A two-dimensional model for quasigeostrophic flow: Comparison with the two-dimensional Euler flow

A simple two-dimensional model for quasigeostrophic flow is contrasted with the two-dimensional incompressible Euler equations. The model arises under the assumptions of fast rotation, uniform stratification and uniform potential vorticity. It is found that the more local feed-back of the quasigeostrophic model gives rise to strongly nonlinear front formation, as opposed to two-dimensional Euler, where the steepening process of mature fronts obeys a nonlocal, nearly Linear mechanism.