北极涛动对我国冬季同期极端气温的影响研究

THE INFLUENCE OF WINTER ARCTIC OSCILLATION ON MAXIMUM AND MINIMUM AIR TEMPERATURE OVER CHINA IN WINTER

使用1955～2004年1月500 hPa高度场和同期我国107个测站最高和最低气温的逐月资料,计算极端气温与北极涛动指数的相关矩场,并对此相关矩场进行经验正交函数分析来研究我国最高和最低气温对北极涛动响应的年际变化。北极涛动指数定义为1月500 hPa标准化高度场经验正交函数分解所得到的第1时间函数。研究过程中对北极涛动一般年份和异常年份两种情况进行比较分析。研究发现北极涛动指数的正负极端异常年份,对我国冬季同期最高和最低气温有十分明显的影响。我国冬季最高气温响应主要表现地域是长江中下游、华北和河套地区,最低气温的响应主要表现地域是东部沿海和长江黄河上游地区。同时分析了不同年份冬季极端气温对于北极涛动响应的不同形势。

With the January 500 hPa geopotential height data and the monthly mean maximum and minimum temperature data at 107 stations in China from 1955 to 2004 in January, correlation moment analysis and empirical orthogonal function analysis are used to study the influence of Arctic Oscillation （AO） on maximum and minimum air temperature over China in winter. The study deals with two cases when AO is general and anomalous respectively. It is found that the influence on the monthly mean maximum and minimum temperature over China is obvious when AO is obviously anomalous. The monthly mean maximum temperature changes occur mainly over the Changjiang River, north of China and the Great Bend of the Yellow River in the corresponding winter when AO is anomalous while the monthly mean minimum temperature changes occur along the coast of the east part of China and upper reaches of the Yellow River.