FINITE-AMPLITUDE ELIASSEN-PALM THEOREM IN ISENTROPIC COORDINATES.

Abstract

Isentropic coordinates are used to generalize to finite amplitude the celebrated theorem (1. 1) of A. Eliassen and E. Palm under non-acceleration conditions. This primitive-equation result also generalizes thefinite-amplitude quasi-geostrophic result of H. J. Edmon et al. A simple physical interpretation is provided, and a set of transformed Eulerian-mean equations arises naturally in the course of the analysis. Isentropes which intersect the lower boundary need special attention; the technique developed to handle them is a generalization of an idea due to E. N. Lorenz, and may be of use in other contexts. Mention is also made of a version of the theorem valid for small-amplitude, transient, non-conservative disturbances.