This Week's Solar Storm

[Ursa major]

In trying to find out what happened regarding the recent solar storm, I read this article in the Grauniad.

The article contained this paragraph (whose main points were repeated in the graphics here):

Forecasters at the US government's Space Weather Prediction Center said the storm is growing in intensity as it speeds outward from the sun. The charged particles hit Earth at 4 million mph (6.4 million kph).

Why does the storm intensify as if moves from the sun towards the Earth? (I can see why it might not dissipate - the storms seems to be directional - but intensification is another matter.) Is this effect caused by the Earth's magnetic field?

[Starbeast]

Solar flares happen every eleven years, but Scientists years ago warned that this time (in 2012) Earth may be hit hard enough to disable satellites and power grids.

I was waiting for this to happen, and now it's starting.

[Metryq]

Originally Posted by Ursa major

Why does the storm intensify as if moves from the sun towards the Earth?

I'm not an astrophysicist, but at a guess I would say that means the later part of the eruption was more energetic and/or spewed more mass. So the storm may not be "intensifying," but the approaching wave may be weaker at the front and more intense farther back.

(The only way I can imagine a CME "intensifying" is through some sort of electrical focusing of the wave. I've read some layman's material on Hannes Alfvén, a physicist who described electrical currents in space, but I can't claim to truly understand his work.)

[Ursa major]

You may be right - that the storm intensifies over time** - but that isn't at all what the quoted words say*** (or imply).

(I suspect this is another example of an article's author not really knowing what they're talking about and in producing a precis of what they've been told, they've garbled the message.)




** - As a layperson, I'd expect the output to grow (in mass and/or energy) to a peak, then fall away to nothing.

*** - "storm grows in intensity as it speeds outward from the sun."

[Metryq]

Originally Posted by Ursa major

but that isn't at all what the quoted words say

Maybe there is some of that Alfvén plasma physics going on. I know that his work was ridiculed when it was first published. And although not everything has held up, I understand that much of it is now accepted. Perhaps that CME is winding up like a rope and getting ready to snap the Earth like a bullwhip as it rumbles by.

So really—how long before the technology exists to control the magnetic field lines so that auroras can be used for product placement? That would be one heckuva big "neon" sign.

Eat at Joe's

[Vertigo]

I think it may be something along those lines Metryq. The storms are not just particles but also "bubbles" of twisted magnetic fields. That is how they start as solar flares and then sometimes (not always) the flare "snaps" it's connection from the sun's atmosphere and hurtles off into space. Apparently if it goes North of the ecliptic the orientation of our magnetosphere gives us excellent protection but if it breaks off headed south of the eclitptic then we are just "an open door".

So he says having just watched Tuesday's Horizon that was on solar storms. And very interesting it was too, if a little melodramatic.

Another interesting thing is that the dangers to satellites are not just electrical. It seems that the storms also heat the atmosphere which then expands making more gas move up higer in the atmosphere. This makes the upper atmosphere that the low orbit satellites travel through more dense slowing their orbits and potentially even bringing the satellite down. They implied that this effect was the final killer for the old Sky Lab. One of the reasons they are so desperate to be able to predict these storm well ahead of time is so they can get the satellites ready to manoeuvre ahead of time.

[mosaix]

Originally Posted by Starbeast

Solar flares happen every eleven years, but Scientists years ago warned that this time (in 2012) Earth may be hit hard enough to disable satellites and power grids.

I was waiting for this to happen, and now it's starting.

Well, according to reports, it should be all over by now. I don't know if this is related but I had no signal at all yesterday on my digital radio, on any channel.

[Vertigo]

It might be over(ish) for now but they are predicting a period of about 2 years of higher solar activity. So I expect we will be seeing more of this sort of thing for a little while.

[Nik]

Never mind the Grauniad's guff, a reputable report is at...
http://www.spaceweather.com/

That's also worth watching for the steadily growing list of Potentially Hazardous Asteroids and their miss distances...