A diagnostic study of the impact of El Niño on the precipitation in China
A diagnostic study of the impact of El Niño on the precipitation in China
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DOI：
10.1007/bf02973084
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发表时间：
1999-04
影响因子：
5.8
通讯作者：
Renhe Zhang;A. Sumi;M. Kimoto
中科院分区：
文献类型：
--
作者：
Renhe Zhang;A. Sumi;M. Kimoto
诊断性研究了厄尔尼诺现象对中国不同季节降水的影响。研究发现，厄尔尼诺现象在成熟期对我国降水有显着影响。北方冬、春、秋三季，厄尔尼诺成熟期我国南方地区出现降水正异常。北半球夏季，厄尔尼诺成熟期降水异常规律与其他季节不同。我国南北地区均出现降水距平负值，江淮下游地区降水距平偏于正值。北方冬、春、秋季厄尔尼诺影响我国南方降水的物理过程可以用厄尔尼诺成熟期东亚地区环流异常的特征来解释。 （张等人，1996）。厄尔尼诺成熟期，海洋大陆以北对流层低层出现反气旋异常，使西太平洋副热带高压增强并西移。与之相关的西南气流是导致中国南方地区出现正降水异常的原因。北半球夏季，西太平洋副热带高压增强，覆盖我国东南周边地区，降水减少。此外，印度季风减弱导致中国北部地区的水汽流入减少。
The impact of El Niño on the precipitation in China for different seasons are investigated diagnostically. It is found that El Niño can influence the precipitation in China significantly during its mature phase. In the Northern winter, spring and autumn, the positive precipitation anomalies are found in the southern part of China during the El Niño mature phase. In the Northern summer, the patterns of the precipitation anomalies in the El Niño mature phase are different from those in the other seasons. The negative precipitation anomalies appear in both southern and northern parts of China, while in between around the lower reaches of the Yangtze River and the Huaihe River valleys the precipitation anomalies tend to be positive.In the Northern winter, spring and autumn, the physical process by which El Niño affects the precipitation in the southern part of China can be explained by the features of the circulation anomalies over East Asia during the El Niño mature phase (Zhang et al., 1996). The appearance of an anticyclonic anomaly to the north of the maritime continent in the lower troposphere during the El Niño mature phase intensifies the subtropical high in the western Pacific and makes it shift westward. The associated southwesterly flow is responsible for the positive precipitation anomalies in the southern part of China. In the Northern summer, the intensified western Pacific subtropical high covers the southeastern periphery of China so that the precipitation there becomes less. In addition, the weakening of the Indian monsoon provides less moisture inflow to the northern part of China.