According to the results of a recent study done by research company Space Environment Technologies, another alarming presence in the Earth’s stratosphere has been discovered. It’s being referred to as ‘radiation clouds’ and are believed to be potential health hazards, especially to people who often travel via air.
Although air travel is supposed to be the safest mode of travel, flyers still can’t help but be scared when they are in the air. First, there’s turbulence — disturbance in the air that can be likened to waves in the ocean. Then there are cosmic rays — extremely energetic particles from space that strike the Earth’s atmosphere and cause a downpour of other particles (such as hydrogen nuclei, helium nuclei and other heavier elements); and solar wind — perpetually flowing charged particles from the sun that penetrate our atmosphere.
For the longest time, it was believed that high-altitude radiation mainly came from cosmic rays and solar wind. That has now changed with the discovery of this new kind of threat — radiation clouds. And worse than cosmic rays, being exposed to radiation clouds might be doubly dangerous.
The discovery of radiation clouds stemmed from the inconsistent data recorded by radiation sensors of NASA’s Automated Radiation Measurements for Aerospace Safety (ARMAS) programme. Apparently, out of 265 high-altitude research flights from 2013 to 2017, there were at least 6 instances when ionising radiation surges were recorded. The presence of cosmic rays and solar winds couldn’t account for the surges. But the presence of a ‘radiation cloud’ might.
Typically, the amount of radiation exposure (while in the air) depends on how long your flight is, and where you’re passing through. The closer you are to the polar regions (considered as high-altitude flight), the higher the amount of radiation you are exposed to. With radiation clouds, the degree of exposure can increase to as much as 200% of the expected dose.
The research suggests that passing through a radiation cloud would increase radiation exposure to the equivalent of 1/20 of a regular chest X-ray. So if you were to pass through 5 radiation clouds in one flight, you increase your exposure to 1/4 of a chest X-ray. To put things into perspective, a chest X-ray theoretically increases the risk of developing a fatal cancer by one in a million.
Tobiska believes that geomagnetic storms may have a hand in creating the so-called radiation clouds. Under normal conditions, the Earth’s magnetic field (also known as the magnetosphere) shields us from harmful cosmic rays and solar particles by trapping these elements in belts like the Van Allen radiation belt. But the trap isn’t leak-proof. When a disturbance like a geomagnetic storm or a solar wind burst occurs, some of the electrons or charged particles tend to leak out and get through the Earth’s upper atmosphere.
As lead researcher and Space Environment Technologies President W. Kent Tobiska told New Scientist, “Those electrons are driven into the upper atmosphere, collide with nitrogen and oxygen atoms and molecules, and then create a spray of secondary and tertiary radiation, likely in the form of gamma rays.” And it is likely this radiation that is being detected by the ARMAS flights.
Knowing that there are other things to look for in the atmosphere may now pave the way for the development of technology that would allow tracking of radiation clouds so flights can be rerouted to avoid them.
The study has been published in the journal Space Weather.
The ICRP Publication 132 provides an excellent characterization of radiation during commercial airline flights. Although the term “radiation cloud” is not used in the report, it does mention “terrestrial gamma ray flashes”, assumed to be associated with thunderstorm activity (lightning, actually).
Could hardly be simpler: flight crews would have vastly higher incidences of cancer. But they don’t. Non-story.