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Publications and source records attributed to Conrath, B..
A retrospective look at the operation and results of the experiment is presented. The design and performance of the infrared interferometer spectrometer are discussed along with the results obtained concerning the atmospheric and surface properties.
The infrared spectroscopy experiment on Mariner 9 obtained data over much of Mars. Interpretation of the thermal emission of Mars in terms of atmospheric temperatures, wind fields and dynamics, surface temperatures, surface pressure and topography, mineral composition, and minor atmospheric constituents including isotopic ratios, as well as a search for unexpected phenomena are reported.
During the almost 1-year operational lifetime of Mariner 9 the infrared spectroscopy experiment obtained data over a large portion of Mars. Between June and October 1972, improvements were made in the CO2 transmittances, which are necessary for the interpretation of the thermal emission spectra. Recently obtained spectra indicate that strong seasonal variations in the water vapor distribution occurred over both polar regions. The wettest atmospheric conditions observed so far contain 20 to 30 precipitable microns of water over the north polar cap during northern spring. A low-resolution pressure map is presented that covers that portion of the planet between latitudes -60 and +25 deg. A more detailed study of the Coprates canyon indicates that, at its lowest point, the canyon floor must be at least 5 km below the rim. Applications of tidal theory to temperature fields derived from the spectra indicate diurnal surface pressure fluctuations of as much as 12% during the Great Dust Storm of 1971-1972.
During the eleven month operational lifetime of Mariner 9, the infrared spectroscopy experiment obtained data over a large portion of Mars. Recently obtained spectra indicate that strong seasonal variations in the water vapor distribution over both polar regions occurred. The wettest atmospheric conditions observed so far contain 20 to 30 precipitable microns of water over the north polar cap during northern spring. A low resolution pressure map is presented which covers that portion of the planet between latitudes -60 deg and +25 deg. A more detailed study of the Coprates canyon indicates that at its lowest point the canyon floor must be at least 5 km below the rim. Applications of tidal theory to temperature fields derived from the spectra indicate diurnal surface pressure fluctuations of as much as 12 percent during the great dust storm of 1971-72. Qualitative arguments based on radiative transfer calculations for model dust clouds composed of spherical quartz particles suggest that particle radii during the storm were of the order of a few microns.
Preliminary analysis of Mariner 9 IR spectroscopic data through May 1972 shows spectral features due to carbon dioxide, water vapor, and silicate dust suspended in the atmosphere. Measurements obtained during and after the planet-wide dust storm indicate that large diurnal variations in atmospheric temperature existed up to at least 30 km. Analysis of spectral features due to the atmospheric dust provides a SiO2 content of 60 (plus or minus 10)%, implying substantial geochemical differentiation. Water vapor estimates yield abundances of 10 to 20 precipitable microns, and no water vapor was detected over the north polar region.
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Nimbus 3 satellite-borne Michelson interferometer IR spectrometer for spectrum measurement, obtaining temperature, water vapor and ozone vertical distribution