space weather, aurora borealis, northern lights | The Old Farmer's Almanac

The Glow of Space Weather

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It’s time for some pretty weather. With the drought in Texas, last week’s Halloween Nor’easter, and a tornado in Oklahoma, the weather has been downright nasty. It’s time for a change.

Fortunately, that’s what is going to happen. We are due for two to three years of extremely beautiful space weather. Prepare for aurora borealis, the “Northern Lights.”

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We are approaching the peak of a sunspot cycle.
Source: NASA

Here is how space weather works. The sun goes through roughly 11-year-long cycles of activity. Until fairly recently, the sun was unusually quiet. Then, last year it began to wake up. The surface began to swarm with sun spots and magnetic fields within Sol began to snap and splatter heated gas into space. By now, over a hundred sun spots a day are swirling on the solar surface.

There are always some gases radiating out from the sun. (It’s called the solar wind.) However, during the peak of the sunspot cycle, things really get crazy. Most of the gas on the sun’s surface gets blown out into space during the three years around the cycle’s maximum.

When the sun’s ionized gas particles hit the Earth’s upper atmosphere, the collisions produce energy and dazzling sheets of light. Source: NASA

Fortunately the Earth’s atmosphere protects us from most of the impact. The sun’s ionized gas particles slam the upper atmosphere. When these ions hit some of the molecules in the air, the energy releases colors, green, red and, on rare occasions, blue. (Different molecules can produce different frequencies of light.) The Earth’s magnetic field guides these energy flows, filling the sky with glowing curtains and ribbons of light.

Some of these solar storms are large enough to cause some problems for satellites and power grids. We have a 25 nation organization that monitors solar activity and issues warnings so that operators can take protective steps. Most storms, however, merely produce glorious lights and occasional radio static.

The auroras borealis tend to be confined to northern latitudes, spectacular shows for Canadians, Alaskans and Vikings. However, during this phase of the sun spot cycle, the storms tend to be stronger and can be seen further south. Two weeks ago, on October 24, a brilliant red aurora was seen as far south as Arkansas. Some lightshows reached the Caribbean. One show in the 1800s was so bright that people in the Northeast could read newspapers by its light.  

Last October, a rare red aurora was seen as far south as Arkansas. Source: NASA

For the next three years, the northern skies will be filled with giant light shows. It is space weather at its finest. And, even better, after a solar storm you don’t have to shovel the driveway.