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已有的大量研究给出了印度洋增暖的气候效应,特别是对于西北太平洋反气旋异常的影响.本文利用观测数据和耦合数值模式进一步分析了厄尔尼诺衰亡年印度洋增暖的气候效应,研究了印度洋海温异常与西北太平洋反气旋异常之间的遥强迫形成条件,提出印度洋背景风场的季节性转换对印度洋增暖效应的关键作用.结果表明,只有在有利的背景风场下,即南亚夏季季风完全爆发时,才更有利于印度洋增暖效应的充分体现.可能是由于Kelvin波-Ekman辐散机制,在北印度洋异常增暖所导致的大气热源异常的东侧低层大气中产生了明显的东风异常,这一东风异常对西北太平洋产生遥强迫,使西北太平洋的反气旋异常加强并维持到厄尔尼诺衰亡年夏季.这对于东亚夏季季风的年变率机制研究及预测有着重要意义.
A large number of studies have given the climatic effects of warming in the Indian Ocean, especially on the anomalous anti-cyclone in the Northwest Pacific. In this paper, the climatic effects of Indian Ocean warming during El Niño decay are further analyzed by observational data and coupled numerical models. And the teleconnection between the anomalous SST anomalies and the anti-cyclonic anomalies in the NW Pacific suggests that the seasonal changes of the Indian background wind field play a key role in the warming of the Indian Ocean.The results show that only in a favorable background wind field, When the monsoon completely broke out, it is more conducive to the full manifestation of the warming in the Indian Ocean, possibly due to the Kelvin wave-Ekman divergence mechanism, which resulted in obvious lower-level atmosphere in the east lower anomalous atmospheric heat source caused by the abnormal warming of the North Indian Ocean The anomaly of the east wind anomalously impacted on the northwestern Pacific Ocean and intensified the anomalous anticyclone in the northwestern Pacific and maintained the El Niño summer decay season, which is of great significance for the study and prediction of the annual variability of the East Asian summer monsoon.