Geophysical Research Letters (Apr 2023)

Small‐Scale Discharges Observed Near the Top of a Thunderstorm

  • O. Scholten,
  • B. M. Hare,
  • J. Dwyer,
  • N. Liu,
  • C. Sterpka,
  • J. Assink,
  • H. Leijnse,
  • S. ter Veen

DOI
https://doi.org/10.1029/2022GL101304
Journal volume & issue
Vol. 50, no. 8
pp. n/a – n/a

Abstract

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Abstract We have used the LOw‐Frequency ARray (LOFAR) to image a few lightning flashes during a particularly severe thunderstorm. The images show an exceptional amount of VHF activity at altitudes above 10 km. Much of this is in the form of small‐scale discharges, not exceeding a few hundred meter, occurring seemingly randomly around the centers of active storm cells. To emphasize the incidental nature of these small‐scale discharges or sparks we refer to them as “sparkles.” A detailed investigation shows evidence that these sparkles are indicative of positive leader channels and that they are equivalent to the needle activity seen around positive leader tracks at lower altitudes.