1951—2008年东北地区冬季气温变化及环流场特征

Variation characteristics of winter air temperature and circulation field from 1951 to 2008 in the Northeast China

利用1951—2008年中国东北地区气温资料和NCEP高度场再分析资料,通过线性趋势分析和M-K检验方法,对东北地区冬季气温变化进行研究。结果表明:东北地区冬季变暖的时间是从20世纪80年代中期开始,突变年为1986年;冬季气温最暖年代出现在21世纪初;东北三省冬季累年气温变化趋势倾向基本是纬度越高气温趋势倾向值越大,特别是在1999—2008年黑龙江省冬季气温趋势倾向增温最显著。而在年气温变化趋势中,东北三省平均趋势倾向值没有冬季趋势倾向值大,其中吉林省气温趋势值最大。冷、暖冬年500 hPa高度距平场分布为冷冬负距平中心位于中国东北地区中部;暖冬年正距平中心位于贝加尔湖到中国东北地区中北部。低空冷冬年,东北地区受西北风、西风和东北风控制,冷空气势力强;暖冬年,东北地区仅受西北风影响,冷空气势力弱。

Based on the air temperature data and the NCEP reanalysis data of height field from 1951 to 2008,the variations of winter air temperature in the Northeast China were analyzed in terms of methods of a linear trend analysis and a Mann-Kendall test.The results indicate that the warming in winter in the Northeast China begins since the middle stage of 1980s,and the abrupt change of winter air temperature occurs in 1986.The warmest decade in winter appears in the early stage of 21 century.For winter air temperature in the Northeast China,the higher the latitude is,the larger the tendency value of winter air temperature is.The warming tendency in Heilongjiang province is the most obvious from 1999 to 2008.For annual air temperature,the tendency value of winter air temperature is larger than that of the average of the Northeast China,and the largest one is in Jilin province.The distributions of height anomaly field in 500 hPa in cold and warm winter years show that the negative and positive anomaly centers in cold and warm winter years are located in the middle of the Northeast China and from Baikal Lake to the mid-north of the Northeast China,respectively.The low level are controlled by the northwestern wind,west wind and northeastern wind in cold winter year in the Northeast China and cold air is strong,while it is only influenced by the northwestern wind in warm winter year and cold air is weak.