Isentropic formation of the tropopause

Abstract

The existence of the extratropical tropopause, which can be defined as the sharp transition between the high potential vorticity in the stratosphere and the low potential vorticity in the troposphere, is attributed to a dynamical equilibrium of diabatic effects and vortex stripping. The process is essentially isentropic and two-dimensional. This picture is examined and confirmed in a simple one-layer quasigeostrophic model of the atmosphere. It is possibly the simplest model context where the formation of a tropopause can be found.