太平洋SSTA同中国东部夏季极端降水事件变化关系的研究

Relation research on between SSTA of Pacfic and extreme prcecipitation events in the eastern China

基于中国东部1955—2004年233个台站逐日降水和NCEP/NCAR再分析高度场、风场、比湿、地面气压以及NOAA海表温度资料,运用SVD、合成分析等方法研究了太平洋SSTA同中国东部夏季极端降水事件之间的相互关系,结果表明：前期冬季太平洋SSTA同我国东部夏季极端降水事件的关系比较显著;前冬赤道中东太平洋是影响我国华北地区夏季极端降水事件的关键区,若前冬该海域海温发生异常,从冬到夏大气环流先后通过PNA（反PNA）和WP（反WP）遥相关型使得西太平洋副热带高压发生异常,进而使得华北夏季极端降水事件发生异常;前冬热带西太平洋是影响我国东北南部及江南地区夏季极端降水事件的关键区,若前冬该海域海温发生异常,从冬到夏105°~135°E的平均经向垂直环流圈发生异常,使得夏季东北南部与江南地区垂直运动发生异常,进而使得东北南部和江南夏季极端降水事件发生异常。

Based on 233 stations daily precipitation datasets in the East China from 1955 to 2004,NCEP/NCAR reanalysis height fields,vertical velocity,specific humidity,surface pressure and NOAA reconstruct sea surface temperature,and with singular value decomposition,compose analysis methods,relation between Pacific sea surface temperature and extreme precipitation events of East China is researched.It is found that winter Pacific sea surface temperature have remarkable relations with anaphase summer extreme precipitation events of East China,and Equator middle and East Pacific is key area which affect to summer extreme precipitation events of East China,when sea surface temperature occur anomaly phenomenon in the Equator middle and East Pacific in winter,by PNA（Anti-PNA） and WP（Anti-WP） teleconnection on atmospheric circulation take place adjustment from winter to summer,thus West Pacfic Sub-Tropic High Pressure also take palce anomaly,at last summer extreme precipitation events of North China occur anomaly phenomenon.It is also found that tropic West Pacific is key area which affect to summer extreme precipitation events of northeast China and south of Changjiang River,when sea surface temperature occur anomaly phenomenon in the tropic West Pacific in winter,the average latitudinal vertical circulation of 105°～135°E take place anomaly phenomenon,and vertical motion occur anomaly in the northeast China and south of Changjiang River,at last the extreme precipitation events of the areas also occur anomaly.