欧亚和我国东北冬春季积雪对东北夏季气温的影响  

Influence of Winter and Spring Snow Cover in Eurasia and Northeast China on Summer Air Temperature over Northeast China

作　　者：张茜[1] 李栋梁[1] 

机构地区：[1]南京信息工程大学大气科学学院/气象灾害省部共建教育部重点实验室,江苏南京210044

出　　处：《冰川冻土》2012年第2期284-295,共12页Journal of Glaciology and Geocryology

基　　金：国家重点基础研究发展计划(973计划)项目(2007CB411506);冰冻圈科学国家重点实验室开放基金项目(SKLCS08-06);江苏高校优势学科建设工程资助项目(PAPD)资助

摘　　要：根据我国东北及邻近地区123个气象站的逐日气温和积雪深度资料,欧亚大陆积雪面积以及NCEP/NCAR全球再分析月平均500hPa高度场资料,通过相关、合成分析等方法,研究了东北夏季气温异常对欧亚和我国东北冬春季积雪的响应,并从大气环流的角度出发分析了欧亚和我国东北冬春季积雪对东北夏季气温异常形成的影响机制.结果表明:东北地区夏季气温与欧亚大陆春季积雪面积以及东北冬季累积雪深的异常存在明显的关系.欧亚春季积雪面积的扩大与维持有利于8月我国东北上空500hPa位势高度的偏低,环流上表现出西欧与我国东北地区槽加深,泰梅尔阻塞高压加强的特征.由于欧亚中高纬上空的环流经向度加大,槽后脊前的西北气流加强,诱导冷空气南下,从而造成东北全区8月气温一致偏低;东北冬季累积雪深减少则有利于6月东北全区、7月东北西南部上空的位势高度偏低(负距平),造成相关区域气温偏低.研究结果对于提高东北夏季气温的短期气候预测水平具有重要意义.Based on the observational data from 123 stations in Northeast China（NEC）,snow cover area in Eurasia and NCEP/NCAR reanalysis data of 500 hPa monthly average height,the response of summer air temperature over NEC to the anomalies of snow cover in Eurasia and Northeast China in winter and spring are studied by synthetic analyzing and correlation analysis methods.Additionally,the mechanism how snow cover in winter and spring influences the summer air temperature over NEC is also analyzed from the aspect of atmospheric general circulation.The results show that the summer air temperature over NEC is highly related with spring snow cover area in Eurasia and winter snow depth in NEC.The expansion and maintenance of spring snow cover area in Eurasia is favorable to the descending of 500 hPa potential height in August over NEC,and the general circulation is characterized by that the trough over Western Europe and NEC is much lower and Taymyr blocking high is much stronger.As the meridional circulation is enhanced in the high latitudes,the northwest flow behind the trough is strengthened,thus inducing cold air to move southward.As a result,the August temperature in NEC is low.Decreasing winter snow depth in NEC is helpful for the decrease of 500 hPa potential height over NEC in June and over the southwest of NEC in July,which leads to low temperature over NEC in June and over the southwest of NEC in July,respectively.This study brightens the short-term forecast of summer air temperature over NEC.

关 键 词：东北夏季气温 欧亚积雪面积 东北累积雪深 大气环流 

分 类 号：P461.6[天文地球—大气科学及气象学]