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May 27, 2011
05/11
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Sliney, Harold E
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A number of ceramic coatings of different compositions containing lead monoxide (PbO) were studied to determine their relative merits as dry-film lubricants. Lead monoxide is known to be an effective solid lubricant at elevated temperatures, and this oxide was the main component in all compositions studied. Friction and wear properties were determined at temperatures from 750 to 1250 F, at a sliding velocity of 430 feet per minute, and at a normal load of 1 kilogram. In all of the coatings, PbO...
Topics: BIBLIOGRAPHIES, INTERNATIONAL GEOPHYSICAL YEAR, METEOROLOGY, ROCKET LAUNCHING, SPACECRAFT...
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May 28, 2011
05/11
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Dufour, Reginald J
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This report summarizes the research performed at Rice University related to NASA-Ames University consortium grant NCC2-5199 during the two year period 1996 September 1 through 1998 August 31. The research program, titled Orion Nebula and Planetary Nebulae, involved the analysis of Hubble Space Telescope (HST) imagery and spectroscopy of the Orion Nebula and of the planetary nebulae NGC 6818 and NGC 6210. In addition, we analyzed infrared spectra of the Orion Nebula taken with the Infrared Space...
Topics: ATMOSPHERIC COMPOSITION, EXPERIMENTATION, RESEARCH, PROPOSALS, OCEANOGRAPHY, DELAY
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May 31, 2011
05/11
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Slater, John W
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Boundary conditions for subsonic inflow, bleed, and subsonic outflow as implemented into the WIND CFD code are assessed with respect to verification for steady and unsteady flows associated with supersonic inlets. Verification procedures include grid convergence studies and comparisons to analytical data. The objective is to examine errors, limitations, capabilities, and behavior of the boundary conditions. Computational studies were performed on configurations derived from a ''parameterized''...
Topics: ATMOSPHERIC COMPOSITION, PHOTOCHEMICAL REACTIONS, QUASI-BIENNIAL OSCILLATION, TROPICAL REGIONS,...
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May 23, 2011
05/11
by
NON
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A workshop on the National Polar-orbiting Operational Satellite System (NPOESS) ozone measurements requirements was held August 30-31, 1995, at the NOAA Science Center, Camp Springs, Maryland. The workshop was sponsored by the Office of Research and Applications of the National Environmental Satellite, Data, and Information Service as part of an internal concept study (ICS) for the Integrated Program Office (IPO). The purpose of the workshop was to acquire scientifically-based ozone...
Topics: RESEARCH PROJECTS, RAYLEIGH SCATTERING, RAMAN SPECTRA, INTERNATIONAL COOPERATION, ATMOSPHERIC...
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May 24, 2011
05/11
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Brummell, Nicholas H.; Hurlburt, Neal E.; Toomre, Jur
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The effects of rotation on turbulent, compressible convection within stellar envelopes are studied through three-dimensional numerical simulations conducted within a local f-plane model. This work seeks to understand the types of differential rotation that can be established in convective envelopes of stars like the Sun, for which recent helioseismic observations suggest an angular velocity profile with depth and latitude at variance with many theoretical predictions. This paper analyzes the...
Topics: AEROSOLS, SULFURIC ACID, ASHES, COAGULATION, DILUTION, DROP SIZE, MASS RATIOS, NUCLEATION, OZONE...
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xiii, 380 pages : 24 cm
Topics: Atmosphere -- Laser observations, Lasers, Monitoring, Atmosphère -- Observations par laser,...
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May 23, 2011
05/11
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Tsurutani, Bruce T.; Glassmeier, K.-H.; Neubauer, F. M
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We examine and intercompare the LF plasma wave turbulence at three comets: Grigg-Skjellerup (GS), Giacobini-Zinner (GZ), and Halley (H). All three have power spectral peaks at the local ion cyclotron frequency (the pump wave) at approx. 10(exp -2) Hz, and a power-law fall-off at higher frequencies that suggest the development of turbulent cascades. The power laws for the three comets are approximately f(exp -1.9), f(exp -1.9) and f(exp -2.1), respectively. However, other than the similarities...
Topics: ATMOSPHERIC CHEMISTRY, ATMOSPHERIC MODELS, DIURNAL VARIATIONS, UPPER ATMOSPHERE RESEARCH SATELLITE...
