  Local generation of vorticity occurs in rotating density-stratified fluids as
fluid parcels move radially, expanding or contracting with respect to the
background density stratification. Thermal convection in rotating 2D equatorial
simulations demonstrates this mechanism. The convergence of the vorticity into
zonal flow structures as a function of radius depends on the shape of the
density profile, with the prograde jet forming in the region of the disk where
the greatest number of density scale heights occurs. The number of stable jets
that form in the fluid increases with decreasing Ekman number and decreases
with increasing thermal driving. This local form of vorticity generation via
the density stratification is likely to be of great importance in bodies that
are quickly rotating, highly turbulent, and have large density changes, such as
Jovian planets. However, it is likely to be of lesser importance in the
interiors of planets such as the Earth, which have smaller density
stratifications and are less turbulent.
