中国西北地区最高、最低气温的非对称变化

THE ASYMMETRIC CHANGE OF MAXIMUM AND MINIMUM TEMPERATURE IN THE NORTHWEST CHINA

中文关键词:  中国西北地区  最高最低气温  非对称变化

英文关键词:Northwest China  Maximum and mimmum temperature  Asymmetry change

中文摘要:

      利用中国西北地区4个台站1932～1992年月平均最高气温(T_max)、最低气温(T_min)及气温日较差(DTR),1971～1992年总云量及低云量资料,分析了西北干旱区最高、最低气温的非对称变化和可能影响因子,并与华北地区、中国东部及北半球进行了比较。发现中国西北地区普遍存在非对称变化现象,可分为3种类型:①西北东部型,以西安、兰州为代表,T_max显著下降,最大达-0.31℃/10a;T_min显著上升,最高为0.41℃/10a;②西北中部型,以安西为代表,T_max和T_min都显著下降,但T_max下降幅度大于T_min;③西北北部型,以乌鲁木齐为代表,T_max和T_min都显著上升,但T_min上升幅度大于T_max。T_max下降主要表现在夏季,T_min上升主要表现在冬季,DTR在所有季节均显著下降,最大为-0.79℃/10a,冬季、春季、秋季及年下降幅度较大,夏季较小。与华北地区和中国东部相比,西北地区非对称变化的幅度更大,DTR大1～4倍。也大于北半球的变化幅度。总云量与DTR,T_max有显著的负相关,东部高于中部和北部,最高可达-0.92,低云量的影响不大。

英文摘要:

      4 stations in Northwest China monthly mean maximum and minimum temperature and cloud from 1932 to 1992 were used to analyse and compare with Beijing. Eastern China and North Hemisphere. The results show that asymmetry is detectable in all seasons, the diurnal temperature range decreases. maximum -0.79℃/decade. There are Three kinds of asymmetry:①T_max decreases, minimum -0.31℃/decade. T_min increases, maximum 0.41℃/decade, in the eastern part of Northwest China (Xian and Lanzhou),② T_max and T_min decrease. but T_max decrease more than T_min, in The middle part of Northwest China (Anxi),③ T_max and T_min increase, but T_min increase more than T_max, in the northern part of Northwest China. The decrease of T_max is mainly in winter, The increase of T_min in summer, The decrease of daily temperature range is in all seasons, winter bigger than summer. The degree of asymmetric trend in Northwest China is bigger than Beijing. Eastern part of China and North Hemisphere. in which daily temperature ranges 1-4 times. The decrease of dai1y temperature range is partially related to increase in cloud. The maximum correlation coefficient is -0.92.