A new study published in Eos is revealing that people need not leave Earth's atmosphere to be exposed to dangerous levels of cosmic radiation. The research shows that violent space weather could put them at risk even when flying on passenger jets.
"Hubert and Aubry  simulate the radiation impact of a very severe, but credible, space weather event on air travel, with a major focus on the busy routes across the North Atlantic. Their simulation looks at many real tracks followed by aircraft in March 2019, and estimates the radiation doses that would have accumulated on-board if exposed to a severe atmospheric radiation storm, such as that thought to have occurred in AD 774/775," Michael A. Hapgood, Editor, Space Weather writes, discussing the new research.
"This simulation confirms previous literature (e.g. Cannon et al., 2013) showing that severe radiation storms could expose passengers and aircrew to radiation doses above the internationally agreed limits for public and occupational exposure to radiation. It adds to that by providing valuable insights into how that exposure might vary depending on several factors including the time profile of the storm, the direction of travel, and the location of the jet stream. I hope that this manuscript provides a stimulus for further work on assessing this rare, but important, space weather risk."
How the data was modeled
The researchers published a paper in the journal Space Weather where they evaluated specific radiation storms that likely happened in the years 774 and 993 using as a basis a less severe storm from 2005. They called the storms solar energetic particle events and found that in storms as severe as the two first, passengers were exposed to dangerous levels of cosmic radiation.
Now, it should be noted that humans absorb radiation safely every day. However, when traveling at higher altitudes, humans are exposed to higher levels of radiation because the atmosphere cannot block it. Still, as long as there is no extreme weather event, that exposure is likely negligible.
The study however does bring an important factor for jet developers to take into consideration when engineering their planes. Extra measures must be taken to ensure both the passengers and electronic equipment are kept safe during extreme weather events.
"The orders of magnitude of the ambient dose equivalent induced during past extreme solar energetic particle (SEP) events raises a number of issues, both for aircrews and for avionics hardware. This study demonstrates that simulations can be useful for the evaluation of risks in case of extreme SEP events," write the researchers in their study.