Aurora alert, Tasmania

[ricktas]

The Bz index is climbing and anyone in Tassie who wants to get away from the city/town lights and has clear skies might be in for a treat this evening.

http://sphotos-a.ak.fbcdn.net/hphotos-ak-snc7/384448_10151108774743645_998546402_n.jpg

The red/yellow area is where an aurora would be visible, as darkness comes on, if this gets much bigger it will cover Tassie and we should get a decent aurora.

[ricktas]

well reports coming in that cloud cover has come in over most of Southern Tas, so whilst the Aurora plays away in our skies, we cannot see it :(

[Cattleprod]

G'day Rick, how often do you get to see it down there?

[ricktas]

G'day Rick, how often do you get to see it down there?

depends there is no way of predicting it beyond about 24 hours. We get advanced warning via the satellite that 'lives' about half way between earth and the sun..

The cause of Auroras is related to coronal mass ejections from the sun, but the sun goes through an 11 year cycle, so some years we get none, but at present the sun is about to hit solar maximus (it's most active time in its 13 year cycle), which is predicted for Feb 2013, and thus for the next few months we should get quite a few opportunities as the sun become very active. When a CME is directed at Earth, then we get the chance of an aurora

More reading

http://en.wikipedia.org/wiki/Coronal_mass_ejection
http://en.wikipedia.org/wiki/Solar_maximum
http://en.wikipedia.org/wiki/Carrington_event ( what would happen if this occurred today with all our electronics etc?)

[harper]

hope to see one on my trip there in November:D

[zollo]

Cheers for the info Rick

[mikec]

Thanks for the heads up Rick. I'm in Tas in November and December so will hopefully get a chance to see it.

We'll be spending most of our time in Freycinet and Port Arthur area so we will hopefully be far away enough from the big lights!

[ricktas]

There was a C9.1 flare a few hours ago. We should know in the next 2-3 hours if it is heading towards Earth. If so, then there is a big chance of a decent aurora over the next couple of nights, that could quite feasibly be visible from most of the Southern mainland states. I will post more info here as it comes to hand.

[Warus]

Would it be visible in dark areas in central NSW or is orange to far north?

[ricktas]

Would it be visible in dark areas in central NSW or is orange to far north?

most likely. A guy in Wagga Wagga photographed one earlier in the year.

[ricktas]

The C9.1 was off-centre, thus it is heading towards Earth but might not hit us, rather going to one side or the other of the planet. However confirmation of its direct path has not been confirmed, so even if the edge of it hits us, we could be in for some decent activity.

To understand the differing classes of flares (there are three C:M:X with X being the strongest): http://spaceweather.com/glossary/flareclasses.html, that article is about their impact on the planet as a whole, but anything above about a C3/4 can create an Aurora visible from Tasmania, and then the higher you go in the classes, the more wide spread the aurora visibility toward the equator.