First observations of elves and their causative very strong lightning discharges in an unusual small‐scale continental spring‐time thunderstorm

0535736 - ÚFA 2022 RIV US eng J - Článek v odborném periodiku
Kolmašová, Ivana - Santolík, Ondřej - Kašpar, Petr - Popek, Martin - Pizzuti, A. - Spurný, Pavel - Borovička, Jiří - Mlynarczyk, J. - Manninen, J. - Macotela, E.L. - Zacharov, Petr, jr. - Lán, Radek - Uhlíř, Luděk - Diendorfer, G. - Bennett, A. - Füllekrug, M. - Slošiar, R.
First observations of elves and their causative very strong lightning discharges in an unusual small‐scale continental spring‐time thunderstorm.
Journal of Geophysical Research-Atmospheres. Roč. 126, č. 1 (2021), č. článku e2020JD032825. ISSN 2169-897X. E-ISSN 2169-8996
Grant CEP: GA ČR GA20-09671S
Grant ostatní: AV ČR(CZ) AP1401; AV ČR(CZ) AP1202
Program: Akademická prémie - Praemium Academiae; Akademická prémie - Praemium Academiae
Institucionální podpora: RVO:68378289 ; RVO:67985815
Klíčová slova: elves * extra strong strokes * thunderstorm
Obor OECD: Fluids and plasma physics (including surface physics); Astronomy (including astrophysics,space science) (ASU-R)
Impakt faktor: 5.217, rok: 2021
Způsob publikování: Omezený přístup
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JD032825

We show for the first time that elves can be produced by an unusual small‐scale continental spring‐time thunderstorm. The storm occurred in Central Europe, covered a very small area of ∼50 km x ∼30 km and lasted only for ∼4 hours on 2 April 2017. The fraction of intense positive cloud‐to‐ground lightning strokes was unusually high, reaching 55 %, with a mean peak current of 64 kA. The peak currents of return strokes (RS) associated with elves exceeded ∼300 kA. Elves and their causative RS have been observed with different optical and electromagnetic recordings. Signatures of ionospheric disturbances indicating the presence of elves were found in measurements of displacement currents, ionospheric reflections of sferics and man‐made narrow‐band transmissions. All these electromagnetic observations coincide with four optical detections of elves and strongly suggest the occurrence of two more elves later in the decaying phase of the storm. Surprisingly, the same electromagnetic measurements indicate that other strong strokes did not produce any elves. Our simulation results show that the formation of an elve is not only determined by the high‐peak current of their causative strokes but that it is also controlled by the conductivity of the lightning channels and velocity of the current wave front. We hypothesize that because of a lower conductivity of RS lightning channels and/or slower current waves only very strong strokes with peak currents above ∼300 kA might have been capable to produce observable elves during this thunderstorm.
Trvalý link: http://hdl.handle.net/11104/0313678