Sun's magnetic poles (need help understanding)

[xerex]

HI There.

So I was reading this article on yahoo and came across this.

http://news.yahoo.com/calm-solar-cycle- ... 12384.html

Cycle 24 has also diverged from the norm in another surprising way.

Typically, around the end of each 11-year sunspot cycle, the sun's magnetic fields switch direction. The northern and southern hemispheres change polarity, usually simultaneously.

During the swap, the strength of the magnetic fields drops to near zero and reappears when the polarity is reversed, scientists explain.

But this time, something different seems to be happening. The north pole already reversed its polarity several months ago -- and so it's now the same polarity as the south pole.

According to the most recent satellite measurements, "the south hemisphere should flip on the near future," said Todd Hoeksema, director of the Wilcox Solar Observatory at Stanford University.

can someone explain to me what that actually means ? If I took a compass to the sun would it spin in circles ? Thanks in advance.

[Borgholio]

Right now, a compass would point to whichever pole was stronger. If they were equally strong, then it would point to whichever pole you were closest to.

[InsaneTD]

How can both poles be south? I thought it was impossible for something like that to happen?

[AMX]

How can both poles be south? I thought it was impossible for something like that to happen?

On an elementary magnet, yes.
But the sun is pretty big, so it's perfectly possible to reverse the polarity of only a part of it - so now both "visible" poles are magnetic south, and each of them has a magnetic-north counterpart that's buried inside the sun.

Yes, that means there are two north poles next to each other - that's an unstable configuration, and would normally cause the rest of the sun to also switch polarity, to align everything again.
The puzzling thing about the current situation is why that hasn't happened yet.

[InsaneTD]

Puzzling? I'd call it mildly disturbing and a cause for concern. Admittedly, I'm working off high school physics and don't know much at all about astrophysics.

[Simon_Jester]

To know whether it's disturbing you'd have to know how fast the magnetized parts of the Sun should move. Understanding anything about what the Sun's interior does requires plasma physics (I know a little and it's not trivial), and bear in mind even then that we're talking about an object roughly a million miles across. It's not small, it takes a very real and significant amount of time for changes to propagate across a mass that large.

This may just be like how when a building collapses, it usually collapses one story at a time instead of all at once.

[Broomstick]

Puzzling? I'd call it mildly disturbing and a cause for concern. Admittedly, I'm working off high school physics and don't know much at all about astrophysics.

It's odd by our frame of reference, but not a cause for concern. As noted in the OP quote, the sun's magnetic field routinely reverses, and it's not unusual for there to be a bit of chaos in around such reversals.

For that matter, the magnetic polarity of the Earth also changes every so often, and moves around. We just don't notice because we can't perceive it directly. Back when I was a pilot our navigation charts used to list magnetic deviation, basically, the difference between geographic north and magnetic north, which is important to know over long distances for some types of navigation. One reason the charts are updated on a regular schedule is because that number changes over time. There are also things called geomagnetic excursions, where the local magnetic field on Earth temporarily differs significantly from the global field so a magnetic compass in such an area may show a north that's 20 or 40 degrees different from what the rest of the planet shows. That's just on Earth.

The sun, not being a solid object but rather a very violently churning ball of plasma, has this sort of thing going on all the time. It's nothing new, it's actually routine, but it's news to us. The biggest concern to us, 150 million kilometers away, is that chaotic solar magnetic fields are associated with things like coronal mass ejections which can fuck up our satellites and cause power outages in our utilities.

[Borgholio]

Sunspots are believed to be a result of the magnetic field twisting up like a rubber band every 11 years or so. It's really quite fascinating, but the physics can be difficult to wrap your head around at times.

[krakonfour]

Puzzling? I'd call it mildly disturbing and a cause for concern. Admittedly, I'm working off high school physics and don't know much at all about astrophysics.

The sun is a hot ball of ionized gas. I'm sure two or three magnets can reach a temporary equilibrium in there.

[InsaneTD]

I knew the Earth's North Pole wobbled about from high school, didn't know about localized magnetic spots. Sounds like something interesting to read about, I don't suppose anyone has a handy link for the layman to look at (Cause I'm lazy)?

[Broomstick]

Google "geomagnetic excursion" and "geomagnetic reversal". There is also the South Atlantic Anomaly which is believed to be caused by the Earth's magnetic axis being offset from its physical axis

[InsaneTD]

Thanks broomstick, I'll do that.

[Irbis]

How can both poles be south? I thought it was impossible for something like that to happen?

Compare:



Reversal isn't something that happens at once, think of avalanche of changes trying to reach stable equilibrium. It's not two south poles, more like whole network becoming a mess trying to untangle.

[InsaneTD]

That is incredibly pretty. Thanks for answering my questions guys.

[krakonfour]

That is incredibly pretty. Thanks for answering my questions guys.

It also looks wickedly dangerous. Are those massive magnetic loops close to the surface the cause for equally massive solar flares?

[Borgholio]

Are those massive magnetic loops close to the surface the cause for equally massive solar flares?

You betcha. Solar flares, Mass Ejections, and Sunspots are all related to the magnetic field. The more twisted it is, the more solar activity you'll get.