Simultaneous observations of electric field changes, wideband magnetic field pulses, and VHF emissions associated with K processes in lightning discharges
2014 (English)In: Journal of Geophysical Research D: Atmospheres, ISSN 2169-897X, Vol. 119, no 6, 2699-2710 p.Article in journal (Refereed) Published
We studied simultaneous electric field changes, microsecond-scale (VLF/LF) magnetic field pulses, and VHF emissions associated with K processes in 37 cloud and 54 cloud-to-ground lightning flashes that occurred in a local convective thunderstorm in Shanghai. All the observed features were very similar for both types of flashes. Over 98% of the 1252 observed K changes were associated with detectable microsecond-scale pulses, although only about 26% of them were accompanied by large pulses whose amplitude exceeds by at least 50% the average amplitude of the five largest pulses in the flash. VHF bursts, which almost always coincide in time with microsecond-scale pulses, can occur either during K changes or during the gaps between K changes. About 9% of K changes were observed to be associated with regular pulse trains, with pulses in the train showing one-to-one correspondence to VHF bursts and occurring at a geometric mean interval of 6.9 mu s. Overall, our results indicate that small microsecond-scale pulses are an inherent feature of K processes. We infer that the K process can be viewed as a fast negative leader, but only those leaders with appreciable charge transfer show step/ramp-like K changes in electric field records.
Place, publisher, year, edition, pages
2014. Vol. 119, no 6, 2699-2710 p.
Ground Flashes, Cloud Flashes, Radiation, Intracloud, Florida
Meteorology and Atmospheric Sciences
IdentifiersURN: urn:nbn:se:kth:diva-146573DOI: 10.1002/2013JD021006ISI: 000336046600001ScopusID: 2-s2.0-84898793386OAI: oai:DiVA.org:kth-146573DiVA: diva2:724603
QC 201406132014-06-132014-06-122014-06-13Bibliographically approved