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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Importance of atmospheric scattering in remote sensing, or everything you've always wanted to know about atmospheric scattering but were afraid to ask.

Discussion of the effects of atmospheric scattering and/or absorption on discrimination between target and background materials in environmental or natural science remote sensing applications. The spectral region considered lies between 0.4 and 3 microns. The results are presented parametrically and include an interesting effect that neighboring materials have on the spectral character of a target as a result of aerosol scattering by atmospheric haze.

Turner, R. E.↗
NASA NTRS1972

Formation of spectral lines in planetary atmospheres. III - The use of analytic scattering diagrams in computations of synthetic spectra for cloudy atmospheres.

Results of some comparisons that have been made of line profiles and equivalent widths computed from atmospheric models where the scattering has been represented by the Mie theory and a simple analytic expression, the Heyney-Greenstein function. These results show that the spectroscopic features for these models are indistinguishable and demonstrate the value of using this simple analytic function in terms of the great saving in computer time when computing synthetic spectra for any cloudy planetary atmosphere.

Hunt, G. E.↗
NASA NTRS1973

A neutral-atmosphere composition experiment for the Atmosphere Explorer-C, -D, and -E.

The neutral-atmosphere composition experiment instrumentation is designed to obtain in-situ measurements of neutral thermosphere composition from Atmosphere Explorer-C, -D, and -E. The system is based on previously flown OGO-6 and San Marco-3 composition instruments. The mass-spectrometer sensor includes a gold-plated thermalizing chamber and ion source, a hyperbolic rod quadrupole analyzer, and an off-axis electron multiplier. Automatic ion-source sensitivity control and pulse-counting techniques provide density measurement capability from approximately 125 to 1000 km altitude. The normal operating mode includes measurement at all masses in the range of 1 to 44 amu, with emphasis on hydrogen, helium, oxygen, nitrogen, and argon.

Pelz, D. T.↗
NASA NTRS1976

Results of a comprehensive atmospheric aerosol-radiation experiment in the southwestern United States. I - Size distribution, extinction optical depth and vertical profiles of aerosols suspended in the atmosphere. II - Radiation flux measurements and

Results are reported for a field test that was aimed at acquiring a sufficient set of measurements of aerosol properties required as input for radiative-transfer calculations relevant to the earth's radiation balance. These measurements include aerosol extinction and size distributions, vertical profiles of aerosols, and radiation fluxes. Physically consistent, vertically inhomogeneous models of the aerosol characteristics of a turbid atmosphere over a desert and an agricultural region are constructed by using direct and indirect sampling techniques. These results are applied for a theoretical interpretation of airborne radiation-flux measurements. The absorption term of the complex refractive index of aerosols is estimated, a regional variation in the refractive index is noted, and the magnitude of solar-radiation absorption by aerosols and atmospheric molecules is determined.

Deluisi, J. J.↗
NASA NTRS1978

Pressure sensing of the atmosphere by solar occultation - An application to remote sensing of atmospheric minor gases

The simultaneous inference of pressure and gas concentration in a remote-sensing experiment will increase the accuracy of inverted gas concentrations and minimize the dependence of the experiment on pressure or mass-path error resulting from use of climatological pressure data, satellite ephemeris, and instrument pointing accuracy. A technique for obtaining tangent-point pressure information needed for inversion of gas concentration in an IR solar occultation experiment is described. By measuring IR absorption in bands of atmospheric CO2 (e.g., 2.0, 2.7, or 4.3 microns) pressure values for each layer (2 km or less in the vertical) of the atmosphere can be obtained with rms errors of less than 3%.

Park, J. H.↗
NASA NTRS1980

Evaluation of atmospheric density models and preliminary functional specifications for the Langley Atmospheric Information Retrieval System (LAIRS)

This document presents the results of an extensive survey and comparative evaluation of current atmosphere and wind models for inclusion in the Langley Atmospheric Information Retrieval System (LAIRS). It includes recommended models for use in LAIRS, estimated accuracies for the recommended models, and functional specifications for the development of LAIRS.

