Numerical Simulation of the Effects of Randomness and Characteristics of Electrical Environment on Ground Strike Location of Cloud‐to‐Ground Lightning

Abstract

AbstractIn terms of the existing stochastic lightning model and four sounding data, this work performs 12.5 m resolution simulations of two‐dimensional thundercloud, gives ground flash cases in various thundercloud charge structures, and analyzes the relationship between the ground stroke location, the distribution of charge structures and potential. The results show that: (1) The distribution of potential which is only defined by space charge determines the maximum spread trend of leader, while ground strike location uncertainty range is limited to 3 km because of the lightning propagation randomness, three ground strike locations are iterated with method of dynamic clustering, and the mutual distance of locations is about 1 km. (2) The distance between the initial horizontal location and ground strike location of negative CG lightning is mainly distributed in the range of 0~6 km, and 93% negative lightning distribution in 0~4 km range, the distribution of positive CG lightning is relatively wide, 0~3 km range accounting for 48%, 3~6 km range accounting for 34%, and 6~10 km accounting for 18%. (3) CG lightning is primarily produced in a pair of charges which are close to the ground, the higher the height of lighting initiation, the larger of range of distance between the initial location and ground strike location. In addition, some positive CG lightning which are produced in tripole charge structure of thundercloud start up between the upper part of positive charge pile and the middle negative charge pile. As the downward positive leader will bypass the bottom positive charge pile, so the distance between the initial location and ground strike location is basically above 6 km.