四川最高最低气温日变化特征分析

基于1990~2019年四川地区156个气象观测站2 m最高、最低气温逐日数据，分析了最高、最低气温的日变化特征。结果表明:（1）2 m最高气温逐日变化幅度大于最低气温逐日变化幅度，最高气温逐日变温的极大值区位于凉山州东北部，最低气温逐日变温的极大值区位于甘孜、阿坝两州北部；（2）春季最高气温逐日变温幅度明显大于夏、秋、冬季，冬、春季最低气温逐日变温幅度大于夏、秋季；（3）最高气温和最低气温的逐日变温频次分布均呈现单峰型特征，前者峰值位于0~2℃，后者峰值位于?2~2℃。（4）最高气温逐日变化超过6℃的年均频次明显高于最低气温，两者高频区的空间分布与变温幅度大值区较为一致。 

Daily Variation Characteristics of Maximum and Minimum Temperature in Sichuan Province

Based on the 2m daily maximum and minimum temperature data in Sichuan province from 1990 to 2019, the daily variation characteristics are analyzed. The results show that: (1) The daily variation range of 2m maximum temperature was greater than that of minimum temperature. The area with the largest maximum temperature variation was located in the northeast of Liangshan Prefecture, while that of the minimum temperature was located in the north of Ganzi and Aba Prefectures. (2) Among the four seasons, the daily variation range of the maximum temperature in spring was significantly greater than those in summer, autumn and winter. The daily variation ranges of the minimum temperature in winter and spring were greater than those in summer and autumn. (3) The frequency distributions of the daily variation of maximum and minimum temperature were unimodal, with the peak value of the former being 0~2℃ and the latter being ?2~2℃. (4) The annual frequency of the maximum temperature with daily variation exceeding 6℃ was significantly higher than that of the minimum temperature. And the spatial distributions of the two high-frequency regions were consistent with the areas of the largest daily temperature variation.