Further Studies of the Circulation of the Venus Atmosphere

Abstract

We have extended our previous calculations of zonally averaged temperature, circulation, and eddy source requirements for the Venus atmosphere to include the region from the surface to 95 km, using a Curtis matrix method for the radiation calculation. We conclude: (i) The cloud top circulation is not significantly changed from our previous calculations based on a radiative-relaxation method, but large differences occur in the lower atmosphere. (ii) The physical and dynamical states of the atmospheric regions above and below the cloud base are effectively independent and are equally important for accounting for the 4-day circulation at the cloud tops. (iii) Above the cloud base, the circulation is effectively inviscid and the eddy source requirements at the low latitudes are consistent with the mean-flow forcing by the semidiurnal tide. (iv) The circulation below the clouds is important compared to viscous dissipation above the lowest scale height. We discuss possible mechanisms for satisfying the tropical eddy source requirements in the lower atmosphere.