Assessment of Impacts to Aviation Radiation by Extreme Space Weather Events and New Atmospheric Radiation Scales

This paper examines the radiation hazards posed to civil aviation by extreme space weather events, focusing on the impacts of Extreme Solar Energetic Particle Events (ESEPs) at flight altitudes. While aviation benefits from atmospheric and geomagnetic shielding, significant residual radiation persists, particularly during the so-called Ground Level Enhancements (GLEs), with implications for both aircrew and avionics reliability. Recent high-profile incidents, such as the Airbus A320 grounding due to cosmic-ray-induced Single Event Upsets (SEUs), underscore the growing vulnerability of modern aircraft systems. The study first assessed the spectral models of GLEs and historical ESEPs, to establish the total event fluence and peak event flux spectra for a selection of the strongest events. These spectra were then used as inputs to the MAIRE+ model to generate the enhanced in-flight radiation doses and SEU rates above the normal GCR values. Impact of a Carrington type geomagnetic storm has also been assessed and analysed. Further, the ongoing efforts to standardise aviation radiation protection is discussed, and a new atmospheric radiation scale is proposed, aiming to enhance operational mitigation and ensure safety in the enhanced space weather environment.