华南前汛期降水与前期印度洋海温的关系

摘要

Based on the precipitation and sea surface temperature(SST) data collected over 54 years from the year 1961 to the year 2014,research on the relationship between pre-flood season precipitation in South China and Indian Ocean SST was conducted by the means of the pearson correlation,singular value decomposition (SVD)method and composite analysis.Besises,the way the unusual changes of Indian Ocean SST affected pre-flood season precipitation in South China was also studied.It was showed that there was a different correlation between the SST in India Ocean and the precipitation in the different months of preceding flood season in Southern China.The central Indian Ocean (64°E-80°E,18°S-EQ) was the key area that affected the April precipitation over South China.The key period of Indian Ocean SSTwas July-August in the previous year.When it was abnormally cold in the key area of the Indian Ocean in July-August in the previous year,precipitation in April increases in South China.On the contrary,when it was abnormally warm in the key area of the Indian Ocean in July-August in the previous year,Southern China is controlled by northerly air currents and precipitation in April is subsequently reduced.%利用1961-2014年共54年的降水及海温资料,采用相关分析、奇异值分解和合成分析方法,研究了印度洋海温与华南前汛期降水的相关关系及海温异常影响华南前汛期降水量的途径.结果表明,印度洋海温与华南前汛期不同月份降水存在不同的相关性,且华南4月降水与前期印度洋海温存在显著的负相关关系.印度洋中部海区(64°E～80°E,18°S-EQ)是影响华南4月降水量的关键海区,前一年7-8月是关键时段.当印度洋关键海区前一年7-8月异常偏冷时,华南4月降水量显著增多;反之,华南受大陆偏北气流控制,4月降水减少.