 404BH UT WOS:000167077200008 PM 11548351 ER PT J AU Pibida, L Nortershauser, W Hutchinson, JMR Bushaw, BA AF Pibida, L Nortershauser, W Hutchinson, JMR Bushaw, BA TI Evaluation of resonance ionization mass spectrometry for the determination of Cs-135/Cs-137 isotope ratios in low-level samples SO RADIOCHIMICA ACTA LA English DT Article DE resonance ionization; trace analysis; Cs-135/Cs-137 isotope ratios; mass spectrometry ID SPECTROSCOPY; SR-90; CA-41; RIMS AB The ability of Resonance Ionization Mass Spectrometry (RIMS) to reliably determine the ratio of Cs-135/Cs-137 in the presence of large backgrounds has been evaluated. Single-resonance excitation of Cs 6s S-2(1/2)(F = 4) --> 6p P-2(3/2)(F ' = 5) with an extended cavity diode laser was followed by photoionization with the 488 nm line of an argon ion laser. While the principal objective was to avoid isobaric interferences, an optical selectivity of 3 orders of magnitude against stable Cs-133 was attained for both Cs-135 and Cs-137. The overall RIMS efficiency was found to be similar to 2x10(-6) with a combined (laser and mass spectrometer) selectivity of similar to 10(10) for both Cs-135 and Cs-137 against Cs-133. The performance with respect to efficiency, selectivity, and isobar suppression has been compared to conventional thermal ionization mass spectrometry (TIMS). Measurements to determine the chronological age of a burn-up sample have been performed using both methods. C1 NIST, Gaithersburg, MD 20899 USA. Pacific NW Natl Lab, Walla Walla, WA 99362 USA. RP Pibida, L (reprint author), NIST, Gaithersburg, MD 20899 USA. RI Nortershauser, Wilfried/A-6671-2013 OI Nortershauser, Wilfried/0000-0001-7432-3687 NR 25 TC 20 Z9 20 U1 0 U2 4 PU R OLDENBOURG VERLAG PI MUNICH PA LEKTORAT M/N, K BERBER-NERLINGER, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2001 VL 89 IS 3 BP 161 EP 168 DI 10.1524/ract.2001.89.3.161 PG 8 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 435BF UT WOS:000168853000008 ER PT J AU Tecklenburg, RE Wallace, WE Chen, HP AF Tecklenburg, RE Wallace, WE Chen, HP TI Characterization of a [(O3/2SiMe)(x)(OSi(OH)Me)(y) (OSiMe2)(z)] silsesquioxane copolymer resin by mass spectrometry SO RAPID COMMUNICATIONS IN MASS SPECTROMETRY LA English DT Article ID CONDENSATION; POLYMERS AB Electrospray ionization Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry were applied to a complex silsesquioxane-siloxane copolymer resin. The wide-polydispersity starting material was fractionated into 21 separate fractions in order to facilitate the analysis by mass spectrometry. ESI-FTICR exact mass measurements were able to identify the specific oligomers present in the lowest mass fractions and showed that very few unreacted silanol groups remained, that is, topologically closed structures predominated. MALDI-TOFMS was able to show that gel-permeation chromatography substantially underestimated the molecular masses of the higher mass fractions. Mass autocorrelation was able to show that the silsesquioxane monomer appeared only in even numbers in any given oligomer. This is a natural consequence of the highly condensed nature of the resin. Copyright (C) 2001 John Wiley & Sons, Ltd. C1 Natl Inst Stand & Technol, Div Polymers, Gaithersburg, MD 20899 USA. Dow Corning Corp, Dept Analyt Sci, Midland, MI 48868 USA. RP Wallace, WE (reprint author), Natl Inst Stand & Technol, Div Polymers, 100 Bur Dr Stop 8541, Gaithersburg, MD 20899 USA. NR 14 TC 17 Z9 17 U1 2 U2 5 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0951-4198 J9 RAPID COMMUN MASS SP JI Rapid Commun. Mass Spectrom. PY 2001 VL 15 IS 22 BP 2176 EP 2185 DI 10.1002/rcm.494 PG 10 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA 492XY UT WOS:000172193900015 ER PT S AU Adams, JM AF Adams, JM BE Williams, JG Vehar, DW Ruddy, FH Gilliam, DM TI Results from the NIST round robin test of fissionable dosimeters in a reactor leakage spectrum SO REACTOR DOSIMETRY: RADIATION METROLOGY AND ASSESSMENT SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT 10th International Symposium on Reactor Dosimetry CY SEP 12-17, 1999 CL OSAKA, JAPAN SP Amer Soc Testing & Mat, Comm E 10 DE neutron dosimetry; reactor dosimetry; rector pressure vessel surveillance; round robin interlaboratory comparison AB The National Institute of Standards and Technology has completed a round robin test of Np-237 and U-238 fissionable dosimeters. The objective of the test was to demonstrate the utility of the Materials Dosimetry Reference Facility for performing neutron metrology testing for applications in fast-neutron dosimetry for reactor pressure vessel surveillance monitoring. For this test, Np-237 and U-238 fission dosimeters were irradiated to a certified fluence in the Facility, and then distributed to the test participants for determination of the fast-neutron fluence, principally by radioassay of long-lived Cs-137 fission product activity. In the present paper are reported the results obtained from this test, showing that the Np-237 results are, on