Global-Scale Disturbances and Dynamic Similarity

Abstract

Terms in the linearized primitive equations for a generally baroclinic atmosphere are evaluated for their significance in maintaining balance for global-scale disturbances. For gravity waves, the linearized advection term v??? reduces to the vertical component, but for Rossby waves, apparently both components are of primary order. Both wind shear terms are shown to be small for the Rossby case. As a by-product of the scaling developed, the traditional viscous and thermal diffusion terms are reduced to simple forms. The disturbance energy equation is developed for the general basic state, and the influence that the approximations have on its balance is evaluated.