"The Climate Dynamics of Atmospheric Collapse on Mars"

Global energy balance models of the Martian atmosphere have predicted that early in Martian history, for a range of initial total CO2 inventories, the atmospheric CO2 may be unstable relative to surface condensation. This is commonly referred to as atmospheric collapse. A collapsed state may limit the amount of time available for physical and chemical weathering. The global energy balance models that predict atmospheric collapse represent the atmospheric heat transport, which controls atmosphere collapse, in terms of a single, globally uniform parameter. This assumption requires reconsideration since at high CO2 inventories atmospheric heat transport may be significant and variable with respect to obliquity, surface pressure, and other factors. Using a general circulation model (GCM), we investigate the details of the three-dimensional, time varying climate dynamics at the threshold for atmospheric collapse. In particular, we highlight the changes in meridional energy transport associated with the atmospheric collapse process.