Dr. J. Bradley Dalton

December 20, 2006

“Modeling the Climates of Mars”

NCC 2–1385

This project addresses the present and early Martian climates, the primary efforts of which include the modeling of carbon dioxide, water and dust clouds in the current and past Martian climates, and modeling the climate effects of large impactors.

Martian Clouds— Martian atmospheric aerosols, including carbon dioxide and water ice clouds, and dust are important elements in the global climate system.

Impact Induced Climates—It is widely accepted that even relatively small impacts (~10 km) have altered the past climate of Earth to such an extent as to cause mass extinctions (Toon et al., 1997). Mars has been impacted with a similar distribution of objects. The impact record at Mars is preserved in the abundance of observable craters on its surface. Impact induced climate change must have occurred on Mars. This effort investigates the effects of impacts on the early Martian climate with an emphasis on changes to the planetary circulation and the injection and redistribution of impact-injected water using a General Circulation Model (GCM). This work is fundamentally new and has never (to our knowledge) been done for either Mars or Earth.

Several fundamental questions will be addressed by this research:

What is the effect of large impacts on the general planetary circulation?

How does the general circulation transport impact-injected water?

How much and where does the injected atmospheric water condense out?

How long does it take for the climate to return to its pre-impact state?

Can impact induced climate change explain the geomorphic evidence for liquid water at the surface?

Can impact induced climate change explain the apparent early Mars erosion rates?