A fata morgana, italian translation of Morgan le Fay, the fairy shapeshifting half-sister of King Arthur, is a mirage, an optical phenomenon which results from a temperature inversion. Objects on the horizon, such as islands, cliffs, ships or icebergs, appear elongated and elevated, like "fairy tale castles".
In calm weather, the undisturbed interface between warm air over cold dense air near the surface of the ground may act as a refracting lens, producing an upside-down image, over which the distant direct image appears to hover. Fata Morgana are usually seen in the morning after a cold night which has resulted in the radiation of heat into space. The first mention of 'Fata Morgana' in English, in 1818, referred to such a mirage noticed in the Strait of Messina, between Calabria and Sicily. It is common in high mountain valleys, such as the San Luis Valley of Colorado where the effect is exaggerated due to the curvature of the floor of the valley canceling out the curvature of the Earth. They may be seen in Arctic seas on very still mornings, or commonly on Antarctic ice shelves.
Fata Morgana are superior mirages, which are distinct from the more common inferior mirages, which create the illusion of distant pools of water in the desert and on hot roads.
(bless you wikipedia!)
No comments:
Post a Comment