|Fire rainbows, known by the proper name of circumhorizon arc, occur when
the sun hits plate shaped ice |
cystals in the clouds, causing the colours of sunlight to separate.
|The colours appear to flicker in the sky and sunlight passes through the ice crystals.|
|The flickering cloud rainbows form a variety of almost hypnotic shapes in the sky.|
|The phenomenon appears several times a year over the US, although is rare in Europe.|