Upper ocean heat and salt variability in the equatorial Pacific

This study uses a three-dimensional ocean model of the equatorial Pacific to study the connections between the salt balance, heat balance, and ocean dynamics in the region. Three different year-long simulations (September 1988-September 1989; September 1990- September 1991, and September 1992 - September 1993) using ECMWF momentum, heat, and freshwater fluxes have been performed; for comparison, three simulations of the same time period but with zero freshwater flux have also been performed. A description of the surface salinity features resulting from the variations in the freshwater flux and differences in sea surface temperature will be discussed. We will also discuss, using heat and salt budgets of the eastern, central, and western Pacific and the ITCZ and SPCZ regions, the varying effects on the heat and salt budgets of the upper ocean. Initial results indicate that the temperature budget is more strongly affected by advection than the salt budget, which appears to be more strongly affected by local freshwater forcing, at least very near the equator. The impact of the salinity variations on the local dynamic structure will also be discussed.