Radio emission from negative lightning leader steps reveals inner meter-scale structure

Abstract

We use the Low Frequency ARray (LOFAR) to probe the dynamics of the stepping process of negatively-charged plasma channels (negative leaders) in a lightning discharge. We observe that at each step of a leader, multiple pulses of VHF (30~--~80 MHz) radiation are emitted in short-duration bursts ($<10\mu$s). This is evidence for streamer formation during corona flashes that occur with each leader step, which has not been observed before in natural lightning and it could help explain X-ray emission from lightning leaders, as X-rays from laboratory leaders tend to be associated with corona flashes. Surprisingly we find that the stepping length is very similar to what was observed near the ground, however with a stepping time that is considerably larger, which as yet is not understood. These results will help to improve lightning propagation models, and eventually lightning protection models.

arXiv comment5 pages

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Cited by in corpus (8)

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• Interferometric imaging of Intensely Radiating Negative Leaders
• Evidence of Ultra-faint Radio Frequency Interference in Deep 21~cm Epoch of Reionization Power Spectra with the Murchison Widefield Array
• Straight Lightning as a Signature of Macroscopic Dark Matter
• Estimating the properties of single positive air streamers from measurable parameters
• Measuring the locations and properties of VHF sources emitted from an aircraft flying through high clouds
• Lightning as a natural accelerator of relativistic particles and a source of synchrotron radiation