6533b874fe1ef96bd12d613c

RESEARCH PRODUCT

A new population of terrestrial gamma‐ray flashes in the RHESSI data

Thomas GjestelandThomas GjestelandAndrew B. CollierNikolai ØStgaardK. H. Albrecthsen

subject

High Energy Astrophysical Phenomena (astro-ph.HE)PhysicsHigh energyGamma rayFOS: Physical sciencesAstronomyterrestrial gamma-ray flashesWorld wideLightningNew populationSpace Physics (physics.space-ph)GeophysicsPhysics - Space PhysicsGeneral Earth and Planetary Sciences:Matematikk og Naturvitenskap: 400 [VDP]Astrophysics - High Energy Astrophysical Phenomenalightningfluence distributionsProduction rate

description

Terrestrial gamma-ray flashes (TGFs) are the most energetic photon phenomenon occurring naturally on Earth. An outstanding question is as follows: Are these flashes just a rare exotic phenomenon or are they an intrinsic part of lightning discharges and therefore occurring more frequently than previously thought? All measurements of TGFs so far have been limited by the dynamic range and sensitivity of spaceborne instruments. In this paper we show that there is a new population of weak TGFs that has not been identified by search algorithms. We use the World Wide Lightning Location Network (WWLLN) to identify lightning that occurred in 2006 and 2012 within the 800 km field of view of Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). By superposing 740,210 100 ms RHESSI data intervals, centered at the time of the WWLLN detected lightning, we identify at least 141 and probably as many as 191 weak TGFs that were not part of the second RHESSI data catalogue. This supports the suggestion that the global TGF production rate is larger than previously reported. publishedVersion

https://doi.org/10.1002/2015gl067064