- a ring of light encircling and
extending outward from the sun or moon
- created as sunlight is refracted
as it passes through ice crystals.
- indicates cirriform clouds (high,
thin clouds composed of ice crystals)
- two types:
- 22° halo - refraction of light through
randomly falling ice crystals.
- 46° halo - refraction of light through
hexagonal column-type ice crystals.
- here is a 22° and 46° halo
photo by N. Atkins