中国东部冬季气温异常的主模态与大气环流的关系

Relationship between main mode of the winter air temperature anomaly and atmospheric circulation in east China

利用中国东部季风区375个测站,1961-2006年历年平均地面气温资料,采用EOF、SVD、相关分析等方法,分析了中国东部季风区冬季气温与500hPa高度场异常变化的关系。结果表明:影响冬季气温的关键区有两个,皆为显著正相关;SVD分析表明:乌山脊弱,东亚槽浅,纬向环流偏强,经向环流偏弱,极涡面积偏小,使南下冷空气偏少,冬季气温易偏高。上年7月北大西洋高压异常偏强(偏弱),次年冬季气温将会异常偏暖(偏冷),北大西洋前期高度场与气温普遍有密切的关系,主要影响长江流域及其以北的季风中北部区;建立了气温距平与北大西洋关键区上年7月高度距平的关系,并建立了均生函数模型,预测了未来20 a的气温变化趋势。

Using the mean surface air temperature data during 1961 - 2006 of 375 stations in the east monsoon area in China and methods of EOF, SVD, correlation analysis, average value generating function method, the authors analyzed the relationship of temperature with height-field changes anomaly at 500 hPa and circulation feature in east China, and forecasted the change tendency of winter average air temperature in the future 20 a. The main results are as follows： there are two key areas which influence winter air temperature, both of the areas were remarkable positive correlation; the SVD analysis shows that the Ural ridge was weak, the east Asia trough was shallow, the zonal circulation was strong, the meridional circulation was weak, the area of polar vorticity was small, leading cold air was lack, winter temperature was high as well, namely the North Atlantic Ocean high pressure was exceptionally strong （weak） in last July, the temperature was high（low） in winter of the year, there were close relation to antecedent height-field and temperature in North Atlantic Ocean, it mainly influenced changing valley and middle-north monsoon area in north of it;it established the relationship between temperature and height departures in North Atlantic Ocean key area in the last July, and established function mode, which can be used to forecast the temperature change tendency in the future 20 a.