the average, within 2.9 % of the certified values, and that the U-238 results are within 4.6 %, both based on Cs-137 radioassay. These results are well within limits acceptable for neutron surveillance monitoring for determining the fast-neutron exposure in commercial nuclear power reactors. C1 Natl Inst Stand & Technol, Neutron Interact & Dosimetry Grp, Gaithersburg, MD 20899 USA. RP Adams, JM (reprint author), Natl Inst Stand & Technol, Neutron Interact & Dosimetry Grp, MS 8461, Gaithersburg, MD 20899 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2884-3 J9 AM SOC TEST MATER PY 2001 VL 1398 BP 295 EP 302 DI 10.1520/STP13609S PG 8 WC Nuclear Science & Technology; Physics, Nuclear SC Nuclear Science & Technology; Physics GA BR88Z UT WOS:000167918300037 ER PT S AU Bateman, FB Boukharouba, N Brient, CE Carlson, AD Grimes, SM Haight, RC Massey, TN Wasson, OA AF Bateman, FB Boukharouba, N Brient, CE Carlson, AD Grimes, SM Haight, RC Massey, TN Wasson, OA BE Williams, JG Vehar, DW Ruddy, FH Gilliam, DM TI New measurements of the H(n,n)H angular distribution SO REACTOR DOSIMETRY: RADIATION METROLOGY AND ASSESSMENT SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT 10th International Symposium on Reactor Dosimetry CY SEP 12-17, 1999 CL OSAKA, JAPAN SP Amer Soc Testing & Mat, Comm E 10 DE H(n,n)H standard cross section; n-p angular distribution; neutron cross section standard; D(d,n) reaction; ENDF/B-V; ENDF/-VI; Arndt ID NEUTRON-PROTON SCATTERING AB Measurements have been made of the shape of the hydrogen differential neutron scattering cross section standard at 10 MeV neutron energy. The data were obtained at the Institute of Nuclear and Particle Physics at Ohio University using the D(d,n) reaction as the neutron source. Two different thin films of polypropylene mounted on tantalum backings were used as the hydrogenous samples in this experiment. Preliminary data obtained with the thicker film will be reported here. Two independent computer-based data acquisition systems were used to obtain the data which were stored in a multi-parameter mode so that analysis could be done under different conditions after the experiment was finished. The differential cross section was measured simultaneously at 11 laboratory angles (0 degrees, +/- 12 degrees, +/- 24 degrees, +/- 36 degrees, +/- 48 degrees and +/- 60 degrees) using DeltaE-E solid state detector telescopes in an evacuated scattering chamber. The data are in better agreement with the Arndt evaluation than the ENDF/B-VI and ENDF/B-V evaluations. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Bateman, FB (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2884-3 J9 AM SOC TEST MATER PY 2001 VL 1398 BP 431 EP 438 DI 10.1520/STP13626S PG 8 WC Nuclear Science & Technology; Physics, Nuclear SC Nuclear Science & Technology; Physics GA BR88Z UT WOS:000167918300054 ER PT S AU Keller, MW AF Keller, MW BE Quinn, TJ Leschiutta, S Tavella, P TI Standards of current and capacitance based on single-electron tunneling devices SO RECENT ADVANCES IN METROLOGY AND FUNDAMENTAL CONSTANTS SE Proceedings of the International School of Physics Enrico Fermi LA English DT Proceedings Paper CT International-School-of-Physics-Enrico-Fermi on Recent Advances in Metrology and Fundamental Constants CY JUL 25-AUG 04, 2000 CL VARENNA, ITALY SP Int Sch Phys Enrico Fermi ID SURFACE ACOUSTIC-WAVES; FINE-STRUCTURE CONSTANT; JOSEPHSON-JUNCTIONS; COULOMB-BLOCKADE; COUNTING ELECTRONS; TURNSTILE DEVICE; PUMP; ACCURACY; TRANSISTOR; TRANSPORT C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Natl Inst Stand & Technol, 325 Broadway, Boulder, CO 80305 USA. EM mark.keller@boulder.nist.gov NR 57 TC 19 Z9 19 U1 0 U2 0 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 0074-784X BN 1-58603-167-8 J9 P INT SCH PHYS PY 2001 VL 146 BP 291 EP 316 PG 26 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA BU76X UT WOS:000176954000016 ER PT S AU Helmerson, K Phillips, WD AF Helmerson, K Phillips, WD BE Quinn, TJ Leschiutta, S Tavella, P TI Cooling, trapping and manipulation of atoms and Bose-Einstein condensates: Applications to metrology SO RECENT ADVANCES IN METROLOGY AND FUNDAMENTAL CONSTANTS SE Proceedings of the International School of Physics Enrico Fermi LA English DT Proceedings Paper CT International-School-of-Physics-Enrico-Fermi on Recent Advances in Metrology and Fundamental Constants CY JUL 25-AUG 04, 2000 CL VARENNA, ITALY SP Int Sch Phys Enrico Fermi ID RESONANCE-RADIATION PRESSURE; PHOTON RECOIL ENERGY; OPTICAL MOLASSES; NEUTRAL ATOMS; SODIUM ATOMS; DOPPLER LIMIT; LASER-LIGHT; ATTRACTIVE INTERACTIONS; MULTILEVEL ATOMS; BRAGG SCATTERING C1 Natl Inst Stand & Technol, Atom Phys Div, Phys Lab, Gaithersburg, MD 20899 USA. RP Natl Inst Stand & Technol, Atom Phys Div, Phys Lab, Gaithersburg, MD 20899 USA. RI Helmerson, Kristian/E-3683-2013 NR 150 TC 1 Z9 1 U1 0 U2 1 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 0074-784X BN 1-58603-167-8 J9 P INT SCH PHYS PY 2001 VL 146 BP 349 EP 395 PG 47 