VHF lightning mapping observations of a triggered lightning flash
Article first published online: 11 OCT 2012
©2012. American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 39, Issue 19, 16 October 2012
How to Cite
2012), VHF lightning mapping observations of a triggered lightning flash, Geophys. Res. Lett., 39, L19807, doi:10.1029/2012GL053666., et al. (
- Issue published online: 11 OCT 2012
- Article first published online: 11 OCT 2012
- Manuscript Accepted: 7 SEP 2012
- Manuscript Received: 22 AUG 2012
- lightning mapping array;
- positive breakdown;
- triggered lightning
 On 3 August 2010 an extensive lightning flash was triggered over Langmuir Laboratory in New Mexico. The upward positive leader propagated into the storm's midlevel negative charge region, extending over a horizontal area of 13 × 13 km and 7.5 km altitude. The storm had a normal-polarity tripolar charge structure with upper positive charge over midlevel negative charge. Lightning Mapping Array (LMA) observations were used to estimate positive leader velocities along various branches, which were in the range of 1–3 × 104 m s−1, slower than in other studies. The upward positive leader initiated at 3.4 km altitude, but was mapped only above 4.0 km altitude after the onset of retrograde negative breakdown, indicating a change in leader propagation and VHF emissions. The observations suggest that both positive and negative breakdown produce VHF emissions that can be located by time-of-arrival systems, and that not all VHF emissions occurring along positive leader channels are associated with retrograde negative breakdown.