@article{d7ce00f7e8cd4501ba93ba9e947919e8,
title = "A distinct negative leader propagation mode",
abstract = "The common phenomenon of lightning still harbors many secrets such as what are the conditions for lightning initiation and what is driving the discharge to propagate over several tens of kilometers through the atmosphere forming conducting ionized channels called leaders. Since lightning is an electric discharge phenomenon, there are positively and negatively charged leaders. In this work we report on measurements made with the LOFAR radio telescope, an instrument primarily build for radio-astronomy observations. It is observed that a negative leader rather suddenly changes, for a few milliseconds, into a mode where it radiates 100 times more VHF power than typical negative leaders after which it spawns a large number of more typical negative leaders. This mode occurs during the initial stage, soon after initiation, of all lightning flashes we have mapped (about 25). For some flashes this mode occurs also well after initiation and we show one case where it is triggered twice, some 100 ms apart. We postulate that this is indicative of a small (order of 5 km2) high charge pocket. Lightning thus appears to be initiated exclusively in the vicinity of such a small but dense charge pocket.",
author = "O. Scholten and Hare, {B. M.} and J. Dwyer and N. Liu and C. Sterpka and I. Kolma{\v s}ov{\'a} and O. Santol{\'i}k and R. L{\'a}n and L. Uhl{\'i}{\v r} and S. Buitink and A. Corstanje and H. Falcke and T. Huege and H{\"o}randel, {J. R.} and Krampah, {G. K.} and P. Mitra and K. Mulrey and A. Nelles and H. Pandya and Rachen, {J. P.} and Trinh, {T. N.G.} and {ter Veen}, S. and S. Thoudam and T. Winchen",
note = "Funding Information: The LOFAR cosmic ray key science project acknowledges funding from an Advanced Grant of the European Research Council (FP/2007-2013) [ERC grant number 227610]; The project has also received funding from the European Research Council (ERC) under the European Union{\textquoteright}s Horizon 2020 research and innovation programme [grant number 640130]; We furthermore acknowledge financial support from FOM [FOM-project 12PR304]; BMH is supported by the NWO [grant number VI.VENI.192.071]; AN is supported by the DFG [grant number NE 2031/2-1]; TW is supported by DFG [grant number 4946/1-1]; The work of the IAP team was supported by European Regional Development Fund-Project CRREAT [grant number CZ.02.1.01/0.0/0.0/15-003/0000481] and by the GACR [grant number 20-09671S]. KM is supported by FWO [grant number FWO-12ZD920N]; TNGT acknowledges funding from the Vietnam National Foundation for Science and Technology Development (NAFOSTED) under [Grant number 103.01-2019.378]; ST acknowledges funding from the Khalifa University Startup grant [project code 8474000237]; This paper is based on data obtained with the International LOFAR Telescope (ILT). LOFAR 38 is the Low Frequency Array designed and constructed by ASTRON. It has observing, data processing, and data storage facilities in several countries, that are owned by various parties (each with their own funding sources), and that are collectively operated by the ILT foundation under a joint scientific policy. The ILT resources have benefitted from the following recent major funding sources: CNRS-INSU, Observatoire de Paris and Universit{\'e} d{\textquoteright}Orl{\'e}ans, France; BMBF, MIWF-NRW, MPG, Germany; Science Foundation Ireland (SFI), Department of Business, Enterprise and Innovation (DBEI), Ireland; NWO, The Netherlands; The Science and Technology Facilities Council, UK. The data are available from the LOFAR Long Term Archive (for access see38). To download this data, please create an account and follow the instructions for “Staging Transient Buffer Board data” at38. In particular, the utility “wget” should be used as follows: wget https:// lofar-download.grid.surfsara.nl/lofigrid/SRMFifoGet.py?surl={"}location{"} where “location” should be specified as: srm://srm.grid.sara.nl/pnfs/grid.sara.nl/data/lofar/ ops/TBB/lightning/ followed by L703974_D20190424T210306.154Z_{"}stat{"}_R000_tbb. h5 (for Flash B) L703974_D20190424T213055.202Z_{"}stat{"}_R000_tbb.h5 (for Flash A) and where “stat” should be replaced by the name of the station, CS001, CS002, CS003, CS004, CS005, CS006, CS007, CS011, CS013, CS017, CS021, CS024, CS026, CS028, CS030, CS031, CS032, CS101, CS103, RS106, CS201, RS205, RS208, RS210, CS301, CS302, RS305, RS306, RS307, RS310, CS401, RS406, RS407, RS409, CS501, RS503, RS508, or RS509. All figures in this work have been made using the Graphics Layout Engine (GLE)39plotting package. Publisher Copyright: {\textcopyright} 2021, The Author(s).",
year = "2021",
month = dec,
doi = "10.1038/s41598-021-95433-5",
language = "British English",
volume = "11",
journal = "Scientific Reports",
issn = "2045-2322",
publisher = "Nature Research",
number = "1",
}