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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 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Remote sensing of atmospheric and surface temperatures with microwaves.

Solids, liquids, and gases emit at microwave wavelengths measurable amounts of black-body thermal radiation. Receiver sensitivities readily approach 0.01 K, and permit accurate measurements of land, sea, and atmospheric temperatures. Sea and land temperature measurements must be corrected for the effects of surface emissivity, but these effects can often be measured or estimated. Observations near the 5 mm wavelength 02 resonances can yield atmospheric temperature profiles with an approximate accuracy of 2 K for altitudes 0-80 km. Such measurements from balloons and aircraft suggest that the planned earth-orbital satellite experiments will yield data valuable for numerical weather prediction. Ground-based radio telescopes and planetary-probes have yielded similar information about the surfaces and atmospheres of other planets.

Staelin, D. H.↗
NASA NTRS1991

Thermal environment of Mars

Thermal observations of Mars are reviewed focusing on surface and atmospheric temperatures. Data obtained indicate that the effect of increasing dust in the atmosphere is to reduce diurnal temperature variation at the surface, while enhancing atmospheric thermal variation. Atmospheric thermal effects can be induced by global dust storms even in regions of polar night. Maximum temperatures occur near the equator in summer or at local sites with sunward facing slopes, where low surface thermal inertias make it possible to achieve values up to about 310 K. Radiation and convection in the daytime affect atmospheric temperatures near the surface, which are limited by radiation at night. Results of thermal observations confirm that Mars' thermal state and climate can significantly vary from year to year, due to the variation in dust activity.

Martin, T. Z.↗
NASA NTRS1969

Model atmospheres of red dwarf stars.

High temperature atmospheric models for red dwarf stars and sun to determine convection effect on atmospheric surface layers and emitted flux

Auman, J. R., Jr.↗
NASA NTRS1977

Investigations with satellite data. 2: Temperature retrievals

A method for retrieving atmospheric temperatures in a severe storm situation was investigated. Retrieval was accomplished through the aid of satellite radiance measurements and nearby radiosondes. A set of coefficients was derived which when multiplied by the measured radiances, yielded smaller temperature retrieval errors than the minimum-information retrieval method.

Fritz, S.↗
NASA NTRS1984

Wind abrasion on Venus: A means for experimental investigations

A study to determine the feasibility of conducting experiments to simulate the aeolian environment on Venus as related to wind abrasion was completed. Ideally, such experiments should involve complete investigation of weathering, in which mechanical, thermal, and chemical parameters are taken into account. This is particularly important for Venus, where atmospheric temperatures and pressures at the surface produce an environment which is equivalent to low or medium grade metamorphic conditions on Earth. Details that describe the Venus Aeolian Abrasion Device (VAAD) are included. The VAAD device would enable experiments to be conducted with the same chemistry, temperature, pressure, and other physical properties of the Venus atmosphere near the surface. The proposed device enables the important aeolian parameters to be controlled and monitored, including particle size, velocity, impact-angle and flux, atmospheric pressure, temperature, and gas composition.

Greeley, R.↗
NASA NTRS1973

A first look at atmospheric dynamics and temperature variations on Titan.

Pollack (1973) has used a radiative equilibrium model to match radiometric data for Titan and infers the atmospheric mass, composition, opacity, and gross vertical thermal structure. These results are used to estimate the atmospheric temperature variations by means of scaling analysis, taking into account dynamics both for a baroclinic wave regime and for an axially symmetric circulation regime. Horizontal temperature variations of the atmosphere and surface are found to be very small, and the circulation is found to be weak and probably axially symmetric. The small temperature variations appear to preclude the storage of volatiles in polar caps, so that the present atmospheric methane content may be due to a balance between outgassing and photodissociation.

Leovy, C. B.↗
NASA NTRS1992

Atmospheric and surface temperatures and airborne dust amounts during late southern summer from Mariner 9 IRIS data

The temperature structure and dust loading of the Martian atmosphere are investigated using thermal emission spectra recorded in 1972 by the Mariner 9 infrared interferometer spectrometer (IRIS). The analysis focuses on a subset of data consisting of approximately 2400 spectra obtained near the end of the southern summer season (L(sub s) equal to 343 deg to 348 deg), after the global dust storm had largely abated and airborne dust amounts were subsiding to background values. Simultaneous retrieval of the vertical distribution of both atmospheric temperature and dust optical depth is accomplished through an iterative procedure which is performed on each individual spectrum. The atmospheric transmittances are calculated using a Voigt quasi-random band model, which includes absorption by CO2 and dust, but neglects the effects of multiple scattering. Vertical profiles of temperature and dust optical depth are obtained using modified algorithms. These profiles are used to construct global maps of temperature and dust optical depth as functions of latitude (+/- 90 deg), altitude (approximately 0-50 km), and local time of day.

