Vorticity fluxes in shallow water ocean models

Abstract

We investigate some of the claims concerning new eddy parametrization schemes for coarse resolution ocean models by analyzing the role of eddies in eddy‐resolving 1½ and 2½ layer models with double‐gyre wind forcing. We find that the divergent part of the eddy flux of potential vorticity is directed down the mean thickness‐weighted potential vorticity gradient. The relationship between the eddy flux of thickness and either the mean thickness or mean thickness‐weighted potential vorticity gradients is less clear. The analysis is complicated by the presence of large rotational fluxes of both thickness and potential vorticity and by the importance of the Reynolds stress terms. We argue that the rotational fluxes have a fundamental role to play and need to be parametrized in a comprehensive parametrization scheme.