Classifying El Niño Modoki I and II by Different Impacts on Rainfall in Southern China and Typhoon Tracks
Classifying El Niño Modoki I and II by Different Impacts on Rainfall in Southern China and Typhoon Tracks
复制标题
DOI：
10.1175/jcli-d-12-00107.1
复制
发表时间：
2013-02
影响因子：
4.9
通讯作者：
Chunzai Wang;Xin Wang
中科院分区：
文献类型：
--
作者：
Chunzai Wang;Xin Wang
基于它们在北半球秋季对中国南方降雨的相反影响，本文将厄尔尼诺模态分为两组：厄尔尼诺模态I和II，它们呈现出不同的海温异常起源和模式。对于厄尔尼诺模态I和II，暖海温异常分别起源于赤道中太平洋和亚热带东北太平洋。因此，厄尔尼诺模态I呈现出关于赤道对称的海温异常分布，赤道中太平洋增温最强，而厄尔尼诺模态II呈现出不对称分布，暖海温异常从东北太平洋延伸至赤道中太平洋。此外，赤道中太平洋的暖海温异常对于厄尔尼诺模态II比厄尔尼诺模态I向西延伸得更远。与典型厄尔尼诺类似，厄尔尼诺模态I与菲律宾海的异常反气旋有关，该反气旋在中国南部沿海诱发西南风异常，并携带水汽使中国南方降雨增加。对于厄尔尼诺模态II，一个异常气旋位于菲律宾以东，与北风异常有关，中国南方降雨减少。典型厄尔尼诺和厄尔尼诺模态I与西北太平洋副热带高压（WNPSH）向西延伸有关，而厄尔尼诺模态II使WNPSH向东移动。与典型厄尔尼诺和厄尔尼诺模态I不同，厄尔尼诺模态II对应着台风引导气流的西北风异常，这不利于台风在中国登陆。
Based on their opposite influences on rainfall in southern China during boreal fall, this paper classifies El Nino Modoki into two groups: El Nino Modoki I and II, which show different origins and patterns of SST anomalies. The warm SST anomalies originate in the equatorial central Pacific and subtropical northeastern Pacific for El Nino Modoki I and II, respectively. Thus, El Nino Modoki I shows a symmetric SST anomaly distribution about the equator with the maximum warming in the equatorial central Pacific, whereas El Nino ModokiII displays an asymmetric distribution with the warmSSTanomaliesextending fromthe northeastern PacifictotheequatorialcentralPacific.Additionally,thewarmSSTanomaliesintheequatorialcentralPacific extend farther westward for El Nino Modoki II than for El Nino Modoki I. Similar to the canonical El Nino, El Nino Modoki I is associated with an anomalous anticyclone in the Philippine Sea that induces south- westerly wind anomalies along the south coast of China and carries the moisture for increasing rainfall in southern China. For El Nino Modoki II, an anomalous cyclone resides east of the Philippines, associated with northerly wind anomalies and a decrease in rainfall in southern China. The canonical El Nino and El Nino Modoki I are associated with a westward extension of the western North Pacific subtropical high (WNPSH), whereas El Nino Modoki II shifts the WNPSH eastward. Differing from canonical El Nino and El Nino Modoki I, El Nino Modoki II corresponds to northwesterly anomalies of the typhoon steeringflow, which are unfavorable for typhoons to make landfall in China.