Locating initial breakdown pulses using electric field change network

Abstract

[1] Initial breakdown pulses (IBPs) observed in the fast electric field change (E-change) at the beginning of intracloud (IC) and cloud-to-ground (CG) lightning flashes are located using a time-of-arrival technique called Position By Fast Antenna (PBFA) with data from a network of 10 E-change sensors located at Kennedy Space Center. Location errors, estimated using a Monte Carlo method, are usually less than 100 m for horizontal coordinates and several hundreds of meters for altitude, depending on distance to the sensors and altitude of the source. Comparison of PBFA source locations to locations from a VHF lightning mapping system (Lightning Detection and Ranging II (LDAR2)) shows that PBFA locates most of the "classic" IBPs while LDAR2 locates only a few percent of them. As the flash develops during the IB stage, PBFA and LDAR2 obtain similar locations when they detect the same IBPs. The overall vertical motion indicated by the PBFA positions of IBPs was downward with time for CG flashes and upward with time for IC flashes. Location of the fast pulses due to return strokes of CG flashes is also determined using PBFA. Comparison to locations from the Cloud-to-Ground Lightning Surveillance System (CGLSS) shows that PBFA reliably locates ground strokes. These results are verified using ground truth data acquired with a high-speed video camera. After cross calibration with the CGLSS data set, peak currents of return strokes are also determined.

Modeling initial breakdown pulses of CG lightning flashes

“…Both Stolzenburg et al [2013a] and Karunarathne et al [2013] found that the initial negative leader of CG flashes moves negative charge downward.…”

“…Stolzenburg et al [2013a] also showed that each luminosity burst was time correlated with a large-amplitude IBP, whose duration was typically 20-40 μs. Marshall et al [2013] used the array of E-change sensors described in Karunarathne et al [2013] and PBFA locations to study IBPs in IC flashes. Marshall et al [2013] interpreted that those IBPs were caused by a negative initial leader that moved upward from the top of the cloud's main negative charge and reached the bottom of the cloud's upper positive charge.…”

Branched dart leaders preceding lightning return strokes

“…(Karunarathne et al [2013] give more complete descriptions of the instrumentation.) Flat-plate E-change antennas [e.g., Kitagawa and Brook, 1960] were operated from 10 locations across an area of about 70 km × 100 km.…”

Competing and cutoff leaders before “upward illumination”‐type lightning ground strokes

“…[] and Karunarathne et al . [] give more complete descriptions of the data acquisition.) During July and August 2011, we operated flat plate E‐change antennas [e.g., Kitagawa and Brook , ] around Kennedy Space Center (KSC) in Florida.…”