January 20, 2018 Auroras
Grand Rapids, Minnesota
An enhanced solar wind stream affected Earth, and some mild auroras developed. The moon was in the last stages of the last quarter, making for a really dark sky, so I headed out to check for green on the northern horizon.
I drove north to Prairie Lake, but right before I arrived, I noticed I was driving underneath a cloud deck. Not a big deal as these low clouds appeared right before my turn into my viewing location. I figured they would quickly move off to the east. Indeed, the clouds overhead moved off rather quickly, but they continued to cover the northern horizon and obscure the northern lights. I took a few pictures and decided to head home because there was nothing dramatic to see.
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| Auroras are glowing just above the clouds on the horizon (lights closer to the horizon are from human light sources at ground). |
I stopped at McKinney Lake on the north side of town to look again and found the clouds on the northern horizon were clearning, and I could also make out a little bit of auroral structure.
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| Auroras shining above the site of the Grand Rapids Pond Hockey Tournament. |
I decided to head back out to Prairie Lake. I was still not expecting much. While I was there, some ground fog was starting to develop. Some moisture had been added to the air after the melting temperatures that had happened during the day. The fog slightly obscured the green on the northern horizon, but the stars were still pretty crisp and clear above. I liked the overall effect of the fog and continued to snap pictures.
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| Fog develops on Prairie Lake. |
Rather than thicken up to the point that the sky became obscured, the fog occasionally dispersed, thanks to westerly winds just above tree top level. The sky stayed clear above, and the auroral arc started to sharpen and intensify.
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| The auroras intensify, and the ground fog disperses a little bit. |
I continued to shoot, anticipating a substorm that usually follows such a brightening of the auroras.
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| A substorm begins. |
The substorm never got very intense, but it provided at least a little bit of structure. I continued to shoot until the auroras started to dim again, and then I went home.
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| Maximum intensity of the substorm. |