我国冬季气温的年际变化及其与大气环流和海温异常的关系  

Interannual Variations of Winter Temperature in China and Their Relationship with the Atmospheric Circulation and Sea Surface Temperature

作　　者：康丽华[1,2] 陈文[1] 王林[1] 陈丽娟[3] 

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,北京100190 [2]总装备部继续教育中心,北京102206 [3]国家气候中心,北京100081

出　　处：《气候与环境研究》2009年第1期45-53,共9页Climatic and Environmental Research

基　　金：中国科学院知识创新工程重要方向项目KZCX2-YW-220;国家自然科学基金资助项目40775035、40730952

摘　　要：利用我国160个台站49个冬季（1951／1952-1999／2000年）的气温资料和NCEP／NCAR再分析资料，通过波谱分析的方法提取变量的年际变化分量（周期小于8年部分）进行分析，结果发现：在年际变化的时间尺度上，我国冬季气温表现为全国一致变化型（EOF1）和南北反相变化型（EOF2）两个主要模态，并可以解释总方差60％以上的变化。进一步分析表明，在年际变化尺度上，与气温全国一致变化型相联系的大气环流表现出海陆气压差的改变以及与此相关的东亚大槽强度的变化和东亚高空急流位置的南北移动；赤道中东太平洋的异常海温对这一模态的出现有一定的预示意义，而中国近海的海温则更多的是被动地随气温改变。与南北反相变化型相联系的大气环流表现出显著的北极涛动特征，这一模态的出现会使得次年春季的西北太平洋海温呈现以30°N为界南北反相变化的形态；而北太平洋的海温异常可能对这一模态的形成有一定的作用。这两个模态的空间分布虽然与年代际尺度上的分布非常相似，但它们的相对强弱和对应的环流却有很大的差异。分析显示，全国一致变化型可能更多地表现出年代际变化的特征，而南北反相变化型更多地表现出年际变化的特征；结果还表明，我国冬季气温的变化在不同的时间尺度上是受不同因子影响的。因此，在研究我国冬季气温变化时，将不同的时间尺度分开考虑是十分必要的。By using the monthly mean temperature in 160 stations mean （November to March of the next year） temperature in China, of China, the interannual whose period is shorter component than eight of winter years, is studied with the empirical orthogonal function （EOF） analysis for the period 1951/1952--1999/2000. Two distinguished modes are clarified, with the first EOF mode depicting a pan-China temperature variation and the second EOF mode describing a temperature oscillation between northern and southern parts of China. These two modes can explain over 60% of the variance. The atmospheric circulation and the sea surface temperature （SST） patterns associated with the two modes are then investigated by using the NCEP/NCAR reanalysis data and NOAA reconstructed SST data through the regression/correlation method. Results reveal that although the leading modes of interannual temperature variation are similar to those on the deeadal time scale （period longer than eight years）, the associated circulations are quite different. The pan-China temperature variation is closely associated with a change in land-sea pressure gradient in sea level pressure field on the interannual time scale. It is also closely related with the intensity of East Asian trough at 500 hPa and the north-south movement of 200 hPa East Asian jet stream. The tropical Pacific SST anomalies are suggested to play an active role to produce this mode, while the SST along the coast of China can only vary with the temperature passively. As to the second EOF mode, it is closely related to Arctic Oscillation on the interannual time scale, and is able to cause a north-south dipole in the SST field over Northwest Pacific in the following spring. The anomalous SST over North Pacific is possibly able to influence this mode, but the detailed process need to be studied further. The comparison of results between interannual and decadal time scale demonstrates that the variation of winter time temperature in China is influenced by different factors on diffe

关 键 词：冬季气温 年际变化 东亚冬季风 大气环流 海面温度 

分 类 号：P434[天文地球—大气科学及气象学]