A recent study by researchers at the British University of Surrey Space Centre has warned that severe solar storms could pose an unexpected risk to aircraft and passengers, by raising radiation levels at cruising altitudes, as well as the potential for high-energy particles to affect some on-board electronic systems.

The study was published in the Journal of Space Weather and Space Climate in 2026, and focused on the impact of severe space weather on aviation, especially since commercial aircraft typically fly at altitudes between 8 and 14 kilometers, where atmospheric protection from cosmic radiation is less than at ground level.

Under normal conditions, radiation levels at these altitudes remain within manageable limits, but powerful solar storms can sharply increase them. During a solar storm on November 11, 2025, the University of Surrey team recorded a temporary rise in radiation levels at an altitude of around 40,000 feet to about ten times background natural levels.

Although this storm did not pose a direct health risk to passengers, researchers warn that much larger solar storms could lead to more worrying radiation levels.

The study is based on the strongest known event of this type, which occurred in 1956. The models used by researchers show that flying through a similar storm could expose passengers to a dose of radiation almost equal to what they receive from cosmic radiation associated with flying for an entire year, but during one flight.

Airplane electronics may be disrupted

The danger is not limited to passengers; high-energy particles produced by solar activity can collide with airplanes' electronic components, causing so-called single event upsets (SEUs), which are electronic errors that could lead to a change in the value of a bit within memory or an electronic circuit.

The study indicates that the rate of these disruptions may increase significantly during severe solar events. During the November 2025 storm, research from Sri University estimated that the error rate in some systems could reach about 60 errors per hour per gigabyte of memory, compared to much lower rates under normal conditions.

This does not mean that a single electronic error will necessarily cause an airplane to malfunction; however, the increased rate of these disruptions during severe solar storms may increase the likelihood of temporary errors in some systems.

Polar flights are more exposed

These risks are particularly relevant for flights near the poles, such as those between London and Vancouver, where the Earth’s magnetic field has a weaker protective effect on aircraft from high-energy particles.

During severe geomagnetic storms, the range of this impact can extend beyond the polar regions to areas further south, including the United Kingdom.

However, researchers do not see the solution in stopping flights whenever there is solar activity. Instead, they advocate for a more precise mechanism to assess the level of risk.

A new scale for monitoring danger

The study indicates that current warning systems, which rely on low-energy protons, may produce around 10 false alarms for every real alarm. This makes relying solely on them for operational decisions suboptimal.

Therefore, a team from the University of Surrey has proposed a new air radiation scale specifically for the aviation sector. It is based on measurements of high-energy protons in space and data from ground neutron monitors located at sites including Lerwick and Camborne.

In the future, this system could help airlines and relevant authorities determine the appropriate action based on the severity of the storm, ranging from increased monitoring to changing flight paths or taking more drastic measures during exceptional solar events.

Researchers stress that the goal is not to raise concerns about air travel, but rather to fill a gap in current safety systems by incorporating space weather as a factor to be considered when planning flights, especially with modern aircraft becoming increasingly reliant on electronic systems.