Multitime scale variations of sea surface temperature in the China seas based on the HadISST dataset

The variability of the sea surface temperature (SST) in the China seas has been studied in seasonal, interannual and interdecadal scales based on the monthly data of HadISST spanning from 1870 to 2007. The main results obtained are SST in the China offshore changes most actively at the seasonal scale with the intensity diminishing from north to south, as the temperature differences between summer and winter reaching 17 and 4℃ in the northern and southern areas, respectively. Moreover, seasonal variation near the coastal regions seems relatively stronger than that far from the coastline; significant interannual variations are detected, with the largest positive anomaly occurring in 1998 in the overall area. But as far as different domains are concerned, there exists great diversity, and the difference is also found between winter and summer. Differed from the seasonal variations, where the strongest interannual variability takes place, resides to the south of that of the seasonal ones in the northern section, nevertheless in the South China Sea, the most significant interannual variability is found in the deep basin; interdecadal changes of summer, winter and annual mean SST in different domains likewise present various features. In addition, a common dominant warming in recent 20 a are found in the overall China offshore with the strongest center located in the vicinity of the Changjiang Estuary in the East China Sea, which intensifies as high as 1.3℃ during the past 130 a.