SURFACE AND SUBSURFACE SALINITY IN THE TROPICAL PACIFIC-OCEAN - RELATIONS WITH CLIMATE

Sea Surface Salinity (SSS) data have been collected in the tropical Pa cific Ocean since 1969. From this data set, relationships of SSS with ENSO have been found in both the western and the eastern Pacific. Thes e have mainly been associated with the presence of the ITCZ and equato rial upwelling. In the Central South Tropical Pacific a surface salini ty maximum is formed by a positive Evaporation-Precipitation balance w hich undergoes seasonal and interannual variations. It is prolonged in the west by a subsurface salinity maximum. During ENSO events, the su rface and subsurface salinity maxima expand westward. Initially, the s ubsurface salinity maximum is strengthened and shoals, but eventually it is driven back eastward by the equatorial jet. Such changes in surf ace and subsurface salinity need to be included in the scenario of an El Nino event.