The Interdecadal Variation Of SST In The Coastal China Seas And Its Response To Global Warming

The trends of sea surface temperature (SST) over the coastal China seas in thepast and future and the causes of SST interdecadal variation in the last20years of the20th are analyzed using two different observation datasets, the un-interpolated dataset(Hadley Centre Sea Surface Temperature3dataset, HadSST3), and the reconstructeddataset (Hadley Centre Sea Ice and Sea Surface Temperature dataset, HadISST1),historical and RCP run of eight climate models from the fifth phase of the CoupledModel intercomparison Project (CMIP5), and the air temperature in Shanghai andQingdao station for comparison. The innovative conclusions can be summarized asfollows:The warming trend of regional mean sea surface temperature (SST) in the past100years (1900-2006) is0.8oC based on un-interpolated HadSST3dataset. It is1oChigher of SST trend in the East China Sea than in the southern South China Sea. The largest warming trend appears in the west side of Taiwan Strait along Fujian coast, itis about1.8oC. The warming trends of SST are higher in winter than summer in thepast100years. The reconstructed dataset HadISST1exaggerates the SST warmingtrends in the past100years over the coastal China seas. Both HadSST3andHadISST1SST have a sudden hiatus after1999.Although SST is warming in the China seas from1900to2005in eight climatemodels, but the most significant warming happens in the last20years of the20thcentury, it is about0.4oC. In the East China Sea (especially the Kuroshio area), theSST warming is mainly caused by the increase of ocean heat advection which isclosely related to the interdecadal variation of the Pacific Ocean. In the southernSouth China Sea, the main cause of SST warming is the decrease of sea surface latentheat flux induced by atmospheric adjustments and the sensible surface heat flux. Inthe northern South China Sea, the cause of SST warming is the decrease of longwaveradiation and sea surface latent heat flux induced by atmospheric adjustments and theincrease of ocean heat advection.In RCP4.5run, the warming trends of SST can reach1oC over the whole Chinaseas from2006-2055. The major cause of SST warming is the decrease of sea surfacelatent heat flux induced by atmospheric adjustments.The comparative analysis above proved that the SST variation on decadal timescales over the coastal China seas depends on the increase of ocean heat advectioninduced by the ocean dynamics; and the long-term SST warming in response to thegreenhouse gas forcing is caused by the change of sea surface heat flux induced by atmospheric adjustments.