中国冬季积雪特征及欧亚大陆积雪对中国气候影响

An Overview of Wintertime Snow Cover Characteristics over China and the Impact of Eurasian Snow Cover on Chinese Climate

该文首先回顾了有关中国冬季积雪的研究进展,包括中国冬季积雪的空间分布气候特征以及季节、年际和年代际变化,中国冬季降雪特征,气象因子对中国冬季积雪水量平衡的影响,外强迫和大气环流系统在积雪形成中的作用等。冬春季欧亚大陆积雪对同期和后期中国气候影响的相关研究说明与欧亚大陆积雪异常相关联的中国气候异常以及积雪通过改变土壤湿度、表面温度和辐射分布,引起大气环流异常,进而对中国气候产生影响的物理过程。应用美国环境预测中心(NCEP)第2版气候预测系统(CFSv2)的回报试验结果,对CFSv2在欧亚大陆积雪变化及其与中国气候关系的可预报性方面的分析表明,CFSv2能够较好地回报出春季欧亚积雪的年际和年代际变异及其与中国夏季降水之间的联系。文章最后提出了在积雪及其气候效应研究方面一些有待解决的问题。

The progress on researches concerning wintertime snow cover over China is reviewed in the first part of the article.This part includes the spatial climatological distribution of snow cover and its seasonal,interannual and decadal variability,features of wintertime snowfall,effects of meteorological factors on the snow mass balance,and roles played by external forcing and atmospheric circulation system in the formation of snow cover China.Then,researches on simultaneous and lagged impacts of wintertime and springtime Eurasian snow cover upon climate over China are summarized.It illustrates climate anomalies over China are in association with Eurasian snow cover anomalies,as well as related physical mechanisms.The Eurasian snow cover anomalies can alter the soil moisture,surface air temperature and net radiation,which trigger abnormal mid-latitude atmospheric circulations over the Eurasian continent and thus affect the climate over China.By applying hindcast results of the climate forecast system version 2（CFSv2） of National Center for Environmental Prediction（NCEP）,the predictability of Eurasian snow cover and its relations with climate over China is analyzed.It demonstrates that hindcasts of CFSv2 can well reproduce the springtime interannual and decadal variability of Eurasian snow cover and associated summer rainfall anomalies in China.Although many meaningful results have been obtained on the linkage of Eurasian snow cover with the climate variability over China,some questions still remain unsolved.In the end,some issues concerning the snow cover and its climate effect are listed,which need further investigation.