September - rain You are here: Home Photo gallery Atmospheric optics Ice crystal halos Subsun


A subsun is caused by horizontally-floating ice plate crystals. The millions of crystals act as a mirror, reflecting the sunlight. The more aligned the crystals are, the more sharply defined the subsun will be. The effect is relatively rare, only because the ice cloud has to be below the observer, like an airplane flight or from another elevated position.

1 photo in gallery
Click images for large photos




w-121-29