Santiago de Compostela, Spain imaged
by Jonathan Shock.
shown with permission.
22° halo or circumscribed halo?
When the sun is high the circumscribed halo is almost
circular and not easy to distinguish from the 22°. It
has brighter colours and is sharper but otherwise is very similar.
The sun was 61° high** when this halo was seen at 14:20 local time
on April 27th. At that altitude a circumscribed bow would be distinctly
oval. This is a 22° halo. Another clue to its identity is the slow
fall off in the bright white halo brightness outside the
**Solar elevation can be calculated with this