Reverse! Sun’s magnetic field on the brink of 180-degree flip

http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2013/08/06/reverse-suns-magnetic-field-on-the-brink-of-180-degree-flip/

It’s nearly time for the current solar cycle’s second half. And stunningly, the sun’s magnetic field will rearrange itself to mark the transition.

“The sun’s polar magnetic fields weaken, go to zero, and then emerge again with the opposite polarity,” Stanford solar physicist Phil Scherrer tells NASA.

The flip could happen at any time.

“It looks like we’re no more than 3 to 4 months away from a complete field reversal,” solar physicist Todd Hoeksema of Stanford University tells NASA.

NASA describes the flip as a “big event” as the field reversal emits a current stream that extends billions of miles beyond Pluto.

The flip won’t affect weather on Earth, but space weather may get a bit bumpy.

Writes NASA: During field reversals, the current sheet becomes very wavy. [Stanford University solar physicist Phil] Scherrer likens the undulations to the seams on a baseball. As Earth orbits the sun, we dip in and out of the current sheet. Transitions from one side to another can stir up stormy space weather around our planet.

Stormy space weather can lead to disruptions in high frequency radio and satellite communication, and – under extreme circumstances – the Earth’s electrical grid.

Links: Understanding space weather forecasts and the risk of solar storms | Are we ready yet for potentially disastrous impacts of space weather?

The coming field reversal is a normal occurrence that coincides with the peak of every solar cycle.
Solar cycle peaks occur when sunspot activity reaches a maximum.

Interestingly, the observed (and/or predicted) maximum in the current sunspot cycle (number 24), is the smallest in over 100 years (since February, 1906) due to depressed sunspot activity.
Related: Could a quiet sun cancel global warming?

Scientists aren’t sure why the sunspot activity in this cycle is so weak, but it’s an ongoing area of exploration.

As for the magnetic field reversal, NASA says Stanford’s Hoeksema and Scherrer will make an announcement once it has occurred.

Here’s a NASA video on the reversal: