Southern Martian winter weather associated with baroclinic topography forced Rossby waves: analysing by Global Mars Multiscale Model

Abstract

Meteorological and physical results from the Global Mars Multiscale Model (GM3) are used for investigating the impact of zonally asymmetric topography on atmospheric temperature and wind structures of Martian southern winter weather associated with the forced topographical Rossby waves. Analysis of the numerical simulations reveals significant thermal and wind patterns at the southern mid and high latitudes during southern winter due to the impact of asymmetric topography. This study shows the presence of warm air advection at southern high latitudes mostly around the cryptic regions controls by a warm ridge and the cold air advection at mid-latitudes is around the Hellas and Argyre basins associated with two cold troughs. Also, there is large temperature advection fluctuation around $50^{\circ}\mbox{S}$ causing by topographical aspects of Hellas and Argyre basins rather than flat topography simulation. This is associated with the baroclinicity structure causing by topography in Martian mid-latitudes. This can act to moderate the temperature field in the Martian southern hemisphere weather during wintertime because of the wind pattern structures. Also, the winter time south zonal westerly jet stream analysis shows the development of disturbances structure (meandering) in the north side of the jet dependent of longitudinal structure of Martian southern topography with a wave-like pattern below the Hellas and Argyre basins. Also, the vertical structure of the zonal wind shows the appearance of a vertical wind shear around $78^{\circ}\mbox{S}$ with smoothly tilting to the higher altitudes associated with the baroclinic structure of the southern Martian winter weather associated with the baroclinic forced topography Rossby waves.