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The First Terrestrial Electron Beam Observed by the Atmosphere‐Space Interactions Monitor
Author(s) -
Sarria D.,
Kochkin P.,
Østgaard N.,
Lehtinen N.,
Mezentsev A.,
Marisaldi M.,
Carlson B. E.,
Maiorana C.,
Albrechtsen K.,
Neubert T.,
Reglero V.,
Ullaland K.,
Yang S.,
Genov G.,
Qureshi B. H.,
BudtzJørgensen C.,
Kuvvetli I.,
Christiansen F.,
Chanrion O.,
Heumesser M.,
Dimitriadou K.,
NavarroGonzález J.,
Connell P.,
Eyles C.
Publication year - 2019
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2019ja027071
Subject(s) - physics , photon , electron , computational physics , atmosphere (unit) , bremsstrahlung , optics , nuclear physics , meteorology
Abstract We report the first Terrestrial Electron Beam detected by the Atmosphere‐Space Interactions Monitor. It happened on 16 September 2018. The Atmosphere‐Space Interactions Monitor Modular X and Gamma ray Sensor recorded a 2 ms long event, with a softer spectrum than typically recorded for Terrestrial Gamma ray Flashes (TGFs). The lightning discharge associated to this event was found in the World Wide Lightning Location Network data, close to the northern footpoint of the magnetic field line that intercepts the International Space Station location. Imaging from a GOES‐R geostationary satellite shows that the source TGF was produced close to an overshooting top of a thunderstorm. Monte‐Carlo simulations were performed to reproduce the observed light curve and energy spectrum. The event can be explained by the secondary electrons and positrons produced by the TGF (i.e., the Terrestrial Electron Beam), even if about 3.5% to 10% of the detected counts may be due to direct TGF photons. A source TGF with a Gaussian angular distribution with standard deviation between 20.6° and 29.8° was found to reproduce the measurement. Assuming an isotropic angular distribution within a cone, compatible half angles are between 30.6° and 41.9°, in agreement with previous studies. The number of required photons for the source TGF could be estimated for various assumption of the source (altitude of production and angular distribution) and is estimated between 10 17.2 and 10 18.9 photons, that is, compatible with the current consensus.