全球变暖背景下重庆主要气象灾害变化趋势

利用重庆地区34个气象台站1961-2008年逐日降水量、平均气温、最高气温和雷暴、冰雹、大风、雾和霾天气现象资料,分析了重庆高温干旱、暴雨、连阴雨、雷暴、冰雹、大风、雾和霾等主要气象灾害的变化趋势.统计结果表明:近48年重庆地区春旱、伏旱和冬旱日数都呈下降趋势,而夏旱和秋旱日数都呈增加趋势,其中春旱日数的减少趋势明显,减少速率为-1.7d/10a;高温日数具有先减少后增多的年代际变化特征,20世纪90年代以来呈明显增加趋势;暴雨日数在20世纪80年代和90年代为多发时段;连阴雨日数整体呈增多趋势,增加速率为1.2d/10a.近36年重庆地区雷暴、冰雹、大风和霾日数的变化特征类似,都呈显著的单调减少趋势,减少速率分别为-3.0,-0.05,-0.6,-1.5d/10a;雾日数整体呈减少趋势,减少速率为-2.2d/10a,同时具有先增多后减少的年代际变化特征.

Changing Trends of Major Meteorological Disasters in Chongqing under Global Warming

Based on the daily observational data of precipitation,mean temperature and other weather phenomena of 34 meteorological stations in Chongqing from 1961 to 2008,the linear trends of some major meteoro1ogical disasters like drought,heat wave,rainstorm,continuous rain,thunderstorm,hail,high wind,fog and haze were analyzed.Statistical analysis indicated that spring drought,midsummer drought and winter drought days all showed a decreasing trend in Chongqing in the recent 48 years,of which spring drought days had a significant trend with a rate of-1.7 d/10 a.There was a slightly increasing trend in seasonal drought days of summer and autumn.The heat wave days had a decadal change with first decreasing and then increasing.Rainstorm took place frequently in the 1980’s and the 1990’s,while annual continuous rainy days increased significantly at a rate of 1.2 d/10 a.The thunderstorm,hail,high wind and haze days exhibited a similar changing trend,with a monotone decrease at a rate of-3.0 d/10 a,-0.05 d/10 a,-0.6 d/10 a and-1.5 d/10 a,respectively,in the recent 36 years.The foggy days showed an increasing trend at a rate of-2.2 d/10 a and a decadal change with first increasing and then decreasing.