As far as I know (which isn't very far), you should try to keep the exposure time fairly short. The aurora "flickers", sometimes rapidly, sometimes slowly. I have seen some very good pictures taken at 30s, f:3.5 with 800 Iso film. And others at 15s, f:4, 100 Iso... So depending on film size I would go for a moderately fast film, wide aperture, and somewhere around 8 to 60 seconds...
There was a story on CNN about huge solor storms knocking out a couple of communication satalites. That is probably why we are getting them so far south.
Judgeing by the level of activity the sunspot group has shown this week, its preaty safe to say they arent done yet. 2 days ago was the 3rd largest flare ever recorded.
Its cool seeing the false color UV Movie (The Big one, not the closeup or the tiny one) of the sun just seconds before the explosion. It looks like the area sparks and then BOOM!
Reported in The Times newspaper this morning as being visible widely across the northern hemisphere after one of the largest recorded solar flare eruptions.