Dynamics of the atmosphere

Observations of and possible explanations for the dynamics of the Venus atmosphere as revelaed by Pioneer Venus and the Venera spacecraft are discussed. An important observation was that the entire atmosphere moves in the same retrograde (westward) direction at average speeds of up to about 110 m/sec, which may be explained by zonal jets arising from interactions of meridional cells, viscosity and solar heating. Atmospheric thermal tides, temperature and wind perturbations caused by solar heating were also observed which may have influences on tidal winds and warming at the poles. In addition, atmospheric waves with periods of 5.3 and 2.9 earth days have been detected between the Venus cloud tops, and calculations of baroclinically unstable waves on Venus have been made with a general circulation model.