中国东北地区冬季气温变化特征及其大气环流异常的关系

利用1957-2010年冬季中国东北地区90站气温资料，应用REOF和聚类分析方法将东北划分为南、北两个冬季气温变化子区，分析讨论其冬季气温的变化趋势和冷暖异常特征，及其与主要环流指数之间的同期和滞后关系。使用向后去除变量选择法，选取最优预测因子，并建立了全区和各子区的回归统计模型。结果表明：东北冬季增温较明显，平均上升速率达到0. 45 ℃/ 10 a，北部略高；与同期欧亚纬向环流指数之间存在着较显著相关；前期8月东太平洋副热带高压面积指数、前期10月亚洲区极涡面积指数和前期8月北半球极涡面积指数与东北冬季气温存在着显著相关，复相关系数达到0.70，并且是回归方程最关键预测因子。在对冷、暖冬预测时，可以把选定时段和区域副热带高压和极涡面积指数作为重要的影响因素，且误报率较低。

Winter temperature variability and its relationship with atmospheric circulation anomalies in Northeast China

Based on air temperature data from 90 metrological stations in winter from 1957 to 2010 in the northeast China, the study area was divided into the south and north subregions in terms of winter air temperature using methods of a rotated empirical orthogonal function (REOF) and a cluster analysis. The variation trends of winter air temperature and warm and cold winter were analyzed, and their relationships with main circulation indexes were discussed. The optimum forecast factor was selected by a back-method, and regression models were built in the whole study area and two subregions. The results indicate that winter air temperature increases obviously in the northeast China, and the ratio reaches 0. 45 ℃/ 10 a, especially in the north area. The correlation between winter air temperature and the simultaneous Euro-Asian zonal circulation indexes is significant. The subtropical high area index in August in the east Pacific Ocean, polar vortex area index in October in the Asia area and polar vortex area index in August in the north hemisphere are in the significantly positive correlations with winter air temperature, and their multiple correlation coefficients all reach 0.70. The above three factors are the key forecast factors in regression equations. If the subtropical high and polar area indexes are used as the important influencing factors when it forecast cold winter and warm winter, the forecast effect is good.