Borealis Or Australis, Last Night’s Aurora Shined

A wide-angle taste of the all-sky aurora display seen widely over North America last night. This was taken near a wind turbine south of Drumheller, Alberta. Details: 25-second exposure at f/3.5 with the 8mm fisheye lens and Canon 5D MkII at ISO 1600. Credit and copyright: Alan Dyer

The geomagnetic storm that began with a jolt yesterday afternoon raged straight through the night and still shows no signs of slowing down. Storm levels reached the “strong” category overnight sending auroras over the farms of Iowa and Kansas, interfering with short wave radio communications and putting satellite operators on edge.

The latest space weather forecast dates predicts much quieter conditions for tonight and tomorrow however it’s a bit outdated (June 28) and makes no reference to the big storm. Maybe no one’s in the office yet?

Forecast or not, I’ll be out watching tonight for the left-overs and encourage you to do the same. Reports and photos not only came in from Canada and the U.S. but also from Tasmania and New Zealand in the southern hemisphere, where the northern lights are known as  the “aurora australis” or southern lights.

The aurora forms two permanent caps centered on Earth’s north and south geomagnetic poles. When stimulated by solar activity the northern oval expands southward (southern oval northward) and becomes visible over more populated regions. Credit: NOAA

The counterpart of our northern lights, the aurora australis is part of a permanent ring of aurora centered on the south geomagnetic pole in Antarctica. Best places for viewing them include the icy continent, southern Australia, New Zealand and southern Chile and Argentina. You don’t see nearly as many photos of the southern lights as you do the northern variety because there’s far more ocean and far less land in the southern auroral zone than in the north. Since people prefer land for their skywatching, a much smaller populace is treated to the aurora australis.

Aurora australis over the Amundsen-Scott South Pole Station on June 3, 2008. Jupiter is at right with the Milky Way above center. The south pole is now in complete darkness until the sun rises again at the September equinox, making an ideal if chilly location for viewing the southern lights. Credit: Keith Vanderlinde/National Science Foundation

Other than that, both northern and southern varieties are virtually identical. If we’re seeing a low, green arc simmering in the northern sky, Tasmanians will see the same in their southern sky. When the lights really go nuts here, they go nuts Down Under. Sudden changes in the extent, activity or brightness of aurora here are mirrored in the southern hemisphere.

Last night’s southern lights from Tasmania, Australia photographed by Jo Malcomson, who writes: “Lots of curtains and beams of light. At times the reds were visible with whites and greens and they danced across the horizon behind a low broken cloud cover. I’ve never seen anything as strong down here. “

If we’re lucky enough to see another show tonight, picture the penguins of New Zealand silhouetted against an aurora-tinted ocean. I’ll post an update later today on how things might shape up this evening.

* Update 7 p.m. CDT: After a lull this afternoon, auroral activity is rising again. Kp index at 7 p.m. was “4”, one level below minor storm.

* Update 1 a.m. CDT: No aurora here in Duluth, Minn. tonight. Activity has dropped off for now.