NOAA’s current space weather forecast reports an M Class (moderate) solar flare from solar region AR2002. Spaceweather.com adds that AR2002 has destabilized its magnetic field, making it more likely to erupt, and that NOAA forecasters are estimating a 60% chance of M-class flares and a 10% chance of X-class flares during the next 24 hours. X-class flares are major solar events that can spawn incredible auroras visible far to the south of us, planet-wide radio blackouts and long-lasting radiation storms. Click to Space Weather for a video of AR2002 development.
While there’s not much chance of a major event, I thought it was interesting that 25 years ago this week, one of the most significant solar storms in memory created a spectacle in the skies as it demonstrated the power and danger of solar weather to modern society. A Conflagration of Storms begins:
On Thursday, March 9, 1989 astronomers at the Kitt Peak Solar Observatory spotted a major solar flare in progress. Eight minutes later, the Earth’s outer atmosphere was struck by a wave of powerful ultraviolet and X-ray radiation. Then the next day, an even more powerful eruption launched a cloud of gas 36 times the size of the from Active Region 5395 nearly dead center on the Sun. The storm cloud rushed out from the Sun at a million miles an hour, and on the evening of Monday, March 13 it struck the Earth. Alaskan and Scandinavian observers were treated to a spectacular auroral display that night. Intense colors from the rare Great Aurora painted the skies around the world in vivid shapes that moved like legendary dragons. Ghostly celestial armies battled from sunset to midnight. Newspapers that reported this event considered the aurora, itself, to be the most newsworthy aspect of the storm. Seen as far south as Florida and Cuba, the vast majority of people in the Northern Hemisphere had never seen such a spectacle. Some even worried that a nuclear first-strike might be in progress.
…Millions marveled at the beautiful celestial spectacle, and solar physicists delighted in the new data it brought to them, but many more were not so happy about it.
Silently, the storm had impacted the magnetic field of the Earth and caused a powerful jet stream of current to flow 1000 miles above the ground. Like a drunken serpent, its coils gyrated and swooped downwards in latitude, deep into North America. As midnight came and went, invisible electromagnetic forces were staging their own pitched battle in a vast arena bounded by the sky above and the rocky subterranean reaches of the Earth. A river of charged particles and electrons in the ionosphere flowed from west to east, inducing powerful electrical currents in the ground that surged into many natural nooks and crannies. There, beneath the surface, natural rock resistance murdered them quietly in the night. Nature has its own effective defenses for these currents, but human technology was not so fortunate on this particular night. The currents eventually found harbor in the electrical systems of Great Britain, the United States and Canada.
You can read on for more about how the storm spawned a power outage in Quebec and pushed US systems to the brink of collapse. If you want to totally geek out on auroral science, check this article out about how the Earth’s magnetosphere actually extends itself to block solar storms.