【摘要】 利用1961—2004年甘肃省80个气象站夏季极端最高气温的标准化资料,运用EOF,REOF等方法,对甘肃省44年夏季(6—8月)极端最高气温的空间分布、时间演变特征等进行了详细分析。结果表明:第一特征向量反映了甘肃省极端最高气温受大尺度天气系统影响下的高温一致性;第二特征向量反映了甘肃省极端最高气温南北相反的差异。甘肃省极端最高气温空间异常可分为4个气候区,即甘肃省中部、陇东南部、河西中部和甘南高原区。各气候区极端最高气温的变化趋势相似:从20世纪60年代到90年代,甘肃省大部分地区夏季极端高温是升高的,极端最高气温90年代最高,其次是70年代,60年代最低;在70年代初期,大部分地区的极端高温发生了一次由低到高的转折性变化。更多还原

【Abstract】 Using the data of the extreme high temperatures in summer from 1961 to 2004 of 80 meteorological stations in Gansu Province,the climatic characteristics of the extreme high temperatures and their distributions in decade are analyzed.Exploring EOF and REOF,the inter-decadal variation,abnormal spatial distributional features,and the temporal evolution of extreme high temperatures in the summer in Gansu Province are studied in detail.The results show: ① the extreme high temperatures in summer are affected by the large-scale weather systems,the first eigenvector represents the same trend of extreme high temperatures in Gansu Province,the second eigenvector represents that there are the temperature anomaly differences between the north and the south,the abnormal distribution of extreme high temperatures in Gansu Province is the same trend pattern and the adverse trend pattern between the Hedong and Hexi corridor district;② there are four climate types representing the spatial abnormal feature of extreme high temperatures in the summer in Gansu Province,they are the middle of Gansu Province,the south of Longdong district,the middle of Hexi corridor and Gannan plateau;③ the temperatures in Hexi corridor and Lanzhou,Baiyin in 1960s are obviously lower than the average value,except that the temperatures in part of Longnan and Tianshui are higher than the average value,the temperatures in the rest parts of Gansu Province are lower in 1960s,the lowest temperatures are in the northwest part of Hexi corridor and the north part of Longdong;④ the evolutional trend of the extreme high temperatures in every climatic district is similar: from 1960s to 1990s,the extreme high temperatures rise in the summer in most part of Gansu Province,and the extreme high temperatures in 1990s are the highest,the next is in 1970s,the lowest is in 1960s,at the beginning of 1970s,the extreme high temperatures experience a change from the low to the high;⑤ there is an apparent inter-decadal variation in the extreme high temperatures in the summer in Gansu Province,the extreme high temperatures in the summer during 1960s,are the lowest and they rise obviously from 1970s,the highest are in 1990s,this feature is not consistent with the phenomenon which the extreme high temperatures begin to rise in 1980s in the globe.It shows that the extreme high temperatures in the summer in Gansu Province are unique,and the change in the extreme high temperatures in summer are local.更多还原