欧亚秋季雪盖与北半球冬季大气环流的联系

利用NOAA 提供的1973-2004 年32 年欧亚雪盖面积资料和NCEP/NCAR 再分析资料, 采用相关和合成方法对比分析了欧亚秋、冬季雪盖与北半球冬季大气环流的关系,得到了一个观测事实: 欧亚秋季雪盖与后期冬季北半球中高纬大气环流存在显著的相关关系, 尤其是与北半球冬季大气环流的最主要模态北极涛动(AO) 或北大西洋涛动(NAO) 呈显著的负相关关系, 而且欧亚秋季雪盖面积与后期冬季北半球大气环流的关系比欧亚冬季雪盖与同期大气环流的关系更好。最后提出了一个联系欧亚秋季雪盖与冬季大气环流的可能原因: 欧亚秋季雪盖异常可能是导致后期冬季北半球大气环流变化的一个主要强迫因子。

The Relationship between Autumn- time Eur asian Snow Cover and Winter - time NH Cir culation

The relationship between the autumn-time and winter-time Eurasian snow cover anomalies and the distributions of winter-time NH circulation has been investigated by using comparative analysis of the correlation and synthetic methods based on the data of the snow cover in Eurasia from NOAA and reanalyzed data from NCEP/NCAR for the period 1973 through 2004,and the results show an observational fact:there is a significant correlation between the Eurasian autumn snow cover and the high-latitude atmospheric circulation of late winter in Northern Hemisphere.Especially it shows an obvious negative correlation between the Eurasian autumn snow cover and the main model Arctic Oscillation(AO),or the North Atlantic Oscillation(NAO)of the winter-time NH circulation.The relationship between the autumn-time snow cover anomalies and the following winter-time circulation is closer than that between the winter-time snow cover anomalies and the winter-time circulation based on observational analysis.Finally,a link between the Eurasian autumn snow cover and the winter-time NH circulation is mentioned.The Eurasian autumn snow cover may be a major factor which forces the variability of the following winter-time NH circulation.