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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 361 records · Page 20
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Global scale diagnoses of FGGE data

Descriptive global scale diagnoses of the First Global Atmospheric Research Experiment SOP-1 analyses were made and compared against controlled, real data integrations of the Goddard Laboratory of Atmospheric Science (GLAS) general circulation model (GCM) as well as other data sets. The effects of critical latitudes were studied; the influence of tropical wind data and latent heating upon the GLAS GCM was diagnosed; planetary wave structure on various time scales from the diurnal to the monthly was studied; and the GLAS analyses were compared with other analyses. Short term controlled GLAS GCM integrations show that: (1) the inclusion of tropical wind data in real data integrations has an important influence in the mid-latitude prediction in both hemispheres; and (2) the tropical divergent wind reacts almost immediately to alteration of the tropical latent heating. The presence or absence of zonally averaged easterlies depends strongly upon the presence of tropical latent heating.

Paegle, J.↗
NASA NTRS1985

Thermal-vacuum testing and in-situ optical alignment measurements of the HALOE telescope/sun sensor assembly

Design features, test data and projected performance levels of the telescope/sun sensor assembly for the Halogen Occultation Experiment (HALOE) on board the Upper Atmosphere Research Satellite are described. HALOE will gather data on stratospheric chemical species with an IR telescope pointed through the atmosphere at the sun during occultation periods. The pointing accuracy will need to be 1 arcmin elevation and 1.6 arcmin azimuthal. Adjustments of the gimbaled instrument are guided by a sun sensor and its associated electronics. The components were subjected to thermal-vacuum, optical boresight stability tests and the data generated were compared with a finite element model of the telescope and sun sensor. The tests consisted of exposure to various thermal gradients while the telescope and sun sensor alignments were tracked by optical deflectometry. The thermal behavior was compared with predictions made with a finite difference model. Alignments were within tolerable ranges and the thermal behavior model was concluded valid for predicting the thermal behavior of orbiting instruments.

Foss, R. A.↗
NASA NTRSDate not supplied

Supercooled Large Droplet Ice Formations from Flight Research

This presentation shows ice formations resulting from research flights in supercooled large droplet conditions (SLD) using NASA’s Twin Otter research aircraft. The flight research was part of a 3-year collaboration between NASA, the Federal Aviation Administration, and the National Center for Atmospheric Research. SLD conditions were occasionally encountered in the flight testing and those results are reported herein. The presentation was part of a SLD Engineering Tools Development Workshop in 2004 and is being routed through STRIVES retroactively for public dissemination on NTRS.

Twin Otter↗
NASA NTRSDate not supplied

Current and Future ESPO Supported Missions

The Earth Science Project Office (ESPO) at NASA Ames Research Center is a group of success-oriented individuals providing project management for NASA's Science Mission Directorate, Earth Science Division. We provide planning, implementation, and post-mission support for large, complex, multi-agency, domestic and international field campaigns. ESPO has led over 60 successful field campaigns, dating back to 1987. ESPO supports several of NASA's Earth Science Division’s programs, including Upper Atmosphere Research, Tropospheric Chemistry, Radiation Sciences, Weather and Atmospheric Dynamics, Ocean Biology and Biochemistry, Airborne Science, and the Earth System Science Pathfinder Program.

Erin Czech↗
NASA NTRS1983

Homogeneous processes of atmospheric interest

Upper atmospheric research programs in the department of chemical kinetics are reported. Topics discussed include: (1) third-order rate constants of atmospheric importance; (2) a computational study of the HO2 + HO2 and DO2 + DO2 reactions; (3) measurement and estimation of rate constants for modeling reactive systems; (4) kinetics and thermodynamics of ion-molecule association reactions; (5) entropy barriers in ion-molecule reactions; (6) reaction rate constant for OH + HOONO2 yields products over the temperature range 246 to 324 K; (7) very low-pressure photolysis of tert-bytyl nitrite at 248 nm; (8) summary of preliminary data for the photolysis of C1ONO2 and N2O5 at 285 nm; and (9) heterogeneous reaction of N2O5 and H2O.

Rossi, M. J.↗
NASA NTRS1984

Middle Atmosphere Program. Handbook for MAP. Volume 14: URSI/SCOSTEP Workshop on Technical Aspects of MST Radar

Various topics relative to middle atmosphere research were discussed. meteorological and aeronomical requirements for mesosphere-stratosphere-troposphere (MST) radar networks, general circulation of the middle atmosphere, the interpretation of radar returns from clear air, spaced antenna and Doppler techniques for velocity measurement, and techniques for the study of gravity waves and turbulence are among the topics discussed.

