Self-Propagating Eddies on the Stratified f Plane

Abstract

Analytical solutions of the shallow-water system of equations in a 1½-layer f-plane model are obtained for stable quasi-monopolar vortices propagating due to a dipolar (azimuthal mode m = 1) component whose amplitude is small compared to the circularly symmetric (m = 0) part. The ability of the f-plane eddies with O(1) Rossby number to propagate distances greater than their size is demonstrated by finite amplitude numerical calculations. Numerical and analytical considerations also indicate that significant departures may occur between the ?centroid of mass anomaly? (commonly used in theoretical estimates of the speed of oceanic vortices) and other measures of the eddy center.