You might have heard the interruption in our afternoon broadcast of ‘Talk of the Nation’ last week. The digital chirps and fading audio happen when the sun passes behind our satellite this time of year. But as Emily Schwing explains, there are other phenomena that can also affect the clarity of communications transmissions.
If your radio signal is a little fuzzy, you might want to check the solar weather forecast before adjusting the dial.
Tiffany Watkins says we are moving into a new era of intense solar activity.
Watkins teaches physics and astronomy at Boise State University. She says we’ll see even more activity on the sun in the next few years, – things like solar mass ejections, sunspots and solar flares – but it’s normal.
It’s a whole 22 year cycle,” she says. “And it has to do ultimately with the magnetic field of the sun. And the sun is actually reversing polarity in that time frame, so the north pole becomes the south pole and it’s been shown that the earth also has flipped poles in the past but not as regularly as the sun.”
But twenty two years seems really fast for the polarity ‘flip.’
“I know,” concedes Watkins, “I know it does! Especially for something that large.”
When the sun’s poles flip, solar weather becomes more erratic. But Watkins says merely referring to “weather” on the sun doesn’t actually get at what really happens in space.
She’s says it’s deceiving. “Because the weather is really kind of talking about more what’s happening in between us and the sun, so it’s like how much stuff is spewing towards us not necessarily at the sun’s surface.”
Unlike our weather on earth, predicting when a sunspot might erupt or solar flare might, well, flare up, is not that easy. When those events happen, lots of particles are released.
Watkins says they are charged particles. “Mostly protons. Massive particles that come racing towards us.”
This is where things get a little tricky, because both the sun and the earth can behave like big magnets.
“If you think about the earth as a big bar magnet,” explains Watkins, “I have these field lines coming in and out of the poles and so these particles come along and they meet our magnetic field and they are accelerated toward the poles and we see some of that radiation as light – the aurora.” Watkins says other kinds of radiation and waves that can be released. “Radio waves, microwaves, infrared, x-rays, gamma rays … those are all different types of electromagnetic radiation,” she says.
The sun also has its own magnetic field. When activity picks up during a solar maximum, those field lines are more likely to intertwine and snap more often. That means more electromagnetic interference. That causes static on the radio, snow on your television… and your smartphone might not behave as intelligently. Space weather is so serious, in fact, that the National Defense University recently held a conference on potential threats to the nation’s electrical grid. The good news is it looks like some of the more recent storms on the sun haven’t been directly pointed at Earth, but the bad news is it’s bound to get worse. The solar maximum isn’t expected to peak until next year.
You can find out more about space weather here. Or Check out NASA’s Solar Dynamics Observatory.