TY  - JOUR
AU  - Sterpka, C.
AU  - Dwyer, J.
AU  - Liu, N.
AU  - Hare, B. M.
AU  - Scholten, O.
AU  - Buitink, S.
AU  - Veen, S. ter
AU  - Nelles, A.
TI  - The Spontaneous Nature of Lightning Initiation Revealed
JO  - Geophysical research letters
VL  - 48
IS  - 23
SN  - 0094-8276
CY  - Hoboken, NJ
PB  - Wiley
M1  - PUBDB-2022-00619
SP  - GL095511
PY  - 2021
AB  - Here, we present new radio interferometer beamforming observations of lightning initiation using data from the Low-Frequency Array (LOFAR). We show that the first lightning source in the flash increases exponentially in intensity by two orders of magnitude in 15 μs, while propagating 88 m away from the initiation location at a constant speed of 4.8 ± 0.1 × 10<sup>6</sup> m/s. A second source replaces the first source at the initiation location, and subsequent propagation of the lightning leader follows. We interpret the first source to be a rapidly propagating and intensifying positive streamer discharge that subsequently produces a hot leader channel near the initiation point. How lightning initiates is one of the greatest unsolved problems in the atmospheric sciences, and these results shed light on this longstanding mystery. 
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000730019700047
DO  - DOI:10.1029/2021GL095511
UR  - https://bib-pubdb1.desy.de/record/474239
ER  -