Photometeors associated with Clouds

(Section 2.5.1.6)

Certain photometeors (haloes, coronae, etc.) may be visible to an airborne observer inside a cloud and close to its upper surface. An observer above a cloud patch, sheet or layer, may see a glory or a fog bow if the cloud is composed of water droplets, or may observe halo phenomena if the cloud is composed of ice crystals.