How the Strongest Geomagnetic Storm in 20 Years Brought The Northern Lights to The North Coast

The Aurora Borealis as seen from Kneeland, 11pm on May 10
The Aurora Borealis as seen from Kneeland, 11pm on May 10

The largest solar storm in two decades led to the aurora being visible across Humboldt and Del Norte counties, along with much of the northern half of our hemisphere, over the weekend.

Viewers from across the area sent their images and videos of the light show in the night sky to Redwood News. From the shores of the Pacific to the mountains, even right outside many viewers’ front doors, and in the middle of town, the aurora was vivid Friday night into Saturday morning.

Commonly referred to as “The Northern Lights”, the auroras (there are also “Southern Lights”) occur when charged particles ejected from the sun make their way through the solar wind and eventually into the earth’s atmosphere.

This geomagnetic storm is from Solar Flare 3944, according to NOAA. Solar flares happen when the sun’s magnetic fields both on and around it reconnect.  flares are classified by their strength, with “x-class” solar flares being the largest and most powerful. The solar flare which brought the aurora to our area was an x-class.

This was the strongest solar storm since October 2003. Active regions are frequently seen as sunspots which are cooler than the surrounding areas of the sun’s surface, hence their darker appearance. A sunspot was visible to the naked eye Friday– using eclipse glasses of course.  Sunspots are where the intense magnetic field has become twisted and concentrated, leading to coronal mass ejections which can cause geomagnetic storms like the one we saw.

While it is impossible to predict solar storms, the sun does behave in a somewhat predictable way: it goes through an eleven-year cycle and we are approaching the peak: 2025 will be the solar maximum, so, more solar flares, sunspots and aurora sightings may be just around the corner.