Mirages above the sea waters

Abstract

This paper, which has teaching and public-science aims, presents some examples, attained in the Southern Bays of Galicia (Spain) of inferior and superior mirages, including castles in the air, fata Morganas and towering. The explanation for the unusual atmospheric refraction is presented, and the different kinds of ray paths distortions that lead to each optical effect and the respective gradient indexes that generate these distortions are shown. In addition, the temperature differences required for each case are related to the successive oceanographic and climatic conditions that occur along the year in this coast.