摘要
利用北极涛动指数 ( AOI)、NCEP/NCAR4 0 a再分析资料中的海平面气压( SLP)、850、50 0、2 0 0 h Pa等压面高度场资料及中国 1 6 0站月平均气温资料 ,运用小波分析、经验正交函数 ( EOF)分析等方法 ,分析了华北冬季气温和冬季北极涛动指数的变化特征及其关系。结果表明它们之间存在着显著相关 ,特别是在年代际尺度上关系尤其密切。华北在 2 0世纪 70年代初以前为持续冷冬 ,80年代中期之后变为持续暖冬 ,其间相对正常 ,而冬季北极涛动指数亦存在类似的 3个阶段。冬季北极涛动高(低 )指数年 ,华北地区为暖 (冷 )冬年。其原因在于 ,北极涛动在对流层低层和高层都可激发类似 EU遥相关型的异常 ,通过影响西伯利亚高压和东亚大槽影响华北地区气温。强 (弱 )涛动年大气环流具有弱 (强 )东亚冬季风特征 ,西伯利亚高压减弱 (增强 ) ,亚洲大陆地面东北风减弱 (增强 ) ,高空东亚大槽减弱 (增强 )。
It is shown in this paper that North China winter air temperature bears a significant relation with Arctic Oscillation(AO),especially on a time scale of decades,by applying the methods such as wavelet analysis,EOF and correlation analysis and by using the AO index,the NCEP/NCAR reanalysis data and monthly mean air temperature at 160 stations in China.The North China winter air temperature was successively cold before 1970s but warm after 1980s,and the years between them were relatively normal.The winter AO index showed similar three-stage variations.When the winter AO index was high/low,North China winter was warm/cold.The reason may be that the AO can excite anomalies like the EU teleconnection pattern from low to high level in the troposphere which affect the Siberian High and East Asian Trough, thus influencing North China air temperature.High/low AO index years are characterized by weak/strong East Asian Winter Monsoon,weak/strong Siberian High and East Asian Trough and by weakened/strengthened northeast surface wind over Asian continent.
出处
《南京气象学院学报》
CSCD
北大核心
2003年第1期1-7,共7页
Journal of Nanjing Institute of Meteorology
基金
国家重点基础研究发展规划 (G1 9980 40 90 0 )项目第 1部分
