15 May 2013
Circumscribed Halo over Ocean City In Maryland On Tuesday
Posted by Dan Satterfield
Correction: Hat tip to Daniel Linek who spotted my mistake. This is a CIRCUMSCRIBED Halo. Not a Circumzenithal Arc . See here: http://www.atoptics.co.uk/halo/circum.htm
The title to this post has also been corrected.
You can read more about this on the great Atmospheric Optics site: http://www.atoptics.co.uk/halo/cza.htm I saw one in Greenland (and at the South Pole for a few seconds). The bottom band I believe is a circumhorizon arc.
Unfortunately, it is incorrectly identified. Circumzenithal means Around the Zenith and not below the sun. This is most likely a Circumhorizon Arc instead based on the time of year allowing the sun to reach the appropriate elevation angle of at least 58°. Using the same website:
The top one is a circumzenithinal arc and the bottom one is a Circumhorizon arc. I am fairly certain that I was correct.
If you note the position of the sun in this photo, it is above the upper halo fragment which cannot be the Circumzenithal Arc but this is part of the Circumscribed Halo which is what the 22º Halo basically becomes when the sun reaches a high enough angle.
Circumscribed Halo: http://www.atoptics.co.uk/halo/circum.htm
Circumhorizon Arc: http://www.atoptics.co.uk/halo/chaim3a.htm
You may have a point about a circumscribed halo. Looking at it.