Recurrent mirages at Puerto Peñasco, Sonora

Abstract

Mirage behavior at Puerto Peñasco, on the Sonoran shore of the Gulf of California, is not only systematic, but is fully compatible with conditions of atmospheric refraction common in that arid area adjacent to a tropical sea. Images of mountains in Baja California, normally hidden below the visual horizon, are regularly loomed into visibility as the lapse rate in the lower layers of the atmosphere increases; and sink again below the horizon with the onset of nocturnal inversions. False sea horizons, due to refraction, are a standard midday condition; as are inferior mirages over adjacent land areas. Air stratification is normally accompanied by “paper doll” duplications of distant images; Fata Morgana is a common occurrence when cold air drainages from high mountains reach the warm waters of the Gulf of California. Photographic differentiation between mirage lakes and actual bodies of water is sometimes possible by use of deep red filters.