EFFECT OF HEAT OF CONSENSATION ON THE SPECTRAL ENERGY DISTRIBUTION OF BAROCLINICALLY UNSTABLE MODES

Abstract

Since one of the main factors governing the circulation of the atmosphere is the instability of zonal flow in middle latitudes, numerical prediction and modeling of large-scale atmospheric processes must duly reproduce the characteristics of the atmosphere that govern the level of kinetic energy of vortices, i.e., the zonal flow profile, the criterial of loss of stability over a wide spectral interval, the rate of increases in amplitude of unstable modes, and the like. It is well known, however, that the development of baroclinically unstable modes is much more rapid in a moist atmosphere and that the criteria of loss of stability in a moist atmosphere differ from those in a dry atmosphere. In the present paper the authors evaluate the effect of atmospheric moisture, its phase transitions and the heat of condensation on the energetics of baroclinically unstable modes over a wide spectral interval.