The impact of topography and albedo on weather patterns and the location of the Martian South polar CO2 ice cap

Meteorological and physical results from the second version of Global Mars Multiscale Model (GM3-v2) were used to investigate the impact of topography and albedo on the Martian southern polar CO2 ice cap. Analysis of the numerical simulations revealed significant differences in the horizontal and vertical cross sections of temperature when model was run for plain topography.

Wind streamlines from Ls= 20° (early southern fall) to Ls = 200° (early southern spring) for every one Ls have been analysed. Wind streamline pattern analysis shows there are two cyclonic circulations during southern winter; one around the Hellas basin (in the eastern hemisphere) and the second one around the Argyre basin (in the western hemisphere). However, between these two cyclonic cells, the pattern is anti-cyclonic.

Since the albedo map which is used in the model represents a mean state of albedo for all seasons of the planet, the albedo values have been modified in the polar regions to allow for the formation of the surface ice in the model. Also this modification will be very important in the water cycle simulation. As a second step in this work, the albedo values at the poles (mostly focusing on south polar regions) were modified for a better representation of the physical situation.

However, the seasonal carbon dioxide ice in the polar regions is presented in the surface ice simulation by the second version of Global Mars Multiscale Model, but it does not produce a permanent south CO2 ice cap, and so it must be modified in the physics code in order to capture the real physical and meteorological processes. The permanent south CO2 ice cap in the model can significantly improve the representation of south polar meteorology for example in predicted surface temperatures, surface pressures, horizontal and zonal winds over the south cap and also possible initiation of dust storms at south polar region during the southern summer period. In the final part to this thesis, the residual CO2 ice cap is simulated in the physics code.