The Northwest Pacific Sea Surface Temperature Interannual Variation Analysis

The climate change, which charactered by the El Ni o and La Nina frequentlyhappened since the1980’s, has caused serious disasters in the world, including China.The Northwest Pacific determines our country’s marine climate change, and theresearch on the variation of sea surface temperature is particularly important. Thesatellite remote sensing can realize the synchronous measurement in large area, andhas high temporal and spacial resolution. For the current researches of SST variationbased on the satellite remote sensing data，the time is short for climate changeresearch and few of them cover the Northwest Pacific.A monthly Northwest Pacific SST data set is established mainly based on theNOAA Pathfinder satellite products from1982to2010in this study. The ReynoldsSST monthly field is used for data quality control and data merging during the dataprocessing steps. Then the empirical orthogonal function (EOF) method is applied tothe monthly anomaly field of the data set to analyze the features of the principlespatial and temporal modes of the Northwest Pacific SST distribution. The first modetime series is compared with the Ni o-3.4SST and the Western Hemisphere WarmPool(WHWP) SST time series respectively. The comparison shows a typical~13years inter-decadal mode and a2~5years El Ni o-like mode in Pacific NorthwestSST variations. The inter-decadal variation is similar to that of the WHWP SST andthe El Ni o-like mode is related to that of the Ni o-3.4SST variation with an about10-month lag. There is a12~14years mode of the lag time of the Northwest PacificSST variation to the West Pacific, especially the equatorial West Pacific. The thirdmode is about El Ni o. Under the background of the WHWP interannual oscillations,East China Sea SST interannual variation is related to the Kuroshio Current’s periods,and is influenced by the Yangtze river runoff. This study suggests that the Northwest Pacific may be under the control of several oceanic/atmospheric systems of differenttime scales or their interactions.Based on the high resolution SST data set, the spacial and temporal variationanalysis of the Northwestern Pacific SST is applied, the results show that the SSTdistribution which is higher on east and lower on west is more and more significant asthe latitude increases. The subequatorial area SST reaches the maximum value in Mayeach year in west, and then the high SST center moves from west to east. In1998,influenced by the El Ni o, the SST reached the maximum value between May andSeptember, which lags behind the other years1~3months.