The seasonal cycle of carbon dioxide on Mars.
Abstract
Carbon dioxide, the major ingredient of the Martian atmosphere, condenses in the polar regions of the planet during their respective polar nights. The latent heat released is the major energy source during these periods. Condensed CO2 sublimes during the spring and summer seasons in response to solar radiation. As much as 30% of the atmosphere takes part in this seasonal CO2 cycle. The extent of the solid CO2 deposits is controlled by their equilibrium with the predominantly CO2 atmosphere which, in turn, depends upon physical properties such as their albedo and infrared emissivity. If the albedo of the condensed CO2 is sufficiently large, condensation may equal or exceed sublimation during an annual cycle; permanent (or residual) CO2 caps which survive the entire seasonal cycle are therefore possible. The existence of such deposits has great significance for the Martian climate. The results of Viking investigations relevant to the CO2 cycle are presented, and the extensive modeling efforts directed towards understanding this cylce and its couplings to the seasonal cycles of water and dust are reviewed.
- Publication:
-
Mars
- Pub Date:
- 1992
- Bibcode:
- 1992mars.book..934J
- Keywords:
-
- Annual Variations;
- Atmospheric Composition;
- Carbon Dioxide Concentration;
- Mars Atmosphere;
- Polar Regions;
- Condensation;
- Energy Sources;
- Latent Heat;
- Solar Radiation;
- Lunar and Planetary Exploration