Schematic representation of the generation of a baroclinic flow: the two columns represent two columns of fluid staying at two different latitudes; the difference in the temperature profile and the assumption of hydrostatic equilibrium in the column leads to two different pressure at their base: the fluid flows then from the high pressure region to the low-pressure one. This circulation transports heat in the latitudinal direction. In the rotating background of a star, the Coriolis acceleration transforms this flow into a differential rotation (the so-called thermal wind in the Earth atmosphere).