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May 30, 2011
05/11
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Yamada, Toshishig
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Since its invention in 1948, the transistor has revolutionized our everyday life - transistor radios and TV's appeared in the early 1960s, personal computers came into widespread use in the mid-1980s, and cellular phones, laptops, and palm-sized organizers dominated the 1990s. The electronics revolution is based upon transistor miniaturization; smaller transistors are faster, and denser circuitry has more functionality. Transistors in current generation chips are 0.25 micron or 250 nanometers...
Topics: RADAR MEASUREMENT, POLAR METEOROLOGY, OZONE, NITRIC ACID, MIXING RATIOS, LOSSES, DEPLOYMENT,...
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May 30, 2011
05/11
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Visentine, James; Kinard, William; Brinker, David; Scheiman, David; Banks, Bruce; Albyn, Keith; Hornung, Steve; See, Thoma
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A solar array segment was recently removed from the Mir core module and returned for ground-based analysis. The segment, which is similar to the ones the Russians have provided for the FGB and Service Modules, was microscopically examined and disassembled by US and Russian science teams. Laboratory analyses have shown the segment to he heavily contaminated by an organic silicone coating, which was converted to an organic silicate film by reactions with atomic oxygen within the. orbital flight...
Topics: DATA ACQUISITION, CONIFERS, FORESTS, ORGANIC PEROXIDES, OXIDIZERS, OZONE, PEROXIDES, CANOPIES...
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1.1K
May 22, 2011
05/11
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NON
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This quarterly publiction provides archival reports on developments in programs managed by JPL Telecommunications and Mission Operations Directorate (TMOD), which now includes the former communications and Data Acquisition (TDA) Office. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are...
Topics: ATMOSPHERIC CHEMISTRY, ATMOSPHERIC COMPOSITION, DATA BASES, OZONE, SULFUR, TROPOSPHERE, ASIA,...
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May 6, 2010
05/10
by
Evans, Tyler, C.; Chan, Kai-Wing; Saha, Timo T
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The optics for the International X-Ray Observatory (IXO) require alignment and integration of about fourteen thousand thin mirror segments to achieve the mission goal of 3.0 square meters of effective area at 1.25 keV with an angular resolution of five arc-seconds. These mirror segments are 0.4 mm thick, and 200 to 400 mm in size, which makes it hard to meet the strict angular resolution requirement of 5 arc-seconds for the telescope. This paper outlines the precise alignment, verification...
Topics: AEROSOLS, SMOG, DECOMPOSITION, FORECASTING, AIR QUALITY, ATMOSPHERIC COMPOSITION, EARTH SCIENCES,...
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402
Jul 12, 2010
07/10
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Richards, F. M., Jr
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The processing behavior of NASTRAN, a general purpose system of computer software used for solving engineering analysis problems by means of the finite element displacement method, is discussed. The host system for the NASTRAN is the Univac 1110, and the primary function is performing static and dynamic structural analyses of the Space Shuttle. The processing implications of the NASTRAN structural analysis are addressed and the current NASTRAN situation on the Univac 1110 is examined. The...
Topics: ATMOSPHERIC OPTICS, OPTICAL RADAR, SATELLITE OBSERVATION, ATMOSPHERIC COMPOSITION, ATMOSPHERIC...
Earth orbital instruments, designed to measure the vertical and spatial distribution of atmospheric water vapor is discussed. Specifically, the operation of the Limb Infrared Monitor of the Stratosphere (LIMS) experiment is examined. The LIMS is a six channel limb scanning radiometer that was launched aboard Nimbus 7 in 1978. Profiles of stratospheric and mesospheric temperature, water vapor, and various other constituents were obtained by inverting the LIMS radiance measurements. This same...
Topics: NASA Technical Reports Server (NTRS), INFRARED IMAGERY, INFRARED RADIOMETERS, RADIANCE,...
Major goals are to gain a better understanding of the planetary-scale tropospheric/stratospheric circulation and to better utilize global-scale routine measurements from satellites. The focus on the latter goal is determining the relationship between total column ozone measurements and the tropopause altitude.
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CIRCULATION, ATMOSPHERIC COMPOSITION, BAROCLINIC...
Research is summarized on applications of stimulated Raman scattering (SRS) of laser light into near infrared wavelengths suitable for atmospheric monitoring. Issues addressed are conversion efficiency, spectral purity, optimization of operating conditions, and amplification techniques. A Raman cell was developed and built for the laboratory program, and is now available to NASA-Langley, either as a design or as a completed cell for laboratory or flight applications. The Raman cell has been...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, MONITORS, OPTICAL RADAR, RAMAN...
