Tuesday night, the Upper Valley experienced an impressive display of the Aurora Borealis. The lights are caused by particles from the sun being thrown into space and interacting with the charged particles in Earth’s ionosphere, which begins about sixty miles above the surface. This is referred to by scientists as a geomagnetic storm. Donald Hampton researches those storms for the University of Alaska Fairbanks. He says the geomagnetic storm on Tuesday was very rare.
“It’s kind of a once-every-ten-year kind of storm. Just the magnitude and the duration were quite spectacular, actually.”
Geomagnetic storms are rated on a scale of one to five, based on their intensity. This week’s event was rated a G4, or ‘severe,’ storm. On Tuesday, the northern lights were visible across substantial areas of the Lower 48. Storms that strong also have another effect, however. Donald Hampton says communications systems, such as telephones and radio, can be impacted when their signals hit the ionosphere.
“That plasma actually reacts to that electromagnetic wave going through there, and it can do things like attenuate it, so the signal you think you’re going to get out of the other side may be a lot weaker. So, instead of hearing a radio station ten miles away, you might only be able to hear it one mile away, or something like that.”>>
No significant outages were reported in the Upper Valley as a result of Tuesday’s geomagnetic storm, meaning that the event amounted to nothing more than an impressive light show.