September 12, 2014 Auroras
Chippewa National Forest
The first of a pair of CMEs to impact Earth struck this evening, and it sparked bright auroras that were visible despite the nearly full moon. This CME was from an M4-class X-ray flare that had happened late Monday and took three days to make the transit from the Sun to Earth. When the CME struck, the magnetic field component, Bz, oscillated back and forth between north and south, and did not have much of a dominant orientation. This behavior likely allowed for enough disruption of Earth's magnetosphere to ignite auroras, but a lack of a persistent southward orientation prevented the auroras from coming equatorward very far from their climatological mean location. Thus, it was a pretty nice show near the northern horizon.
As is typical for this time of year, with relatively warm lake waters and the first frost-producing cold air mass of the season, we had a lot of clouds around, not all of which would dissipate at sunset. The trick to seeing the auroras this evening would be to find a local clearing area at the same time the auroras were bright and set up in a spot with a view to the northern horizon. This brought me to Cottonwood Lake in the Chippewa National Forest.
I was not the only one there. For several weeks, we had anticipate a visit from Lon Hodge, a Vietnam Veteran, and his service dog Gander who travel the country to raise awareness of post-traumatic stress disorder in veterans and service dogs, who help prevent the symptoms of PTSD. Their web site can be found at http://veterantraveler.com/, and on Facebook at https://www.facebook.com/Ganderservicedog. One thing Lon was hoping for, in his visit to Grand Rapids, was to see the northern lights. For a typical two day visit, the chances really aren't that great, but his timing was impeccable, and for two nights in a row, we had good chances of seeing auroras. He was being hosted by my good friends Mary and Chuck Corwin. I called them to let them know where I was headed, and they started the drive to my location shortly after I got there.
I set up the camera and took a few shots, but the auroras were initially barely visible, and the clouds were just clearing. Soon enough, the lights brightened with the arrival of a substorm.
 |
|---|
| A substorm starts at Cottonwood Lake in the Chippewa National Forest. |
Lon and Chuck were not here yet, and I was worried the show would subside before they arrived. Soon, I got a call over amateur radio from Chuck, who said they had pulled over in a field to watch the lights when they brightened up. Great! That was a relief. I'd hate to have my scouting efforts be futile. Chuck was an astute observer of the atmosphere and immediately recognized the lights. Not everybody would be able to do that. The show continued for a bit after they arrived at Cottonwood Lake. Some tall auroras appeared, and we watched as they paraded across the sky.
 |
|---|
| A tall column appears. |
The substorm subsided before I got the camera out to take a picture of Lon and Gander, but the green glow persisted for another hour before the clouds drifted back in.
 |
|---|
| Gander takes in the auroras. |
 |
|---|
| Lon and Gander. |