A quantitative study of the transmission loss through the entire atmosphere for optical frequencies likely to be used for an earth-space communication link using existing data bases on scattering and absorption characteristics of the atmospheric constituents is presented.
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC ATTENUATION, ATMOSPHERIC SCATTERING, DATA LINKS,...
The results presented show that spectral emissions which arise as a result of vehicle-ambient atmospheric interactions are significant and can become competitive with the natural zodiacal background up to altitudes as high as 400 km for the Vacuun Ultraviolet (VUV) and Visible Infrared Spectra (VIS) for the worst case conditions used. The empirical database on the induced environment of space vehicles is very sparse, and these results are based on a number of assumptions and cannot be regarded...
Topics: NASA Technical Reports Server (NTRS), ABSORPTION SPECTRA, ATMOSPHERIC COMPOSITION, BRIGHTNESS,...
It has been suggested that (CO2)2 and Ar-CO2 are important constituents of the planetary atmospheres of Venus and Mars. Recent results on the laboratory spectroscopy of CO2 containing van der Waals complexes which may be of use in the modeling of the spectra of planetary atmospheres are presented. Sub-Doppler infrared spectra were obtained for (CO2)2, (CO2)3, and rare-gas-CO2 complexes in the vicinity of the CO2 Fermi diad at 2.7 micrometers using a color-center-laser optothermal spectrometer....
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, INFRARED SPECTRA, MARS ATMOSPHERE,...
Because of the great environmental significance of ozone and to support continuing research at the Antarctic and other Southern Hemisphere stations, the development of the 1990 ozone hole was monitored using data from the Nimbus-7 Total Ozone Mapping Spectrometer (TOMS) instrument, produced in near-real-time. This Atlas provides a complete set of daily polar orthographic projections of the TOMS total ozone measurements over the Southern Hemisphere for the period 1 Aug. through 31 Dec. 1990. The...
Topics: NASA Technical Reports Server (NTRS), ANTARCTIC REGIONS, CALIBRATING, NIMBUS 7 SATELLITE, OZONE,...
The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, ATMOSPHERIC ENTRY, MASS...
The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, ATMOSPHERIC ENTRY, MASS...
Source gases are defined as those gases that influence levels of stratospheric ozone (O3) by transporting species containing halogen, hydrogen, and nitrogen to the stratosphere. Examples are the CFC's, methane (CH4), and nitrous oxide (N2O). Other source gases that also come under consideration in an atmospheric O3 context are those that are involved in the O3 or hydroxyl (OH) radical chemistry of the troposphere. Examples are CH4, carbon monoxide (CO), and nonmethane hydrocarbons (NMHC's)....
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, CLIMATE CHANGE, CLIMATOLOGY, OZONE,...
To one interested in atmospheric evolution, the most intriguing aspect of our neighboring planet Venus is its lack of water. Measurements made by Pioneer Venus and by Several Venera spacecraft indicate that the present water abundance in Venus' lower atmosphere is of the order of 20 to 200 ppmv, or 3 x 10( exp -6) to 3 x 10 (exp -5) of the amount of water in Earth's oceans. The exact depletion factor is uncertain, in part because of an unexplained vertical gradient in H2O concentration in the...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, ATMOSPHERIC MOISTURE, GREENHOUSE...
The Cassini Atmospheric Chemistry Mapper (ACM) enables a broad range of atmospheric science investigations for Saturn and Titan by providing high spectral and spatial resolution mapping and occultation capabilities at 3 and 5 microns. ACM can directly address the major atmospheric science objectives for Saturn and for Titan, as defined by the Announcement of Opportunity, with pivotal diagnostic measurements not accessible to any other proposed Cassini instrument. ACM determines mixing ratios...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CHEMISTRY, ATMOSPHERIC COMPOSITION, ATMOSPHERIC...
We discuss the formation of an artificial atmosphere generated by vigorous lunar base activity in this paper. We developed an analytical, steady-state model for a lunar atmosphere based upon previous investigations of the Moon's atmosphere from Apollo. Constant gas-injection rates, ballistic trajectories, and a Maxwellian particle distribution for an oxygen-like gas are assumed. Even for the extreme case of continuous He-3 mining of the lunar regolith, we find that the lunar atmosphere would...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, CONTROLLED ATMOSPHERES, HELIUM...
