Abstract: From the view of single station and region, based on the daily average temperature and minimum temperature data at 5 meteorological stations in eastern Hexi Corridor of Gansu Province from 1960 to 2017, the temporal and spatial variation characteristics of cold waves frequency were analyzed statistically by using linear trend analysis, Mann-Kendall test and Morlet wavelet methods. The results show that the spatial distribution of cold waves frequency and intensity was obviously different at each station of eastern Hexi Corridor. The frequency of cold waves decreased gradually from north to south except for Wuwei station, while the intensity of cold wave was strong in the north and the south and weak in the middle. The single-station cold waves mainly occurred from September to next May, while the regional cold waves distributed from October to next May, and the single-station and regional cold waves tended to happen in spring, while the strongest was easily to occur in autumn. The frequency of cold waves mutated significantly from many to few at Minqin, Yongchang and Wuwei stations of eastern Hexi Corridor from 1960 to 2017, and the mutation occurred in 1973, 1973 and 2014, respectively. The frequency of cold waves existed 41 a periodic change at five stations of eastern Hexi Corridor. The frequency of regional cold waves appeared interdecadal variation in phase, it significantly decreased firstly and then slowly increased, but the mutation wasn’t significant, and there were 42 a, 15 a, 8 a and 4 a periodic changes. The current statistical standard of cold waves can’t fully reflect cold air activity with temperature slowly declining.

Key words: cold waves, temporal and spatial variation characteristics, eastern Hexi Corridor

摘要： 利用甘肃河西走廊东部5个气象站1960—2017年平均气温和最低气温逐日资料，采用线性趋势法、Mann-Kendall检验及Morlet小波分析等方法，从单站和区域角度出发，统计分析河西走廊东部地区寒潮的时空变化特征。结果表明：河西走廊东部单站寒潮次数及强度存在明显的空间差异，除武威站外寒潮频次自北向南逐渐减少，而寒潮强度则呈现南北两端强、中间弱的分布特征。单站寒潮主要发生在9月到次年5月，而区域性寒潮多发生在10月至次年5月，单站和区域性寒潮在春季最易发生，而最强区域性寒潮易出现在秋季。近58 a 来，河西走廊东部民勤、永昌、武威3站寒潮次数均发生了由多到少的显著突变，突变点分别为1973、1973、2014年，且5站寒潮频次均存在41 a左右的周期变化；区域性寒潮频次呈现明显的“显著减少-波动变化-缓慢增加”阶段性年代际变化，但未发生显著突变，且具有42 a、15 a、8 a、4 a的变化周期。现行寒潮统计标准无法完全反映气温缓慢下降的冷空气活动。

关键词: 寒潮, 时空变化特征, 河西走廊东部