Estimation of Global increase of radiation dose rates during the ground level enhancement on 11–12 November 2025 using WASAVIES

Solar energetic particle (SEP) events associated with large solar flares can substantially enhance cosmic-radiation dose rates at typical aviation altitudes, particularly on high-latitude routes where geomagnetic shielding is weak. To support aviation operators during such events, we developed WArning System for AVIation Exposure to Solar energetic particles (WASAVIES), an automated system that uses real-time satellite proton measurements and ground-based neutron monitor data to estimate global increases in radiation dose rates within minutes. On 11 November 2025, a ground level enhancement event (GLE77) occurred and successfully triggered the “SEP mode” of WASAVIES, demonstrating fully autonomous start-up of global dose-rate nowcasting during an extreme space-weather event. We then performed a post-event reanalysis using a patched version of the WASAVIES algorithm. The reanalysis shows that GLE77 consisted of multiple peaks and had an unusually hard particle spectrum compared with recent events. The estimated global maximum effective dose rate (including the galactic cosmic-ray background) briefly exceeded the ICAO “Moderate” advisory threshold, but the exceedance was short-lived and limited in magnitude and geographic extent, suggesting that major operational responses such as route or altitude changes were unlikely to be required. Overall, this event highlights specific upgrades needed to strengthen future nowcasts.

Recommended citation: Sato, T., Shiota, D., Kubo, Y., Kataoka, R., Yasuda, H., Miyake, S., et al. (2026). "Estimation of Global increase of radiation dose rates during the ground level enhancement on 11–12 November 2025 using WASAVIES" Space Weather, 24, e2026SW004949. https://doi.org/10.1029/2026SW004949