东北夏季气温变化与北半球温度及极涡的关系

利用1961-2002年中国东北地区80个气象站夏季6-8月逐日气温、美国NCAR/NCEP再分析资料和国家气候中心环流因子资料,采用相关分析、SVD分解等方法,对中国东北夏季气温变化与中高纬主要环流系统的关系进行探讨.结果发现:中国东北位于东西伯利亚变温区南缘,其夏季气温年际变化规律和东西伯利亚一致;北极极涡边缘的形态变化影响东北夏季气温,不同的边缘形态对应东北不同的温度分布特征,主要是极涡边缘70 °N左右的150～180 °E和60～90 °W两个关键区,其高度场的变化决定着东北夏季气温的变化.

The relationship of variability of summer temperature between Northeast China and the Northern Hemisphere and the impacts of the polar vortex

With the NCAR/NCEP monthly reanalysis data and the monthly mean temperature at 80 stations in Northeast China from 1961 to 2002, as well as 74 factors of general circulation from Chinese National Climate Center, the feature of summer temperature over northeast China and the correlation between summer temperature and middle-high latitude circulation system are studied by the method of SVD and correlation analysis. The following conclusions are reached: Northeast China is located in the south edge of Siberia temperature variation region with the same inter-annual summer temperature variation that east Siberia has. Polar vortex is an important system which affects the variation of summer temperature over northeast of China. The variation of its edge of height field as well as the extent or contraction of the polar vortex in different directions leads to different distribution and variation of the summer temperature. The height field located in about 70 °N ,150～180 °E and 60～90 °W which are two key regions.