Post by meldrew on Jan 8, 2013 21:04:25 GMT 1
this is something you should all know about, this could account for a lot of high strangeness reports, so far the best write up on this phenomenon comes from wikipedia, so I will use that as the source.
A Fata Morgana is an unusual and complex form of superior mirage that is seen in a narrow band right above the horizon. It is an Italian phrase derived from the vulgar Latin for "fairy" and the Arthurian sorceress Morgan le Fay, from a belief that these mirages, often seen in the Strait of Messina, were fairy castles in the air or false land created by her witchcraft to lure sailors to their death. Although the term Fata Morgana is sometimes incorrectly applied to other, more common kinds of mirages, the true Fata Morgana is not the same as an ordinary superior mirage, nor is it the same as an inferior mirage.
Fata Morgana mirages distort the object or objects which they are based on significantly, often such that the object is completely unrecognizable. A Fata Morgana can be seen on land or at sea, in polar regions or in deserts. This kind of mirage can involve almost any kind of distant object, including boats, islands, and the coastline.
A Fata Morgana is often rapidly changing. The mirage comprises several inverted (upside down) and erect (right side up) images that are stacked on top of one another. Fata Morgana mirages also show alternating compressed and stretched zones.
This optical phenomenon occurs because rays of light are bent when they pass through air layers of different temperatures in a steep thermal inversion where an atmospheric duct has formed. (A thermal inversion is an atmospheric condition where warmer air exists in a well-defined layer above a layer of significantly cooler air. This temperature inversion is the opposite of what is normally the case; air is usually warmer close to the surface, and cooler higher up.)
In calm weather, a layer of significantly warmer air can rest over colder dense air, forming an atmospheric duct which acts like a refracting lens, producing a series of both inverted and erect images. A Fata Morgana requires a duct to be present; thermal inversion alone is not enough to produce this kind of mirage. While a thermal inversion often takes place without there being an atmospheric duct, an atmospheric duct cannot exist without there first being a thermal inversion.
[img src=""]
A Fata Morgana is most commonly seen in polar regions, especially over large sheets of ice which have a uniform low temperature. It can however be observed in almost any area. In polar regions the Fata Morgana phenomenon is observed on relatively cold days, however in deserts, over oceans, and over lakes, a Fata Morgana can be observed on hot days.
To generate the Fata Morgana phenomenon, the thermal inversion has to be strong enough that the curvature of the light rays within the inversion layer is stronger than the curvature of the Earth.Under these conditions, the rays bend and create arcs. An observer needs to be within or below an atmospheric duct in order to be able to see a Fata Morgana.
A Fata Morgana can be observed from any altitude within the Earth's atmosphere, from sea level up to mountain tops, and even including the view from airplanes.
A sequence of a Fata Morgana of the Farallon Islands as seen from San Francisco
A Fata Morgana can be described as a very complex superior mirage with more than three distorted erect and inverted images. Because of the constantly changing conditions of the atmosphere, a Fata Morgana can change in various ways within just a few seconds of time, including changing to become a straightforward superior mirage.
The sequential image here shows sixteen photographic frames of a mirage of the Farallon Islands as seen from San Francisco; the images were all taken on the same day.
In the first fourteen frames, elements of the Fata Morgana mirage display alternations of compressed and stretched zones. The last two frames were photographed few hours later, around sunset time. At that point in time, the air was cooler while the ocean was probably a little bit warmer, which caused the thermal inversion to be not as extreme as it was few hours before. A mirage was still present at that point, but it was not as complex as few hours before sunset: the mirage was no longer a Fata Morgana, but instead had become a simple superior mirage.
Fata Morgana mirages are visible to the naked eye, but in order to be able to see the detail within them, it is best to view them through binoculars, a telescope, or as is the case in the image here, through a telephoto lens.
en.wikipedia.org/wiki/Fata_Morgana_(mirage)
Fata Morgana (mirage)
A Fata Morgana is an unusual and complex form of superior mirage that is seen in a narrow band right above the horizon. It is an Italian phrase derived from the vulgar Latin for "fairy" and the Arthurian sorceress Morgan le Fay, from a belief that these mirages, often seen in the Strait of Messina, were fairy castles in the air or false land created by her witchcraft to lure sailors to their death. Although the term Fata Morgana is sometimes incorrectly applied to other, more common kinds of mirages, the true Fata Morgana is not the same as an ordinary superior mirage, nor is it the same as an inferior mirage.
Fata Morgana mirages distort the object or objects which they are based on significantly, often such that the object is completely unrecognizable. A Fata Morgana can be seen on land or at sea, in polar regions or in deserts. This kind of mirage can involve almost any kind of distant object, including boats, islands, and the coastline.
A Fata Morgana is often rapidly changing. The mirage comprises several inverted (upside down) and erect (right side up) images that are stacked on top of one another. Fata Morgana mirages also show alternating compressed and stretched zones.
This optical phenomenon occurs because rays of light are bent when they pass through air layers of different temperatures in a steep thermal inversion where an atmospheric duct has formed. (A thermal inversion is an atmospheric condition where warmer air exists in a well-defined layer above a layer of significantly cooler air. This temperature inversion is the opposite of what is normally the case; air is usually warmer close to the surface, and cooler higher up.)
In calm weather, a layer of significantly warmer air can rest over colder dense air, forming an atmospheric duct which acts like a refracting lens, producing a series of both inverted and erect images. A Fata Morgana requires a duct to be present; thermal inversion alone is not enough to produce this kind of mirage. While a thermal inversion often takes place without there being an atmospheric duct, an atmospheric duct cannot exist without there first being a thermal inversion.
Observing a Fata Morgana
[img src=""]
A Fata Morgana is most commonly seen in polar regions, especially over large sheets of ice which have a uniform low temperature. It can however be observed in almost any area. In polar regions the Fata Morgana phenomenon is observed on relatively cold days, however in deserts, over oceans, and over lakes, a Fata Morgana can be observed on hot days.
To generate the Fata Morgana phenomenon, the thermal inversion has to be strong enough that the curvature of the light rays within the inversion layer is stronger than the curvature of the Earth.Under these conditions, the rays bend and create arcs. An observer needs to be within or below an atmospheric duct in order to be able to see a Fata Morgana.
A Fata Morgana can be observed from any altitude within the Earth's atmosphere, from sea level up to mountain tops, and even including the view from airplanes.
A sequence of a Fata Morgana of the Farallon Islands as seen from San Francisco
A Fata Morgana can be described as a very complex superior mirage with more than three distorted erect and inverted images. Because of the constantly changing conditions of the atmosphere, a Fata Morgana can change in various ways within just a few seconds of time, including changing to become a straightforward superior mirage.
The sequential image here shows sixteen photographic frames of a mirage of the Farallon Islands as seen from San Francisco; the images were all taken on the same day.
In the first fourteen frames, elements of the Fata Morgana mirage display alternations of compressed and stretched zones. The last two frames were photographed few hours later, around sunset time. At that point in time, the air was cooler while the ocean was probably a little bit warmer, which caused the thermal inversion to be not as extreme as it was few hours before. A mirage was still present at that point, but it was not as complex as few hours before sunset: the mirage was no longer a Fata Morgana, but instead had become a simple superior mirage.
Fata Morgana mirages are visible to the naked eye, but in order to be able to see the detail within them, it is best to view them through binoculars, a telescope, or as is the case in the image here, through a telephoto lens.
en.wikipedia.org/wiki/Fata_Morgana_(mirage)