1961~2019年哈密市霜冻气候特征分析

Characteristics of Frost in the Hami City dur-ing 1961-2019

摘要: 利用哈密市4个国家气象站1961~2019年的逐日最低气温资料及低温冻害调查资料，采用数理统计方法和Morlet小波分析法，分析了初、终霜冻和无霜冻期的变化特征。结果表明：(1) 近59a全市及各站点终霜冻绝对变率均大于初霜冻，表明终霜冻稳定性差，对农牧业生产的危害更大。(2) 全市及各站点初霜冻呈推迟趋势，终霜冻呈提前趋势，无霜冻期呈延长趋势，其中以巴里坤、淖毛湖变化最为显著。(3) 各地无霜期日数有各自的周期变化特征，但也有共性存在，目前各地无霜期均处于偏长时期。(4) 特晚终霜冻发生年份最少，发生频率为仅为1.7%~5.1%，特早初霜冻发生频率为特晚终霜冻的近2倍。偏晚终霜冻和偏早初霜冻发生频率在10.2%~18.6%之间，两者均主要出现在20世纪90年代之前。

Abstract: Using the data of the minimum temperature from 1961 to 2019 and the survey data of cryogenic injury from four national meteorological stations in Hami with mathematical statistics and Morlet wavelet analysis, the change characteristics of the first frost, the last frost and the frost-free period were analyzed. The results showed that the absolute change rate of first frost was higher than that of last frost, so the last frost is more harmful to farming and animal husbandry. In the whole city and all four stations, the first frost showed a trend of delay, the last frost showed a trend of advance, and the frost-free period showed a trend of extension, among which Balikun and Naomaohu had the most significant changes. Frost-free periods have their own cycle variation characteristics, but also a common existence, the frost-free in a relatively time at present. The occurrence frequency of the latest first frost is only 1.7 - 5.1%, and the occurrence frequency of the arliest first frost is nearly 2 times that of the latest last frost. The frequency of later last frost and earlier first frost ranged from 10.2 to 18.6%, both of which mainly appeared before the 1990 s.