EVOLUTION OF AN ELLIPSOIDAL VORTEX IN A STRATIFIED OCEAN - SURVIVABILITY OF THE VORTEX IN A FLOW WITH VERTICAL SHEAR

A problem of the behaviour of the ellipsoidal eddy with a constant potential vorticity of the core in a boundless stratified ocean is considered. It is shown that without an external flow at infinity the boundary of the core is not deformed. In case of the arbitrary initial orientation of eddy, the core rotates with precession and nutation. In the limiting case the results of 6 are obtained. The deformation of the core by the flow with vertical shear is studied. It is shown that depending of its vorticity and the shear of the flow, the vortex at first rotates several times, then stops and is stretched infinitely along the flow. The lifetime of the vortices is estimated being the duration time of the first type of behaviour (rotation).