Mystery Halo

Last Saturday I was out in the yard, chasing a Great Blue Heron that Patty had spotted out the living room window. She said it was headed toward the back pond. Alas, it was not there (which I suppose is a good thing).

As is my habit, I looked up. And saw this.

Look closely left of center in the wispy clouds and you can see the hint of a rainbow like arc. (As always, click on any image to bigafy it.)

Here is a closeup of that area.

I had a camera, actually two with me, but neither had the right focal length lens for the scene. I had a zoom telephoto on my DSLR to shoot the heron. And I had my iPhone. I needed a wide angle lens on my DSLR. But as these atmospheric phenomena are often fleeting, I had to use what I had.

The mystery comes from the geometry of the situation.

The shot above shows the halo fragment, center left, and the Sun, lower right, through the trees. Using the tools I had at hand (pun!) I measured the angle between the sun and the arc, and it was over fifty degrees. This meant it was not a fragment of the 22° nor 46° halos. And it was not a circumzenithal arc as it was not at the zenith.

So I next headed over to Atmospheric Optics, but the answer was not obvious. So I emailed the proprietor of that fine site, Dr. Les Cowley, and he was kind enough to respond. He thinks it might be a fragment of a Supralateral Arc. He also noted that the wispy clouds were likely Ice Crystal Fall Streaks from Hole Punch Clouds.

❄️☁️❄️☁️❄️

I've seen punch clouds before, but this is my life Supralateral Arc. Very cool.

Keep looking up!