Santee, M.↗
NASA NTRS2007

Atmospheric Environments for Entry, Descent and Landing (EDL)

Scientific measurements of atmospheric properties have been made by a wide variety of planetary flyby missions, orbiters, and landers. Although landers can make in-situ observations of near-surface atmospheric conditions (and can collect atmospheric data during their entry phase), the vast majority of data on planetary atmospheres has been collected by remote sensing techniques from flyby and orbiter spacecraft (and to some extent by Earth-based remote sensing). Many of these remote sensing observations (made over a variety of spectral ranges), consist of vertical profiles of atmospheric temperature as a function of atmospheric pressure level. While these measurements are of great interest to atmospheric scientists and modelers of planetary atmospheres, the primary interest for engineers designing entry descent and landing (EDL) systems is information about atmospheric density as a function of geometric altitude. Fortunately, as described in in this paper, it is possible to use a combination of the gas-law relation and the hydrostatic balance relation to convert temperature-versus-pressure, scientific observations into density-versus-altitude data for use in engineering applications. The following section provides a brief introduction to atmospheric thermodynamics, as well as constituents, and winds for EDL. It also gives methodology for using atmospheric information to do "back-of-the-envelope" calculations of various EDL aeroheating parameters, including peak deceleration rate ("g-load"), peak convective heat rate. and total heat load on EDL spacecraft thermal protection systems. Brief information is also provided about atmospheric variations and perturbations for EDL guidance and control issues, and atmospheric issues for EDL parachute systems. Subsequent sections give details of the atmospheric environments for five destinations for possible EDL missions: Venus. Earth. Mars, Saturn, and Titan. Specific atmospheric information is provided for these destinations, and example results are presented for the "back-of-the-envelope" calculations mentioned above.

Justus, Carl G.↗
NASA NTRS1992

WAMDII: The Wide Angle Michelson Doppler Imaging Interferometer

As part of an effort to learn more about the upper atmosphere and how it is linked to the weather experienced each day, NASA and NRCC are jointly sponsoring the Wide Angle Michelson Doppler Imaging Interferometer (WAMDII) Mission. WAMDII will measure atmospheric temperature and wind speed in the upper atmosphere. In addition to providing data on the upper atmosphere, the wind speed and temperature readings WAMDII takes will also be highly useful in developing and updating computer simulated models of the upper atmosphere. These models are used in the design and testing of equipment and software for Shuttles, satellites, and reentry vehicles. In making its wind speed and temperature measurements, WAMDII examines the Earth's airglow, a faint photochemical luminescence caused by the influx of solar ultraviolet energy into the upper atmosphere. During periods of high solar flare activity, the amount of this UV energy entering the upper atmosphere increases, and this increase may effect airglow emissions.

Source record↗
NASA NTRS1978

Comment on ion and electron temperatures in the Martian upper atmosphere

Ion temperature profiles measured by the retarding potential analyzers on Viking I and II are examined. It is found that the thermal conduction must be modified by other transport processes or by the presence of magnetic fields to account for the observed profiles. Such processes also effect the electron temperature profile, which, however, was not measured. Estimates of the magnetic field parameters are obtained assuming the magnetic field is the dominant effect.

Johnson, R. E.↗
NASA NTRS1982

Vertical density and temperature structure over northern Europe

Vertical profiles of upper-atmosphere temperature and density over northern Europe constructed from data obtained in November and December 1980, as part of the Energy Budget Campaign, are presented and discussed. Temperature sondes, passive spheres, accelerometers, mass and IR spectrometers, and density gauges were rocket launched from ESRANGE, Sweden and Andoya, Norway; the data are combined with ground measurements to construct 20-120-km-altitude profiles for night periods of severe, moderate, and minimal geomagnetic storm activity. The profiles are compared with each other and with the 1976 U.S. Standard Atmosphere (USSA). In the temperature profiles, increased geomagnetic activity is associated with lower temperatures and flattened profiles in the stratopause region, and higher temperatures in the 70-90-km range. The density profiles show a variation of less than about 15 percent, except for a 25-percent range for the moderate-geomagnetic-activity period. The inferred wavelengths and periods are those expected for internal gravity waves at this altitude, and the divergence from USSA is accounted for by season and latitude dependence.

Philbrick, C. R.↗
NASA NTRS1976

Pioneer 10 ultraviolet photometer observations of Jupiter - The helium to hydrogen ratio

Pioneer 10 UV photometric observations of solar He I 584-A emissions diffusely reflected from the atmosphere of Jupiter are discussed which establish the expected presence of He in the planet. The intensity and profile of the solar He line are remeasured and found to be more intense than originally supposed, implying a lower value for the diffuse 584-A reflectivity of Jupiter and less He than previously estimated. Other measurements of the solar He line are reviewed, resonance scattering by He is analyzed, and radiative-transfer calculations for Jovian model atmospheres are improved by including the anisotropic phase function for helium resonance scattering. The assumption of coherent scattering in the formation of the Jovian airglow line is shown to be an accurate approximation, and present estimates of the atmospheric temperature and eddy diffusion coefficient are examined. An atmospheric He/H abundance ratio greater than zero but less than approximately 28% is determined by assuming an isothermal atmosphere with a temperature of 150 K and the range of eddy-diffusion values given by Pioneer 10 Ly-alpha observations. The effect of higher temperatures on the He/H abundance is briefly evaluated.