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA BU76X UT WOS:000176954000018 ER PT S AU Stoup, J Doiron, T AF Stoup, J Doiron, T BE Decker, JE Brown, N TI The accuracy and versatility of the NIST M48 coordinate measuring machine SO RECENT DEVELOPMENTS IN TRACEABLE DIMENSIONAL MEASUREMENTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Recent Developments in Traceable Dimensional Measurements CY JUN 20-21, 2001 CL MUNICH, GERMANY SP SPIE, European Opt Soc, WLT AB The National Institute of Standards and Technology (NIST) is continuing to develop the ability to perform accurate, traceable measurements on a wide range of artifacts using a very precise, error-mapped coordinate measuring machine (CMM). The NIST M48 CMM has promised accuracy and versatility for many years. Recently, these promises have been realized in a reliable, reproducible way for many types of 1D, 2D, and 3D engineering metrology artifacts. The versatility of the machine has permitted state-of-the-art, accurate measurements of one meter step gages and precision ball plates as well as 500 micrometer holes and small precision parts made of aluminum or glass. To accomplish this wide range of measurements the CMM has required extensive assessment of machine positioning and straightness errors, probe response, machine motion control and speed, environmental stability, and measurement procedures. The CMM has been used as an absolute instrument and as a very complicated comparator. The data collection techniques have been designed to acquire statistical information on the machine and probe performance and to evaluate and remove any potential thermal drift in the machine coordinate system during operation. This paper will present the data collection and measurement techniques used by NIST to achieve excellent measurement results for gage blocks, long end standards, step gages, ring and plug gages, small holes, ball plates, and angular artifacts. Comparison data with existing independent primary measuring instruments will also be presented to show agreement and correlation with those historical methods. Current plans for incorporating the CMM into existing measurement services, such as plain ring gages, large plug gages, and long end standards, will be presented along with other proposed development of this CMM. C1 NIST, Engn Metrol Grp, Gaithersburg, MD 20899 USA. RP Stoup, J (reprint author), NIST, Engn Metrol Grp, Gaithersburg, MD 20899 USA. NR 6 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4096-5 J9 P SOC PHOTO-OPT INS PY 2001 VL 4401 BP 136 EP 146 DI 10.1117/12.445614 PG 11 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA BU48U UT WOS:000176127100016 ER PT S AU Swyt, DA Phillips, SD Palmateer, J AF Swyt, DA Phillips, SD Palmateer, J BE Decker, JE Brown, N TI Developments at NIST on traceability in dimensional measurements SO RECENT DEVELOPMENTS IN TRACEABLE DIMENSIONAL MEASUREMENTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Recent Developments in Traceable Dimensional Measurements CY JUN 20-21, 2001 CL MUNICH, GERMANY SP SPIE, European Opt Soc, WLT ID CALIBRATION AB This paper reports to the international community on recent developments in technical policies, programs, and capabilities at the U.S. (United States) National Institute of Standards and Technology (NIST) related to traceability in dimensional measurements. These developments include: formal NIST policies on traceability and assuring quality in the results of the measurements it delivers to customers in calibration and measurement certificates, and a program to support the achievement of traceability to the SI (International System of Units) unit of length in dimensional measurements by manufacturers without direct recourse to a National Metrology Institute (NMI) for dimensional calibrations. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Swyt, DA (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 7 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4096-5 J9 P SOC PHOTO-OPT INS PY 2001 VL 4401 BP 245 EP 252 DI 10.1117/12.445626 PG 8 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA BU48U UT WOS:000176127100027 ER PT S AU Wood, BE Linsky, JL Valenti, JA AF Wood, BE Linsky, JL Valenti, JA BE Brekke, P Fleck, B Gurman, JB TI HST observations of heliospheric and astrospheric Ly alpha absorption toward the alpha Cen system SO RECENT INSIGHTS INTO THE PHYSICS OF THE SUN AND HELIOSPHERE: HIGHLIGHTS FROM SOHO AND OTHER SPACE MISSIONS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union ID ONE-SHOCK; HYDROGEN; CENTAURI; STARS AB We use HST observations of the nearest star system (the alpha Cen system) to search for Lyalpha absorption from both heliospheric material around the Sun and analogous astrospheric material around the stars which has been heated by the collision between the solar/stellar winds and the interstellar medium. For alpha Cen A and B, both heliospheric and astrospheric absorption are detected, whereas for alpha Cen's distant companion star Proxima Cen only