The mean Circulation of Unstratified Water Bodies Drive by Nonlinear Topographic Wave Interactions

Abstract

A critical evaluation is presented of the conventional view that long-term mean circulation of homogeneous basins may be identified with the quasi-steady response of linear models to atmospheric forcing. Based on climatological wind records for the Great Lakes region, it is shown that the mean circulation for unstratified seasons is dominated by rectified effects of nonlinear topographic wave interactions. It is also shown that the dependence of the rectified flow on the frequency of periodic forcing is similar to the linear topographic response to wind with resonance characteristics for certain frequencies determined by topography and friction.