丹寨县山区雾气候特征及成因分析

Climatic Characteristics and Cause Analysis of Mountainous Fog of Danzhai County

摘要: 利用2014年至2023年丹寨县国家基本气象站和龙泉山区域自动气象站资料，分析丹寨县山区雾的气候特征及天气成因。结果表明：(1) 丹寨县山区雾雾日数有逐年增加趋势，出现雾最多的月份为1、2、3、11月，峰值出现在3月份，且雾多生成于夜间，常伴有降雨现象，白天最易生成雾的时间为8、9、17、19时，雾持续时间主要为1、2、3、4、12小时，频次最多为1小时；(2) 丹寨县山区雾多出现在夜间降温、夜间平均相对湿度在90%以上以及1 ≤ 日平均风速 < 3 m/s的条件下，0℃ < 夜间降温幅度 ≤ 3℃、1℃ ≤ 气温日较差 < 9℃的雾日数分别占总雾日数61.6%、86.3%，平均相对湿度在90%以上的雾日数占总雾日数83.63%，1 ≤ 日平均风速 < 3 m/s的雾日数占总雾日数的78.48%；(3) 近地面层逆温对丹寨县山区雾的出现有所影响，但不是最主要原因，近地面层逆温对雾的出现影响最大的月份为11月；(4) 丹寨县山区雾的形成与喇叭口地形的地形收缩作用密切相关。

Abstract: Using data from the Danzhai County National Basic Meteorological Station and the Longquanshan Regional Automatic Meteorological Station during 2014 to 2023, analyze the climatic characteristics and causes of mountainous fog of Danzhai County. The results showed that: (1) The number of foggy days in the mountainous areas of Danzhai County has been increasing year by year. The months with the most fog are January, February, March, and November, with the peak appearing in March. Fog is mostly generated at night, often accompanied by rainfall. The time when fog is most easily generated during the day is 8, 9, 17, and 19 o’clock, and the duration of fog is mainly 1, 2, 3, 4, and 12 hours, with a maximum frequency of 1 hour. (2) Mountainous fog often occurs of Danzhai County under conditions of nighttime cooling, average relative humidity above 90% at night, and 1 ≤ daily average wind speed < 3 m/s. The number of foggy days with 0˚C ≤ nighttime cooling amplitude ≤ 3˚C and 1˚C ≤ daily temperature difference < 9˚C accounts for 61.6% and 86.3% of the total foggy days, respectively. The number of foggy days with average relative humidity above 90% accounts for 83.63% of the total foggy days, and the number of foggy days with 1 ≤ daily average wind speed < 3 m/s accounts for 78.48% of the total foggy days. (3) The inversion of the near surface layer has an impact on the occurrence of mountainous fog of Danzhai County, but it is not the main reason. The month with the greatest impact of near surface layer inversion on fog occurrence is November. (4) The formation of mountainous fog of Danzhai County is closely related to the terrain contraction effect of the horn shaped terrain.