Details

Autor(en) / Beteiligte

• Roberts, O. J.
• Fitzpatrick, G.
• Stanbro, M.
• McBreen, S.
• Briggs, M. S.
• Holzworth, R. H.
• Grove, J. E.
• Chekhtman, A.
• Cramer, E. S.
• Mailyan, B. G.

Titel

The First Fermi‐GBM Terrestrial Gamma Ray Flash Catalog

Ist Teil von

• Journal of geophysical research. Space physics, 2018-05, Vol.123 (5), p.4381-4401

Ort / Verlag

Washington: Blackwell Publishing Ltd

Erscheinungsjahr

2018

Quelle

Wiley Blackwell Single Titles

Beschreibungen/Notizen

• We present the first Fermi Space Telescope Gamma Ray Burst Monitor (GBM) catalog of 4,144 terrestrial gamma ray flashes (TGFs), detected since launch in 11 July 2008 through 31 July 2016. We discuss the updates and improvements to the triggered data and off‐line search algorithms, comparing this improved detection rate of ∼800 TGFs per year with event rates from previously published TGF catalogs from other missions. A Bayesian block algorithm calculated the temporal and spectral properties of the TGFs, revealing a delay between the hard (>300 keV) and soft (≤300 keV) photons of around 27 μs. Detector count rates of “low‐fluence” events were found to have average rates exceeding 150 kHz. Searching the World‐Wide Lightning Location Network data for radio sferics within ±5 min of each TGF revealed a clean sample of 1,314 World‐Wide Lightning Location Network locations, which were used to to accurately locate TGF‐producing storms. It also revealed lightning and storm activity for specific regions, as well as seasonal and daily variations of global lightning patterns. Correcting for the orbit of Fermi, we quantitatively find a marginal excess of TGFs being produced from storms over land near oceans (i.e., narrow isthmuses and small islands). No difference was observed between the duration of TGFs over the ocean and land. The distribution of TGFs at a given local solar time for predefined American, Asian, and African regions were confirmed to correlate well with known regional lightning rates. Key Points This catalog contains the largest released samples of TGFs and associated radio data This study shows quantitatively that TGFs preferentially occur over land near coastlines A Bayesian block algorithm was used to extract the spectral and temporal properties of each TGF