摘要
Based on the daily rainfall datasets of 743 stations in China and the NCEP/NCAR monthly reanalysis data during the period of 1960-2003,the relationship between the anomalous extreme precipitation(EP) in the south of China and atmospheric circulation in the Southern Hemisphere is analyzed.The phenomenon of opposite changes in the sea level pressure and geopotential height anomalies over the Ross Sea and New Zealand is defined as RN,and the index which describes this phenomenon is expressed as RNI.The results show that the RN has barotropic structure and the RNI in May is closely related to the June EP amount in the south of China(SCEP) and the East Asian summer monsoon(EASM).The positive correlations between the May RNI at each level and the June SCEP are significant,and the related simultaneous correlations between the RNI and the June SCEP are also positive,suggesting that the potential impact of RN on the SCEP persists from May to June.Therefore,RN in May can be taken as one of the predictive factors for the June SCEP.Furthermore,one possible physical mechanism by which the RN affects the June SCEP is a barotropic meridional teleconnection emanating from the Southern Hemisphere to the western North Pacific.
Based on the daily rainfall datasets of 743 stations in China and the NCEP/NCAR monthly reanalysis data during the period of 1960- 2003, the relationship between the anomalous extreme precipitation （EP） in the south of China and atmospheric circulation in the Southern Hemisphere is analyzed. The phenomenon of opposite changes in the sea level pressure and geopotential height anomalies over the Ross Sea and New Zealand is defined as RN, and the index which describes this phenomenon is expressed as RNI. The results show that the RN has barotropic structure and the RNI in May is closely related to the June EP amount in the south of China （SCEP） and the East Asian summer monsoon （EASM）. The positive correlations between the May RNI at each level and the June SCEP are significant, and the related simultaneous correlations between the RNI and the June SCEP are also positive, suggesting that the potential impact of RN on the SCEP persists from May to June. Therefore, RN in May can be taken as one of the predictive factors for the June SCEP. Furthermore, one possible physical mechanism by which the RN affects the June SCEP is a barotropic meridional teleconnection emanating from the Southern Hemisphere to the western North Pacific.
基金
National Basic Research Program of China (2004CB418300, 2010CB833406)
National Natural Science Foundation of China (40675042, 40890054, 40871007)
