Relativistic electron avalanches as a thunderstorm discharge competing with lightning

Kelley, N. A.; Smith, David M.; Dwyer, J. R.; Splitt, M. E.; Lazarus, S. M.; Martinez-McKinney, F.; Hazelton, B. J.; Grefenstette, Brian W.; Lowell, A.; Rassoul, H. K.

doi:10.1038/ncomms8845

Cited by 66 publications

(109 citation statements)

References 44 publications

(52 reference statements)

Supporting

Mentioning

105

Contrasting

Unclassified

Order By: Relevance

“…This raises the question if such a large field can be sustained for a long time (1 min) and over large regions (>12 km) without the RREA discharging the cloud system. Following a similar approach as in Kelley et al (; see Appendix for details) we find that the multiplication factor is too low for self‐sustained feedback mechanism and that the discharge current is low enough to be compensated by the convection charging current and the RREA will not discharge the cloud. However, this raises another question.…”

Section: Discussionmentioning

confidence: 63%

Gamma Ray Glow Observations at 20‐km Altitude

et al. 2019

View full text Add to dashboard Cite

In the spring of 2017 an ER‐2 aircraft campaign was undertaken over continental United States to observe energetic radiation from thunderstorms and lightning. The payload consisted of a suite of instruments designed to detect optical signals, electric fields, and gamma rays from lightning. Starting from Georgia, USA, 16 flights were performed, for a total of about 70 flight hours at a cruise altitude of 20 km. Of these, 45 flight hours were over thunderstorm regions. An analysis of two gamma ray glow events that were observed over Colorado at 21:47 UT on 8 May 2017 is presented. We explore the charge structure of the cloud system, as well as possible mechanisms that can produce the gamma ray glows. The thundercloud system we passed during the gamma ray glow observation had strong convection in the core of the cloud system. Electric field measurements combined with radar and radio measurements suggest an inverted charge structure, with an upper negative charge layer and a lower positive charge layer. Based on modeling results, we were not able to unambiguously determine the production mechanism. Possible mechanisms are either an enhancement of cosmic background locally (above or below 20 km) by an electric field below the local threshold or an enhancement of the cosmic background inside the cloud but then with normal polarity and an electric field well above the Relativistic Runaway Electron Avalanche threshold.

show abstract

Section: Discussionmentioning

confidence: 63%

Gamma Ray Glow Observations at 20‐km Altitude

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The Airborne Detector for Energetic Lightning Emissions (ADELE) recorded 12 gamma ray glows (Kelley et al, ). They lasted from 4 to 112 s. For 11 glows their duration was consistent with the motion of the aircraft through the active thundercloud but not the brightest one.…”

Section: Introductionmentioning

confidence: 55%

In‐Flight Observation of Gamma Ray Glows by ILDAS

et al. 2017

View full text Add to dashboard Cite

An Airbus A340 aircraft flew over Northern Australia with the In‐Flight Lightning Damage Assessment System (ILDAS) installed onboard. A long‐duration gamma ray emission was detected. The most intense emission was observed at 12 km altitude and lasted for 20 s. Its intensity was 20 times the background counts, and it was abruptly terminated by a distant lightning flash. In this work we reconstruct the aircraft path and event timeline. The glow‐terminating flash triggered a discharge from the aircraft wing that was recorded by a video camera operating onboard. Another count rate increase was observed 6 min later and lasted for 30 s. The lightning activity as reported by ground networks in this region was analyzed. The measured spectra characteristics of the emission were estimated.

show abstract

“…Kelley et al () also discussed, based on their airborne observation, that their instrument was flying at a cruise altitude of 14–15 km and then observed downward avalanches between a main upper positive layer and a negative screening layer above. In our case, the cloud top altitude was measured as 7 km.…”

Section: Discussionmentioning

confidence: 99%

Termination of Electron Acceleration in Thundercloud by Intracloud/Intercloud Discharge

Wada

Bowers

Enoto

et al. 2018

Geophysical Research Letters

View full text Add to dashboard Cite

An on‐ground observation program for high‐energy atmospheric phenomena in winter thunderstorms along the Japan Sea has been performed via measurements of gamma ray radiation, atmospheric electric field, and low‐frequency radio band. On 11 February 2017, the radiation detectors recorded gamma ray emission lasting for 75 s, and then abruptly terminated with a nearby lightning discharge. The gamma ray spectrum extended up to 20 MeV and was reproduced by a cutoff power law model with a photon index of 1.36−0.04+0.03, being consistent with Bremsstrahlung radiation from a thundercloud (known as a gamma‐ray glow or a thunderstorm ground enhancement). The low‐frequency radio monitors, installed ∼50 km away from the gamma ray observation site recorded leader development of an intracloud/intercloud discharge spreading over ∼60 km area with a ∼300‐ms duration. The timing of the gamma ray termination coincided with the moment when the leader development of the intracloud/intercloud discharge passed 0.7 km horizontally away from the radiation monitors. The intracloud/intercloud discharge started ∼15 km away from the gamma ray observation site. Therefore, the glow was terminated by the leader development, while it did not trigger the lightning discharge in the present case.

show abstract

Relativistic electron avalanches as a thunderstorm discharge competing with lightning

Cited by 66 publications

References 44 publications

Gamma Ray Glow Observations at 20‐km Altitude

Gamma Ray Glow Observations at 20‐km Altitude

In‐Flight Observation of Gamma Ray Glows by ILDAS

Termination of Electron Acceleration in Thundercloud by Intracloud/Intercloud Discharge

Contact Info

Product

Resources

About