Geomagnetic Activity and Airglow

Taking starscape photos last week I was surprised at the intense red glow appearing in the photographs. All across the southern sky were glowing areas of sky, here and there dark rifts cut through the glow. Set beside the Winter Milky Way it created beautiful photographs.

Airglow or auroral glow?
Airglow or auroral glow? An odd red glow in the photos during a strong geomagnetic storm.
The airglow was intense enough to be visually seen when I stepped away from the camera and let my eyes adapt to the darkness. Away from the Milky Way, in what should be dark sky, a faint red glow pervaded. I wondered what was going on, the normal airglow over Mauna Kea is quite faint and usually very green.

I was even further surprised when I later found out that a strong geomagnetic storm was in progress that night. Kp=6 conditions from back to back CME’s were creating strong aurora over Canada and the upper US.

Was I seeing some sort of auroral glow? In Hawaii? At 20°N latitude? This did not seem likely, but something unusual was occurring!

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Staying Late at Work

The plan was simple. Stay on the summit after work to do some nighttime scenic photography.

I was hesitant in going up after suffering my recent ear infection. The ear is vastly better, no problems with clearing the ear for several days. After two weeks absence the list of things I needed to get done on the summit was getting lengthy and urgent. Yet I worried a bit about going up. An idea… Take my own vehicle. If I have trouble I can go at my own pace without holding up the rest of the guys. If the trouble is serious I can abort and head back down.

If I did bring my own vehicle I could get in a little photography along the way. I had not really had a chance to try out the Rokinon 14mm f/2.8 lens I had bought specifically for starry sky work. Why not stay late, watch sunset and take a few photos after dark? There is snow on the summit, the weather looked promising, the Moon would not rise until after 10pm, all good things.

The plan worked as envisioned. A good day getting stuff done. Actually a rather hectic day. The filter wheel problem of TRICK found and eliminated, the heater circuit at least looked at, I think the problem is still there. Warping data recorded for a segment in Keck 2 for the refurbishment project. Some wiring on TBAD completed, still more to do. An issue with the Keck 2 interlocks that popped up during the day was dealt with. Yes, a very good day.

A minimal dinner of instant ramen, and some paperwork accomplished while waiting for sunset.

Into the cold dark I go… The combination of the Canon 6D and the fast 14mm lens is impressive. This gear will really allow me to step up my game. I was able to shoot great material under very dark conditions. Photos that had been just out of reach for me until now. It will take me a couple days to go through and process the material, but a first look is very pleasing.

Only one problem… What is this red stuff showing up in my photos? Normal airglow is green, but this is crimson red and has very distinct structure? The idea of aurora crosses my mind, almost immediately dismissed as I am standing at 20°N latitude. I step away from the camera and the light for a bit. With some effort I can convince myself that I am seeing red in the sky, at least in the darker areas away from the Milky Way. But it is fleeting, and perhaps just an overactive desire to see something.

I get home and just out of curiosity I check the planetary Kp index… What?!? We have a Kp=6 geomagnetic storm in progress! Beautiful aurora photos are being posted from the upper midwest. Reports of aurora from across much of the United States. There is certainly a dramatic storm in progress. Perhaps this is a low latitude auroral glow!

There are some references to auroral glows detected at all latitudes during strong geomagnetic storms. Is this what my camera is detecting?

It is a nice photo. You can see the glow from the lava lake at Halema Ľuma Ľu, the winter Milky Way, and a research laser shining straight up from the atmospheric lab atop Mauna Loa.

Airglow or auroral glow?
Airglow or auroral glow? An odd red glow in the photos during a strong geomagnetic storm.