heliospheric absorption is detected, suggesting that Proxima Cen's astrosphere must be smaller and its wind therefore weaker than that of alpha Cen. Based on observations of these stars taken many years apart, we find that neither the heliospheric absorption nor the astrospheric absorption detected toward alpha Cen AB varies significantly. C1 Univ Colorado, JILA, Boulder, CO 80309 USA. NIST, Boulder, CO 80309 USA. STScI, Baltimore, MD 21218 USA. RP Wood, BE (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-069-2 J9 IAU SYMP PY 2001 IS 203 BP 599 EP 601 PG 3 WC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences GA BU43X UT WOS:000175997400137 ER PT B AU Basist, A Williams, C AF Basist, A Williams, C BE Beniston, M Verstraete, MM TI Using the Special Sensor Microwave Imager to monitor surface wetness and temperature SO REMOTE SENSING AND CLIMATE MODELING: SYNERGIES AND LIMITATIONS SE ADVANCES IN GLOBAL CHANGE RESEARCH LA English DT Proceedings Paper CT Workshop on Satellite Remote Sensing and Climate Simulations CY SEP 20-24, 1999 CL LES DIABLERETS, SWITZERLAND SP ENAMORS, Swiss Natl Sci Fdn ID BRIGHTNESS TEMPERATURES; SSM/I MEASUREMENTS; SNOW COVER AB The current network of in situ stations is inadequate for monitoring regional temperature and moisture anomalies across the land surface, leaving the climate monitoring community insufficient information to identify spatial structure and variations over many areas of the world. Therefore, we need to blend satellite observations with in situ data to obtain global coverage. In order to accomplish this task, we have calibrated and independently validated an algorithm that derives land surface temperatures from the Special Sensor Microwave Imager (SSMI). The goal of this exercise is to blend both the in situ and satellite data sets into one superior product, then merge this product with an sea surface temperature anomaly field form the same base period. The value of the global product has extremely valuable applications to climate modeling community, since it can serve as a validation tool and/or direct input to the surface parameterization, allowing the radiation feed back to be realistically grounded on surface temperature and humidity observations. C1 NOAA, NCDC, Asheville, NC 28804 USA. RP Basist, A (reprint author), NOAA, NCDC, Asheville, NC 28804 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6801-0 J9 ADV GLOB CHANGE RES PY 2001 VL 7 BP 181 EP 202 PG 22 WC Geography, Physical; Meteorology & Atmospheric Sciences; Remote Sensing SC Physical Geography; Meteorology & Atmospheric Sciences; Remote Sensing GA BS25L UT WOS:000169197900008 ER PT S AU Li, QH Ferraro, R AF Li, QH Ferraro, R BE Owe, M Braubaker, K Ritchie, J Rango, A TI SSM/I-derived global rainfall statistics and their application in surface hydrology modelling SO REMOTE SENSING AND HYDROLOGY 2000 SE IAHS PUBLICATION LA English DT Proceedings Paper CT International Symposium on Remote Sensing and Hydrology 2000 CY APR 02-07, 2000 CL SANTA FE, NM SP Int Commiss Remote Sensing, Int Assoc Hydrol Sci DE algorithms correlation; error; fraction; frequency; global; monthly; rainfall; SSM/I; variance AB A new global 2.5degrees monthly rainfall statistics dataset has recently been produced by the NOAA/NESDIS/Office of Research and Applications. This dataset is based on the SSM/I rainfall algorithms and covers the period from July 1987 to the most recent month. It includes the following parameters: monthly rain estimates, sampling and algorithm errors associated with the monthly rain estimates, variance and auto-correlation at 4-h and 8-h lag times of instantaneous rain rate. frequency of rain, fractional coverage of rain, and the number of available samples. This dataset provides, on the global scale, more detailed information about rainfall beyond simple monthly rainfall amount. and will be useful to the hydrology and climatology communities. The utilization of this dataset is demonstrated through a simulation of the effects of the fractional coverage of rainfall on evapotranspiration. C1 NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD 20746 USA. RP Li, QH (reprint author), NOAA, NESDIS, Off Res & Applicat, 5200 Auth Rd 703, Camp Springs, MD 20746 USA. RI Ferraro, Ralph/F-5587-2010 OI Ferraro, Ralph/0000-0002-8393-7135 NR 7 TC 0 Z9 0 U1 0 U2 0 PU INT ASSOC HYDROLOGICAL SCIENCES PI WALLINGFORD PA INST OF HYDROLOGY, WALLINGFORD OX10 8BB, ENGLAND SN 0144-7815 BN 1-901502-46-5 J9 IAHS-AISH P PY 2001 IS 267 BP 38 EP 40 PG 3 WC Engineering, Civil; Remote Sensing; Water Resources SC Engineering; Remote Sensing; Water Resources GA BT42U UT WOS:000172971600008 ER PT S AU Pibida, L Nortershauser, W Hutchinson, JMR Bushaw, BA AF Pibida, L Nortershauser, W Hutchinson, JMR Bushaw, BA BE Parks, JE Young, JP TI Isotopic ratio measurements of Cs-135/Cs-137 using Resonance Ionization Mass Spectrometry SO RESONANCE IONIZATION SPECTROSCOPY 2000 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Symposium on Resonance Ionization