ENSO及其年代际异常对全球及亚洲季风降水影响的数值研究

根据诊断分析结果，利用ＬＡＧＳ改进的Ｌ９Ｒ１５气候谱模式，设计了３个数值试验，讨论了不同的年代际背景下ＥＮＳＯ异常对全球降水，特别是对亚洲季风降水的影响。试验结果表明，在年代际的冷、暖背景下，当出现ＥＮＳＯ事件时，降水响应的异常场在ＥＮＳＯ的不同发展阶段上，表现显著不同。出现这种差异的物理过程可以用与垂直环流相联系的势函数的变化来表示。暖背景下，当ＥＮＳＯ处于发展时期，比冷背景下更容易出现强烈反Ｗａｌｋｅｒ的环流，但在ＥＮＳＯ处于衰减期更容易产生强烈的Ｗａｌｋｅｒ环流，这就意味着暖背景时的ＥＮＳＯ异常对大气影响的幅度更大。

THE NUMERICAL STUDY OF THE EFFECT OF ENSO AND ITS INTERDECADAL VARIATION ON THE GLOBAL AND ASIAN MONSOON PRECIPITATION

Based on L9R15 climatic model, the results by the three numerical experiments show that the global precipitation, espectially Asian summer monsoon counterpart is difference at different stage of ENSO events under the cold and warm interdecadal background. The different physics can be showed in potential function. Compared to that under the cold background, the anti Walker cell is stronger in the increasing stage of ENSO with stronger Walker cell in the decreasing stage of ENSO under the warm background. It means that the effect of ENSO events on precipitation anomaly under the warm background is stronger than that under the cold background.