The research reported resulted in a detailed proposal for the Cassini Mission that addressed fundamental atmospheric structure and composition questions for both Saturn and Titan. Due to the brief time available between the initiation of the research and the proposal date, it was necessary to develop the science goals in close synchronicity with the instrument design. A major goal of the program was to acquire, implement, and test SWIR and MWIR arrays suitable for use with the DIGITAL ARRAY...
Topics: NASA Technical Reports Server (NTRS), ASTRONOMICAL INTERFEROMETRY, CASSINI MISSION, EQUIPMENT...
Reduced quantities of ozone in the atmosphere allow greater levels of ultraviolet light (UV) radiation to reach the earth's surface. This is known to cause skin cancer and mutations. Chlorine liberated from Chlorofluorocarbons (CFC's) and natural sources initiate the destruction of stratospheric ozone through a free radical chain reaction. The project goals are to understand the processes which contribute to stratospheric ozone loss, examine ways to prevent ozone loss, and design a...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, CHLOROFLUOROCARBONS, FREE RADICALS,...
In March of 1992 a workshop sponsored by NASA and NSF was held at SRI International to assess the current ability to measure atmospheric OH and HO2. The measurement techniques reviewed during the workshop for detection of OH included five laser-induced fluorescence schemes, five laser-based adsorption techniques, and four non-laser methods. Six instruments or instrument concepts for HO2 detection, including chemical amplification, conversion to OH with subsequent OH detection, or direct...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CHEMISTRY, CONFERENCES, HYDROGEN COMPOUNDS,...
This volume contains papers that were accepted for presentation at the workshop on Mars: Past, Present, and Future -- Results from the MSATT Program. Topics include, but are not limited to: Martian impact craters; thermal emission measurements of Hawaiian palagonitic soils with implications for Mars; thermal studies of the Martian surface; Martian atmospheric composition studies; temporal and spatial mapping of Mars' atmospheric dust opacity and surface albedo; studies of atmospheric dust from...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, MARS (PLANET), MARS ATMOSPHERE, MARS...
A suborbital experiment was designed to study the photochemistry of the mesosphere by observing simultaneously the airglow emissions with in-situ minor species number density profiles. The experiment was very successful and some preliminary results have already been reported in various scientific meetings. Two scientific papers are currently in the process of final preparation for submission for publication. In this final project report, we will first give a background description of the...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, ATMOSPHERIC DENSITY, ATMOSPHERIC...
Daily maps of the spatial distributions of precipitating energetic electrons were produced for the period 10-20 May 1992. These data will serve as the input for potential changes in upper atmosphere composition.
Topics: NASA Technical Reports Server (NTRS), MESOSPHERE, ELECTRON PRECIPITATION, RELATIVISTIC ELECTRON...
Measurements of CO2, N2O and CH4 are analyzed to define hemispheric average vertical exchange rates in the lower stratosphere from November 1992 to October 1993. Effective vertical diffusion coefficients were small in summer, less than or equal to 1 m(exp 2)/sec at altitudes below 25 km; values were similar near the tropopause in winter, but increased markedly with altitude. The analysis suggests possibly longer residence times for exhaust from stratospheric aircraft, and more efficient...
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE, METHANE, NITROGEN OXIDES, STRATOSPHERE,...
The overall objective of this project is to improve the understanding of coupling processes between atmospheric chemistry and climate. Model predictions of the future distributions of trace gases in the atmosphere constitute an important component of the input necessary for quantitative assessments of global change. We will concentrate on the changes in ozone and stratospheric sulfate aerosol, with emphasis on how ozone in the lower stratosphere would respond to natural or anthropogenic...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CHEMISTRY, MATHEMATICAL MODELS, CLIMATE CHANGE,...
Aerosol samples collected over the western Pacific during the NASA/Global Tropospheric Experiment Pacific Exploratory Mission (PEM-West A) expedition (September - October 1991) revealed mean Pb-210 concentrations in the free troposphere in the 5-10 fCi m(exp -3) STP range. Most soluble ionic aerosol-associated species were near detection limits [much less than 40 parts per trillion by volume (pptv)] in these same samples. The altitude distribution of O3 near Asia closely resembled that of...
Topics: NASA Technical Reports Server (NTRS), LEAD ISOTOPES, AEROSOLS, AIR SAMPLING, FREE ATMOSPHERE,...