Bowhill, S. A.↗
NASA NTRS1998

Evaluation and optimization of lidar temperature analysis algorithms using simulated data

The middle atmosphere (20 to 90 km altitude) ha received increasing interest from the scientific community during the last decades, especially since such problems as polar ozone depletion and climatic change have become so important. Temperature profiles have been obtained in this region using a variety of satellite-, rocket-, and balloon-borne instruments as well as some ground-based systems. One of the more promising of these instruments, especially for long-term high resolution measurements, is the lidar. Measurements of laser radiation Rayleigh backscattered, or Raman scattered, by atmospheric air molecules can be used to determine the relative air density profile and subsequently the temperature profile if it is assumed that the atmosphere is in hydrostatic equilibrium and follows the ideal gas law. The high vertical and spatial resolution make the lidar a well adapted instrument for the study of many middle atmospheric processes and phenomena as well as for the evaluation and validation of temperature measurements from satellites, such as the Upper Atmosphere Research Satellite (UARS). In the Network for Detection of Stratospheric Change (NDSC) lidar is the core instrument for measuring middle atmosphere temperature profiles. Using the best lidar analysis algorithm possible is therefore of crucial importance. In this work, the JPL and CNRS/SA lidar analysis software were evaluated. The results of this evaluation allowed the programs to be corrected and optimized and new production software versions were produced. First, a brief description of the lidar technique and the method used to simulate lidar raw-data profiles from a given temperature profile is presented. Evaluation and optimization of the JPL and CNRS/SA algorithms are then discussed.

Leblanc, Thierry↗
NASA NTRS1999

Juneau Airport Doppler Lidar Deployment: Extraction of Accurate Turbulent Wind Statistics

A 2 micrometer pulsed Doppler lidar was deployed to the Juneau Airport in 1998 to measure turbulence and wind shear in and around the departure and arrival corridors. The primary objective of the measurement program was to demonstrate and evaluate the capability of a pulsed coherent lidar to remotely and unambiguously measure wind turbulence. Lidar measurements were coordinated with flights of an instrumented research aircraft operated by representatives of the University of North Dakota (UND) under the direction of the National Center for Atmospheric Research (NCAR). The data collected is expected to aid both turbulence characterization as well as airborne turbulence detection algorithm development activities within NASA and the FAA. This paper presents a summary of the deployment and results of analysis and simulation which address important issues regarding the measurement requirements for accurate turbulent wind statistics extraction.

Hannon, Stephen M.↗
NASA NTRS2002

CRYSTAL, EOS Validation, and CAMEX-5

CAMEX-5 is at an early phase of concept development. This future field deployment (2004 or 2005) concerning hurricanes could potentially benefit from collaboration with other programs within NASA. Specifically, the recently completed CRYSTAL- Florida Area Cirrus Experiment (FACE) offers a useful model of such a collaborative endeavor. CRYSTAL-FACE was concerned with deep tropical convection and its impact on the upper troposphere. Three separate NASA R&A Programs joined in supporting CRYSTAL-FACE, including the Radiation Sciences Program, the Atmospheric Chemistry, Modeling & Analysis Program, and the Upper Atmosphere Research Program as well as the EOS Validation Program. In addition, the National Science Foundation and the Department of Energy Atmospheric Measurements Programs were also substantive partners. Insights will be given into how this cooperative field experiment came to be and how it worked in the field. Possibilities for similar model for CAMEX-5 will be explored.

Starr, David↗
NASA NTRS2014

Analyzing Source Apportioned Methane in Northern California During DISCOVER-AQ-CA Using Airborne Measurements and Model Simulations

