Solar activity ramping up to a 2013 peak
(Credit: NASA/SDO )
We've seen a lot of solar activity in the last few months as the sun nears the active peak in its 11-year cycle.
Every 11 years, the sun goes through what is called the solar cycle: measurable and repeated changes in its activity. Next year, 2013, is when it will reach the peak of its current cycle — as we can see in the image above, comparing the sun's activity two years ago to last month.
The last inactive period — known as solar minimum — was in 2008; next year, as the sun reaches solar maximum, we can expect to see an increase in sunspot activity.
What does this mean for us down here on Earth? Well, a lot of aurora borealis and australis activity, for one, so if you're heading to or living in regions that are most likely to be affected, we envy you.
Unfortunately, the same solar activity that causes aurora — coronal mass ejections (CMEs), or solar flares — also cause magnetic storms. These can disrupt communications and navigation equipment, damage satellites and result in power surges that harm power lines and cause outages.
There are a few other effects, too: solar flares increase the concentration of the ozone layer, which means that there are fewer harmful UV rays penetrating to the surface. That is not a good reason to stop applying sunscreen, just so you know.
Skywave radio equipment can also be affected by the increased ionisation of the ionosphere during a solar peak, either for better or worse.
Our prediction? Mostly, it's going to be fascinating.
Oh, and for Aussie photographers looking to chase the aurora: Space Academy has a guide on the ideal camera settings to use and a link so you can sign up to SMS alerts from the Bureau of Meteorology.