February 16, 2021 Auroras

Grand Rapids

I was on my way home from the Twin Cities, and I decided to bring up the solar wind graph in my center console. It showed a steadily southward magnetic field-- around -5 to -7 nT.  As I drove north, I kept scanning the northern horizon for the green glow, but for quite a while, there was nothing present.  I was not necessarily expecting to see much since the magnetic field wasn't terribly strong, and it hadn't pointed south for more than a couple hours.  It can take several hours of weakly southward-pointing magnetic field to get the auroras going.  I got north of MacGregor and still saw nothing.     

When I got to Jacobson and turned west on Highway 200 for a bit, I did see an auroral glow along the horizon. I turned north on County Road 10 toward Grand Rapids, stopped, and attempted a couple shots with my cell phone. I did not have my DSLR camera in the car. The cell phone did pick up a bit of the glow

Auroral glow capture by iPhone 11 Pro Max.

I got home, unpacked, had a bite to eat, dressed in some warmer clothes, and headed out with my camera and tripod. When I arrived at the closest decent shooting location, the auroras had dimmed quite a bit. This is not what I really expected, but I was not surprised since auroras can be highly variable in intensity, even when solar wind conditions aren't changing much. They would likely brighten again, so a bit of patience was in order.

View at Prairie Lake when I showed up to start shooting at 11:41 PM.

It took a bit of time, but I guess the time passed relatively quickly because the timestamps on my photos show that the auroras brightened and expanded southward over the next hour. Little did I know that I was shooting during a NPP satellite overpass. The overpass occurred about as the auroras were reaching their brightest intensity. The images below were taken at about the same time. Both images show a single, relatively narrow auroral band. There is a thicker region in the center of my image that probably appears at the western end of the satellite image that was taken at the same time.

12:57 AM: auroras were brightening. This was during a satellite overpass.

Corresponding Suomi NPP satellite overpass with a slight bulge in the western part of the image that corresponds to the bulge in the center of my image.

I continued shooting, and I managed to capture a pretty big meteor. At first, I thought it was above the top of my camera frame, but it turns out that the camera captured the whole thing, AND the shutter happened to be open for the duration of the meteor (it probably lasted a couple seconds).

1:00 AM: a big meteor hits.

While the auroras were brightening is never a good time to stop shooting and go home, so I decided to stay put until the first substorm I saw. Soon, it appeared one might be starting as some structure began to show in the auroras. One bright band showed up and portions of the oval appeared to start moving toward the horizon. This is often an indication that a substorm is commencing, but in this case, the brightening did not continue. The auroras went back into their basic, arc form.

1:22 AM: it looked like a substorm was starting, but it did not happen.

I kept shooting until nearly 2:00 am and then suddenly remembered that satellite overpasses often occur after 2:00 AM CST, and it was getting close to that time. I could stay up another half hour or so until the satellite passed overhead, and then I could go home and get some sleep. Until this point, I had forgotten about the satellite and didn't realize that it had already made an image over North America once tonight, but that image was cropped on its western side. At 2:35 AM CST, it would begin another pass. I decided to wait.

2:27 AM: auroras were expanding a bit further.

2:41 AM: auroras at the time of the NPP satellite overpass.

2:39 AM: Suomi NPP image. You can see parts of the image that might resemble my photograph.

2:39 AM: Annotated Suomi NPP image. The lines show the edges of my the field of view of my camera.

Also as the satellite began to pass over, an airplane took off from Grand Rapids airport and flew straight north. I thought that was a bit unusual in that nobody really takes off this late at night. Then, I wondered if it might be a friend and fellow photographer Jordan Weis. He does some medical flights and might take off at this time of the night. Indeed it was Jordan! He posted an image the next day of the auroras he shot from the cockpit of the airplane as he was approaching International Falls. I made a GIF image of his departure from Grand Rapids.

Jordan Weis passed overhead at about 2:30 a.m.

Back to Auroras | Home