Spectroscopy and Its Applications (RIS-2000) CY OCT 08-12, 2000 CL UNIV TENNESSEE, INST RESONANCE IONIZAT SPECT, KNOXVILLE, TN SP Atom Sci Inc, UT-Battelle LLC HO UNIV TENNESSEE, INST RESONANCE IONIZAT SPECT ID SPECTROSCOPY; SR-90; RIMS AB Cs-135/Cs-137 isotopic ratios were measured in the presence of high levels of Cs-133 using Resonance Ionization Mass Spectrometry (RIMS). Single- and double-resonance excitation of Cs with high-resolution continuous-wave (cw) lasers along 6s S-2(1/2) --> 6p P-2(3/2), 6s S-2(1/2) --> 6p P-2(3/2) --> 7d D-2(5/2), and 6s S-2(1/2) --> 6p P-2(3/2) --> 8s S-2(1/2) pathways were followed by photoionization with an Ar ion laser. The age of a standard burn-up sample was determined using RIMS and compared to Thermal Ionization Mass Spectrometry (TIMS). The efficiency, selectivity and isobar suppression for TIMS and RIMS has been compared. The overall RIMS efficiency was found to be approximate to 2X10(-6) with a combined selectivity of approximate to 10(10) for both Cs-135 and Cs-137 against Cs-133 using the preferred single-resonance excitation scheme. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Pibida, L (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 16 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0024-5 J9 AIP CONF PROC PY 2001 VL 584 BP 106 EP 111 PG 6 WC Physics, Applied; Spectroscopy SC Physics; Spectroscopy GA BT04K UT WOS:000171763100016 ER PT B AU Hurley, DC Richards, AJ AF Hurley, DC Richards, AJ BE Thompson, DO Chimenti, DE TI Laser-ultrasonic methods for thin-film property measurements using high-frequency surface acoustic waves SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 20A AND 20B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 27th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 16-20, 2000 CL IOWA STATE UNIV, AMES, IA SP Amer Soc Nondestruct Testing, FAA, Inst Phys Sci & Technol, NASA, Natl Sci Fdn HO IOWA STATE UNIV ID NONDESTRUCTIVE EVALUATION; MICHELSON INTERFEROMETER AB Laser-ultrasonic methods to measure thin-film elastic properties have been developed. Surface acoustic waves (SAWs) were generated by a 0.2 ns pulsed laser and detected by a line-focused Michelson interferometer with a -3 dB bandwidth of 800 MHz. Waveforms at several propagation distances were used to determine the SAW dispersion relation for a series of titanium nitride film samples. The measurements can be related to thin-film elastic properties using theoretical models. C1 Natl Inst Stand & Technol, Boulder, CO 80305 USA. RP Hurley, DC (reprint author), Natl Inst Stand & Technol, Boulder, CO 80305 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA BN 1-56396-988-2 J9 REV PROG Q PY 2001 VL 557 BP 263 EP 270 PN A&B PG 8 WC Acoustics; Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Acoustics; Engineering; Materials Science; Optics; Physics GA BT38Q UT WOS:000172833800033 ER PT J AU Terceiro, M AF Terceiro, M TI The summer flounder chronicles: Science, politics, and litigation, 1975-2000 SO REVIEWS IN FISH BIOLOGY AND FISHERIES LA English DT Editorial Material DE assessment; fisheries; management; summer flounder AB The summer flounder, or fluke (Paralichthys dentatus) supports the most important commercial and recreational flatfish fisheries of the U.S. Atlantic coast. The stock and fishery range from Massachusetts to North Carolina. Spawning takes place during a protracted season that can extend from September to March, during an annual offshore and southern migration to the outer continental shelf off Virginia and North Carolina. The fish are con-centrated in bays and estuaries from late spring through early autumn, when the next offshore migration begins. The assessment and management of the summer flounder fishery has been very contentious since the implementation of the joint Atlantic States Marine Fisheries Commission/Mid-Atlantic Fishery Management Council Fishery Management Plan (FMP) in 1989, when the poor status of the summer flounder stock was evident to scientists, managers, and fishermen. Amendment 2 to the FMP, approved in 1992, implemented several major regulatory provisions including annual commercial quotas and recreational harvest limits, and annually adjustable minimum landed fish sizes, minimum mesh sizes, possession limits, and seasonal closures. By 1999, fishing mortality on summer flounder had declined to its lowest level since the 1960s, and summer flounder total stock biomass was the highest since the mid-1970s. Monitoring of stock status is ongoing to reliably determine ``how much fish is enough'' to provide for long-term sustainability. Many changes are made annually to management measures due to differing interpretations of stock status by managers, and fishery and environmental advocacy groups. Attainment of the annual fishing mortality targets remains elusive. The multiple layers of science, management, and politics in place since 1992 continue to spark much controversy and litigation that increasingly places the management of the summer flounder fishery in the hands of the courts. