3.5
Modeling Milankovitch cycles on Mars
Mark I. Richardson, CALTECH, Pasadena, CA; and M. Mischna
In the absence of a major moon, Mars experiences much greater obliquity variations than does the Earth. These large variations (from less than 10 degrees to over 70 degrees), in concert with smaller variations in eccentricity, yield significant variation in the pattern of deposition of insolation. With active climate cycles involving carbon dioxide (ice-gas exchange), water (ice-gas exchange) and dust (lifting, suspension, and deposition) there is significant scope for major changes in the Martian climate system as these various cycles progress. Mars general circulation models have been applied to the problem of Milankovitch cycles on Mars. These models suggest significant changes in the circulation and in the location of surface ice sheets. These results are consistent with evidence for glacial deposits on volcanoes and other terrains within the Martian tropics. Major issues remaining unresolved include how the atmospheric dust loading might change with different insolation patterns, and most significantly, how the variations of climate relate to the massive polar layered deposits at both Martian poles.
Session 3, Martian Atmosphere and Climate
Thursday, 21 January 2010, 11:00 AM-12:15 PM, B211
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