Magnetic field cracking open
MARCH 1, 2012
AURORA OUTBURST: Last night, for the second night in a row, sky watchers around the Arctic Circle witnessed an impressive display of auroras. “I’ve never seen anything close to this,” says Aaro Kukkohovi, who photographed an eruption of light over Lumijoki, Finland:
“What a fantastic burst of energy–like something blew a hole into Earth’s magnetic field just above us!”
Spotted this fascinating piece on http://www.spaceweather.com/ today:
Kukkohovi’s rhetorical flourish isn’t far wrong. The cause of the display was the interplanetary magnetic field (IMF) tipping south and opening a ‘crack‘ in Earth’s magnetosphere. Solar wind poured in and fuelled a G1-class geomagnetic storm. This was a high latitude event; the lights were brightest over Scandinavia, Iceland and Greenland.