An optical phenomenon that occurs as a result of the bending of light rays through layers of air having very large temperature gradients. An inferior mirage occurs when the ground surface is strongly heated and the air near the ground is much warmer that the air above. Light rays from the sky are strongly refracted upwards near the surface giving the appearance of a pool of water. A superior mirage occurs if the air close to the ground surface is much colder than the air above. Light is bent downwards from the object towards the viewer so that it appears to be elevated or floating in the air.
Geology and Earth Sciences
Optical effect in which a major variation in temperature between layers of the lower atmosphere produces differential refraction of light, resulting for example in raised images and in gaps, which may give the appearance of a water surface.