Optical observation of needles in upward lightning flashes.

Autor: Saba MMF; INPE-National Institute for Space Research, Av. dos Astronautas, S. José dos Campos, 1758, Brazil. marcelo.saba@inpe.br., de Paiva AR; INPE-National Institute for Space Research, Av. dos Astronautas, S. José dos Campos, 1758, Brazil., Concollato LC; Department of Physics, University of Oxford, Oxford, UK., Warner TA; ZT Research, Rapid City, SD, USA., Schumann C; Johannesburg Lightning Research Laboratory, School of Electrical and Information Engineering, University of the Witwatersrand, Johannesburg, South Africa.
Jazyk: angličtina
Zdroj: Scientific reports [Sci Rep] 2020 Oct 15; Vol. 10 (1), pp. 17460. Date of Electronic Publication: 2020 Oct 15.
DOI: 10.1038/s41598-020-74597-6
Abstrakt: Why lightning sometimes has multiple discharges to ground is an unanswered question. Recently, the observation of small plasma structures on positive leaders re-ignited the search. These small plasma structures were observed as pulsing radio sources along the positive leader length and were named "needles". Needles may be the missing link in explaining why lightning flickers with multiple discharges, but this requires further confirmation. In this work we present the first optical observations of these intriguing plasma structures. Our high-speed videos show needles blinking in slow motion in a sequential mode. We show that they are formed at unsuccessful leader branches, are as bright as the lightning leaders, and report several other optical characteristics.
Databáze: MEDLINE
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