The Physical Origin of In-Cloud Lightning Processes Determined from Multiple-Station Wideband Electric Field Research
Abstract
The overall objective was to understand better the physics of in cloud lightning processes that give rise to radiation pulses in the electric field record. The most significant progress made was in the areas of theoretical development and analysis of 1992 data. The fundamental expressions for electric and magnetic fields from an extending lightning channel were shown to be incomplete. Specifically, a different interpretation of the classical electrostatic, induction and radiation components was found and a simpler expression for the far field expression was derived. Electric field reversals were used in inter simultaneous development of multiple in cloud channels. Electric field waveshapes were consistent with point sources for the first 200ns but not necessarily for longer times. Velocities of propagation are shown to vary with repeating processes in an intra-cloud flash. Two return strokes separated by less than a millisecond but both showing fine structure are located in spatially separate channels at ground that joined a common channel higher up. A dart stepped leader retraced the common channel section but became a stepped leader after emerging below cloud base.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 02, 1998
- Accession Number
- ADA340207
Entities
People
- Ewen M. Thomson
Organizations
- University of Florida