Surface Heat Budgets and Sea Surface Temperature in the Pacific Warm Pool during TOGA COARE

Abstract

The daily mean heat and momentum fluxes at the surface derived from the Special Sensor Microwave/Imager and Japan’s Geostationary Meteorological Satellite radiance measurements are used to study the temporal and spatial variability of the surface energy budgets and their relationship to the sea surface temperature during the Coupled Ocean–Atmosphere Response Experiment intensive observing period (IOP). For three time legs observed during the IOP, the retrieved surface fluxes compare reasonably well with those from the Improved Meteorological Instrument (IMET) buoy, RV Moana Wave, and RV Wecoma. The characteristics of surface heat and momentum fluxes are very different between the southern and northern warm pool. In the southern warm pool, the net surface heat flux is dominated by solar radiation, which is, in turn, modulated by the two Madden–Julian oscillations. The surface winds are generally weak, leading to a shallow ocean mixed layer. The solar radiation penetrating through the bottom of the mixed layer is significant, and the change in the sea surface temperature during the IOP does not follow the net surface heat flux. In the northern warm pool, the northeasterly trade wind is strong and undergoes strong seasonal variation. The variation of the net surface heat flux is dominated by evaporation. The two westerly wind bursts associated with the Madden–Julian oscillations seem to have little effect on the net surface heat flux. The ocean mixed layer is deep, and the solar radiation penetrating through the bottom of the mixed layer is small. As opposed to the southern warm pool, the trend of the sea surface temperature in the northern warm pool during the IOP is in agreement with the variation of the net heat flux at the surface.