Počet záznamů: 1  

First observation of significant long-lasting Thunderstorm Ground Enhancements on the Milešovka peak (altitude 837 m) in Czechia

  1. 1.
    SYSNO ASEP0542842
    Druh ASEPA - Abstrakt
    Zařazení RIVZáznam nebyl označen do RIV
    Zařazení RIVNení vybrán druh dokumentu
    NázevFirst observation of significant long-lasting Thunderstorm Ground Enhancements on the Milešovka peak (altitude 837 m) in Czechia
    Tvůrce(i) Kolmašová, Ivana (UFA-U) RID, ORCID
    Santolík, Ondřej (UFA-U) RID, ORCID
    Ploc, Ondřej (UJF-V) RID, ORCID, SAI
    Langer, Ronald (UJF-V) ORCID, SAI
    Popová, Jana (UFA-U) RID, ORCID
    Sokol, Zbyněk (UFA-U) RID, ORCID
    Zacharov, Petr, jr. (UFA-U) RID, ORCID
    Šlegl, Jakub (UJF-V) ORCID, SAI
    Diendorfer, G. (AT)
    Strhárský, I. (SK)
    Lán, Radek (UFA-U) RID, ORCID
    Kákona, Martin (UJF-V) ORCID, SAI
    Celkový počet autorů12
    Zdroj.dok.EGU General Assembly 2021 (vEGU21: Gather Online). - Göttingen : European Geosciences Union, 2021
    Poč.str.2 s.
    Forma vydáníOnline - E
    AkceEGU General Assembly Conference 2021
    Datum konání19.04.2021 - 30.04.2021
    Místo konáníonline
    ZeměDE - Německo
    Typ akceWRD
    Jazyk dok.eng - angličtina
    Země vyd.DE - Německo
    Klíč. slovacosmic rays ; particle detector SEVAN ; Thunderstorm Ground Enhancements (TGE) ; thunderstorm clouds
    Vědní obor RIVBL - Fyzika plazmatu a výboje v plynech
    Obor OECDFluids and plasma physics (including surface physics)
    Vědní obor RIV – spolupráceÚstav jaderné fyziky - Fyzika plazmatu a výboje v plynech
    Institucionální podporaUFA-U - RVO:68378289 ; UJF-V - RVO:61389005
    DOI10.5194/egusphere-egu21-3141
    AnotaceBursts of gamma rays observed on the Earth’s surface – so called Thunderstorm Ground
    Enhancements (TGE) were detected by a plastic scintillator (disassembled from the particle
    detector SEVAN) located in the observatory building on the Milešovka peak (50.6N, 13.9E, altitude
    837 m) in Czechia. The TGEs observed during two thunderstorms on 23 April 2018 respectively
    lasted 65 and 15 minutes and exceeded the background radiation levels by 30 and 40 percent.
    The first storm was a part of an evolving squall line which crossed the Milešovka peak. The second
    storm was probably a supercell, which moved near Milešovka but did not hit its top. Both storms
    caused heavy precipitation and strong wind gusts. The onset of the TGEs preceded the onset of
    precipitation by approximately 8 minutes. During the increases of TGE radiation, the European
    lightning detection network EUCLID detected numerous predominantly negative intracloud
    lightning discharges at distances closer than 5 km from the particle detector.
    To understand the conditions for the TGE observation we investigated the data collected during
    the enhancements by a Ka-band cloud radar, an electric field mill, and a broadband
    electromagnetic receiver installed in the Milešovka peak observatory. Using the cloud radar
    measurements, we estimated the vertical extent of the thunderclouds. The cloud base was found
    at about 500 m above the observatory. Estimated heights of the cloud tops for the two storms
    were 12 and 8 km, respectively, indicating that the storm center of the second storm was not
    directly above the cloud radar. The updraft velocities reached 10 m/s. A composition of
    hydrometeors suggested good conditions for cloud electrification.
    We have found that the increases of TGE radiation corresponded to the large negative electric
    fields (up to – 20 kV/m) measured by the electric field mill rather than to individual discharges. We
    also identified numerous microsecond-scale pulses in the broadband magnetic field records,
    which can be attributed to corona-type discharges occurring near the receiving antenna in high
    local electric fields below the thunderstorm.
    Based on our analysis we assume that observed TGEs corresponded to the bremsstrahlung
    generated during collisions of electrons accelerated in the thunderstorm electric field with the air
    molecules. Because of a very small number of cloud-to-ground lighting discharges we hypothesize
    that the electrons might have been accelerated by a strong lower positive charge center at the
    bottom of the thundercloud. As the TGE radiation increases were unusually long, we speculate
    that their later part might have been assigned to the radon progeny which was lifted to the
    atmosphere by a near-surface electric field and returned back to the ground with the rain
    precipitation
    PracovištěÚstav fyziky atmosféry
    KontaktKateřina Adamovičová, adamovicova@ufa.cas.cz, Tel.: 272 016 012 ; Kateřina Potužníková, kaca@ufa.cas.cz, Tel.: 272 016 019
    Rok sběru2022
Počet záznamů: 1  

  Tyto stránky využívají soubory cookies, které usnadňují jejich prohlížení. Další informace o tom jak používáme cookies.