菲律宾海地区异常环流与长江中下游6月旱涝的关系

利用1951—2010年NCEP/NCAR逐月再分析资料和中国160站月降水总量资料,研究了菲律宾海地区大气环流异常与长江中下游6月旱涝的关系。结果表明,菲律宾海附近是影响长江中下游地区6月降水的关键区。菲律宾异常反气旋（气旋）在对流层低层明显,强度随高度衰减。且这种大气环流异常与长江中下游地区6月降水的相关关系在低层850hPa最显著,到高层相关性减弱。当出现菲律宾异常反气旋环流时,垂直速度和水汽输送等异常分布特征有利于降水发生,使得长江中下游地区偏涝,反之则偏旱。

Relationship between anomalous atmospheric circulation over the Philippine Sea and flood/drought in the middle and lower reaches of the Yangtze River

Based on the NCEP/NCAR reanalysis datasets and the precipitation data from 160 stations in China during 1951—2010,the relationship between the flood/drought in the middle and lower reaches of the Yangtze River and the anomalous atmospheric circulation over Philippine Sea was investigated.Results indicate that the area around the Philippine Sea is the key region to significantly affect the precipitation over the middle and lower reaches of the Yangtze River.The intensity of the anomalous anticyclone（cyclone）located over the Philippine Sea is strongest at 850 hPa and decreases as altitude increases as well as its relationship with the above mentioned precipitation.When the anomalous anticyclone appears around the Philippine Sea,the distributions of the vertical velocity and water vapor flux,among others,are all favorable to bring more precipitation around the Yangtze River basin,and vise versa.