Annual Heat Flux Variations across the Tropic Circles

Abstract

The global poleward heat transport by the oceans tends to have a maximum in the vicinity of the Tropic circles. We have investigated the contribution of the Ekman flux to the heat transport in the Pacific and the Atlantic. Two different datasets were used for the Pacific computations. The results suggest that Ekman flows contribute about half of the grow transport in the Atlantic. In the much wider Pacific, they are the dominant influence. The meridional migration of the trade wind belt and the simultaneous seasonal changes in the mixed layer temperature tend to cause the Ekman part of the heat flux to be larger in summer than in winter. Semiannual harmonics in the zonally integrated Ekman heat-transport component can be associated with longitudinal variations of the specific heat flux, due to seasonal position shifts of the atmospheric centers of action.