1961～2010年内蒙古地区极端气候事件变化特征

Variable Characteristics of Extreme Climate Events During 1961-2010 in Inner Mongolia

基于内蒙古地区71 个地面气象站1961 ～ 2010 年逐日最高气温、最低气温以及逐日降水资料,结合温度和降水极端值和极端事件指标,采用气温资料均一性检验和订正、多项式法、线性倾向、Mann - Kendall 法等统计学方法诊断分析其变化特征.结果表明：（1）近50 a 内蒙古地区年和四季平均气温均发生了突变,1987 年为年平均气温突变转折点,四季气温突变时间春季最早,夏季最晚;（2）内蒙古地区表征极端气温增暖的极端最高气温、极端最低气温、高温日数、暖夜日数和暖日日数等指数均呈明显增加趋势;极端低温事件指标如低温日数、冷夜日数和冷日日数等均呈现出减少趋势,尤其在气温突变之后,增暖趋势和低温减少趋势更为明显.同时,气温突变后,大多数极端气温事件指数变差系数增大,说明极端气温事件的波动性增大;（3）内蒙古地区除极端降雪量呈略微增加趋势外,其余极端降水事件指标均呈明显减少趋势,尤其在气温突变后,其极端降水事件减少,降水强度减弱.

Based on daily maximum and minimum temperature and precipitation of 71 weather stations in Inner Mongolia during 1961 -2010,according to the extreme indexes of temperature and precipitation,the variable characteristics of extreme climate events were analyzed by using homogeneity test and revisal,the polynomial method,linear tendency estimation,Mann - Kendall test. The results areas follows：（1）In recent 50 years,the annual and seasonal average temperatures occurred mutations in Inner Mongolia,but the mutation time of them had difference. The annual temperature had an abrupt change in 1988. The mutation of temperature in spring was earliest,and in summer was latest. （2）The indexes of extreme high temperature such as maximum and minimum temperature,high temperature days,warm night days and warm daytime days increased obviously,while the extreme low temperature indexes such as lowtemperature days,cold night days and cold daytime days decreased significantly especially after mutation. However,the fluctuation ofextreme temperature increased after mutation. （3）The indexes of the extreme precipitation events reduced significantly except for theextreme snowfall especially after mutation in Inner Mongolia.