Radiation Risk Assessment Associated With Terrestrial Gamma Ray Flashes for Commercial Flights

Abstract

Terrestrial gamma ray flashes (TGFs) are bursts of high-energy photons produced in thunderstorms. They are associated with lightning leaders and intracloud discharges (Lu et al., 2010;Stanley et al., 2006). Most models are based on relativistic runaway electron avalanche processes (e.g., Dwyer et al., 2012), which allow the production of a great number of high-energy electrons to comply with satellite observations of gamma rays, that is, ∼10 18 photons through bremsstrahlung (e.g.,

XStorm: A New Gamma Ray Spectrometer for Detection of Close Proximity Gamma Ray Glows and TGFs

“…We therefore assume that a TGF would be detectable within a 20 km-radius around the source. Using Fermi TGF catalog provided by Roberts et al (2018), we calculate a map of TGF densities in units of/s/20 km-radius to take into account the field of view of XStorm, similarly to that shown in Pallu et al (2023). Using the trajectories of the 8 balloon flights performed in the Stratéole-2 preliminary campaign in 2019 (with a mean of 85 days per flight), we calculate the probabilities to find one balloon in a TGF beam, applying the same method as described in Pallu et al (2023).…”

“…Therefore it is interesting to study these events simultaneously. The aims in detecting TGFs with XStorm are to observe these events in close proximity, to quantify radiation doses in thunderstorms, because only estimations by calculation have been made until now (e.g., Pallu et al, 2021), assess their frequency of occurrence (Pallu et al, 2023), and to detect radionuclide and neutron signatures (e.g., Bowers et al, 2017;Enoto et al, 2017;Rutjes et al, 2017). Ground-based measurements are now quite frequent as well, especially thanks to the Telescope Array that is continuously able to detect downward TGFs (Abbasi et al, 2017(Abbasi et al, , 2018Belz et al, 2020).…”

“…The main objectives of the gamma ray spectrometer are to detect high-energy atmospheric electric events such as gamma ray glows usually produced and detected inside thunderstorms, but also detected above thundercloud tops at high-altitude (20 km) as recently reported by Østgaard, Christian, et al (2019), and TGFs, which are usually detected by satellites. In fact, the spectrometer is due for flying on balloons to perform in situ and close proximity measurements in thunderstorms to improve understanding of physical processes that are still uncertain as to how seeding and acceleration process are engaged, to quantify better the rarity of weak TGFs (i.e., not detectable by satellite), and refine reported results about radiation dose and exposure risks associated with TGFs (e.g., Dwyer et al, 2010;Pallu et al, 2021Pallu et al, , 2023.…”

“…(2019), and TGFs, which are usually detected by satellites. In fact, the spectrometer is due for flying on balloons to perform in situ and close proximity measurements in thunderstorms to improve understanding of physical processes that are still uncertain as to how seeding and acceleration process are engaged, to quantify better the rarity of weak TGFs (i.e., not detectable by satellite), and refine reported results about radiation dose and exposure risks associated with TGFs (e.g., Dwyer et al., 2010; Pallu et al., 2021, 2023).…”

“…Using the trajectories of the 8 balloon flights performed in the Stratéole‐2 preliminary campaign in 2019 (with a mean of 85 days per flight), we calculate the probabilities to find one balloon in a TGF beam, applying the same method as described in Pallu et al. (2023). One finds that ∼1/2.3 Stratéole‐2 balloon flights will be able to detect a TGF.…”