青神大雾特征分析

Analysis of Fog Characteristics in Qingshen

摘要: 使用青神县国家气象观测站1971~2022年逐日能见度数据、2017~2022年逐小时能见度数据，对青神大雾年和月际变化、生消时间、持续性特点等进行了研究分析，得出以下结论：青神雾日具有明显的年际和月际变化，1971~1977年、2003~2015年是少雾年，1978~2002年、2016~2022年是多雾年；1、12月各类雾出现频次较高，5、6月各类雾出现频次较低；1978~2000年、2016~2021年出现持续性广义大雾(V < 1 km)的次数在10次以上，1988~2000年持续性大雾(500 m ≤ V < 1 km)的次数在5次以上，持续性浓雾、强浓雾或特强浓雾每年出现次数较小，一般在3次以下；持续性雾天气以3 d最多，随着天数的增多其占比迅速减小；早上到上午是各类雾发生的主要时段，雾生成的高发时段一般在09时之前，消散时间一般在11时之前，下午和前半夜各类雾生消占比很低；各类雾出现时长以1 h为主，占比超过40%，随着时长的增加占比迅速减小，持续6 h及以上的占比极低。

Abstract: This paper uses daily visibility data from 1971 to 2022 and hourly visibility data from 2017 to 2022 of national meteorological observation station in Qingshen to analyze the annual and inter-monthly changes, generation and dissipation time, and persistence characteristics of fog. The result shows: The fog in Qingshen has obvious inter-annual and inter-monthly changes. There are many foggy days from 1978 to 2002, 2016 to 2022, and less foggy days from 1971 to 1977, 2003 to 2015. There’s high frequency of fog occurrence in January and December, while low frequency in May and June. The persistent generalized fog (V < 1 km) occurred more than 10 times every year from 1978 to 2000 and 2016 to 2021, the persistent fog (500 m ≤ V < 1 km) occurred more than 5 times every year from 1988 to 2000. There’re less than 3 times every year for persistent dense fog, strong dense fog and extremely strong dense fog. The most duration is three days for persistent foggy events, and the proportion decreased rapidly with the increase of duration days. Morning is main period of oc-currence for all kinds of fog. The high incidence time of fog generation is before 9 am, and the dissi-pation time is generally before 11 am. Proportion of generation and dissipation for all kinds of fog is very small in the afternoon and the first half of the night. The duration time for all kinds of fog is mainly 1 h, which accounts for more than 40%. Occurrence proportion decreases rapidly with the increase of time, and the proportion for 6 h and above is very small.