Catherine Rusoff
A severe geomagnetic storm heading towards Earth has the potential to disrupt power and electronics this weekend, but it could also bring a spectacular light show from the Northern Lights as far south as Alabama and northern California.
After days of intense solar activity, NOAA’s Space Weather Prediction Center on Thursday issued its first warning for a Storm G4 — the second strongest classification in a scale from G1 to G5 – in almost 20 years.
“Geomagnetic storms can impact infrastructure in near-Earth orbit and at the Earth’s surface, potentially disrupting communications, the electrical power grid, navigation, radio and satellite operations,” NOAA said. “[The Space Weather Prediction Center] notified the operators of these systems so they can take protective measures.”
Risks to the electrical grid
A G4 geomagnetic storm is considered “severe” and has the potential to cause widespread voltage control problems on the power grid. According to NOAAit could also cause some protection systems to “mistakenly disable important network assets.”
These types of effects on energy systems have been first observed in 1940 and have been reported over the years, with incidents including a power blackout in 1958, equipment shutdowns and voltage stability problems in 1972 and a nine-hour blackout in Canada in 1989, according to NOAA.
The last time there was a G5 or “extreme” geomagnetic storm was in October 2003, when it caused power outages in Sweden and damaged transformers in South Africa.
Effect on satellite and radio operations
By Friday afternoon, NOAA had also observed a moderate storm of solar radiation that could expose people in high-flying aircraft to “elevated radiation risk” and could cause infrequent problems with satellite operations.
With a G4 storm, “satellite navigation can be degraded for hours”, he warns.
Radio blackouts were also detected with the designation R3, meaning the blackouts were “severe” on a scale from R1 (minor) to R5 (extreme). At this level, large blackouts of high-frequency radio communications, as well as loss of radio contact, are expected for about an hour on the light side of the Earth as low-frequency navigation signals fade for about an hour. hour.
Expansion of the Northern Lights
The same phenomenon that causes these disturbances is also responsible for making the aurora borealis visible in places where we normally can’t see them.
“The Earth’s magnetic field guides the electrons in such a way that the aurora forms two ovals approximately centered on the magnetic poles,” NOAA said. “During large geomagnetic storms, these ovals expand away from the poles, so the aurora can be seen across most of the United States.”
Vivid displays were visible across parts of Europe and the UK on Friday night.
Images by Owen Humphreys/PA via Getty Images
“If you happen to be in a dark, cloud-free, and relatively unpolluted area by light, you might see a pretty impressive aurora display,” Rob Steenburgh, space scientist at the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center . , he told reporters on Friday. “and that’s really the gift of space weather, it’s the aurora.”
