images

Sun Halo

by

L.Laveder/Novapix

Reference

t-met03-00007

Date

2007-10-23

Halos are caused by sunlight being refracted by cirro-stratus clouds. These are thin clouds, very high in the atmosphere, and are composed of ice crystals. They bend light at a 22 degree angle, which creates a halo around the sun that is 44 degrees in diameter. In brief:- around the Sun, the 22° halo, not very contrasted.- on the right of the Sun, a bright parhelia uncolored.- atop the 22° halo, the upper tangent arc (a splayed U shape).- above it, ""parallel" to the 22° halo, the Parry arc.- near the zenith, the circumzenithal arc, very colorful.- just under, tangent to it, the inconspicuous supralateral arc.