1958—2015年长江中下游寒潮时空演变特征

基于长江中下游地区54个气象站点1958—2015年日最低气温数据,从时间和空间的角度,定量分析该地区寒潮发生发展的演变特征和空间变化。结果表明：过去58年,寒潮发生次数呈不显著减少趋势,平均减少幅度为1.2次/站;寒潮过程中,最低气温的平均降温幅度呈南高北低分布,最低气温的极端降温幅度呈自区域中心向四周逐渐降低分布。寒潮发生的首次最早为8月1日（九江站）,末次最晚为5月4日（寿县站和六安站）,出现时间的空间分布差异显著。冬季寒潮频发,春季和秋季次之。

Spatio-temporal characteristics of cold wave in the middle and lower reaches of the Yangtze River between 1958 and 2015

The daily cooling rate of station was calculated based on daily minimum temperature data of 54 meteorological stations in the middle and lower reaches of the Yangtze River from 1958 to 2015. A quantitative analysis of the evolutionary characteristics and spatial changes of cold wave occurrence and development was conducted in the region. The results showed that in the past 58 years, the frequency of cold wave presented an insignificant decrease trend with an average of 1.2 times/station (P>0.05). During cold wave processing, the spatial distribution of average difference of the minimum temperature was higher in the south and lower in the north; and the extreme of average difference of the minimum temperature gradually decreased from the regional center to the surroundings. The first cold wave occurred on August 1 (Jiujiang), and the last on May 4 (Shouxian and Lu'an). The spatial distribution of the time difference was significant. The frequent cold waves occurred in winter, followed by spring and autumn.