摘要
利用中国西北地区4个台站1932～1992年月平均最高气温（Tmax）、最低气温（Tmin）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，Tmax显著下降，最大达-0．31℃／10a；Tmin显著上升，最高为0．41℃／10a；②西北中部型，以安西为代表，Tmax和Tmin都显著下降，但Tmax下降幅度大于Tmin；③西北北部型，以乌鲁木齐为代表，Tmax和Tmin都显著上升，但Tmin上升幅度大于Tmax。Tmax下降主要表现在夏季，Tmin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，Tmax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。
4 stations in Northwest China monthly mean maximum and minimum temperature andcloud from 1932 to 1992 were used to analyse and compare with Beijing, Eastern China andNorth Hemisphere. The results show that asymmetry is detectable in all seasons, the diurnal temperature range decreases, maximum - 0. 79 ℃ /decade. There are Three kinds ofasymmetry f ① Tmax decreases, minimum - 0. 31℃ /decade, Tmin increases, maximum0. 41 ℃ /decade, in the eastern part of Northwest China (Xian and Lanzhou), ②Tmax andTmin decrease, but Tmax decrease more than Tmin, in The middle part of Northwest China(Anxi), ③Tmax and Tmin increase, but Tmin increase more than Tmax. in the northern part ofNorthwest China. The decrease of Tmax is mainly in winter, The increase of Tmin in summer,The decrease of daily temperature range is in all seas0ns, winter bigger than summer. Thedegree of asymmetric trend in Northwest China is bigger than Beijing, Eastern part of Chinaand North Hemisphere, in which daily temperature ranges 1 -4 times. The decrease of daily temperature range is partially related to increase in cloud. The maximum correlation coeffic ient is -0. 92.
出处
《气象学报》
CSCD
北大核心
1999年第5期613-621,共9页
Acta Meteorologica Sinica
基金
我国西北地区干旱气候变化规律及趋势资助
