Caption
Halo around sun, Tibetan Plateau, June 2010. Halos are a sign of high thin cirrus clouds drifting 20,000 feet or more above our heads. These clouds contain millions of tiny ice crystals. The halos are caused by both refraction, or splitting of light, and also by reflection, or glints of light from these ice crystals.
Availability
Only inBelgium, Canada, France, Luxembourg, Switzerland