印度洋偶极子与中国南方夏季降水的可能联系

利用1951—2000年NCEP/NCAR再分析资料、英国气象局全球海温资料、中国气象局整编的160站气温资料,采用EOF、合成、相关、奇异值分解等方法讨论了印度洋偶极子（Indian Ocean Di-pole,IOD）对南方夏季降水的影响。结果表明：印度洋海温异常,激发了大气环流的异常,从而导致南方降水异常。当印度洋海温一致变化时,南方降水分布也呈一致;当印度洋上海温距平偶极振荡时,长江流域与华南也出现偶极变化的现象。IOD正位相年,华南降水异常偏多;IOD负位相年,长江流域降水偏多。

Effect of Indian Ocean Dipole on Rainfall Anomaly in South of China

Based on the NCEP/NCAR reanalysis, British Meteorological Office global sea surface temperature（SST） and China 160 stations temperature data during 1951--2000, the empirical orthogonal function（EOF） ,composite analysis, correlation and singular value decomposition（SVD） methods are used to study the effect of the Indian Ocean Dipole （IOD） on South of China rainfall （ in China south of 33~N）. Results show that the SST anomaly in Indian Ocean aroses the atmospheric circulation anomaly, which induces the rainfall anomaly in South China. When Indian Ocean SST is higher （lower）, South China rainfall is more （less） than the normal. When IOD is positive （ negative）, the precipitation is more（less） in South China and less（more） in the Yangtze River Basin.