The theory of free inertial currents I. Path and structure

Abstract

An equilibrium theory is developed for a flow which conserves potential vorticity and consists of a stream of high relative vorticity imbedded in a geostrophic drift. Effects of bottom topography stratification and variation of Coriolis parameter are included. Transformation is made to stream axis coordinates, and a multiple expansion is made appropriate to the many scales involved. The variety of paths pertaining to flow over a uniformly sloping bottom are studied numerically. Some cross-stream profiles are obtained consistent with overall divergence. A result of importance is that a baroclinic meandering jet necessarily exchanges mass with the open ocean, i.e. a standing geostrophic wave field is a feature of the equilibrium. The broadening and narrowing of the current is obtained.