Atmospheric dynamics on Venus and Mars

In this paper, recent information concerning the atmospheric dynamics of Venus and Mars is discussed. In the Venusian atmosphere, the Vega balloon results disclosed the presence of major vertical motions at the 53 km level and demonstrated the near zonality of the atmospheric circulation below the level of the clouds. Pioneer Orbiter observations indicated a continued vortex organization of the cloud level atmosphere in either hemisphere, centered over respective poles. In the case of the Martian atmospheric circulation, the observations are scant. Viking lander data and orbit images have been used to derive cloud motions and compare the measured winds with the predictions for surface conditions from general circulation models.