Analysis of sea surface temperature in the Indo-Pacific warm pool

The sea surface temperature(SST) of the HadISST data from 1951 to 2003 was used to document temporal-spatial characteristics of seasonal and interannual variations in the SST in the Indo-western Pacific warm pool(IPWP),especially in the Indonesian throughflow(ITF) and beyond.These findings indicate that interannual variations in SST throughout the region are closely related to ENSO;however,the response patterns in the Indian Ocean and the South China Sea are opposed to and out of phase with those of the western Pacific Ocean.SST variations in the former lag behind the Nio 3 index by 3~6 months,while SST variations in the Pacific western boundary and the ITF region lead the Nio 3 index by 1~3 months.Along the pathway of the ITF and its outlet in the eastern Indian Ocean,interannual variation in the features of SST are different from those in the tropical Indian Ocean,but similar to those in the Pacific Ocean,which is largely the result of the role of the ITF oceanic bridge.Seasonal fluctuations in the SST in the equatorial Indian Ocean and in the equatorial Pacific Ocean are also distinctly different.Bounded by the Sunda Islands(Sumatra,Java and the Lesser Sunda Islands) along the pathway of the ITF starting from the equatorial western Pacific Ocean,semi-annual fluctuations are dominant on the Pacific Ocean side,while annual fluctuations are dominant on the Indian Ocean side.