This study analyzes source apportioned methane (CH4) emissions and atmospheric concentrations in northern California during the Discover-AQ-CA field campaign using airborne measurement data and model simulations. Source apportioned CH4 emissions from the Emissions Database for Global Atmospheric Research (EDGAR) version 4.2 were applied in the 3-D chemical transport model GEOS-Chem and analyzed using airborne measurements taken as part of the Alpha Jet Atmospheric eXperiment over the San Francisco Bay Area (SFBA) and northern San Joaquin Valley (SJV). During the time period of the Discover-AQ-CA field campaign EDGAR inventory CH4 emissions were 5.30 Gg/day (Gg 1.0 109 grams) (equating to 1.9 103 Gg/yr) for all of California. According to EDGAR, the SFBA and northern SJV region contributes 30 of total emissions from California. Source apportionment analysis during this study shows that CH4 concentrations over this area of northern California are largely influenced by global emissions from wetlands and local/global emissions from gas and oil production and distribution, waste treatment processes, and livestock management. Model simulations, using EDGAR emissions, suggest that the model under-estimates CH4 concentrations in northern California (average normalized mean bias (NMB) -5 and linear regression slope 0.25). The largest negative biases in the model were calculated on days when hot spots of local emission sources were measured and atmospheric CH4 concentrations reached values 3.0 parts per million (model NMB -10). Sensitivity emission studies conducted during this research suggest that local emissions of CH4 from livestock management processes are likely the primary source of the negative model bias. These results indicate that a variety, and larger quantity, of measurement data needs to be obtained and additional research is necessary to better quantify source apportioned CH4 emissions in California and further the understanding of the physical processes controlling them.

Methane↗
NASA NTRS1973

Satellite-tracking and earth-dynamics research programs

The following activities in Smithsonian Astrophysical Observatory's (SAO) earth-dynamics programs are covered: (1) satellite-tracking network operations; (2) satellite geodesy and geophysics programs; (3) atmospheric research. Approximately 46,000 successful range measurements were acquired by the SAO laser stations in Peru, South Africa, Brazil, and Arizona. The Peole satellite-tracking campaign conducted in conjunction with the Centre National d'Etudes Spatiales was completed in August 1973. The SAO network obtained 4482 validated returns of 310 arcs of Peole. These data are of particular value for obtaining more accurate gravity-field and zonal-harmonics coefficients.

Weiffenbach, G. C.↗
NASA NTRS1978

Atmospheric electrification

Research areas of atmospheric electricity that could be explored from the shuttle or the tethered satellite are discussed. Emphasis is placed on atmospheric current flow and telluric currents. A model depicting the atmospheric electric global circuit is presented.

Kasemir, H. W.↗
NASA NTRS1984

Design of a precision etalon position control system for a cryogenic spectrometer

The Upper Atmosphere Research Satellite (UARS) will be launched in 1988 to study the distribution of a series of trace elements in the upper atmosphere and to study atmospheric dynamics. The UARS carries on board a cryogenically cooled infrared spectrometer to measure the concentration of a series of chemical species that are important for understanding the ozone layer in the stratosphere. This device, known as the Cryogenic Limb Array Etalon Spectrometer (CLAES), uses a multiposition filter wheel combined with tilt-scanned Fabry Perot etalons to obtain the high resolution required for these experiments. The CLAES optical system is sealed in a dewar where it is maintained at cryogenic temperatures by a supply of solid hydrogen. Operating temperatures for CLAES range from 130 K at the entrance aperture to 13 K at the focal plane. The design and test of a special control system using a unique actuator concept to provide position and can control for the CLAES etalon are described. Results of performance tests at cryogenic temperatures simulating the CLAES on-orbit environment are discussed.

Aubrun, J. N.↗
NASA NTRS1986

University participation via UNIDATA, part 1

The UNIDATA Project is a cooperative university project, operated by the University Corporation for Atmospheric Research (UCAR) with National Science Foundation (NSF) funding, aimed at providing interactive communication and computations to the university community in the atmospheric and oceanic sciences. The initial focus has been on providing access to data for weather analysis and prediction. However, UNIDATA is in the process of expanding and possibly providing access to the Pilot Climate Data System (PCDS) through the UNIDATA system in an effort to develop prototypes for an Earth science information system. The notion of an Earth science information system evolved from discussions within NASA and several advisory committees in anticipation of receiving data from the many Earth observing instruments on the space station complex (Earth Observing System).

Dutton, J.↗
NASA NTRS1989

Inspecting our upper atmosphere

The Upper Atmosphere Research Satellite (UARS) has been proposed for intensive studies of the 15-100 km-altitude region of the earth's atmosphere, begining in 1991. This 14,000-lb satellite will carry a suite of 10 instruments able to study the energy input and loss, photochemistry, and circulation of the upper atmosphere, as well as the extensive web of interactions among these three processes. UARS's remote sensors will give attention to the atmospheric molecular species of the nitrogen, hydrogen, and chlorine families.

