halo

The name grouping a set of optical phenomena that occur in the atmosphere, as a consequence of the refraction and reflection of light in the ice crystals suspended within it, particularly those forming high, cirriform-type clouds. It can take the shape of a ring, arc, column, or luminary. Under the generic name "halo," the ordinary halo is known, as it is the most common of all. It is also called cerco. There can be both lunar and solar halos. The former are more frequent in winter than in summer and at high latitudes than at low ones.