An unusual sequence of sprites followed by a secondary TLE: An analysis of ELF radio measurements and optical observations

Abstract

We present an extraordinary case of sprites in rapid succession-four sprite clusters in only 400 ms -followed by a secondary jet. Simultaneous ELF and optical observations, as well as lightning data, enabled us to thoroughly document this unique event. Locations of the transient luminous events (TLEs) were triangulated using video recordings from Nydek (Czech Republic) and Sopron (Hungary). We found that sprites were displaced up to 70 km from their parent lightning. The current moment waveform and charge moment changes associated with the event were reconstructed from the ELF electromagnetic signature recorded at the Hylaty station (Poland) by a new method. The results suggest that both a short-delayed and a long-delayed sprite were generated by a single positive cloud-to-ground discharge that had an intense continuing current. It had an unusual progression and lasted 200 ms. A large increase in the current moment during the development of a massive carrot sprite provides evidence in favor of sprite current. Our results also support the formation of an electric environment hypothesized to be necessary for the generation of the secondary TLEs.

Dancing sprites: Detailed analysis of two case studies

“…They can also last longer times as observed, for example, in Mlynarczyk et al . [] and Füllekrug et al . [] with a few tens of milliseconds.…”

“…Previous studies reported pulse‐shaped current signature related to sprites, in particular, when they are very bright [ Cummer et al ., ; Füllekrug et al ., ; Hu et al ., ; Soula et al ., ; Mlynarczyk et al ., ]. Figure displays the electric field radiated in ELF/VLF/LF (upper/central/lower graphs) during 120 ms, 25 ms before, and 95 ms after the SP + CG in both cases of series of dancing sprites: (a) at 1803:10.123 UTC that corresponds to the brightest sprite element in F62 of Figure a and (b) at 1808:20.899 UTC that corresponds to the brightest sprite element in F40 of Figure a.…”

Time and space correlation between sprites and their parent lightning flashes for a thunderstorm observed during the HyMeX campaign

“…The charge moment change (CMC), the impulsive CMC (iCMC), and the current moment waveform associated with the CG flashes [ Hu et al ., ; Cummer and Lyons , ] were reconstructed from ELF receiver measurements, by using the method presented by Mlynarczyk et al []. The ELF recordings were made by the Hylaty ELF station in Poland [ Kulak et al ., ].…”

Globally coherent short duration magnetic field transients and their effect on ground based gravitational-wave detectors

“…Using inverse solutions developed for this purpose [29,26,25] we can determine the current and charge moments of these discharges. Each of these stations have two ferrite core active magnetic field antennas, with one oriented to observe magnetic fields along the North-South direction, and the other oriented to observe magnetic fields along the East-West direction.…”