北京城区气温变化特征

利用1975—2012年朝阳、海淀和丰台气象站年平均气温、最高和最低气温及降水资料研究北京城区气温变化特征。结果表明:1北京气温近40年来增温显著,年平均、最高和最低气温增温率分别为0.445、0.33、0.5℃/10a。北京近年来的增温以20世纪90年代和21世纪初最为显著。2用M-K方法检验北京气温存在跃变现象,平均、最高和最低气温的跃变时间分别为1992、1992、1991年。3跃变后比跃变前年平均最低气温上升幅度最大,达1.1℃;平均气温次之达1.0℃;最高气温上升达0.8℃。4跃变后比跃变前高温日数增加,冷的日数减少,即跃变后气温达到更暖阶段。降水在跃变后比跃变前减少,即降水和气温变化呈反位相向分布。

Characteristics of Temperature Variation in Beijing Urban Area

The annual-average, maximum, and minimum temperature data from Chaoyang, Haidian, and Fengtai （Beiiing urban area） from 1975 to 2012 are studied. The results show： （1） Temperature in Beiiing in recent 40 years increased significantly, and the warming rates of annual mean, maximum and minimum air temperature are 0. 445, 0.33, and 0.5 ℃ per 10 years, respectively; the warming in Beijing was most significant in the 1990＇s and 2000＇ s. （2） The M-K method is used to test temperature jumps in Beijing, and the results indicate that there were lumps in average, maximum, and minimum temperature with time in 1992, 1992, and 1991, respectively. （3） After the mutation, the average minimum temperature rose most noticeably with the rising amplitude up to 1.1 ℃, then the average temperature and maximun temperature, with the rising amplitudes being 1.0 ℃ and 0.8 ℃. （4） After the mutation, the number of high-temperature days increased, while the number of cold days reduced, but precipitation decreased; precipitation and temperature change with anti-phase distribution.