Halo in the Sky
Thanks to Beth Alexander for posting this on my Facebook page earlier today! This is a photo of a solar halo that Beth took from St. George Island in Florida on September 20th.
A solar halo is an optical phenomenon created by sunlight that is refracted by ice crystals in high, thin cirrus clouds. There’s a great scientific explainer at <a href="http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/opt/ice/halo/22.rxml
In short, as the light passes through “columnar” crystals. Snowflakes and crystals in cirrus clouds (20,000 to 30,000 feet above the surface) often fit the mold of being shaped partially like columns.
The refracted light is bent at a 22º angle from the original direction, and that makes a ring of light seen 22º from the Sun. This also happens around the Moon!
There’s a saying in old-time weather lore: “ring around the moon means rain is coming soon!” There is some truth to that statement. Since that 22º halo is usually caused by high, thin cirrus clouds moving in ahead of a storm system, you will usually have at the least an increase in clouds if not some rain a within 36 hours of seeing that ring!