Abstract
The particular electric pulse discharges are observed in thunderclouds during the initiation stage of negative cloud-to-ground lightning. The discharges are quite different from conventional streamers or leaders. A detailed analysis reveals that the shape of the pulses is determined by the runaway breakdown of air in the thundercloud electric field initiated by extensive atmospheric showers (RB-EAS). The high amplitude of the pulse electric current is due to the multiple microdischarges at hydrometeors stimulated and synchronized by the low-energy electrons generated in the RB-EAS process. The series of specific pulse discharges leads to charge reset from hydrometeors to the free ions and creates numerous stretched ion clusters, both positive and negative. As a result, a wide region in the thundercloud with a sufficiently high fractal ion conductivity is formed. The charge transport by ions plays a decisive role in the lightning leader preconditioning.
- Received 21 December 2012
DOI:https://doi.org/10.1103/PhysRevLett.110.185005
© 2013 American Physical Society
Synopsis
A Crackling in the Air
Published 2 May 2013
Cosmic-ray-induced discharges from tiny bits of water or ice in thunderclouds may explain how a lightning strike is initiated.
See more in Physics