Zonal Superrotation above Venus' Cloud Base Induced by the Semidiurnal Tide and the Mean Meridional Circulation

Abstract

We have calculated the equilibrium zonal wind structure resulting from the interaction of the semidiurnal tide and the mean meridional circulation driven by the zonally averaged solar heating above the Venus cloud base. The results show that the tidal mechanism proposed by Fels and Lindzen can account for a substantial fraction?and possibly all?of the increase of the equatorial wind speed above the cloud base. Above the cloud tops, tidal deceleration may be too small to produce the zonal wind decrease with height inferred from thermal data. Tidal forcing does not explain the superrotation below the clouds and additional eddy sources are needed to account for the zonal wind structure at mid and high latitudes.