DYNAMICS OF AN ISOLATED INTERATHERMOCLINE EDDY

Abstract

The β-plane approximation is used to discuss the dynamics of a thin vortical liquid lens of homogenous density floating on a free surface, on the bottom, or at the boundary in a liquid with a two-layer stratification. The orbital speeds of the liquid are assumed to be considerably greater than the speeds produced by the β-effect of drift of the lens, and the Kibel number is assumed to be much less than unity. An equation for the dynamics of a lens in steady-station motion is derived and its exact analytical solution is found. The constraints on the unperturbed characteristics of the lend (i.e., those calculated in the f-plane approximation) are identified. Calculations are made for specific examples of liquid circulation in the lens and are compared with the theory of nonlinear Rossby waves.