A Strong Pulsing Nature of Negative Intracloud Dart Leaders Accompanied by Regular Trains of Microsecond‐Scale Pulses

0572198 - ÚFA 2024 RIV US eng J - Journal Article
Kolmašová, Ivana - Scholten, O. - Santolík, Ondřej - Hare, B.M. - Zacharov, Petr, jr. - Lán, Radek - Liu, N. - Dwyer, J.R.
A Strong Pulsing Nature of Negative Intracloud Dart Leaders Accompanied by Regular Trains of Microsecond‐Scale Pulses.
Geophysical Research Letters. Roč. 50, č. 10 (2023), č. článku e2023GL103864. ISSN 0094-8276. E-ISSN 1944-8007
R&D Projects: GA MŠMT EF15_003/0000481; GA ČR GA20-09671S; GA ČR(CZ) GA23-06430S
Institutional support: RVO:68378289
Keywords : lightning * dart-stepped leader * pulse train
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 5.2, year: 2022
Method of publishing: Open access
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL103864

We report the first observations of negative intracloud (IC) dart-stepped leaders accompanied by regular trains of microsecond-scale pulses, simultaneously detected by shielded broadband magnetic loop antennas and the radio telescope Low Frequency Array (LOFAR). Four investigated pulse trains occurred during complicated IC flashes on 18 June 2021, when heavy thunderstorms hit the Netherlands. The pulses within the trains are unipolar, a few microseconds wide, and with an average inter-pulse interval of 5–7 μs. The broadband pulses perfectly match energetic, regularly distributed, and relatively isolated bursts of very high frequency sources localized by LOFAR. All trains were generated by negative dart-stepped leaders propagating at a lower speed than usual dart leaders. They followed channels of previous leaders occurring within the same flash several tens of milliseconds before the reported observations. The physical mechanism remains unclear as to why we observe dart-stepped leaders, which show mostly regular stepping, emitting energetic microsecond-scale pulses.
Permanent Link: https://hdl.handle.net/11104/0342997