Boundary-Forced Nonlinear Planetary Radiation

Abstract

Abstract In recent years there has been renewed interest in the Gulf Stream system and its interaction with the mesoscale oceanic eddy field. An important question, not yet adequately addressed, concern the possible generation mechanisms of the mesoscale eddy field and, in general, the problem of radiation of mesoscale energy from a meandering current. This problem has been investigated in a variety of studies, the basic result of which is that, in the quiescent ocean, the far field can transmit energy radiated by a meandering northern current only if the latter has a westward phase speed. All the proposed models are, however, linear. Nonlinear effects may be expected to modify the above results, as indicated by numerical experiments carried out with fully nonlinear models. In the present study, the question is addressed in the context of a fully nonlinear but simple model, the quasi-geostrophic equivalent barotropic potential velocity equation in a zonal channel over variable relief. The meandering curre...