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22 degree halo x 2/3?
Posted: Fri Mar 21, 2014 6:11 pm
by Dodd
Here's a 22 degree halo with a couple of twists that I cannot find an answer to. Note that the "main" halo around the sun seems to be a double. Also note the separate -- and seemingly larger than 22 degrees and without the rainbow effect -- halo to the right of the main one. Thoughts?
The shot was taken on 3.21.14 around 1 pm in Columbus, GA, USA.
Re: 22 degree halo x 2/3?
Posted: Fri Mar 21, 2014 7:20 pm
by BMAONE23
Here is an interesting WIKI article on
Solar Halo Phenomena
Re: 22 degree halo x 2/3?
Posted: Fri Mar 21, 2014 7:31 pm
by geckzilla
I think Dodd knows what this halo is, B. The point is that it's oddly distorted. Personally, I'm having trouble understanding how distorted it actually was in the sky versus what the photographic panorama did to it.
Re: 22 degree halo x 2/3?
Posted: Sat Mar 22, 2014 12:42 am
by Dodd
Thanks for the replies. Please check out my edit of the original post. I added a non-panoramic photo that might help with perspective. Thoughts?
Re: 22 degree halo x 2/3?
Posted: Sat Mar 22, 2014 1:03 am
by geckzilla
I think that faint one might just be a cloud which happens to look arc-like. It looks something like a parahelic arc but doesn't match up. If you haven't already, check out
frequent halos and
infrequent arcs.
Re: 22 degree halo x 2/3?
Posted: Sat Mar 22, 2014 1:06 am
by geckzilla
Oh, maybe it is a parahelic circle. I was unaware that the size shrinks when the sun is high. How does this look to you?
http://www.atoptics.co.uk/halo/pchigh.htm
Re: 22 degree halo x 2/3?
Posted: Sat Mar 22, 2014 1:57 pm
by Dodd
Parhelic arc! That has to be it! Thanks, G!
I edited the original post and added one more shot that shows double 22 degree halo a little better. I wonder if there are two separate layers of ice crystals?
APOD is the best!
Re: 22 degree halo x 2/3?
Posted: Sat Mar 22, 2014 4:48 pm
by geckzilla
Running HaloSim, it predicts the same shape will appear when the sun is about 60 degrees above the horizon. So, nothing unusual to report, here.