This volume contains extended abstracts that have been accepted for presentation at the In Situ Resource Utilization (ISRU II) Technical Interchange Meeting, November 18-19, 1997, at the Lunar and Planetary Institute, Houston, Texas. Included are topics which include: Extraterrestrial resources, in situ propellant production, sampling of planetary surfaces, oxygen production, water vapor extraction from the Martian atmosphere, gas generation, cryogenic refrigeration, and propellant transport...
Topics: NASA Technical Reports Server (NTRS), ABSTRACTS, RESOURCES MANAGEMENT, PLANETARY GEOLOGY, PLANETARY...
The advent of manned satellites has made it possible for man to observe Earth from great distances. Many new phenomena have been discovered in the atmosphere. These are evidently caused by reflection, scattering or refraction of light on crystals and drops of water. It is possible to see small objects on the surface of Earth because of these anomalies.
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, EARTH OBSERVATIONS (FROM SPACE),...
The brightness temperatures of Jupiter, Saturn, Uranus, and Neptune in the range 35 to 1000 micron. The effective temperatures derived from the measurements, supplemented by shorter wavelength Voyager data for Jupiter and Saturn, are 126.8 + or - 4.5 K, 93.4 + or - 3.3 K, 58.3 + or - 2.0 K, and 60.3 + or - 2.0 K, respectively. The implications of the measurements for bolometric output and for atmospheric structure and composition are discussed. The temperature spectrum of Jupiter shows a strong...
Topics: NASA Technical Reports Server (NTRS), BRIGHTNESS TEMPERATURE, JUPITER (PLANET), NEPTUNE (PLANET),...
A new experiment concept has been proposed for the shuttle/tethered satellite system missions, which can provide high resolution, global density mappings of certain ionospheric species. The technique utilizes bistatic LIDAR to take advantage of the unique dual platform configuration offered by these missions. A tuned, shuttle-based laser is used to excite a column of the atmosphere adjacent to the tethered satellite, while triangulating photometic detectors on the satellite are employed to...
Topics: NASA Technical Reports Server (NTRS), IONOSPHERIC SOUNDING, OPTICAL RADAR, SPACE BASED RADAR, SPACE...
Composition data obtained by the quadrupole mass spectrometer (NACS) carried aboard the DE-B satellite were examined for variations in the polar regions during magnetically quiet conditions. The corresponding predictions of the MSIS-83 model are often used for comparison. The MSIS-83 model is used to emphasize the variations of interest by suppressing all other variations. A persistent enhancement of N2 density and a depletion of He density are present in the vicinity of the magnetic poles with...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CHEMISTRY, ATMOSPHERIC COMPOSITION, ATMOSPHERIC...
The objectives included: compiling and selecting the Scientific Data Requirements (SDRs) pertinent to the CO2 Research Program that have the potential to be more successfully achieved by utilizing space-based sensor systems; assessment of potential space technology in monitoring those parameters which may be important first indicators of climate change due to increasing atmospheric CO2, including the behavior of the West Antarctic ice sheet; and determine the potential of space technology for...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CHEMISTRY, ATMOSPHERIC COMPOSITION, CARBON...
A series of plots that describe the state of the stratosphere and to some degree, the mesosphere as revealed by satellite observations are shown. The pertinent instrument features, spatial and temporal coverage, and details of accuracy and precision for the experiments providing the data were described. The main features of zonal mean cross sections and polar stereographic projections were noted and intercomparisons were discussed where a parameter was measured by more than one experiment. The...
Topics: NASA Technical Reports Server (NTRS), AEROSOLS, ATMOSPHERIC COMPOSITION, MEASURING INSTRUMENTS,...
The detection efficiency is greatest at low pressures, where the subsequent removal of the HO product by the NO reagent (via HO + NO + M yields HONO + M) is relatively slow. Moreover, nozzle expansion of the air from ambient to low pressures produces a turbulent zone that assists in mixing the reagent with the sample. If the HO product is observed by laser-excited fluorescence, then the other advantages of low-pressure detection by FAGE (Fluorescence Assay with Gas Expansion) also apply. The...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, FLUORESCENCE, GAS EXPANSION,...
