西北干旱区极端高温时空变化特征分析

利用1961—2010年西北干旱区83个气象观测站的日气温资料,通过线性倾向率、百分位法及Mann-Kendall法得出西北干旱区极端高温的具体变化特征。用百分位法对西北干旱区日气温数据进行处理,确定极端高温指标的阈值,得出极端高温强度和极端高温事件的频率。结论如下:自1989年开始,西北干旱区年极端高温呈显著上升趋势,空间上西部大于东部,局部地区盆地南缘大于北缘;极端高温日数呈明显的上升趋势;四季极端高温均有上升趋势,秋季增长率最高、冬季最低,秋季极端高温日数增长速率最大;季极端高温及高温日数高值区分布在西北干旱区西北和东南部的盆地边缘,干旱区沙漠边缘及戈壁区;西北干旱区年、季极端高温日数均与年平均气温相关性突出。

Temporal and spatial distribution of the extreme high temperatures in arid regions of Northwest China

Using daily temperature records from 83 meteorological stations in arid regions of northwest China, taking the period 1961-2010 as research time. The climatic trend coefficient method, the percentile method and the Mann-Kendall trend test were utilized to detect the spatio-temporal distribution in the northwest arid. To process the daily temperature by the percentile method that can determine the threshold of extreme high temperature index, the occurrence frequency of extreme high temperature in northwest arid, intensity changes were analyzed. Results shows that: years of extreme high temperature rised since 1989, space on the west higher than the east, southern margin of the basin is greater than the north rim, extreme high temperature days showed a trend of obvious rising; The seasons of extreme high temperature were rising trend, autumn growth maximum and winter minimum, extreme high temperature days in autumn showed a maximum rising speed; the maximum extreme high temperature consistent with its days all distribution in the northwest, basin edge of the southeast, edge of the desert and gobi areas; years extreme high temperature days were correlation with annual average temperature and prominently, the same as the seasons extreme high temperature days.