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

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F21%3A00535736" target="_blank" >RIV/67985815:_____/21:00535736 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378289:_____/21:00535736 RIV/00216208:11320/21:10439547

Výsledek na webu

<a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JD032825" target="_blank" >https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JD032825</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2020JD032825" target="_blank" >10.1029/2020JD032825</a>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GA20-09671S" target="_blank" >GA20-09671S: Výzkum bleskových výbojů na velkých i malých škálách</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Geophysical Research-Atmospheres

ISSN

2169-897X

e-ISSN

2169-8996

Svazek periodika

126

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

23

Strana od-do

e2020JD032825

Kód UT WoS článku

000616529300007

EID výsledku v databázi Scopus

2-s2.0-85099538927