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02548 USA. RP Terceiro, M (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 166 Water St, Woods Hole, MA 02548 USA. EM mtercer@whsun1.wh.whoi.edu NR 96 TC 4 Z9 4 U1 2 U2 7 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0960-3166 J9 REV FISH BIOL FISHER JI Rev. Fish. Biol. Fish. PY 2001 VL 11 IS 2 BP 125 EP 168 DI 10.1023/A:1015260005887 PG 44 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 546LZ UT WOS:000175276700003 ER PT J AU Ostrovsky, LA Johnson, PA AF Ostrovsky, LA Johnson, PA TI Dynamic nonlinear elasticity in geomaterials SO RIVISTA DEL NUOVO CIMENTO LA English DT Article ID HIGHER-ORDER NONLINEARITY; PULSED WAVE-PROPAGATION; DISCERN MATERIAL DAMAGE; GRANULAR MEDIA; SEDIMENTARY-ROCKS; SEISMIC ATTENUATION; BEREA SANDSTONE; NEWS TECHNIQUES; ACOUSTIC-WAVES; SLOW DYNAMICS C1 Univ Colorado, CIRES, NOAA, Environm Technol Lab, Boulder, CO 80309 USA. Russian Acad Sci, Inst Phys Appl, Nizhnii Novgorod 603600, Russia. Los Alamos Natl Lab, Los Alamos, NM USA. RP Ostrovsky, LA (reprint author), Univ Colorado, CIRES, NOAA, Environm Technol Lab, Boulder, CO 80309 USA. OI Ostrovsky, Lev/0000-0003-2233-1305 NR 99 TC 161 Z9 172 U1 4 U2 17 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 0393-697X EI 1826-9850 J9 RIV NUOVO CIMENTO JI Riv. Nuovo Cimento PY 2001 VL 24 IS 7 BP 1 EP 46 PG 46 WC Physics, Multidisciplinary SC Physics GA 483DP UT WOS:000171618700001 ER PT J AU Baker, DJ AF Baker, DJ TI NOAA 2001: Beginning of a new ocean era SO SEA TECHNOLOGY LA English DT Article C1 NOAA, Washington, DC 20230 USA. RP Baker, DJ (reprint author), NOAA, Washington, DC 20230 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 USA SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD JAN PY 2001 VL 42 IS 1 BP 10 EP 11 PG 2 WC Engineering, Ocean SC Engineering GA 398TG UT WOS:000166772000002 ER PT J AU Baird, RC AF Baird, RC TI Sea Grant: Science serving America's coast SO SEA TECHNOLOGY LA English DT Article C1 NOAA, Natl Sea Grant Coll Program, Washington, DC 20230 USA. RP Baird, RC (reprint author), NOAA, Natl Sea Grant Coll Program, Washington, DC 20230 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 USA SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD JAN PY 2001 VL 42 IS 1 BP 16 EP + PG 2 WC Engineering, Ocean SC Engineering GA 398TG UT WOS:000166772000004 ER PT B AU Boggs, CH AF Boggs, CH BE Melvin, EF Parrish, JK TI Deterring albatrosses from contacting baits during swordfish longline sets SO SEABIRD BYCATCH: TRENDS,ROADBLOCKS AND SOLUTIONS SE UNIVERSITY OF ALASKA SEA GRANT COLLEGE PROGRAM REPORT LA English DT Proceedings Paper CT 26th Annual Meeting of the Pacific-Seabird-Group CY FEB 26-27, 1999 CL BLAINE, WA SP Pacific Seabird Grp, US Fish & Wildlife Serv, Portland Migrator Bird Off ID CATCH RATES; FISHERY AB The effectiveness of albatross deterrent techniques was examined during line setting operations in the Hawaii-based longline fishery for swordfish (Xiphias gladius). Methods tested were bird scaring streamer lines, weights added to baits, and camouflaging bait with food coloring. Observations were made on ca. 66 baited branch lines deployed on 96 occasions. Baits dyed blue and baits with added weight both reduced the number of contacts between baits and Black-footed (Phoebastria nigripes) and Laysan (P. immutabilis) Albatrosses by about 90%. Streamer lines reduced contacts between baits and albatrosses by about 70%. C1 NOAA, Natl Marine Fisheries Serv, Honolulu, HI 96822 USA. RP Boggs, CH (reprint author), NOAA, Natl Marine Fisheries Serv, Honolulu, HI 96822 USA. NR 15 TC 22 Z9 25 U1 0 U2 1 PU UNIV ALASKA SEA GRANT PI FAIRBANKS PA POB 755040, 205 ONEILL BLDG, FAIRBANKS, AK 99775 USA BN 1-56612-066-7 J9 UASGCP REP PY 2001 VL 2001 IS 1 BP 79 EP 94 PG 16 WC Zoology SC Zoology GA BS49J UT WOS:000170086700007 ER PT B AU Cousins, KL AF Cousins, KL BE Melvin, EF Parrish, JK TI The Black-footed Albatross population biology workshop: A step to understanding the impacts of longline fishing on seabird populations SO SEABIRD BYCATCH: TRENDS,ROADBLOCKS AND SOLUTIONS SE UNIVERSITY OF ALASKA SEA GRANT COLLEGE PROGRAM REPORT LA English DT Proceedings Paper CT 26th Annual Meeting of the Pacific-Seabird-Group CY FEB 26-27, 1999 CL BLAINE, WA SP Pacific Seabird Grp, US Fish & Wildlife Serv, Portland Migrator Bird Off AB Experts in seabird ecology, fisheries management, and population modeling participated in a three-day workshop (October 8-10, 1998) at the Western Pacific Regional Fishery Management Council (WPRFMC) offices in Honolulu to investigate the population dynamics of the Black-footed Albatross (Phoebastria nigripes). The workshop's primary goal was to characterize the population biology of the Black-footed Albatross and evaluate its resilience to the effects of mortality due to longline fishery interactions. Worldwide there are 61,866 and 558,415 breeding pairs of Black-footed and Laysan (P. immutabilis) Albatrosses, respectively, and