Evolution of an Unstable Elongated Eddy

Abstract

Elongaged anticyclonic vortices are modeled by the reduced gravity equations: a finite volume of water on top of an inert heavier fluid, with allowance for horizontal divergence and Coriolis effects. Stable eddies experience pulsations in shape and size, rotations of its orientation, and inertial oscillations of their center of mass. In addition to these motions, unstable vortices also have a tendency to sharpen in the extremes; a process that might lead to filament formation, as the nondivergent case does.