Influence of Surface Currents on the Sea Surface Temperature in the Tropical Pacific Ocean

Abstract

Abstract Currents at 15-m depth derived from buoy drifts and current meter records for the 1987–93 period are used to study the influence of thermal advection on SST variations. Horizontal advection is found to be important for maintaining the yearly mean SST distribution in the central-western Pacific and in the northeastern region. At the equator, zonal advection compensates for and exceeds the semiannual autumn peak in air–sea heat flux, consistent with seasonal cooling of the ocean surface throughout this period. In the eastern equatorial region, zonal and meridional advection are much weaker than net air–sea heat flux, implicitly revealing the crucial role played by vertical advection and mixing. The residual, certainly dominated by vertical heat tranfers, plays a dominant role in the eastern area, mostly compensating for the mean annual air–sea heat flux, and, throughout the year, combining with air–sea heat flux to balance the SST tendency. The effect of horizontal advection on the anomalous SST ch...