Line charge densities and currents of downward negative leaders estimated from VHF images and VLF electric fields observed at close distances

Yan Chi Shen, Ming Li Chen, Ya Ping Du, Wan Sheng Dong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

2 Citations (Scopus)

Abstract

In this paper, a method for retrieving the line charge density and the current of a downward leader based on ground observations of lightning images and electric field changes was proposed and examined. The method was then applied to two downward negative leaders in a rocket-triggered lightning discharge with measurements of broadband interferometric images and electric field changes at close distance. Only the descending channel portion between about 900-400 m high of the two leaders were analyzed, where the channel was in free air rather than the trace of triggering wire. The line charge density for both leaders showed a general increasing trend with a big impulsive change around 500 m high, as the leaders moved downward, which was in good agreement with the prediction of existing downward leader models. The range of the line charge density was similar for the two leaders (-0.03 to -0.32 mC/m and -0.02 to -0.33 mC/m, respectively). The impulsive change of the line charge density was corresponding to a sharp turn of the leader channel around 500 m high, which may imply that the sharp turn of the leader channel was probably associated with a pre-existing local positive space charge pocket. The estimated leader currents for two leaders (-20 to -315 A and -77 to -541 A, respectively) were also in good agreement with independent estimations in the literature.

Original languageEnglish
Article number8444465
Pages (from-to)1507-1514
Number of pages8
JournalIEEE Transactions on Electromagnetic Compatibility
Volume61
Issue number5
DOIs
Publication statusPublished - Oct 2019

Keywords

  • Downward leader
  • leader current
  • leader speed
  • line charge density

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Cite this