Good Aurora Forecast This Week Could Be Due to Solar Magnetic 'Flip'

Aug 20, 2013

The sun is the largest star in our solar system.
Credit / NASA

Fairbanks, AK - Geophysical Institute is forecasting strong auroras at the end of the week.  Some of that activity could be in response to changes in the suns magnetic field.  Over the next few months, the sun will undergo a magnetic flip.  Is an event that happens every eleven years, but scientists have only been able to monitor what happens at the solar poles since the 1970’s.

Much like the Earth, the sun has a magnetic field with a north pole and a south pole.  But in just a few months, the sun’s negatively charged north pole will have a positive charge.  Its south pole will switch from a positive charge to a negative charge. “It’s part of the normal process," says Roger Smith.  "The sun has cycles of activity,” Smith is the Emeritus Director of the Geophysical Institute at the University of Alaska, Fairbanks. “If you have your cup of coffee in the morning, and you have cream on the top, and you spin it up with a spoon, you see some circulation," he explains.  "What’s happening on the sun, it’s the same as having the spinning on the top of your cup reverse and go the other way.”

Because the sun is so hot, charged particles in its magnetic field move in a constant fury.  Those particles interact with others throughout the solar system, causing auroras among other things.  Smith says this “flip” stirs up those particles and gases that stream off the sun.   “The sun actually in a larger scale behaves like a comet," says Smith.  "All the gases that stream off, stream off into a tail, and it takes a long time for anything that’s got into that tail to propagate down, so there will be a ripple effect which will go on for possibly years,” he explains.

This year, the sun’s magnetic reversal is asymmetric, meaning the north pole is changing faster than it’s south pole.  But Smith says that might be normal.  Because of limitations in technology, this is only the fourth time scientists have been able to record an event like this.  “To be able to detect the polarity of the magnetic field on the sun, you need optical techniques that are relatively advanced compared to 100 years ago,” says Smith.

A magnetic reversal could affect some radio transmissions and satellite communications.  Here in Alaska, Smith says it’s more likely we’ll see the effects in the form of medium level auroras.