Lee, T.↗
NASA NTRS1982

Noble gases in planetary atmospheres - Implications for the origin and evolution of atmospheres

The radiogenic and primordial noble gas contents of the Venus, earth, and Mars atmospheres are compared with one another and with the noble gas content of other extraterrestrial samples, particularly meteorites. Key trends in the primordial noble gas content of terrestrial planetary atmospheres are shown to include: (1) a several-orders-of-magnitude decrease in Ne-20 and Ar-36 from Venus to earth to Mars; (2) a nearly constant Ne-20/Ar-36 ratio, which is comparable to that found in the more primitive carbonaceous chondrites and which is two orders of magnitude smaller than the solar ratio; (3) a sizable fractionation of Ar, Kr, and Xe from their solar ratios, though the degree of fractionation (especially for Ar-36/Xe-132) appears to decrease systematically from carbonaceous chondrites to Mars to earth to Venus; and (4) large differences in Ne and Xe isotopic ratios among earth, meteorites, and the sun. It is suggested that the grain-accretion hypothesis can explain all four trends, though the assumptions needed to achieve this agreement are far from proven.

Pollack, J. B.↗
NASA NTRS1983

Modelling atmospheric aerosol backscatter at CO2 laser wavelengths. I - Aerosol properties, modeling techniques, and associated problems. II - Modeled values in the atmosphere. III - Effects of changes in wavelength and ambient conditions

The various methods of calculating the atmospheric aerosol backscattering function, beta(CO2), both from measured aerosol characteristics and from optical measurements made at other wavelengths, are discussed in detail, with limits placed on their accuracy. The most significant factor in determining beta(CO2) is found to be the aerosol size distribution and concentration; this should be known accurately for particle radii up to at least 1 micron for stratospheric particles and 5 microns for tropospheric particles. Results are then presented from the modeling of the aerosol backscattering function at a wavelength of 10.6 microns in the lowest 20 km of the atmosphere. It is found that beta(CO2) varies from 10 to the -6th per m per sr in the planetary boundary layer to less than 10 to the -11th per m per sr in the stratosphere. It is next shown that, with the exception of (NH4)2SO4-containing aerosols, whose size distributions have relatively large numbers of small particles, the variation of backscattering with CO2 wavelength is less than a factor of approximately 3. For such (NH4)2SO4 aerosol distributions, however, the variation of backscatter function with CO2 wavelengths between 9.1 and 11.1 microns may reach one order of magnitude.

Kent, G.S.↗
NASA NTRS1985

The SO2 atmosphere and ionosphere of Io - Ion chemistry, atmospheric escape, and models corresponding to the Pioneer 10 radio occultation measurements

Some numerical models of the SO2 atmosphere and ionosphere of Io at the time of the Pioneer 10 fly-by are calculated. It is shown that the formation of the observed ionosphere in the downstream direction may have required the precipitation of electrons, and that solar EUV radiation alone cannot account for it. In a comparison with Pioneer 10 radio occultation measurements, an electron impact in the range 500-800 eV was found to agree with Pioneer 10 radio occultation data for a SO2 atmosphere with a surface density of 4 x 10 to the 10th per cu cm. The relatively narrow energy range and flux required for incident electrons suggests that a fraction of a torus plasma compresses the ionosphere. It is pointed out on the basis of the model calculations that a weak magnetic field may be associated with Io.

Kumar, S.↗
NASA NTRS1984

Satellite derived atmosphere water vapor as a tracer of large scale interactions between the atmosphere and ocean

Two water-vapor distributions and the accompanying circulation patterns which occurred over the North and South Atlantic Ocean during February 1979 are described. It is shown that scanning multichannel microwave radiometer observations from the Nimbus-7 satellite are used to remotely sense the vertically integrated atmospheric water vapor and liquid water, and the surface wind speed over the ocean and that they provide information on the ocean-atmosphere interaction. To provide evidence of the events revealed in the satellite observations, FGGE data are used.

Short, D. A.↗
NASA NTRS1986

Evidence of atmospheric gravity wave perturbations of the Brunt-Vaisala frequency in the atmosphere

A series of high altitude, medium resolution, measurements of temperature, pressure and turbulence have been performed by the Air Force Geophysics Laboratory. These measurements were conducted using the VIZ Manufacturing Co. microsondes with attached micro-thermal probes measuring the temperature structure coefficient. A typical atmospheric temperature measurement is given. Several small temperature inversions are evident in the troposphere. The stratosphere is marked with numerous fluctuations in the temperature profile. Microsondes provide temperature and pressure measurements every 4 seconds up to a maximum altitude of 30 km (MSL). Since the average ascent rate is 5 m/s, the altitude interval between the measurement reports is 20 m. The potential temperature is calculated from the temperature and pressure. Spectral analysis of atmospheric Brunt-Vaisala frequencies reveal spectra similiar to the velocity spectra of Dewan et al. (1984), Daniels (1982), and Endlich and Singleton (1969). The Brunt-Vaisala spectra indicate the existence of separate, distinguishable wave modes.

