In Thessaloniki yesterday it was possible to admire a rare optical phenomenon – ships “floated” over the Thermaikos Gulf (Θερμαϊκός Κόλπος).
Fantastic footage was recorded on Thursday afternoon – for a few minutes the ships “soared” over the water surface of the Thessaloniki Gulf. The reason lay in the complex optical effect of Fata Morgana, which occurs due to the difference in air and sea temperatures.
Reference: fata Morgana [ˈfaːta morˈɡaːna]) is a rare complex optical phenomenon in the atmosphere, consisting of several forms of mirages, in which distant objects are seen repeatedly and with various distortions. It got its name in honor of the sorceress – the character of English legends Fairy Morgana.
Explanations of meteorologist Dr. Stavros Keppas quotes GRTimes.gr:
“Initially, the fact that we have apnea and the sea is calm plays an important role. At this time of the year, the sea is still quite cold due to its high heat capacity, so it changes its temperature much more slowly than air. Basically, a thin layer of air that is directly above the sea – a few centimeters to several meters thick – much colder than the air above.”
Stavros Keppas explains that in mild weather, the interaction of warm air above and denser cold air near the surface can look like a refractive lens effect, creating a vertically inverted image in which it appears to float. As a rule, Fata Morgana is observed in the morning and very rarely at noon:
“In this case, we see the ship a little higher than it really is. You can usually see the reflection of the ship, because the radiation passes through layers of air with different densities.”
In addition, objects on the horizon in this case – islands, shelves, ships or icebergs – look like composites, that is, they are two images of the same object, connected at the top by the reverse side.
A similar phenomenon was observed in several parts of Greece, for example, in the west of Samothrace (Σαμοθράκης). A similar mirage has been observed in Toyama Bay (Κόλπο Τογιάμα) on the western coast of Japan and on the Great Lakes of North America. It can be seen on the ice-covered shelves of Antarctica and in the Arctic seas.
The first mention of “Fata Morgana” in English, as told by newsbeast.gr, was associated with a mirage observed in 1818 in the Strait of Messina, between Calabria and Sicily. The phenomenon belongs to the category of higher mirages, which differ from the more common lower mirages, which create the illusion of distant reservoirs in the desert and “wet pavement” on very hot roads.