In the presence of surface currents, a stress perturbation at the air-sea interface is induced by the surface currents. It is directly correlated to the surface current pattern, and thus causes a feed-back effect in the sea-air system. This effect is studied for an equatorial sea-air system of the geometry of the equatorial Pacific Ocean by using a simple coupled atmosphere-ocean model. It is shown that the effect of the current-induced stress perturbation appears as a damping mechanism for the ocean circulation in general. However, in the presence of a zonally-asymmetric surface wind field, the stress perturbation associated with the zonal-mean current creates an opposing perturbation current. As a result, in the presence of a westward zonal-mean current, the eastward component of the perturbation current is enhanced by the current-induced stress perturbation. In a coupled sea-air system, both the damping and the forcing mechanisms associated with the current-induced stress perturbation can significantly influence the coupling strength, and hence influence the behavior of the coupled modes.
Xie, Lian, and Claes Rooth. 1994. "The effect of current-induced stress perturbation in a coupled atmosphere-ocean model." Journal of Marine Research 52, (2). https://elischolar.library.yale.edu/journal_of_marine_research/2095