SEA SURFACE SALINITY VARIABILITY OF THE 1999 CLIMATE SHIFT IN THE TROPICAL PACIFIC

An analysis of 1980-2007 sea surface salinity (SSS) data collected from Geophysical Fluid Dynamics Laboratory coupled with climate model enables us to comprehend the decadal signals of climate change in the tropical Pacific. The magnitude of decadal variability connected with the Pacific Decadal Oscillation (PDO) is higher than that of interannual cycle for salinity changes. Although a -0.024 +/- 0.011 psu/decade reveals a freshening trend during the data span, the SSS shows dramatic decadal shift approximately -0.840 +/- 0.013 psu/decade during 1980-1999 in the positive phase of the PDO and 0.361 +/- 0.036 psu/decade during 2000-2007 in the negative phase of the PDO. The result indicates that the 1999 climate shift has strong influence on SSS changes. Possible implication of these SSS changes for ocean-atmosphere interaction and with the PDO events are discussed.