Geostrophic adjustment of linear disturbances in two-component media

Abstract

The linear problem of geostrophic adjustment in a rotating stratified medium is generalized to the case of binary mixtures stratified with respect to both the temperature and admixture concentration (such as, for example, saline seawater and humid air). It is shown that, if the initial ageostrophicity is related to the temperature and/or admixture concentration disturbances, the evolution of the fields of these substances may qualitatively differ from the classical solutions of the adjustment problems. For example, in the course of adjustment, jumps in the temperature and salinity may be retained and enhanced, in contrast to those in the velocity, pressure, and buoyancy. The latter are smoothed by the adjustment process and are distributed over relatively spacious areas with horizontal sizes of the order of the Rossby scale. The initial thermal pulse may lead to the development of a temperature disturbance with a significantly greater amplitude and/or opposite sign and to an intensive disturbance in the admixture concentration.