青岛沿海地区雷暴过程闪电始发位置的微物理参量特征分析OA北大核心CSTPCD

This study used the observation data of a three-dimensional lightning-pulse location system comprising seven low-frequency magnetic sensors and dual-polarization radar to analyze five lightning events in the Qingdao coastal area from 2019 to 2020 and demonstrate the relationship between microphysical parameters and the initial lightning strike position.The results show that(1)most lightning strikes initially occurred in strong echo regions with composite reflectivity greater than 45 dBz.The distance between the cloud-to-ground lightning arrester could reach approximately 10-30 km.The median of vertically integrated liquid water was 37 kg/m2.(2)At the initial lightning strike position,the radar's horizontal reflectivity was mainly 35-45 dBz.Further,the radar's differential reflectivity was mainly 1.5-2.5 dB,and the correlation coefficient ranged from 0.97 to 0.99.Most lightning strikes were initiated between a thermal layer with temperatures-10℃to 0℃comprising rain,wet graupel,and dry graupel.Some lightning strikes were initiated in the middle and upper parts of the wet graupel region,which gener-ally showed a large value of ZDR.(3)Wet graupel existed in the isothermal layer with temperatures-10℃to 0℃in a supercooled water zone,and the radar's horizontal reflectivity and correlation coefficient were higher.Large-diameter graupel particles were more likely to be produced in the supercooled water zone.With strong up-drafts,large-diameter graupel particles collided with ice crystals that were prone to lightning processes.