Effect of the El Niño Decaying Pace on the East Asian Summer Monsoon Circulation Pattern during Post-El Niño Summers
Effect of the El Niño Decaying Pace on the East Asian Summer Monsoon Circulation Pattern during Post-El Niño Summers
复制标题
DOI：
10.3390/atmos12020140
复制
发表时间：
2021-01
期刊：
影响因子：
2.9
通讯作者：
Wenping Jiang;Gen Li;Gongjie Wang
中科院分区：
文献类型：
--
作者：
Wenping Jiang;Gen Li;Gongjie Wang
厄尔尼诺现象因案例而异，其衰减速度也不同。在这项研究中，我们证明了不同的厄尔尼诺衰减速度对后厄尔尼诺夏季的东亚季风环流有不同的影响。对于快速衰减型(FD)厄尔尼诺夏季，东亚和北太平洋从副热带到中纬度地区以大尺度反气旋为主，而对于缓慢衰减型(SD)厄尔尼诺夏季，东亚季风环流呈现出北部异常气旋和南部反气旋的偶极子环流格局。东亚季风环流异常的差异与热带海温异常密切相关。在夏季，热带中东部太平洋的冷海温异常和海洋大陆的暖海温异常是西北太平洋反气旋异常的诱因。相反，在SD El Nino夏季期间停泊在热带印度洋上空的暖开尔文波对维持西北太平洋的反气旋异常起着至关重要的作用。尤其是东北亚和中纬度北太平洋地区夏季相反的大气环流异常主要受热带东太平洋相反海温异常所触发的定常Rossby波列的调制。最后，还讨论了与厄尔尼诺现象相关的不同夏季风环流类型对东亚夏季气候的影响。
El Niño events vary from case to case with different decaying paces. In this study, we demonstrate that the different El Niño decaying paces have distinct impacts on the East Asian monsoon circulation pattern during post-El Niño summers. For fast decaying (FD) El Niño summers, a large-scale anomalous anticyclone dominates over East Asia and the North Pacific from subtropical to mid-latitude; whereas, the East Asian monsoon circulation display a dipole pattern with anomalous northern cyclone and southern anticyclone for slow decaying (SD) El Niño summers. The difference in anomalous East Asian monsoon circulation patterns was closely associated with the sea surface temperature (SST) anomaly patterns in the tropics. In FD El Niño summers, the cold SST anomalies in the tropical central-eastern Pacific and warm SST anomalies in the Maritime Continent induce the anticyclone anomalies over the Northwest Pacific. In contrast, the warm Kelvin wave anchored over the tropical Indian Ocean during SD El Niño summers plays a crucial role in sustaining the anticyclone anomalies over the Northwest Pacific. In particular, the opposite atmospheric circulation anomaly patterns over Northeast Asia and the mid-latitude North Pacific are mainly modulated by the stationary Rossby wave trains triggered by the opposite SST anomalies in the tropical eastern Pacific during FD and SD El Niño summers. Finally, the effect of distinct summer monsoon circulation patterns associated with the El Niño decay pace on the summer climate over East Asia are also discussed.