ON THE SEASONAL SEA-SURFACE TEMPERATURE-VARIATIONS IN THE TROPICAL PACIFIC

In this paper, we investigated physical processes that control the sea sonal variations of sea surface temperature in the tropical Pacific, u sing an intermediate ocean model. It is found that the westward propag ation of sea surface temperature along the equator is attributed to dy namic response of the ocean to the wind (that consists of 3-dimensiona l temperature advection), whereas the northward propagation of sea sur face temperature in the eastern Pacific results from the thermodynamic response of the ocean to the surface heat flux, primarily shortwave r adiation that includes the effect of low-level stratus clouds. The rem ote response of the eastern Pacific sea surface temperature to seasona lly varying wind in the western Pacific is of secondary importance, co mpared to the local wind forcing. The results suggest that the mechani sm that controls the seasonal cycle of sea surface temperature is diff erent from that associated with El Nine-Southern Oscillation.