PLANETARY WAVES IN HORIZONTAL AND VERTICAL SHEAR: THE GENERALIZED ELIASSEN-PALM RELATION AND THE MEAN ZONAL ACCELERATION.

Abstract

Using a new generalization of the Eliassen-Palm relations, the zonal-mean-flow tendency due to waves in a stratified, rotating atmosphere is discussed, with particular attention to equatorially trapped modes. Wave transience, forcing and dissipation are taken into account in a very general way. The theory makes it possible to discuss the latitudinal and vertical dependence of the zonal-mean-flow tendency qualitatively and calculate it directly from an approximate knowledge of the wave structure. Implications for the quasi-biennial oscillation in the equatorial stratosphere are discussed. The probable importance of low-frequency Rossby waves for the momentum budget of the descending easterlies is suggested.