The present study analyzes the connection of rainfall anomalies over East and Southeast Asia between spring and summer. Spatial patterns of contrasting rainfall anomalies between East Asia and the Indochina Peninsula are identified in both spring and summer. The persistence of more rainfall over East Asia and less rainfall over the Indochina Peninsula from spring to summer is associated with the maintenance of an anomalous low‐level anticyclone over the tropical western North Pacific. Further analysis shows that this anomalous anticyclone is attributed to the combined effects of persisting positive sea surface temperature anomalies (SSTAs) in the tropical Indian Ocean and negative SSTAs in the subtropical western Pacific. In contrast, in the nonpersistent rainfall anomaly years, the anomalous anticyclone over the western North Pacific displaces southward from spring to summer. One factor accounting for such a change is the dissipation of the negative SSTAs in the subtropical western Pacific from spring to summer, which weakens the SST forcing on the western North Pacific anticyclone. The other factor is an atmospheric wave train associated with the negative SSTAs in the eastern North Atlantic Ocean. The atmospheric wave train propagates eastward across the Eurasian continent and reaches East Asia. The wave pattern contributes to the development and southward displacement of an anomalous cyclone over East Asia, which causes a southward shift in the western North Pacific anticyclone. The effect of the North Atlantic negative SSTAs on the atmospheric wave pattern is supported by numerical experiments.

中文翻译：

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春季至夏季东亚和东南亚降水异常模式的持久性和非持久性

本研究分析了春季和夏季之间东亚和东南亚降雨异常的联系。在春季和夏季，确定了东亚和印度支那半岛之间降雨异常对比的空间格局。从春季到夏季，东亚持续降雨增多，印度支那半岛持续降雨减少，这与北半球热带西太平洋异常低空反气旋的维持有关。进一步的分析表明，这种反气旋异常是由于热带印度洋持续存在的正海表温度异常（SSTA）和亚热带西太平洋持续的负SSTA共同作用所致。相反，在非持续降雨异常年份，北太平洋西部的反气旋异常从春季到夏季向南移动。造成这种变化的一个因素是，从春季到夏季，亚热带西太平洋的负性SSTA消散，这削弱了北太平洋西部反旋风的SST强迫。另一个因素是与北大西洋东部的负SSTA相关的大气波列。大气波列火车向东跨欧亚大陆传播并到达东亚。波动模式有助于东亚上空异常气旋的发展和向南位移，从而引起北太平洋西部反气旋的南移。数值实验支持了北大西洋负SSTA对大气波型的影响。