Northern Lights Track South

Generally people in the far northern latitudes get to see the solar wind dancing with the magnetic field around Earth. But because of increased solar activity, the northern lights have been more visible further south, including Alabama, Georgia and even Florida.

An automated NASA camera that takes a picture of the sky every minute in Huntsville, Alabama captured 20 minutes of the vibrant red and green aurora borealis.

Storm chasers, shutterbugs and curious onlookers took pictures, video and just marveled at the rare treat.

Arkansas photographer Brian Emfinger called the view “extremely vivid, the most vivid I have ever seen.” And he says this is only the second time he’s seen the northern lights so far south in a decade.

NASA scientist Bill Cooke found the aurora photos in the Alabama camera’s archive and posted them on the Marshall Space Flight Center’s blog. He says, “They are very rare events and we don’t see them this far south that often.”

Space Weather Prediction Center in Boulder, Colorado monitors solar activity and solar storms, which trigger the colorful auroras. Space weather chief Bob Rutledge says that the solar storm that created the vivid light show was only in the moderate range and shouldn’t have been visible south of Iowa. He also says the storm was unusual because it arrived 8 hours ahead of schedule.

An aurora begins when the sun blasts a magnetic solar wind toward Earth. The wind hits the Earth’s magnetic field, compressing it. That compression excites electrons of oxygen and nitrogen in the atmosphere. When those excited electrons return to their normal state, they release a photon burst seen as red and green colored light.

The most commonly seen northern lights color is green, often seen in nighttime pictures of Norway and the Arctic. Green results from excited oxygen.

Monday night’s display featured the not often seen red light. In fact, most of the sightings in northern Michigan described seeing a blood-red sky. Red auroras also result from excited oxygen atoms. The difference in color comes from the altitude of the excited atoms returning to their ground state. Red northern lights occur higher in the atmosphere while green is at a lower altitude.

The strongest color emissions from nitrogen are in the deep violet end of the rainbow spectrum, which are generally invisible to the human eye. A Nitrogen excited state can also create a red lower border to the northern lights.

According to NOAA this storm was classified as a G2 on a scale of G1-G5. It was spectacular but didn’t pose a threat to satellites or power grids. As solar activity increases in this new 11-year solar cycle more solar storms will give way to more brilliant sky shows. And some will even be seen as far south as the Gulf Coast.

So keep your eyes peeled.