我国冬季气温年代际变化及其与大气环流异常变化的关系  

The Interdecadal Variation of Winter Temperature in China and Its Relation to the Anomalies in Atmospheric General Circulation

作　　者：康丽华[1] 陈文[1] 魏科[1] 

机构地区：[1]中国科学院大气物理研究所季风系统研究中心

出　　处：《气候与环境研究》2006年第3期330-339,共10页Climatic and Environmental Research

基　　金：中国科学院知识创新工程重要方向项目KZCX3-SW-218;国家自然科学基金项目40375021和40231005

摘　　要：利用我国160个台站50年（1951-2000年）的月平均温度资料和NCEP／NCAR再分析资料，对我国从1951／1952-1999／2000共49个冬季（11月至次年3月平均）的气温进行经验正交函数（E（）F）分解。第1模态表现为全国一致的增温或者降温，20世纪70年代中期以后，我国冬季气温增暖明显，发生了显著的年代际变化；第2模态则表现为南北温度的反相关系，20世纪80和90年代，我国北部地区，特别是东北和西北的温度增加，而我国南部则温度降低。采用频谱分析方法提取我国冬季气温的年代际变化信号更清楚地反映出这些变化。而且这两种模态从20世纪80年代开始的正位相叠加使得我国冬季持续偏暖，在降水场没有显著变化的情况下，加剧了华北地区的干旱程度。对气温的年代际变化与大气环流的回归分析表明，我国冬季气温年代际变化的第1模态与半球尺度上的北极涛动（A0）的变化有密切的关系，它在高度场上表现为一个准正压的南北环状模态；而第2模态则与中高纬大气环流中的一波结构联系密切，它在高度场上表现为一个准正压的太平洋和大西洋上反相的振荡模态。这就表明，我国冬季气温的年代际变化与大气环流中的基本气流及其扰动有密切的关联。作者还讨论了大气环流影响我国冬季气温年代际变化的可能机理，并指出进一步需要研究的问题。By using the monthly temperature in 160 stations of China and the NCEP/NCAR reanalysis data, the winter （November to March） temperature variations from 1951 to 2000 are studied with the empirical orthogonal function （EOF） analysis. The first EOF has an identical signal in whole China and demonstrates that the winter temperature has increased since the middle of 1970s in China. The second EOF has a seesaw pattern between southern and northern China and shows a warming in the 1980s and 1990s in Northwest China and Northeast China. The interdecadal variation with periods longer than 8 years can also be revealed using Fourier harmonics analysis. In addition, the warming superimposition of EOF1 and EOF2 probably causes persistent warming winter in China from the 1980s. This significant warming may intensify the drought in North China, since there are no obvious changes in the regional precipitation. The linear regressions of the atmospheric general circulation upon the winter temperature on interdecadal time scales indicate that the first EOF of temperature is significantly correlated to the Arctic Oscillation （AO）, with a quasi-barotropic annular mode in the geopotential height field. However, the second EOF of temperature is closely associated with. height anomalies of wavenumber one in middle-high latitudes, with a quasi-barotropic out-of-phase oscillation between the Pacific Ocean and the Atlantic Ocean. The results show that the interdecadal variations of winter temperature in China are closely related to the basic flows and perturbations in the atmosphere. The possible mechanisms of the atmospheric general circulation influencing the winter temperature in China are discussed and the questions needed to be further studied are presented.

关 键 词：东亚冬季风 经验正交函数 年代际变化 大气环流 

分 类 号：P434[天文地球—大气科学及气象学]