The interaction of an eddy with an unstable jet

Abstract

Interactions between an unstable jet and eddy are explored using a jet with piecewise constant potential vorticity. A linear theory is developed for the case where the jet is nearly zonal and the eddy is far away in the sense that the eddy may be replaced by a point vortex that induces velocity perturbations in the jet small compared with the maximum jet velocity. The calculations are extended into the nonlinear domain by the method of contour dynamics. Specific examples of barotropic and equivalent barotropic jets are discussed, with particular attention to processes leading to eddy propagation. -from Authors