Ageostrophic

It might sound puzzling that the ageostrophic geopotential (or the ageostrophic pressure in z-coordinate) has no impact on the evolution of the vorticity of a quasi-geostrophic disturbance and yet it affects the perturbation kinetic energetics (not globally but locally).

Note that the ageostrophic wind has both a divergent and a nondivergent part.

Ageostrophic circulations play a significant role in the kinematics and dynamics of a variety of synoptic- and mesoscale weather systems found within extratropical baroclinic wave regimes.