Modeling the Martian climate with a new general circulation model

We have adapted the National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM3.0) to Martian conditions. Several modifications to the original model have been made. These include adjusting the physical parameters to Mars-like values, changing atmospheric composition, changing the calendar to cover a Martian year, and the addition of a carbon dioxide condensation scheme. The Martian atmosphere is composed of 95% carbon dioxide, and as much as 25% of the atmosphere can condense out at the winter pole so it is important to include the carbon dioxide condensation in the model. We plan to use the model to simulate impacts on Mars during the late Noachian. As a reference point we have performed some climate simulations with a 500 mbar carbon dioxide atmosphere. The results will be presented at the meeting. Currently a few general circulation models are available for Mars. However instead of using one of these previously developed models, we have chosen to develop our own based off of CAM3 for a number of reasons. These include the model’s support for multi-processor runs, the model’s compatibility with other models including land, aerosol, and chemistry, and the fact many in our group already use the Earth version of this model, so we are familiar with it. During the development of our model, we have been in contact with NCAR, and have plans to make the model readily available to the public through NCAR.