不同类型El Nino事件及其与我国夏季气候异常的关系

Different Types of El Nino Events and Their Relationships with China Summer Climate Anomaly

详细讨论了不同类型El Nino事件与东亚夏季风(east Asian summer monsoon,EASM)和夏季降水的关系。结果表明,在西部型和驻波型El Nino事件的发展年,EASM都是偏弱的,而东部型的EASM偏强;在西部型和驻波型El Nino事件的衰减年,EASM偏强,而东部型的EASM正常。对于我国夏季降水,在西部型的发展年,华北、黄河中上游、洞庭湖与鄱阳湖流域以及华南部分地区降水偏少,而江淮流域降水偏多;在衰减年则相反。在驻波型的发展年,长江流域和华北北部降水显著偏少,华南、华北中部等地区降水偏多;在衰减年,四川盆地、华南等地区降水偏少,而长江流域、华北中部等地区降水偏多。在东部型的发展年,我国以少雨为主要特征,多雨区主要集中在四川盆地、黄淮流域;在衰减年,我国降水仍以干旱少雨为主要特征,多雨区主要位于华南、华北部分区域。

The relationships between different types of El Nino events and East Asian summer monsoon （EASM） as well as summer precipitation in China are discussed in detail. In the developing years of western and standing-wave/eastern patterns E1 Nino events, EASM is weaker/stronger than the normal. In the decaying years of western and standing-wave/eastern patterns, EASM is rather stronger/normal. Moreover, in the developing years of western pattern E1 Nino events, the summer precipitation is less than the normal in North China, the upper and middle reaches of Yellow River, Dongting Lake and Poy- ang Lake valleys, and parts of South China, but it is relatively more in the Yangtze-Huaihe River Val- ley, and it is the reverse in the decaying years. In the developing years of standing-wave pattern, there are less rainfall in the Yangtze River Valley and the northern part of North China, and more one in South China and the middle part of North China. Rainfall in Sichuan basin and South China is less than the normal in the decaying years, meanwhile it is more in the Yangtze River Valley and the middle part of North China. Despite in the developing or decaying years of eastern pattern, the rainfall is less than the normal in most of China except for in Sichuan basin and Huanghe-Huaihe Valley in the developing year, and in parts of South China and North China in the decaying years.