Study of the lightning temporal and spatial characteristics based on CMA Lightning Detection Network in China

Abstract

Based on the lightning location data during 2009-2013 from China Meteorological Administration National-Lightning-Detection-Network (CMA LDN), this study analysed the temporal-spatial characteristics of the lightning in mainland China, and the results show: 1) Lightning detection systems used the Improved Performance through Combined Technology (IMPACT) method, which combined the direction finding (DF) and the time difference of arrival (TOA) technology. Among the four localization algorithms, the four-station method had the highest positioning accuracy, and its usage frequency also increased continuously, accounted for 50 %, up to 6000-10000 times by 2013. 2) Lightning activities showed clearly seasonal variation, and it had an increasing trend with a little inter-annual variation during the period of 2009 to 2013, which was mainly affected or restricted by ground temperature (rising from May every year, reaching its peak in August, and then gradually decreasing), potential water and convection in the atmosphere. 3) The negative cloud-to-ground (-CG) flashes were the absolute majority in China, positive cloud-to-ground (+CG) flashes accounted for 5.1 % of the total. Most of lightning currents ranged from -60 to +60kA. 4) The average lightning intensity of +CG and -CG flashes were 64.2kA and -40.28kA respectively. The positive lightning ratio is prominently high in December and January, most of which distributed in southern Anhui province, northern Jiangxi province, North Central Guangxi province, Yunnan province and West of Xinjiang Uygur Autonomous Region.