Solar Storm May Trigger Aurora Visible Across the U.S. South

A severe geomagnetic storm may have disrupted some radio and satellite communications, caused voltage control problems for power plants and created an aurora so bright it may be seen as far south as Alabama.

The storm, which grew in intensity to a G4 on the five-step geomagnetic scale, was caused by a flare on the sun that erupted Sunday, according to the U.S. Space Weather Prediction Center in Boulder, Colorado. Another flare has since gone off from the same area on the sun.

“We’ve had some decent storming so far,” said Robert Rutledge, lead of the Space Weather Forecast Office. “We have a close eye on it.”

So far there haven’t been reports of problems caused by the storm, which can disrupt the electric grid, Rutledge said. It often takes a few days to compile data on the effects of a geomagnetic storm.

The events were triggered when a coronal mass ejection reached the Earth Monday. An ejection is an explosion of the magnetic fields and plasma from the sun.

Hundreds occur each year, depending on the sunspot cycle, according to the National Aeronautics and Space Administration. The vast majority don’t come in Earth’s direction.

Solar storms can create geomagnetic storms, radio blackouts and solar radiation storms, each ranked on a five-step scale, with 1 being minor and 5 being extreme. The current event has created an R2 radio blackout and S3 solar radiation storm as well as the G4 geomagnetic storm.

The solar radiation storm can mean crews in certain high-flying aircraft need to take precautions while astronauts shouldn’t go on space walks.

Rutledge said the Earth may be in the cloud of the coronal mass ejection for another 18 to 24 hours. The center will be trying to forecast what the next wave may bring in a few days.

While the aurora, commonly called Northern Lights, may be visible deep into the southern U.S., Rutledge said people should consult the center’s forecast on its Web page before heading out on a search.

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