The northern lights have been particularly spectacular in 2013 as the sun is expected to reach the peak of its 11-year solar cycle later this year.

CNN: Northern lights dazzle Northern Hemisphere

The sun is currently in an active phase of its 11-year solar cycle, and it should continue to fire off big storms for a while yet.

MSN: Amazing video captures magical-looking sun storm

The data, from NASA's TIMED mission, show that Earth's thermosphere (the layer above 62 miles or 100 km above the Earth's surface) "responds quite dramatically to the effects of the 11-year solar cycle, " Stan Solomon of the National Center for Atmospheric Research in Boulder, Colo.

MSN: Earth's upper atmosphere cooling dramatically

Solar activity fluctuates over an approximate 11-year cycle.

BBC: System could warn of solar storms

The sun is in an active phase of its current 11-year weather cycle, which scientists call Solar Cycle 24.

MSN: Big sunspot unleashes an intense solar flare

Solar experts believe that the tachocline may be the source of powerful magnetic fields that produce strong solar flares and solar winds, and create sunspots that mysteriously appear and disappear during an 11-year cycle.

BBC: Sun has strange 'spin cycle'