Images refuting the myth that magnificent ice halo displays are only the stuff of Polar regions or at least very cold weather. These, over the tropical rainforests of Peru were in high and icy cold cirrus cloud which occurs anywhere on the planet.
|Close-up of the brightly coloured circumscribed halo.
When the sun is high this is often mistaken for the common 22° circular halo but the latter's colours are less saturated and slightly more widely spread.
|Below the sun are two huge coloured arcs. The lower one, always parallel to the horizon, is a circumhorizon arc formed by sun rays passing through plate shaped ice crystals.,
Curving upwards from the circumhorizon arc is a rarer halo, a high-sun infralateral arc formed by rays passing between the end and side faces of horizontal column crystals.
See the simulation below for identification.
|A HaloSim computer ray tracing of the display. The program traces millions of rays through mathematical representations of cloud ice crystals.|