both species are caught in approximately equal numbers during longline fishing. This suggests that the Black-footed Albatross population may be more seriously affected. The Black-footed Albatross population suffers different combinations of both anthropogenic and natural mortalities, in common with many seabird populations. Thus, a series of simulations were conducted to investigate how population removals added onto baseline mortality would affect the sustainable population growth rates. Also, analyses generated from the bird-banding data sets found that juvenile Black-footed Albatrosses were caught on longline more frequently than adults. Simulated experiments also investigated how differences in juvenile and adult removals would affect the Black-footed Albatross population dynamics. The findings showed that over the long term, a chronic mortality such as longline fishing resulted in slow decline of species population size irrespective of uncertainties associated with the estimated parameters. Workshop participants generated seven recommendations for consideration by the WPRFMC, including the improvement and standardization of data collection and the completion of analyses as studies progress. C1 NOAA, Natl Marine Fisheries Serv, Honolulu, HI 96822 USA. RP Cousins, KL (reprint author), NOAA, Natl Marine Fisheries Serv, Honolulu, HI 96822 USA. NR 15 TC 2 Z9 3 U1 0 U2 0 PU UNIV ALASKA SEA GRANT PI FAIRBANKS PA POB 755040, 205 ONEILL BLDG, FAIRBANKS, AK 99775 USA BN 1-56612-066-7 J9 UASGCP REP PY 2001 VL 2001 IS 1 BP 95 EP 114 PG 20 WC Zoology SC Zoology GA BS49J UT WOS:000170086700008 ER PT B AU Forney, KA Benson, SR Cameron, GA AF Forney, KA Benson, SR Cameron, GA BE Melvin, EF Parrish, JK TI Central California gillnet effort and bycatch of sensitive species, 1990-1998 SO SEABIRD BYCATCH: TRENDS,ROADBLOCKS AND SOLUTIONS SE UNIVERSITY OF ALASKA SEA GRANT COLLEGE PROGRAM REPORT LA English DT Proceedings Paper CT 26th Annual Meeting of the Pacific-Seabird-Group CY FEB 26-27, 1999 CL BLAINE, WA SP Pacific Seabird Grp, US Fish & Wildlife Serv, Portland Migrator Bird Off AB During the 1980s, extensive bycatch of seabirds and marine mammals in central California's set gillnet fisheries prompted a series of area and depth closures, which ultimately appeared successful at reducing mortality of the species of primary concern, Common Murre (Uria aalge), sea otter (Enhydra lutris), and harbor porpoise (Phocoena phocoena). The effects of the restrictions, however, were confounded with changes in the distribution and intensity of fishing effort during the early 1990s. This study documents 1990-1998 patterns of fishing effort in the central California halibut (Paralichthys californicus) gillnet fishery and presents information on bycatch of the above three species. A National Marine Fisheries Service observer program obtained bycatch data from 1990 to 1994, but was discontinued after 1994. Since then, gillnet effort has increased and shifted into the southern areas of Monterey Bay, where bycatch was high during the 1980s. The recent increase in gillnet effort coincides with higher beach deposition rates for all three species. In this study, historical entanglement rate data are combined with estimates of fishing effort for 1995-1998 to produce several sets of mortality estimates based on a variety of assumptions. Without further data, it is not possible to validate most of the assumptions. The range of total mortality estimates for the 4-year period 1995-1998 is 5,918-13,060 Common Murres (S.E. 477-1,252),144-662 harbor porpoises (S.E. 18-53), and 17-125 sea otters (S.E. 4-25), raising concern for all three species. The recent changes in fishing effort and distribution underscore the importance of monitoring variability in both fishing practices and the distribution of vulnerable species when evaluating long-term fishery impacts. C1 Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Santa Cruz, CA USA. RP Forney, KA (reprint author), Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Santa Cruz, CA USA. NR 20 TC 9 Z9 12 U1 0 U2 3 PU UNIV ALASKA SEA GRANT PI FAIRBANKS PA POB 755040, 205 ONEILL BLDG, FAIRBANKS, AK 99775 USA BN 1-56612-066-7 J9 UASGCP REP PY 2001 VL 2001 IS 1 BP 141 EP 160 PG 20 WC Zoology SC Zoology GA BS49J UT WOS:000170086700010 ER PT S AU Sonnenberg-Klein, B Silverman, KL Mirin, RP AF Sonnenberg-Klein, B Silverman, KL Mirin, RP BE Menoni, CS Mirin, RP TI Multimode lasing at room temperature from InGaAs/GaAs quantum dot lasers SO SEMICONDUCTOR LASERS FOR LIGHTWAVE COMMUNICATION SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Semiconductor Lasers for Lightwave Communication Systems CY AUG 21-22, 2001 CL DENVER, CO SP SPIE, Colorado Photon Ind Assoc ID EMISSION-SPECTRA; OPTICAL GAIN AB We demonstrate InGaAs/GaAs quantum dot lasers with multimode lasing at room temperature immediately above threshold. The lasing modes are separated by about ten times the Fabry-Perot mode spacing, with several dark modes