中文摘要：

运用1960—2014年内蒙古46个站点的日气象资料,利用Rclimax软件分析WMO发布的12种极端气温指数及其时空变化规律。结果表明：1960—2014年,内蒙古极端气温指数变化与全球变暖相同步,冰日、霜日、冷日和冷夜指数趋于减少,而夏日、热夜、暖日、暖夜和生长季长度指数区域增大。极端最高（最低）指数呈增加的趋势,而气温日较差趋势则趋于减小。空间分布上,内蒙古西部极端天气指数变化明显,显示出地表裸露的地区对气候的变化敏感。相比于1960—1985年,1986—2014年气温上升更加的强烈,在此期间,冷指数（ID0、FD0、TN10和TX10）显著下降而暖指数（SU25、TR20、TN90和TX90）显著上升。1985年前各站点极端气温指数变化趋势复杂,而1986年后大部分站点冷（暖）指数表现为下降（上升）趋势。极端指数的变化与纬度和海拔相关性较弱,但各指数与经度却存在广泛的关联。北极涛动（AO）对内蒙古的气候有着一定的影响,各站点的极端指数与AO有显著相关,冷指数表现尤其明显。

英文摘要：

Based on the daily temperature data from 46 meteorological stations in Inner Mongolia during the period from 1960 to 2014,the spatiotemporal variations of extreme temperature events in the study area were investigated. The RClim Dex software was used to calculate and analyze the 12 kinds of extreme temperature indices released by WMO. The results revealed that,in recent 55 years,the extreme temperature indices in Inner Mongolia were in sync with global warming trend,the ID0,FD0,TN10 and TX10 were gradually decreased,whereas the SU25,TR20,TN90 and TX90 were significantly increased. TXx and TNn were in an increase trend,however DTR was tended to decrease. Spatially,the most obvious trend of extreme temperature occurred in west Inner Mongolia,and the bare underlying surface was highly sensitive to climate change. The temperature increase during the period of 1986-2014 was more significant than that during the period of 1960-1985. During this period,the cold indices（ ID0,FD0,TN10 and TX10） were significantly decreased,but the heat indices（ SU25,TR20,TN90 and TX90） were obviously increased. Moreover,the change trend of extreme temperature indices at the stations was complex before 1985,but the cold（ heat） indices at almost all stations were decreased（ increased） after 1986. The correlations between the extreme temperature indices and the latitude and elevation were weak,but it was strong with longitude. The Arctic Oscillation（ AO） affected climate change in Inner Mongolia to a certain extent,and AO had the significant correlations with the extreme temperature indices,especially with the cold indices.