Baroclinic Instability of a Slowly Varying Zonal Flow. Part 2

Abstract

Further results are presented using Eady's model of baroclinic instability with a zonal flow varying slowly in the meridional direction. Now, however, the basic flow is more in keeping with observations and this means the WKB method used to solve the ensuing linear eigenvalue problem has to be considered in the complex plane. The overall effect of meridional shear is a slight stabilization and the meridional scale of the growing waves is governed by the scale of the jet in the basic zonal flow and by the radius of deformation. Further results are also presented for the two-layer model including the ?-effect, and far from neutral stability they complement the findings of the continuous model. Close to neutral stability, however, the method can be used to explain the differences between the previous solutions of Simmons and Stone.