黄、东海沿岸海表温度变化与厄尔尼诺的关系

Relationship between El Nio and sea surface temperature variation in coastal region of Yellow Sea and East China Sea

利用黄、东海沿岸8个长期水文观测站多年海表温度资料,分析黄、东海沿岸海表温度的季节和年际变化特征,重点分析在1982—1983年和1997—1998年两次厄尔尼诺年期间的异常变化,以及ENSO影响黄、东海沿岸海表温度的可能机制。结果表明,在厄尔尼诺发生年,夏季风较弱,鄂霍次克海高压加强,西太平洋副高位置偏南,强度偏强,江淮流域及长江中下游降水偏多,黄、东海沿岸海表温度偏低。黄、东海沿岸海表温度受到ENSO和PDO(太平洋年代际振荡)的影响和调制,在厄尔尼诺发生的前冬半年及当年,黄、东海沿岸海表温度偏低;在厄尔尼诺发生次年,黄、东海沿岸海表温度偏高。厄尔尼诺对黄、东海沿岸海表温度变化的影响通过海洋和大气2个通道,1982—1983年海表温度异常以负异常为主,1997—1998年海表温度异常以正异常为主;ENSO期间,北赤道流减弱,黑潮流量减少,海表温度降低。海表温度受局地气温影响显著,如果ENSO期间东亚气温升高,则黄、东海沿岸海表温度偏高。

Based on long-term sea surface temperature （SST） data from eight hydrological observation stations, the seasonal and inter-annual variations of SST, especially the SST anomaly variation during two El Nino periods from 1982 to 1983 and from 1997 to 1998, in the coastal region of the Yellow Sea and East China Sea were analyzed. The possible mechanism of the El Nino southern oscillation （ENSO） effect on the SST variation in the coastal region of the Yellow Sea and East China Sea was analyzed. The results show that in the El Nino years the summer monsoon, was weak, the Okhotsk high was strong, the Western Pacific subtropical high ridge surface moved southward and strengthened, and the rainfall in the Huaihe Basin and the middle and lower reaches of the Yangtze River, was above normal, leading to alow SST in the coastal region of the Yellow Sea and East China Sea. The SST in the coastal region of the Yellow Sea and East China Sea was affected by ENSO and Pacific decadal oscillation （PDO）. The SST was low in the winter half-year before the occurrence of the El Nino event and in the El Nino year, and high in the year subsequent to the El Nino event. El Nino affected SST variation through atmospheric and oceanic channels. The SST anomaly was dominated by a negative anomaly during the period from 1982 to 1983 and a positive anomaly during the period from 1997 to 1998. During the ENSO period, the north equatorial current was weak, resulting in a dramatic drop in the heat transport of the Kuroshio Current and a low SST. The SST was significantly affected by the local temperature. If the temperature over East Asia rose during the ENSO period, the SST would be high over the Yellow Sea and East China Sea.