Nonlinear waves and coherent vortex structures in barotropic BETA-plane jets.

Abstract

A study is presented of te temporal evolution of an unstable, highly nonlinear, barotropic jet in the parameter space defined by beta and the initial wave number k of the growing perturbation. The duration of the numerical evolution was sufficient to allow the single mode perturbations to reach a quasi steady state. The behaviour is investigated over a wide range of parameter space rather than focussing on the punch off phenomenon. Results with beta = 0 agree qualitatively with previous studies and the results are extended to beta less than 0.