On the initiation of lightning discharge in a cloud: 1. The high field regions in a thundercloud

Abstract

A question of the existence of high electric field regions in thunderclouds and possible local enhancements of this field is discussed. The effects of precipitation particle motions on the local electric field distribution are estimated. It is shown that the high field regions, of the order of 300–400 kV m−1 or more, can appear within a cloud on the boundary of large charge centers. The higher transient field needed for lightning initiation can appear in small regions between the charge centers, especially when an advancing draft or precipitation is coming. The very high field regions have not been detected because of their small space‐time scale.