Sea Surface Temperature Characteristics and Trends in China Offshore Seas from 1982 to 2017

This paper examines the spatial distribution and temporal variability of sea surface temperature (SST) in marginal seas off China at seasonal and inter-annual scales based on long-term high spatial-resolution optimum interpolation sea surface temperature (OISST) data from 1982-2017. Based on these data, annual mean SST ranges from 12 degrees C to 30 degrees C. Annual mean SST for the entire China offshore region is 25.03 degrees C; 12.75 degrees C for the Bohai Sea (BHS), 15.31 degrees C for the Yellow Sea (YS), 23.70 degrees C for the East China Sea (ECS), and 27.62 degrees C for the South China Sea (SCS). From south to north, SST exhibits a slow decrease with increasing latitude followed by a rapid decrease. Latitudinal SST gradients increase from south to north and are smallest in the SCS, followed by the ECS, and the YS and BHS. Over the past 36 years, annual mean SST has increased at a rate of approximately 0.0181 degrees C/yr and different marginal seas exhibit different features and inter-annual changes. Overall, the China offshore region exhibited long-term warming over the past 36 years. The strongest center of warming, which exceeds 0.04 degrees C/yr, is located in the ECS near the Yangtze River estuary and the Taiwan Strait. Variations in SST in the China offshore region are related to global natural climate variability and changes in the East Asian Monsoon.