Carlson, R. W.↗
NASA NTRS1994

Thermal and albedo mapping of the polar regions of Mars using Viking thermal mapper observations: 2. South polar region

We present the first maps of the apparent thermal inertia and albedo of the south polar region of Mars. The observations used to create these maps were acquired by the infrared thermal mapper (IRTM) instruments on the two Viking Orbiters over a 30-day period in 1977 during the Martian late southern summer season. The maps cover the region from 60 deg S to the south pole at a spatial resolution of 1 deg of latitude, thus completing the initial thermal mapping of the entire planet. The analysis and interpretation of these maps is aided by the results of a one-dimensional radiative convective model, which is used to calculate diurnal variations in surface and atmospheric temperatures, and brightness temperatures at the top of the atmosphere for a range of assumptions concerning dust optical properties and dust optical depths. The maps show that apparent thermal inertias of bare ground regions decrease systematically from 60 deg S to the south pole. In unfrosted regions close to the south pole, apparent thermal inertias are among the lowest observed anywhere on the planet. On the south residual cap, apparent thermal inertias are very high due to the presence of CO2 frost. In most other regions of Mars, best fit apparent albedos based on thermal emission measurements are generally in good agreement with actual surface albedos based on broadband solar reflectance measurements. The one-dimensional atmospheric model calculations also predict anomalously cold brightness temperatures close to the pole during late summer, and after considering a number of alternatives, it is concluded that the net surface cooling due to atmospheric dust is the best explanation for this phenomenon. The region of lowest apparent thermal inertia close to the pole, which includes the south polar layered deposits, is interpreted to be mantled by a continuous layer of aeolian material that must be at least a few millimeters thick. The low thermal inertias mapped in the south polar region imply an absence of surface water ice deposits, which is consistent with Viking Mars atmospheric water detector (MAWD) measurements which show low atmospheric water vapor abundances throughout the summer season.

Paige, David A.↗
NASA NTRS1994

Isolating Gas Sensor From Pressure And Temperature Effects

Two-stage flow system enables oxygen sensor in system to measure oxygen content of low-pressure, possibly-high-temperature atmosphere in test environment while protecting sensor against possibly high temperature and fluctuations in pressure of atmosphere. Sensor for which flow system designed is zirconium oxide oxygen sensor sampling atmospheres in high-temperature wind tunnels. Also adapted to other gas-analysis instruments that must be isolated from pressure and temperature effects of test environments.

Sprinkle, Danny R.↗
NASA NTRS1983

Remote measurements of ozone, water vapor and liquid water content, and vertical profiles of temperature in the lower troposphere

Several advanced atmospheric remote sensing systems developed at the Jet Propulsion Laboratory were demonstrated under various field conditions to determine how useful they would be for general use by the California Air Resources Board and local air quality districts. One of the instruments reported on is the Laser Absorption Spectrometer (LAS). It has a pair of carbon dioxide lasers with a transmitter and receiver and can be flown in an aircraft to measure the column abundance of such gases as ozone. From an aircraft, it can be used to rapidly survey a large region. The LAS is usually operated from an aircraft, although it can also be used at a fixed location on the ground. Some tests were performed with the LAS to measure ozone over a 2-km horizontal path. Another system reported on is the Microwave Atmospheric Remote Sensing System (MARS). It is tuned to microwave emissions from water vapor, liquid water, and oxygen molecules (for atmospheric temperature). It can measure water vapor and liquid water in the line-of-sight, and can measure the vertical temperature profile.

Grant, W. B.↗
NASA NTRS1986

Remote sensing of land-surface temperature from HIRS/MSU data

A relaxation algorithm which permits meteorological parameters to be obtained from satellite data, without a priori assumptions about the properties of the other unknowns in the field of view, was developed. Atmospheric temperature profiles, atmospheric humidity, cloud cover, cloud top height, cloud top temperature, sea-surface temperature, land-surface temperature, snow cover, and ice cover are derived. Simultaneous determination of atmospheric and surface thermal structure and the cloud distribution provides information on heat sources and sinks, storage rates, and transport phenomena in the atmosphere. Such information is critical in determining the driving mechanisms for motions in the atmosphere and oceans and in improving numerical weather prediction.

Chahine, M. T.↗
NASA NTRS1999

The Martian Surface Boundary Layer

The acquisition of meteorological data from the surface of Mars by the two Viking Landers and Mars Pathfinder make it possible to estimate atmospheric boundary layer parameters and surface properties at three different locations on the planet. Because the Martian atmosphere is so thin the majority of the solar radiance is converted to heat at the surface. The difference between surface and atmospheric temperature can also constraint surface albedo, thermal inertia, and infrared emissivity. The Mars Pathfinder Atmospheric Structure Instrument/Meteorological package (ASI/MET) was the most capable weather monitoring system ever sent to the surface of another planet to date. One of the prime objectives of the ASI/MET package is to characterize the surface boundary layer parameters, particularly the heat and momentum fluxes, scaling temperature and friction velocity, and estimate surface roughness. Other important boundary layer parameters, such as Richardson Number, Monin-Obukhov length, analysis of turbulence characteristics of wind and temperature, and atmospheric stability class can also be determined from these measurements.

Wilson, G. R.↗