Responses of the Sea Surface Temperature and Suspended Matter Concentration to ENSO Events in the Bohai Sea

The sea surface temperature (SST) and sea surface suspended matter concentration data in the Bohai Sea were collected by multiple NOAA satellites from 1985 to 2018. The background calibration method was used to correct the systematic errors caused by the long-term observations through multiple NOAA satellites in this paper. Then, we studied the long-term variations of the sea surface temperature (SST) and sea surface suspended matter concentration (SSC) and their response to ENSO events in the Bohai Sea. Our results show that the SST and SSC of the Bohai Sea have been increasing since 1985, with an average rate of 0.04°C per year for SST, which is higher than the global average. The average increasing rate of SSC was 0.51 mg L−1 yr−1, which may be mainly due to the enhancement of winter monsoon in the Bohai. In winter, the SST and SSC of the Bohai Sea were higher in El Niño years than in La Niña years. In El Niño years, the ocean circulations were the main factor affecting the variation in SST. The robust circulation system caused by the strong winter monsoon enhances the water exchange between the cold water of the Bohai Sea and the warm water of the Yellow Sea, resulting in a higher SST in La Niña years. In summer, the SSTs of the Bohai Sea were lower in El Niño years than those in the La Niña years because of the decrease of the SST in the Western Pacific Ocean, the weakening of the subtropical high in the western Pacific, and its eastward shift caused by the El Niño events.