Momentum balance of the Venusian midlatitude mesosphere

The downward control principle is applied to estimate the vertically integrated zonal force driving the midlatitude lower mesosphere on Venus. The distinct localization of the forcing in the midlatitude implies two candidates for the momentum carrier: Rossby wave; and internal gravity waves generated by shear instability. Rough estimates of the Eliassen‐Palm (EP) flux suggest that the meridional circulation will be driven principally by the EP flux divergence associated with a Rossby wave, although the contribution of gravity waves cannot be ruled out. It is also shown that advective transport is as important as eddy diffusion for tracer transport.