Two basic leader connection scenarios observed in negative lightning attachment process  

作　　者：Weitao Lu Qi Qi Ying Ma Luwen Chen Xu Yan Vladimir ARakov Daohong Wang Yijun Zhang 

机构地区：[1]State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing,People’s Republic of China [2]Laboratory of Lightning Physics and Protection Engineering,Chinese Academy of Meteorological Sciences,Beijing,People’s Republic of China [3]Institute of Tropical and Marine Meteorology,China Meteorological Administration,Guangzhou,Guangdong,People’s Republic of China [4]Department of Electrical and Computer Engineering,University of Florida,Gainesville,Florida,USA [5]Department of Electrical,Electronic and Computer Engineering,Gifu University,Gifu,Japan

出　　处：《High Voltage》2016年第1期11-17,共7页高电压（英文）

基　　金：the National Natural Science Foundations of China under grant no.41475003;the National Key Basic Research Program of China under grant no.2014CB441405;by the Basic Research Fund of Chinese Academy of Meteorological Sciences under grant no.2014R015;the GRF grant no.14.B25.31.0023.

摘　　要：High-speed video images of 24 downward negative lightning flashes terminating on tall structures in Guangzhouare selected to analyse the connecting behaviour of the downward and upward leaders during the attachment processpreceding the first return stroke.Three types of leader connecting behaviour have been observed:Type I,the tip ofdownward leader(DL)to the tip of upward connecting leader(UCL),which accounts for 42%of all the events(10/24);Type II,the DL’s tip to the lateral surface of UCL,which accounts for 50%(12/24);and Type III,the combination ofTypes I and II,which accounts for 8%(2/24).For the two cases of Type III behaviour,each case had two junction points(one with Type I and the other with Type II behaviour)between the downward and upward leaders.Therefore,Types Iand II can be viewed as the two basic types of the leader connecting behaviour during the attachment process innegative lightning.No attachment process exhibited the connection of the UCL’s tip to the lateral surface of DL.Thepresence of multiple DL branches and their integrated effect on the development of positive UCL/UCLs are likely to bethe main reasons for the Type II behaviour.

关 键 词：connecting behaviour DOWNWARD 

分 类 号：TG1[金属学及工艺—金属学]