Good, R. E.↗
NASA NTRS1989

Middle Atmosphere Program. Handbook for MAP, volume 29. Part 1: Extended Abstracts, International Symposium on Solar Activity Forcing of the Middle Atmosphere. Part 2: MASH Workshop

The proceedings of the symposium is presented. Eight different sessions were presented: (1) Papers generally related to the subject; (2) Papers on the influence of the Quasi Biennial Oscillation; (3) Papers on the influence of the solar electromagnetic radiation variability; (4) Papers on the solar wind and high energy particle influence; (5) Papers on atmospheric circulation; (6) Papers on atmospheric electricity; (7) Papers on lower ionospheric variability; and (8) Solar posters, which are not included in this compilation.

Lastovicka, Jan↗
NASA NTRS1990

Extensive middle atmosphere (20-120 KM) modification in the Global Reference Atmospheric Model (GRAM-90)

The Global Reference Atmospheric Model (GRAM) is currently available in the 'GRAM-88' version (Justus, et al., 1986; 1988), which includes relatively minor upgrades and changes from the 'MOD-3' version (Justus, et al., 1980). Currently a project is underway to use large amounts of data, mostly collected under the Middle Atmosphere Program (MAP) to produce a major upgrade of the program planned for release as the GRAM-90 version. The new data and program revisions will particularly affect the 25-90 km height range. Sources of data and preliminary results are described here in the form of cross-sectional plots.

Justus, C. G.↗
NASA NTRS1989

Middle Atmosphere Program. Handbook for MAP. Volume 31: Reference models of trace species for the COSPAR international reference atmosphere

A set of preliminary reference atmosphere models of significant trace species which play important roles in controlling the chemistry, radiation budget, and circulation patterns of the atmosphere were produced. These models of trace species distributions are considered to be reference models rather than standard models; thus, it was not crucial that they be correct in an absolute sense. These reference models can serve as a means of comparison between individual observations, as a first guess in inversion algorithms, and as an approximate representation of observations for comparison to theoretical calculations.

Keating, G. M.↗
NASA NTRS1992

Role of a cumulus parameterization scheme in simulating atmospheric circulation and rainfall in the nine-layer Goddard Laboratory for Atmospheres General Circulation Model

The influence of a cumulus convection scheme on the simulated atmospheric circulation and hydrologic cycle is investigated by means of a coarse version of the GCM. Two sets of integrations, each containing an ensemble of three summer simulations, were produced. The ensemble sets of control and experiment simulations are compared and differentially analyzed to determine the influence of a cumulus convection scheme on the simulated circulation and hydrologic cycle. The results show that cumulus parameterization has a very significant influence on the simulation circulation and precipitation. The upper-level condensation heating over the ITCZ is much smaller for the experiment simulations as compared to the control simulations; correspondingly, the Hadley and Walker cells for the control simulations are also weaker and are accompanied by a weaker Ferrel cell in the Southern Hemisphere. Overall, the difference fields show that experiment simulations (without cumulus convection) produce a cooler and less energetic atmosphere.

Sud, Y. C.↗
NASA NTRS1992

The Chemistry of the Global Atmosphere; International Symposium of the Commission for Atmospheric Chemistry and Global Pollution of IAMAP, 7th, Chamrousse, France, Sept. 5-11, 1990, Selected Papers

Topics presented include the adsorption and reaction of trichlorofluoromethane on various particles, equilibria of the marine multiphase ammonia system, a novel ozone sensor for direct eddy flux measurements, and characterization of the carbonate content of atmospheric aerosols. Also presented are variations in heavy metals concentrations in Antarctic snows, sources of continental dust over Antarctica during the last glacial cycle, an inventory of anthropogenic emissions and air pollution in the USSR, and atmospheric nuclei in the remote free-troposphere.

Buat-Menard, P.↗