华北冬季气温年代际变化特征分析

Analysis of Winter-temperature Inter-decadal Variations in North China

利用NCAR／NCEP再分析资料和华北地区19个站点月平均气温资料，运用EOF分解、相关分析、合成分析、t检验等方法，分析了华北地区近60年冬季及各月平均气温年代际变化特征；并分析了其环流背景场的变化特征。结果表明，近60年华北地区1月、2月、冬季平均气温有升温趋势和明显的年代际变化特征；1月、2月、冬季平均气温在20世纪80年代中后期之前偏冷，在80年代中后期之后偏暖；12月平均气温没有趋势变化。但年代际变化显著。1961-1971年偏冷，1972-1991年偏暖。1、2月华北冬季气温年代际变化与东亚冬季风年代际变化有很好的一致性，80年代中后期之前东亚冬季风偏强，华北地区冬季1、2月偏冷；80年代中后期之后东亚冬季风偏弱，华北地区冬季1、2月偏暖。但12月气温的年代际变化除了与东亚冬季风的强度年代际变化有关外，可能还与其他因子有关。

According to NCEP/NCAR reanalyzed data and 19 stations average temperature data of North China in winter, by applying the meth- ods of EOF, correlation, composite and t test ete ~ the inter-decadal variations characteristics of winter average temperature in North China of lately 60 years and its atmospheric circulation characteristics are studied. Results show that in North China of January and February, the trend of winter average temperature of lately 60 years is positive and the inter-decadal variations characteristics is significant. In January and February, the winter average temperature was colder before the late 1980s, and warmer after the late 1980s. There is no trend variations in December, but the inter-decadal variations characteristics is significant, colder in 1961-1971 and warmer in 1972-1991. In January and February, the inter-dec- adal variations of the winter temperature in North China and the inter-decadal variations of the East Asian Winter Monsoon have significant consis- tency. The East Asian Winter Monsoon was stronger before the late 1980s and the temperature in North China of January and February was lower. While the East Asia Winter Monsoon was weak after the late 1980s, and the temperature in North China of January and February was higher. The inter-decadal variations of temperature in December may also links with other factors besides the intensity of the inter-decadal variations of the East Asian Winter Monsoon.