MIRAGES WITH ATMOSPHERIC GRAVITY-WAVES

The temperature inversions that produce superior mirages are capable o f supporting gravity (buoyancy) waves of very low frequency and long w avelength. This paper describes the optics of single mode gravity wave s that propagate in a four-layer atmosphere. Images calculated by ray tracing show that (1) relatively short waves add a fine structure to t he basic static mirage, and (2) long waves produce cyclic images, simi lar to those observed in the field, that display significant variation from a base image.