Gamma Ray Flashes Produced by Lightning Observed at Ground Level by TETRA‐II

D J Pleshinger,J Arias,R Rodriguez,Y Banadaki,S Bai,M L Cherry,D Smith,M D Legault,J C Trepanier,S T Alnussirat,E Khosravi,J H Hoffman,A Sunda‐Meya,E Del Toro

doi:10.1029/2019ja026820

Abstract

AbstractIn its first 2 years of operation, the ground‐based Terrestrial gamma ray flash and Energetic Thunderstorm Rooftop Array (TETRA)‐II array of gamma ray detectors has recorded 22 bursts of gamma rays of millisecond‐scale duration associated with lightning. In this study, we present the TETRA‐II observations detected at the three TETRA‐II ground‐level sites in Louisiana, Puerto Rico, and Panama together with the simultaneous radio frequency signals from the lightning data sets VAISALA Global Lightning Dataset, VAISALA National Lightning Detection Network, Earth Networks Total Lightning Network, and World Wide Lightning Location Network. The relative timing between the gamma ray events and the lightning activity is a key parameter for understanding the production mechanism(s) of the bursts. The gamma ray time profiles and their correlation with radio sferics suggest that the gamma ray events are initiated by lightning leader activity and are produced near the last stage of lightning leader channel development prior to the lightning return stroke.

Highlights

Lightning provides one of the most powerful natural high-energy charged particle accelerators available on Earth
We present the Thunderstorm Rooftop Array (TETRA)-II observations detected at the three TETRA-II ground-level sites in Louisiana, Puerto Rico, and Panama together with the simultaneous radio frequency signals from the lightning data sets VAISALA Global Lightning Dataset, VAISALA National Lightning Detection Network, Earth Networks Total Lightning Network, and World Wide Lightning Location Network
We report the detection by the upgraded terrestrial gamma ray flashes (TGFs) and Energetic Thunderstorm Rooftop Array (TETRA)-II of 22 X-ray/gamma ray bursts observed at ground level, simultaneously with radio frequency (RF) emission

Summary

Introduction

Lightning provides one of the most powerful natural high-energy charged particle accelerators available on Earth. TGFs were initially detected by the Burst and Transient Source Experiment onboard the Compton Gamma-Ray Observatory (Fishman et al, 1994), followed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (Smith et al, 2003), the BeppoSAX satellite (Ursi et al, 2017), and the Relativistic ELECtrons experiment (Panasyuk et al, 2016) and are currently being observed in space by the Gamma ray Burst Monitor (Roberts et al, 2018), the AstroRivelatore Gamma a Immagini Leggero (Marisaldi et al, 2010), the Large Area Telescope (Grove et al, 2012), and the Atmosphere-Space Interactions Monitor (Ostgaard et al, 2018) These observations, associated mainly with intracloud lightning that produces upward moving negative charge, have been correlated with regions of intense lightning and source regions at the altitudes of thunderstorm tops, typically 10–15 km above ground level.

TETRA-II

Observations

Discussion

Conclusions