Taken by the Solar Dynamics Observatory, this image shows the solar flare observed on 19 January 2012.
Credit: NASA
WASHINGTON: A potent solar flare has unleashed the biggest radiation storm since 2005 and could disrupt some satellite communications in the polar regions.
The event started late on Sunday 22 January (Washington time), with a moderate-sized solar flare that erupted right near the centre of the Sun, said Doug Biesecker, a physicist with the U.S. National Oceanic and Atmospheric Administration (NOAA) Space Weather Prediction Centre.
"The flare itself was nothing spectacular, but it sent off a very fast coronal mass ejection travelling 6.4 million km per hour," he said.
Largest kind of radiation storm
The Sun erupted with an M8.7 class flare, an Earth-directed coronal mass ejection (CME), and a burst of fast moving, highly energetic protons known as a 'solar energetic particle' event.
NASA's Goddard Space Weather Centre's models predict that the CME is moving at almost 2,253 km per second, and could soon reach Earth's magnetosphere - the magnetic envelope that surrounds Earth. This has the potential to provide good auroral displays, possibly at lower latitudes than normal.
The radiation storm is the largest of its kind since May 2005 but still ranks only a three (S3) on the scale of one to five, enough to be considered 'strong' but not 'severe', Biesecker said.
This means "it could, for example, cause isolated reboots of computers onboard Earth-orbiting satellites and interfere with polar radio communications," according to the NOAA. The conditions are expected to last through to Wednesday.
Biesecker said that when it comes to radiation storms, the polar regions are affected most. For instance, the storm could spell disruptions to airline flights, oil operations, Arctic exploration and space satellites.
Not to worry
The geomagnetic storm is expected to kick off today and is likely to reach G2 (moderate) levels, with a possibility of G3 (strong) storms. High latitudes have a possibility of even stronger, isolated geomagnetic storming. Stronger geomagnetic activity than this has occurred as recently as October 2010.
Night-sky viewers in Asia and Europe may be able to witness an aurora, or Northern Lights, later today as a result of the storm. "We don't expect major impacts from an event like this," Biesecker said. "It's the people who need GPS (global positioning system) accuracy of centimetres who have to worry, not people who want to know if you're going to turn the car 30 m ahead."
