Interesting Shapes
A high speed stream of solar wind had hit, and Bz values had been down to -10 nT during the day, but now the wind speeds were higher (above 500 km/s) with more modestly southward Bz values (near -5 nT). I decided to go out, but I did not make it out until around midnight. By then, there had already probably been a nice substorm, and now, the auroras were in a sort of post-substorm phase. This is otherwise known as the recovery phase. During this phase, the auroras typically take on a more patchy appearance, but tonight, they were somewhat more blob-like, and I was seeing the patches of dim, diffuse auroras much higher above the horizon than the main band. These auroras were fading in and out on a timescale of a few seconds. Normally, these auroras don't look too dramatic, and I'm not too excited about them. However, tonight, these fading in/out features were more pronounced and a bit sharper.
I kept photographing, and these auroras took on a more horizontally radiating appearance. Whereas most auroras feature vertical structures that align with precipitating electron paths into the upper atmosphere, these appeared to radiate horizontally with rays from the north and fading out southward. They resembled long spikes on the crown of the Statue of Liberty. I decided to make a gif image of these since the motion was rather interesting. This is what I show below.
