Discrimination Techniques of Heavy Foggy Days in Leizhou Peninsula and the Application Effect Analysis

There are several discrimination techniques of foggy days for processing heavy fog data at home and abroad, but their applicability in Leizhou Peninsula is still unclear. Based on the hourly average observation data of 11 automatic meteorological observation stations in Maoming and Zhanjiang regions in the north, middle and south of Leizhou Peninsula from 2011 to 2020, this paper compares the applicability of three foggy days discrimination techniques, namely, daily average visibility method, 14:00 visibility method and visibility duration method, in Leizhou Peninsula, and selects the best discrimination technique to analyze the spatial-temporal distribution characteristics of heavy foggy days. The results show that the visibility duration method has the highest applicability in Leizhou Peninsula, and is the most accurate for judging the heavy foggy days. Using the method of visibility duration to judge the number of foggy days, it is found that the average foggy days in Gaozhou area in the south of Leizhou Peninsula are 26 days. The seasonal distribution of foggy days in Gaozhou is generally uniform, with the highest number of foggy days in May being 20 days. The spatial distribution of foggy days in Leizhou Peninsula is characterized by the maximum number of average foggy days at observation stations in coastal areas, and the closer the station is to the inland, the fewer foggy days it will have.