The Imaging Spectrometric Observatory (ISO) is capable of recording spectra in the wavelength range of 200 to 12000 Angstroms. Data from a recent Spacelab 1 ATLAS mission has imaged the terrestrial airglow at tangent ray heights of 90 and 150 km. These data contain information about trace atmospheric constituents such as bromine oxide (BrO), hydroxyl (OH), and chlorine dioxide (OClO). The abundances of these species are critical to stratospheric models of catalytic ozone destruction....
Topics: NASA Technical Reports Server (NTRS), APPLICATIONS PROGRAMS (COMPUTERS), ATMOSPHERIC COMPOSITION,...
Observations of CH3D in the atmospheres of the outer planets provide a test of the theory of deuterium fractionation equilibrium in the formation and evolution of these planets. Recent measurements of the CH3D/CH4 mixing ratios made for Saturn and Uranus are presented and intercompared with current values of Jupiter, illustrating large differences between the planets. Their implied D/H ratios are compared to D/H ratios derived from measurements of HD/H2; and, in the cases of Jupiter and Saturn,...
Topics: NASA Technical Reports Server (NTRS), DEUTERIUM COMPOUNDS, JUPITER ATMOSPHERE, METHANE, SATURN...
Results are presented of one-dimensional radiation convection modeling of the early Mars atmosphere. Up to 5 bars of CO2 would have been required to raise the surface temperature (orbitally and globally averaged) above the freezing point, although at the equator at perihelion, 1 bar would have sufficed. Such an atmospheric CO2 invertory, the author argued, is not inconsistent with any known constraint on Mars' degassed volatile inventory.
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, CARBON DIOXIDE CONCENTRATION,...
Tropospheric concentrations of methane have increased steadily over the past ten years at an average rate of 16.5 ppbv per year, to a value in January 1988 of 1.69 ppmv. Measurements of CH sub 4 concentrations in air bubbles trapped in ice cores have shown concentrations of about 0.7 ppmv 200 years ago, with little further change for thousands of years before that. Interpolation earlier into this century suggests a concentration of about 1.1 to 1.2 ppmv in the 1940's. The only important pathway...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CHEMISTRY, ATMOSPHERIC COMPOSITION, GREENHOUSE...
During the Airborne Antarctic Ozone Experiment campaign, a filter sampler was flown to measure the bulk composition of aerosol and gas phases. The background sulfate aerosol was measured in regions inside and outside of the chemically perturbed region (CPR) of the polar vortex. The mass ratio of sulfate outside to inside was 2.8. This is indicative of a cleansing mechanism effecting the CPR or of a different air mass inside versus outside. The absolute value of the sulfate mixing ratio shows...
Topics: NASA Technical Reports Server (NTRS), AEROSOLS, AIR SAMPLING, ANTARCTIC REGIONS, ATMOSPHERIC...
The data base for the vertical column abundance of atmospheric hydroxyl (OH) for Fritz Peak Observatory, Colorado (40 N, 105 W), now extends from 1976 through 1988 and is composed of 8849 independent data sets, averaging about 15 percent uncertainty and 20-minute time resolution each. The dominant solar zenith angle (chi) dependence of the OH abundance is characterized by an empirical curve, N(88), which has been updated from N(82) to include all valid data from 1980 through 1988. The...
Topics: NASA Technical Reports Server (NTRS), ABUNDANCE, ATMOSPHERIC COMPOSITION, HYDROXYL RADICALS,...
The Mariner 6/7 Infrared Spectrometer (IRS) experiment data from the 1969 Mars flyby encounters represent a valuable source of information about the IR reflection/emission spectrum of Mars in the 1.9 and 14.4 micron region. During 1990, the wavelength calibration of the IRS data was completely redone, using information from inflight spectra of Mars taken through a polystyrene film and from the locations of Martian CO2 bands. The response functions of the two instruments were then rederived...
Topics: NASA Technical Reports Server (NTRS), ALBEDO, ATMOSPHERIC COMPOSITION, CALIBRATING, CARBON DIOXIDE,...
The sodium and potassium atmospheres of Mercury and the Moon are mapped using spectroscopic measurements of resonance scattered sunlight. The objective is to define the sources and sinks for these atmospheric constituents, and in doing so, provide a better understanding of atmospheric processes on these bodies. These bodies are unique in that their atmospheres consist solely of an exosphere with the planetary surface at its base.
Topics: NASA Technical Reports Server (NTRS), ASTRONOMICAL SPECTROSCOPY, ATMOSPHERIC COMPOSITION,...
