2012/2013年东北地区冬季异常低温多雪的气候背景分析

Climate Background Analysis of Anomalously Low Temperature and Snowy in Northeast China during 2012/2013 Winter

摘要: 2012/2013年冬季我国大部分，尤其是东北地区气温异常偏低，降雪异常频繁，本文利用NCEP/NCAR再分析等资料对东北地区冬季异常低温多雪的气候背景进行初步分析，结果表明，2012/2013年冬季500 hPa引导层上东亚大槽较常年加深并偏西发展，极涡较常年偏大，有利于冷空气的南下堆积，造成东北地区的持续低温，并且该年冬季AO指数一直持续在负位相，容易造成该年的低温天气；850 hPa异常的偏东气流给东北地区带来了一定的水汽资源。北极海冰面积的减小或可为中高纬的低温多雪天气造成重要影响。

Abstract: Most of our country, especially northeast China, is cold and snowy during 2012/2013 winter. The Climate Background of Anomalously Low temperature and Snowy in Northeast China has been investigated by using the NCEP/NCAR reanalysis data. Results showed that East Asian trough was deeper and experienced a westward movement, and the polar vortex was larger than normal year, which were conducive to the southward accumulation of cold air, and then caused low temperature in Northeast China, at the same time, the AO index was continuing in the negative phase which was also favor for the low temperature weather. The anomalously eastward air current at 850 hPa height field brought moisture resources for Northeast. Moreover, the reduction of the arctic sea ice extent may be the important implications which cause cold and snowy in middle-high latitude regions.