Lightning initiation: Strong pulses of VHF radiation accompany preliminary breakdown

Autor: Dominique Lambert, Jean-Pierre Pinty, Luděk Uhlíř, Véronique Pont, Radek Lan, S. Pedeboy, Sylvain Coquillat, Eric Defer, Ivana Kolmasova, Serge Prieur, W. Rison, Ondřej Santolík
Přispěvatelé: Laboratoire d'aérologie (LAERO), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), METEORAGE, ANR-16-CE04-0005,EXAEDRE,Exploitation de nouvelles observations en électricité atmosphérique pour la recherche et l'environnement(2016)
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Scientific Reports
Scientific Reports, 2018, 8, ⟨10.1038/s41598-018-21972-z⟩
Scientific Reports, Vol 8, Iss 1, Pp 1-10 (2018)
ISSN: 2045-2322
DOI: 10.1038/s41598-018-21972-z⟩
Popis: We analyze lightning initiation process using magnetic field waveforms of preliminary breakdown (PB) pulses observed at time scales of a few tens of microseconds by a broad-band receiver. We compare these pulses with sources of narrow-band very high frequency (VHF) radiation at 60–66 MHz recorded by two separate Lightning Mapping Arrays (LMAs). We find that almost none of the observed PB pulses correspond to geo-located VHF radiation sources, in agreement with previous results and with the hypothesis that processes generating VHF radiation and PB pulses are only weakly related. However, our detailed analysis discovers that individual peaks of strong VHF radiation seen by separate LMA stations correspond surprisingly well to the PB pulses. This result shows that electromagnetic radiation generated during fast stepwise extension of developing lightning channels is spread over a large interval of frequencies. We also show that intense VHF radiation abruptly starts with the first PB pulse and that it is then continuously present during the entire PB phase of developing discharges.
Databáze: OpenAIRE