ANALYSIS OF LIGHTNING CHARACTERISTICS IN BEIJING BASED ON VLF/LF 3D LIGHTNING LOCATION MONITORING SYSTEM

GUO Run-xia; WANG Ying-chun; ZHANG Wen-long; LI Jing-xiao

doi:10.16032/j.issn.1004-4965.2018.03.013

Abstract：Based on the lightning data of VLF/LF 3D lightning location system from January 2015 to December 2016 in Beijing, the temporal and spatial characteristics of total lightning, intracloud lightning flashes(IC) and cloud-to-ground lightning flashes(CG) and the characteristic of the lightning current intensity were analyzed. The results are as follows. (1) Most lightning flashes occur between June and September, and the peak frequency occurs in July.The lightning flashes occur mostly from 15 BST of the day to 02 BST of the next day. There are three peaks in diurnal variation of total lightning,which is at around 15 BST, 20 BST and 02 BST of Next day. (2) There are two high value regions of spatial density of total flashes, and one is located in central and southern area of Mentougou and central and western area of Changping, the other is in the junction area among Miyun, Shunyi, and Pinggu. The high value regions of spatial density of IC and CG flashes have the distributions just as that of total flashes. The occurrence of high value regions of lightning density is mainly attributed to the local terrain uplift which is helpful to initiate or enhance thunderstorms. (3) The most IC occur at the height below 9 km and mainly concentrated in the height between 3 and 6 km. and when below about 15 km, the average intensity of lightning current is proportional to the height of IC. Otherwise, when above about 15 km, they are inversely proportional to each other. (4) The lightning current intensity is mainly concentrated in the 5～50 kA, and the lightning current intensity greater than 100 kA rarely occur. The averaged lightning current intensity is smaller when the lightning frequency is higher, and the averaged lightning current intensity is larger when the lightning frequency is lower.