Space and Temporal Distribution Characteristics of Lightning in Aircraft Flight Areas in Sichuan and Gansu Regions

Lightning is one of the disastrous weather phenomena affecting the safety of aviation aircraft. It is very necessary to study the spatial and temporal distribution characteristics of lightning in the flight airspace. Based on the lightning observation data provided by the National Lightning Monitoring Network, we analyzed the time and space distribution of lightning in Sichuan and Gansu areas from 2010 to 2019. The results showed that the monthly frequency of lightning presented a single-peak feature, which was mainly concentrated in April-September, with the highest occurrence month from June to August, and the peak of lightning occurrence appeared in July, with 3.61 million times. Lightning rarely occurs from October to March, but it occurs every month. The frequency of lightning occurrence is the most in summer, accounting for 68% of the whole year, spring and autumn account for 19% and 13% respectively; winter is the least, less than 1%. The frequency of lightning occurrence has obvious annual variation characteristics, and the frequency of annual occurrence in high frequency years can reach more than twice in low frequency years. The spatial distribution of lightning in the region has an obvious large value center, which is located in Luzhou, the southern part of the basin. Generally speaking, the frequency of lightning occurrence varies greatly among regions. The frequency of lightning in Sichuan Basin is higher than Panxi area, and the western Sichuan Plateau is the least. The frequency of lightning activity is relatively consistent with the heavy precipitation in the region, and the precipitation from the western to the southern Sichuan Basin is relatively large, which also corresponds to the most active area of lightning, which has a good consistency.