Different ENSO teleconnections over East Asia in early and late winter: role of precipitation anomalies in the tropical Indian Ocean–far western Pacific
Different ENSO teleconnections over East Asia in early and late winter: role of precipitation anomalies in the tropical Indian Ocean–far western Pacific
复制标题
东亚早冬和晚冬不同的ENSO遥相关：热带印度洋-远西太平洋降水异常的作用
DOI：
10.1175/jcli-d-21-0805.1
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发表时间：
2022
影响因子：
4.9
通讯作者：
Wei Zhao
中科院分区：
文献类型：
--
作者：
Tianjiao Ma;Wen Chen;Shangfeng Chen;C. Garfinkel;Shuoyi Ding;Lei Song;Zhibo Li;Yulian Tang;Jingliang Huangfu;H. Gong;Wei Zhao
本研究旨在更好地了解ENSO对东亚地区初冬（11 - 12月）和冬末（1 - 2月）气候异常的影响。特别是，在初冬可能的机制进行了研究。结果表明，ENSO与初冬从热带印度洋向东亚方向发出的Rossby波列（tIO-EA）有关。厄尔尼诺（La Niña）中的tIO-EA波列与东亚大槽的减弱（加强）、东亚冬季风的减弱（加强）以及中国东北和日本的暖（冷）气温异常密切相关。通过偏回归分析和数值试验，发现tIO-EA波列的形成与热带东印度洋/西太平洋降水异常（eIO/wP）密切相关。此外，ENSO引起的北大西洋异常也可能有助于形成的tIO-EA波列与eIO/wP降水。eIO/wP降水对ENSO的响应在初冬强于冬末。这可能是由于印度洋上空步行者环流异常偏强，而这又是由初冬印度洋较高的气候海温和较强的平均降水状态造成的。
This study aims to better understand the ENSO impacts on climate anomalies over East Asia in early winter (November–December) and late winter (January–February). In particular, the possible mechanisms during early winter are investigated. The results show that ENSO is associated with a Rossby wave train emanating from the tropical Indian Ocean toward East Asia (denoted as tIO-EA) in early winter. This tIO–EA wave train in El Niño (La Niña) is closely related to a weakening (strengthening) of the East Asian trough, and thereby a weakened (strengthened) East Asian winter monsoon and warm (cold) temperature anomalies over northeastern China and Japan. By using partial regression analysis and numerical experiments, we identify that the formation of tIO–EA wave train is closely related to precipitation anomaly in the tropical eastern Indian Ocean/western Pacific (denoted as eIO/wP). In addition, the ENSO-induced North Atlantic anomalies may also contribute to formation of the tIO-EA wave train in conjunction with the eIO/wP precipitation. The response of eIO/wP precipitation to ENSO is stronger in early winter than in late winter. This can be attributed to the stronger anomalous Walker circulation over the Indian Ocean, which in turn is caused by higher climatological SST and stronger mean precipitation state in the Indian Ocean during early winter.