in between the lasing modes. Rate equation simulations indicate that this multimode behavior can be explained by a homogeneous broadening that is on the order of the mode spacing. C1 Natl Inst Stand & Technol, Optoelect Mfg Grp, Boulder, CO 80305 USA. RP Sonnenberg-Klein, B (reprint author), Natl Inst Stand & Technol, Optoelect Mfg Grp, 325 Broadway, Boulder, CO 80305 USA. RI Menoni, Carmen/B-4989-2011; OI Mirin, Richard/0000-0002-4472-4655 NR 10 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4257-7 J9 P SOC PHOTO-OPT INS PY 2001 VL 4533 BP 1 EP 8 DI 10.1117/12.447768 PG 8 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BT65H UT WOS:000173646400001 ER PT J AU Zullo, SJ AF Zullo, SJ TI Gene therapy of mitochondrial DNA mutations: A brief, biased history of allotopic expression in mammalian cells SO SEMINARS IN NEUROLOGY LA English DT Article DE allotopic gene expression; mitochondrial DNA; gene therapy; ATPase6; Leigh syndrome; oxidative phosphorylation; mitochondrial disease; somatic mutations; mitochondrial targeting leader sequence; heteroplasmy ID KEARNS-SAYRE SYNDROME; OXIDATIVE-PHOSPHORYLATION; DEHYDROGENASE-DEFICIENCY; TRANSFER-RNAS; IN-VIVO; MTDNA; COENZYME-Q10; DELETIONS; PROTEINS; MYOPATHY AB Successful treatment of mitochondrial DNA (mtDNA) mutations might be possible by construction of mtDNA-encoded protein genes so that they can be inserted into the nuclear genome and the protein expressed in the mitochondria (allotopic expression). This technique would require individual assembly of all 13 mtDNA-encoded protein genes with an aminoterminal leader peptide that directs the cytoplasmic translated protein to the mitochondrial membrane. The 13 allotopic genes could be inserted into the nuclear genome of a patient's stem cell that had been "cured" of its nascent mtDNA via ethidium bromide treatment (tho-zero cell). The rho-zero cell would be a uridine auxotroph, and recovery from uridine auxotrophy would indicate successful transformation. The patient's own cells could then be returned to the patient's body. With a selective advantage of recovered oxidative phosphorylation, the transformed cells could replace cells with mtDNA mutations. Results of experiments by us on allotopically expressed CHO ATPase6 and of experiments by other workers suggest that there might be competition with endogenous mtDNA-encoded proteins if the particular protein gene is not removed from the endogenous mitochondrial genomes. Thus, it is likely that an 13 mtDNA-encoded protein genes will need to be allotopically expressed, with concomitant removal of all mtDNA genomes, in order for this form of mtDNA gene therapy to be successful. C1 NIMH, Lab Biochem Genet, Warren Grant Magnuson Clin Ctr, Bethesda, MD 20892 USA. RP Zullo, SJ (reprint author), Natl Inst Stand & Technol, Chem & Life Sci Div, Adv Technol Program, A239, Gaithersburg, MD 20899 USA. NR 68 TC 22 Z9 22 U1 0 U2 3 PU THIEME MEDICAL PUBL INC PI NEW YORK PA 333 SEVENTH AVE, NEW YORK, NY 10001 USA SN 0271-8235 J9 SEMIN NEUROL JI Semin. Neurol. PY 2001 VL 21 IS 3 BP 327 EP 335 DI 10.1055/s-2001-17949 PG 9 WC Clinical Neurology SC Neurosciences & Neurology GA 485QB UT WOS:000171764900011 PM 11641822 ER PT S AU Brown, SW Larason, TC Habauzit, C Eppeldauer, GP Ohno, Y Lykke, KR AF Brown, SW Larason, TC Habauzit, C Eppeldauer, GP Ohno, Y Lykke, KR BE Blouke, MM Canosa, J Sampat, N TI Absolute radiometric calibration of digital imaging systems SO SENSORS AND CAMERA SYSTEMS FOR SCIENTIFIC, INDUSTRIAL, AND DIGITAL PHOTOGRAPHY APPLICATIONS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors and Camera Systems for Scientific, Industrial, and Digital Photography Applications CY JAN 24-26, 2000 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE DE calibration; CCD; digital camera; radiometry AB We have developed a tunable laser-based facility for the absolute radiometric calibration of digital imaging systems such as CCD cameras, spectrographs, and microscopes. Several types of silicon-based digital imaging systems have been calibrated in this new facility, including a commercially available camera equipped with a removable photopic filter, a custom-designed digital microscope, and a CCD spectrograph. We present results of the CCD camera calibration in detail and discuss relevant aspects of the microscope and spectrograph calibrations. During the radiometric calibration, the pixel-to-pixel uniformity, linearity, and absolute spectral responsivity of each system were determined over the visible spectral range (400 nm to 800 nm). Each of these aspects of the CCD camera calibration will be presented, along with a discussion of the measurement uncertainties. C1 NIST, Gaithersburg, MD 20899 USA. RP Brown, SW (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 8 TC 7 Z9 7 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3984-3 J9 P SOC PHOTO-OPT INS PY 2001 VL 4306 BP 13 EP 21 DI 10.1117/12.426952 PG 3 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BS57Y UT WOS:000170428700002 ER EF