The Mars limited area model and simulations of atmospheric circulations for the Phoenix landing area and season of operation

The Mars limited area model (MLAM) has been used to simulate Martian northern polar atmospheric circulation phenomena during the planned season of the Phoenix Lander touching down on the surface (L-s approximate to 76 degrees). Initial and boundary conditions are from Thermal Emission Spectrometer observations assimilated via the United Kingdom Mars General Circulation Model. The higher-resolution north pole-centric nestings (grid lengths about 17-30 km and 8.5-15 km, respectively) resolve phenomena such as shallow mesoscale katabatic drainage flows spiraling out of the cold polar dome, strong valley winds out of Chasma Borealis, and diurnal slope winds embedded on the easterly basic flow, e. g., at Phoenix landing area D. There conditions appear to be mild (for Mars) and baroclinic activity is low. Low-level jets with wind speeds exceeding 20 m/s are, however, possible, but they are most likely nocturnal and would hence not endanger the early afternoon landing of Phoenix. Dust lifting is predicted for strong wind areas near the landing area B (where baroclinic activity appears to be high) and in the general area of the landing area D, primarily east of it.