The key facts
- The solar storm of November 11, 2025 became the most powerful surge of solar radiation in nearly 20 years
- The dose aboard a London — New York flight exceeded the usual background by 46%
- For the first time, radiation was tracked through all layers of the atmosphere simultaneously
A Rare X5-Class Flare
The most powerful surge of solar radiation in nearly 20 years reached Earth on November 11, 2025. The storm was caused by a rare X5-class flare — one of the most powerful categories of solar eruptions. Its particles penetrated through the entire atmosphere and reached the Earth's surface. Specialists from the University of Surrey measured the event's impact on aviation in detail, combining data from ground-based sensors, weather balloons, and transatlantic airliners. The results are described in the journal Space Weather.
Rise in Dose Onboard
The radiation dose aboard one flight from London to New York exceeded the usual background by 46%. Several hours after the storm's peak, weather balloons launched from the town of Lerwick in the Shetland Islands recorded radiation above the 'moderate' threshold at business aviation altitudes, which fly above regular airliners. At altitudes of supersonic aircraft, readings crossed the 'severe' mark.
Researchers' Reaction and the Course of Measurements
'I have been studying such events for years, so at the first alerts I assumed it was just another small surge. But when I saw the data over Lerwick, I simply could not believe my eyes,' said Fraser Baird, co-lead of the study from the Surrey Space Centre. According to him, the first balloon recorded an extraordinary level of radiation in the upper layers of the atmosphere. He noted that such storms manifest differently depending on the region, so aviation needs a coordinated monitoring system. As soon as neutron monitors, which register the flux of cosmic rays, detected the anomaly, research balloons took to the sky within minutes, and data arrived to scientists in real time. For the first time, it was possible to trace radiation through all layers of the atmosphere at once; detailed measurements became possible thanks to a monitoring network that appeared in Britain only in recent years.
Significance for Aviation
The study will help improve space weather forecasts, on which flight safety depends. The need for them will grow, as airlines increasingly rely on sensitive electronics and route flights through high latitudes, where the radiation background is at its maximum. Earlier, the Russian Academy of Sciences explained that the radiation level aboard a space station is 200 times higher than on Earth.
