利用内蒙古地区1961~2003年101个气象站的月平均气温资料和旋转经验正交函数分解的方法,根据四季气温变化的一致性进行区域的划分,并分析气温变化的季节和区域差异。结果表明:内蒙古地区的四季气温变化存在着明显的东、西分异,春、秋、冬季的气温场划分为东部和西部两大区域,而在夏季,则划分为西部、东南部和东北部三大区域;在年际波动方面,除夏季的东南区以外,近43年中各区四季气温的变化都经历了一次显著的由降而升的转折,转折点大致出现在80年代中、后期或90年代初、中期;在线性趋势方面,东部区春、夏季的升温幅度和显著性大于西部区,而西部区秋、冬季的升温幅度和显著性则大于东部区。一般而言,冬季和夏季升温最为显著,其次是春季,秋季升温最为微弱。

Using monthly mean air temperature data from 101 meteorological stations during 1961-2003 in the entire Inner Mongolia and the method of Rotated Empirical Orthogonal Functions (REOF), we implemented a regionalization according to consistency in air temperature variations of the four seasons, and analyzed seasonal and regional differences of air temperature variations. The seasonal air temperature changes indicate an apparent east-west difference in Inner Mongolia. The air temperature fields of spring, autumn and winter could be divided into two regions, namely, the West Region and the East Region, whereas the air temperature field in summer could be classified into three regions, namely, the West Region, the Southeast Region and the Northeast Region. In terms of the interannual variation, the seasonal air temperatures in each region experienced an obvious transition from decrease to increase during the recent 43 years except the Southeast Region in summer, and the turning points appeared either in the middle and late 1980s (in the East Region of spring and summer, and in the East and West Regions in autumn and winter) or in the early and mid-1990s (in the West Region of spring and summer). Dealing with the linear trend, the slope and significance of increased temperature trends in the East Region are larger than in the West Region during spring and summer, whereas the slope and significance of increased temperature trends in the West Region are larger than in the East Region during autumn and winter. Generally speaking, the most significant temperature increase appeared in winter and summer and then in spring, and the slightest temperature increase was shown in autumn.