Parameterizing Eddies in Ocean Climate Models

Gent and McWilliams(1990) proposed a parameterization for the effects of mesoscale eddies on the large-scale flow for use in ocean climate models. It proposes that eddies advect tracers in addition to mixing them along isopycnal surfaces. This parameterization can be considered as a generalization of the residual-mean meridional circulation of (1976) to three dimensions. The resulting Eliassen-Palm fluxes have to be parameterized in order to determine the momentum equation used in non-eddy-resolving ocean climate models. The Antarctic Circumpolar Current region of the ocean is most like the atmosphere in that there are no continents to block the zonal jet. The nonacceleration theo rem would suggest that the eddy-induced advection of tracers should oppose mean flow advection at the latitude of Drake Passage, and this is confirmed in global ocean model simulations.