The Daily Traveler: Solar Flares

 

How Solar Flares Interfere with Flights

Yesterday a massive solar flare—the biggest since 2005—had irksome consequences here on Earth, including forcing airlines to divert some of their flights. But how could the sun affect our air travel—and how big is the danger? We asked scientists to break it down for us.

First off, the phenomenon is not rare. "Solar flares happen all the time," says C. Megan Urry, chair of the Department of Physics at Yale University and director of the Yale Center for Astronomy & Astrophysics. "They have a range of brightnesses and most are too small to affect the Earth very much, but, occasionally, there are super big ones, like the flare of November 4 last year."

During the solar flares, Urry explains, "Much of the energy is emitted at very short wavelengths: X-rays and ultraviolet light. The largest ones involve 'coronal mass ejections', or CME, that also send very energetic particles our way."

These particles are the source of the troubles—especially for airplane equipment. "Energetic particles from the solar flare impact on the upper atmosphere of the Earth and ionize it, or release charged particles," says Jules Halpern, professor of astronomy at Columbia University. "The more ions there are, the more difficult it is for radio waves to propagate. This is particularly a problem for communication with flights going over the North Pole."

The equipment isn't the only thing at risk, however. "Exposing flight attendants and passengers to these particles is not a good idea," Urry says. "They could cause cell damage or mutations."

On the bright—no pun intended—side, Urry notes that "these particles should also cause unusually bright Northern Lights," for those lucky enough to be in areas that can see them.