厄尔尼诺期间和后期南海海面温度的两次显著增暖过程

Two sea-surface warming events in the South China Sea during and after El Nio

通过分析ICOADS海洋气象资料,结合ISCCP短波辐射和OISST海面温度,研究并探讨了ENSO等大尺度海气相互作用过程背景下南海海表面温度(SST)的年际变化。研究表明,南海SSTA的年际变化和ENSO关系密切,并且分为两个阶段。以增暖事件为例,在厄尔尼诺(ElNio)发生年的冬季和消亡年的夏季,南海出现了两次显著增暖。第一次增暖出现在ElNio盛期,是ElNio影响的一部分,这时南海云量减少,净太阳辐射通量增加,SST上升。第二次增暖出现在ElNio结束后的夏季,不是ElNio直接作用的结果;这时夏季风减弱,一方面使得海洋的潜热损失减少,另一方面减弱了越南东部沿岸的上升流,两者的共同作用导致SST增加。

Using monthly products from the International Comprehensive Ocean-Atmosphere Data Set （ICOADS）, the International Satellite Cloud Climatology Project （ISCCP）, and the Optimum Interpolation Sea Surface Temperature （OISST）, the authors investigate the interannual variation of sea-surface temperature （SST）along a meridional transection in the South China Sea （SCS）. It is found that the air-sea interaction in the tropical Pacific plays an important role in the SCS SST variation. Taking warming as an example, the SCS SST warms up in the winter of El Nino developing year and again in the following summer. The first SCS warming occurs during the mature phase of El Nino. The decrease in eloudage and increase in net shortwave radiation flux contribute to the SST warming in the winter. The air-sea interaction associated with El Nino has a direct impact on this SCS warming process. The second warming occurs in the summer after the decay of El Nino. The weakening summer monsoon reduces the latent heat flux release and coastal upwelling off the southeastern Vietnam, which could not he attributed to the direct impact of the El Nino.