|Summer Ice Halos imaged
by Michael Beets, Corvalis, Oregon 20th June '08. ©Michael
Beets, shown with permission.
The summer halos produced
by ice crystals in high cirrus clouds show some arcs in less
familiar guises. Here a diminutive parhelic
circle is near the
zenith. The halo around the sun is double, a circular 22° halo
and a fainter, near circular, circumscribed halo. Below the sun is
another sign of summer, a huge and colourful circumhorizon arc.
The labelled HaloSim ray tracing simulation shows the whole sky with
the zenith at the centre.