JpGU-AGU Joint Meeting 2020

Presentation information

[E] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-OS Ocean Sciences & Ocean Environment

[A-OS25] Continental-Oceanic Mutual Interaction: Planetary scale Material Circulation

convener:Yosuke Alexandre Yamashiki(Earth & Planetary Water Resources Assessment Laboratory Graduate School of Advanced Integrated Studies in Human Survivability Kyoto University), Yukio Masumoto(Graduate School of Science, The University of Tokyo), Swadhin Behera(Climate Variation Predictability and Applicability Research Group, Application Laboratory, JAMSTEC, 3173-25 Showa-machi, Yokohama 236-0001), Takanori Sasaki(Department of Astronomy, Kyoto University)

[AOS25-05] Probabilistic Risk Assessment of Solar Particle Events Considering the Cost of Counter Measures to Reduce the Aviation Exposure Dose

*Moe Fujita1, Yosuke Yamashiki1, Tatsuhiko Sato2 (1.Graduate School of Advanced Integrated Studies in Human Survivability Kyoto University, 2.Japan Atomic Energy Agency)

Keywords:Aviation Exposure, Solar particle event, Ground-level enhancement, Risk Evaluation, Insurance

Radiation exposure to flight crews and passengers, called aviation exposure, is an important topic in radiological protection. In order to develop an integrated insurance approach for the risk of aviation exposure, particularly against severe solar particle events (SPE), we examined eight flight routes to calculate the maximum doses during five ground level enhancements (GLE). Four-dimensional (altitude, latitude, longitude, and time) dose data evaluated by WASAVIES were used in this calculation. Then, we estimated the probability of the occurrence of harmful GLE events that would bring the maximum flight route dose over 1.0 mSv and 0.08 mSv/h, based on past records of GLE as well as historically large SPE observed by the cosmogenic nuclide concentrations in tree rings and ice cores. Our calculation suggests that average probability of exceeding the threshold value of EII and PEI becomes 0.011 to 0.012, corresponding to an occurrence every 86 to 90 years. Our calculations suggest that aviation exposure with flight route doses over 1 mSv may occur approximately once every 90 years. The dose can be reduced by lower-altitude aviation with compensation of fuel consumption, which would be much cheaper than flight cancellation. Extremely severe SPE, such as the Miyake event in 774-775 AD, may cause the maximum flight route dose to become greater than 10 mSv. Low-altitude aviation may effectively reduce the costs and risks of aviation exposure, which can be used in designing an insurance product for SPE risk.