Reber, C. A.↗
NASA NTRS1991

Nonlinear dynamics of global atmospheric and Earth-system processes

General Circulation Model (GCM) studies of the atmospheric response to change boundary conditions are discussed. Results are reported on an extensive series of numerical studies based on the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM) general circulation model. In these studies the authors determined the response to systematic changes in atmospheric CO2 ranging from 100 to 1000 ppm; to changes in the prescribed sea surface temperature (SST) in the Gulf of Mexico, such as occurred during the deglaciation phase of the last ice age; to changes in soil moisture over North America; and to changes in sea ice extent in the Southern Hemisphere. Study results show that the response of surface temperature and other variables is nearly logarithmic, with lower levels of CO2 implying greater sensitivity of the atmospheric state to changes in CO2. It was found that the surface temperature of the Gulf of Mexico exerts considerable control over the storm track and behavior of storm systems over the North Atlantic through its influence on evaporation and the source of latent heat. It was found that reductions in soil moisture can play a significant role in amplifying and maintaining North American drought, particularly when a negative soil moisture anomaly prevails late in the spring.

Saltzman, Barry↗
NASA NTRS2022

Tropospheric and Stratospheric Ozone Profiles during the 2019 TROpomi vaLIdation eXperiment (TROLIX-19)

A TROPOspheric Monitoring Instrument (TROPOMI) validation campaign was held in the Netherlands based at the CESAR (Cabauw Experimental Site for Atmospheric Research) observatory during September 2019. The TROpomi vaLIdation eXperiment (TROLIX-19) consisted of active and passive remote sensing platforms in conjunction with several balloon-borne and surface chemical (e.g., ozone and nitrogen dioxide) measurements. The goal of this joint NASA-KNMI geophysical validation campaign was to make intensive observations in the TROPOMI domain in order to be able to establish the quality of the L2 satellite data products under realistic conditions, such as non-idealized conditions with varying cloud cover and a range of atmospheric conditions at a rural site. The research presented here focuses on using ozone lidars from NASA's Goddard Space Flight Center to better evaluate the characterization of ozone throughout TROLIX-19. Results of comparisons to the lidar systems with balloon, space-borne and ground-based passive measurements are shown. In addition, results are compared to a global coupled chemistry meteorology model to illustrate the vertical variability and columnar amounts of both tropospheric and stratospheric ozone during the campaign period.

ozone↗
NASA NTRS1999

Its a Wind, Its a Wave, Its Two Phenomena in One: Jerry Schubert, Superrotation, and the UV Markings on Venus

In the early 1970's, ground-based astronomers had already discovered that Ultraviolet (UV) cloud markings on Venus reappeared every 4 days. When radar evidence later revealed a 243-day rotation period for the solid planet, planetary scientists were faced with a quandary: Could the Venus atmosphere really move 60 times as fast as the planet below, or were the apparent movements of the UV features just an illusion caused by propagating waves? The former explanation seemed unlikely - a planet that hardly rotates should generate only a very sluggish circulation. The historical impact of Jerry Schubert's moving flame theory was twofold: It was the forerunner of current thermal tide explanations of the cloud-level superrotation, but it was also the first plausible mechanism for explaining a seemingly inconsistent set of observations. In 1974, Mariner 10 acquired UV images of the Venus clouds at unprecedented levels of detail. Although few have noted it, this began the shift of planetary atmospheric research primarily from the domain of astronomy to that of meteorology. Jerry was among the first scientists to apply terrestrial meteorology to the analysis of planetary data. At that time a young UCLA graduate student with plans to do research on mantle convection, but having flunked the solid earth geophysics section of his departmental comprehensive exam, was gently invited by Jerry to switch to atmospheric science. Jerry suggested that the Venus UV features could be revealing both superrotating winds and planetary-scale waves at the same time, and that we could distinguish the two by looking at motions on different spatial scales. This was my first science research lesson - the complexity of real geophysical systems. Over the next couple of years I was inculcated with Jerry's philosophy of a comprehensive, rigorous approach to research, which manifested itself as a scouring of the literature and the UCLA meteorology faculty to learn about every possible type of planetary-scale wave. The resulting identification of large-scale UV features on Venus as the product of Kelvin and Rossby-type wave motions was validated by extensive Pioneer Venus observations a decade later and remains one of the best examples of the use of terrestrial knowledge to understand other planets.

DelGenio, Anthony↗