A comparative study of the electrical characteristics of positive and negative narrow bipolar events  

作　　者：FeiFan Liu BaoYou Zhu HeLin Zhou GaoPeng Lu Ming Ma JiuHou Lei 

机构地区：[1]CAS Key Laboratory of Geospace Environment,School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China [2]Mengcheng National Geophysical Observatory,University of Science and Technology of China,Hefei 230026,China [3]CAS Center for Excellence in Comparative Planetology,Hefei 230026,China [4]Provinn AB,Gothenburg,Sweden [5]Key Laboratory of Atmospheric Optics,Anhui Institute of Optics and Fine Mechanics,HFIPS,Chinese Academy of Sciences,Hefei 230026,China

出　　处：《Earth and Planetary Physics》2023年第6期675-683,共9页地球与行星物理（英文版）

基　　金：The authors would acknowledge financial support from the National Key Laboratory on Electromagnetic Environmental Effects and Electro-optical Engineering(NO.JCKYS2022LD6);the National Natural Science Foundation of China(42005068 and 42375074);the Project of Stable Support for Youth Team in Basic Research Field CAS(YSBR-018);the Joint Open Fund of Mengcheng National Geophysical Observatory(MENGO-202208).

摘　　要：Narrow bipolar events(NBEs)are intriguing intra-cloud discharge that have attracted enormous interest in the lightning community.They come with two polarities that dominate at different altitudes in thunderclouds.The sources of negative NBEs are usually located near the top of thunderclouds;those of positive NBEs are at the middle levels.NBEs may occur at the onset of lightning.The electrical properties of NBEs remain poorly understood.We present here the first comparative study of the electrical characteristics of negative and positive NBEs.To derive electrical parameters from the fast electric field change waveforms of 1673 positive NBEs and 364 negative NBEs recorded by the Jianghuai Area Sferic Array(JASA)in China,we use an improved method based on the transmission line model.This approach concludes that negative NBEs occurring at high altitudes tend to produce a narrower current pulse and take a shorter time to traverse the channel than their positive counterparts.Moreover,compared to positive NBEs,a larger portion of negative NBEs are associated with slightly greater peak current moments but smaller overall charge moments.The differences reported herein between electrical properties of negative and positive NBEs suggest that charge distribution in NBE-producing thunderstorms tends to vary systematically with altitude.

关 键 词：LIGHTNING THUNDERSTORM narrow bipolar events 

分 类 号：P427.3[天文地球—大气科学及气象学]