On the Trapping of Unstable Baroclinic Waves

Abstract

Abstract The Charney-Pedlosky theorem on the trapping of unstable baroclinic waves is generalized to show that unstable waves which satisfy a condition analogous to the Charney-Drazin condition for the trapping of neutral planetary waves are trapped even in the presence of a local energy source provided by vertical shear of the mean zonal wind. This generalization provides a depth scale for the trapped waves which, unlike that derived by Charney and Pedlosky, does not become infinite as the growth rate of the unstable waves goes to zero.