近60a河西走廊极端气温的变化特征分析

Extreme temperature variation of Hexi Corridor in recent 60 years

选取河西走廊具有代表性的11个气象站1953年1月-2013年2月逐月极端最高、最低气温观测资料,运用趋势拟合、小波分析和Mann-Kendall方法,对近60 a来河西走廊年、季极端气温进行了趋势拟合,分析了年和季节的变化规律,并对其时间序列进行了小波及突变分析。结果表明：近60 a来、季极端最高和最低气温都是增高的。极端最低气温的增温幅度明显高于极端最高气温,且秋、冬季极端最高、最低气温增温最强。年极端最高气温演变呈现为二次曲线;年极端最低气温线性递增趋势显著[0.337℃·（10 a）^-1]。年、季极端最高、最低气温空间分布存在差异,夏季最炎热的地区分布在安敦盆地和民勤等与沙漠接壤的地域,偏暖时段更容易出现极端最高气温的极值,冬季最寒冷的地区位于马鬃山区。年极端最高气温存在着5 a左右的主周期性变化,50-60 a超长周期尺度较为明显;夏季极端最高气温的周期变化与年极端最高气温的周期变化有相似之处。年极端最低气温的变化表现为3 a、6-8 a、10-12 a周期和50-60 a超长周期尺度;冬季还存在40 a超长周期尺度。年极端最高气温暖突变出现在1996年,夏季极端最高气温暖突变出现在2006年;年极端最低气温暖突变出现在1993年;冬季极端最低气温暖突变出现在1977年。

With the monthly extreme maximum and minimum temperature data of 11 ground meteorological observation stations at Dunhuang,Guazhou,Yumen Town,Jiuquan,Gaotai,Zhangye,Shandan,Wuwei,Minqin and Wushaoling regions in Hexi Corridor,Gansu Province,China from January 1953 to February 2013,using linear regression,wavelet and Mann-Kendall method,the paper simulated the trends of annual and seasonal extreme maximum and minimum temperatures of Hexi Corridor in near 60 years,interpreted the changing laws of the annual and seasonal extreme maximum and minimum temperatures,and conducted wavelet and mutation analysis to their time series. The results show that both the annual and seasonal extreme maximum and minimum temperatures are increasing in near60 years. The warming extent of the extreme minimum temperature is obviously higher than that of the extreme maximum temperature,and the autumn and winter extreme maximum and minimum temperatures have the highest warming extent. The evolution of annual extreme maximum temperature is in accord with quadratic curve,and the annual extreme minimum temperature shows a linear increasing tendency with a rate of 0.337 ℃·（10 a）^-1. Spatial distribution of annual and seasonal extreme maximum and minimum temperatures has disparities;the hottest districts in summer appear at the areas joining the deserts such as Andun Basin and Minqin County,where the extreme value of the maximum temperatures is more possibly presented during the warmer stage. The coldest district in winter appears at Mazong Mountain. The annual extreme maximum temperature has 5 a main periodic changes,simultaneously with more obvious 50-60 a ultra-long periodic changes; and the periodic change of the summer extreme maximum temperature is similar to that of the annual extreme maximum temperature. The annual extreme minimum temperature has 3 a,6-8 a,10-12 a periodic changes and 50-60 a ultra-long periodic changes,additionally the winter extreme maximum temperature has 40 a ultra-long periodic changes. The warm abrupt change of the annual extreme maximum temperature of Hexi Corridor is appeared in 1996,and that of the summer extreme maximum temperature is appeared in 2006. Whereas,the warm abrupt change of the annual extreme minimum temperature is appeared in 1993,and that of the winter extreme maximum temperature is appeared in 1977.