TUCSON, Ariz. (KOLD News 13) - Like something out of this world, iridescent clouds appeared in the sky in southwest China on Monday, Jan. 4.
Experts say “rainbow clouds” are a kind of optical phenomenon produced by the diffraction of sunlight by individual tiny ice crystals inside clouds.
In the province of Yunnan, the thin layer of colorful clouds appeared with the rise of the sun. The phenomenon also appeared in such cities as Dali and Kunming in different segments of time.
Under suitable weather conditions, the sunlight and the clouds form a suitable angle. As the sunlight passes through the clouds, the ice crystals in the clouds separate the solar spectrum through refraction, causing a rainbow effect.