Flows due to a thermal gradient
Baroclinic instability in a rotating tank
This experiment follows directly from the thermal wind experiment. The only difference is that the rotation rate is increased from 1 rpm to about 10 rpm. Eddies are prominent instead of a balanced sheared vertical flow as compared to a slower rotation rate.
From the above video, the vertical sheared flows driven by the temperature gradient becomes unstable under higher rotation rate. Large eddies form to increase the mixing process between regions of warm and cold fluid. Noticeably, the wobble in the tank is exacerbated at 10 rpm.
Mechanism of baroclinic instability
In ther thermal wind equation, a balance occurs between the temperature gradient and the Coriolis effect. However, this is not the state of least energy. A shear flow exists due to the horizontal density distribution. The available process that allows the relaxation of the density distribution is through relative vorticity. Hence, baroclinic instability develops in order for the system access frictional dissipation provided by velocity shear in vortices.