Northern Lights?

[garethrl]

Out of the polar regions, it's rare that a single storm - and therefore an auroral display - lasts more than a single night. If you see it two nights running then it's typically separate events, which can happen but normally closer to solar maximum. So if you missed it the other night then you'll have to wait for the next one! Not that that should stop you heading out in night rides just-in-case, though ...

There's a also a distinction worth making between flares and CMEs. Whilst they're often observed 'together' - ie as part of the same solar eruptive event - not all CMEs are accompanied by flares. There's another class of solar eruptions called solar prominence eruptions, like this:

which generally don't have a flare to accompany them. A flare, OTOH, looks like this:

so you can easily tell the difference from the colour ...

Prominence-related events tend not to lead to the most intense geomagnetic storms (that's for the flares, a-la Carrington) but having said that they can happen at any time during the solar cycle, and the aurorae the other night were due to a prominence like this. This current period of the solar cycle is often often productive for prominence eruptions for a variety of reasons, so it may not be a long wait til the next one. Of course, it may be a very long time, these things are hard to predict ...

As you might intuitively think, these prominence events are typically slower than flare-related events (more mass directly involved, so harder to accelerate), which is why this one took four days to arrive rather than the 17 hours for the Carrington event.

Cheers, Gareth.

 

[legrandefromage]

Read 'Sunstorm' by Arthur C. Clarke and you'll learn all about CMEs and why they can be just a wee bit dangerous.

 

[garethrl]

I haven't read in but I would imagine that like ACC's stuff it's based in scientific fact and exaggerated to make it fiction. As in, worst case scenario inflated by a 1000+ times.

It's not going to happen, of course, but there's reason to believe it could have in the past. Sun-like stars are known to be extremely active in their younger ('teenage') phases, before calming down to boring mediocrity with the occasional outbursts for most of their lives (sound familiar?). I think it's been postulated that one reason for the relatively late appearance of multicellular life on Earth could be much higher levels of solar activity at the time. This would be one of many reasons of course.

In any case, solar activity is not expected to increase to levels like that again. So-called 'flare stars' are common throughout the Milky Way and other galaxies, and data from them is used to put together an overall picture of stellar theory and evolution.

Read 'Sunstorm' by Arthur C. Clarke and you'll learn all about CMEs and why they can be just a wee bit dangerous.

 

[legrandefromage]

Solar storms cause all sorts of grief to power lines and any long length of metal cables.

stuff like this too:

http://www.techeye.net/science/experts- ... le-and-gps


ACC books dont usually exaggerate - you've perhaps been watching too many Roland Emmerich films?


Although, the premise of his book is that an ancient civilization slingshots a gas giant into the Sun around 2000 years ago so a CME microwaves the Earth clean down to about 2 metres...

 

[dyna-ti]

ACC is a pedo,the less said about him the better

 

[legrandefromage]

ACC is a pedo,the less said about him the better

That was never proved and he never would have had his nighthood :roll:


The guy had polio FFS

 

[garethrl]

Power lines and cables - just like power substations - and also above-ground oil pipelines are at risk for the same reason. When you take any magnetic field and change it - squeeze it, bend it, kink it, stretch it - then you induce and electric current within that field. So, when a CME comes along and slams into the Earth's magnetic field, then besides all the particle acceleration it also generates large scale currents. They're called geomagnetically induced currents, or GICs. Naturally these GICs want to go somewhere so they look for the point of highest electromagnetic potential. It's the same principle as a lightning strike.

If the polar regions were flat and featureless - like they used to be - then it would be any trees in the region that got it. Nowadays, electrically charged objects like power systems and pipelines are more attractive since they they are at higher EM potential. There are relatively few overhead power lines in the polar regions partly for this reason, so it's more of an issue at lower latitudes when the storms are particularly intense.

As for the AC plot, I'm not sure that a super-CME would be the likely result of a gas giant being hurled into the Sun. I would have thought perhaps it would be even more catastrophic, maybe even a nova. In such an event, the CME would be the least of our worries, we'd be wiped out by gamma radiation more or less instantly.

Solar storms cause all sorts of grief to power lines and any long length of metal cables.

stuff like this too:

http://www.techeye.net/science/experts- ... le-and-gps


ACC books dont usually exaggerate - you've perhaps been watching too many Roland Emmerich films?


Although, the premise of his book is that an ancient civilization slingshots a gas giant into the Sun around 2000 years ago so a CME microwaves the Earth clean down to about 2 metres...

 

[legrandefromage]

Power lines and cables - just like power substations - and also above-ground oil pipelines are at risk for the same reason. When you take any magnetic field and change it - squeeze it, bend it, kink it, stretch it - then you induce and electric current within that field. So, when a CME comes along and slams into the Earth's magnetic field, then besides all the particle acceleration it also generates large scale currents. They're called geomagnetically induced currents, or GICs. Naturally these GICs want to go somewhere so they look for the point of highest electromagnetic potential. It's the same principle as a lightning strike.

If the polar regions were flat and featureless - like they used to be - then it would be any trees in the region that got it. Nowadays, electrically charged objects like power systems and pipelines are more attractive since they they are at higher EM potential. There are relatively few overhead power lines in the polar regions partly for this reason, so it's more of an issue at lower latitudes when the storms are particularly intense.

As for the AC plot, I'm not sure that a super-CME would be the likely result of a gas giant being hurled into the Sun. I would have thought perhaps it would be even more catastrophic, maybe even a nova. In such an event, the CME would be the least of our worries, we'd be wiped out by gamma radiation more or less instantly.

Solar storms cause all sorts of grief to power lines and any long length of metal cables.

stuff like this too:

http://www.techeye.net/science/experts- ... le-and-gps


ACC books dont usually exaggerate - you've perhaps been watching too many Roland Emmerich films?


Although, the premise of his book is that an ancient civilization slingshots a gas giant into the Sun around 2000 years ago so a CME microwaves the Earth clean down to about 2 metres...

Its a ripping yarn of a story, Gamma rays included, Gas giant gets fired into the Sun, Sun rings like a bell for 2000 years and firs out like a holed balloon at the peak of mankind.

A hifi company I worked for made an experimental speaker but it was a bit dangerous to be around as it charged itself of the earth's magnetic field

 

[highlandsflyer]

ACC is a pedo,the less said about him the better

That was never proved and he never would have had his nighthood :roll:


The guy had polio FFS

That is an unusual name for a Sri Lankan boy.

 

[REKIBorter]

ACC is a pedo,the less said about him the better

That was never proved and he never would have had his nighthood :roll:


The guy had polio FFS

That is an unusual name for a Sri Lankan boy.

I know it's wrong but I just LOL