A “flip-flop” for the sun's magnetic field

From the Los Angeles Times....

Sun's magnetic field is about to flip: What it means for Earth

By DEBORAH NETBURN | 1:55PM - Wednesday, August 07, 2013

• PHOTOS: Stunning views of the Sun

THE SUN's enormous magnetic field is about to flip, and the effects of this massive realignment will be felt throughout the solar system, including here on Earth.

But don't expect anything too crazy to happen. Chances are you've experienced a major solar magnetic flip already, probably without even realizing it.

The sun flips its magnetic field once every 11 years, at the same time it reaches solar maximum, when sun spots and solar flares are at their height.

The magnetic flip doesn't happen all at once, explained Phil Scherrer, a researcher at Stanford University who studies the sun.

"It's a long, slow process, and in fact it has already begun," he told the Los Angeles Times.

The north pole of the sun, which has a greater share of sun spots, has already switched its magnetic sign, Scherrer said, and the south pole will probably switch its in the next three or four months.

Here on Earth we won't feel any phsyical effects from this major change, but we may get to see some cool auroras because of it.

The sun's magnetic field creates what's called a "current sheet" that emanates from its equator and stretches millions of miles beyond Pluto. NASA officials describe the sheet as "a sprawling surface jutting outward from the sun's equator where the sun's slowly rotating magnetic field induces an electrical current."

When the solar field flips, this "sheet" gets extra wavy, and as Earth moves around the sun, we dip in and out of it. The changes in the magnetic field interact with Earth's own magnetic field, which can cause auroras.

As for why it takes the sun 11 years to flip its magnetic field, scientists aren't totally sure yet.

"It is believed that it is just this big oscillating magnetic dynamo and this whole chain of events just takes time," Scherrer said, "but when you make a model of it, you don't actually manage to come up with an 11-year cycle unless you have a lot of free parameters."

In other words, they're still working on it.

http://www.latimes.com/news/science/sciencenow/la-sci-sn-sun-magnetic-field-flip-20130807,0,7988373.story