A Generalized Solution for the Large-Scale, Time-Average Perturbations in the Atmosphere

Abstract

A solution is given, in the form of influence functions, for the forced geostrophic response of the atmosphere to the combined effects of zonal asymmetries in (i) the lower boundary orography and (ii) the mean, geographically-fixed source field of heat and momentum originating from all causes including transient eddy transports. As such, the solution represents a generalization of the work of Smagorinsky, and Charney and Eliassen. No attempt is made to improve upon either the ??-plane? approximation or the quasi-geostrophic approximation. As an example, calculations for two harmonic components of the complete Fourier representation are made, based on idealized distributions of the forcing functions suggested by observations. It is shown that a variety of modes of response are possible, all of which can contribute to a greater or lesser extent in accounting for the observed mean state. Suggestions are made for improving the formalism and extending it into a more satisfactory theory of the observed normal state of the atmosphere.