page_title: Fata Morgana (mirage)
section_title: Observing a Fata Morgana
hierarchical_section_title: Fata Morgana (mirage) / Observing a Fata Morgana
caption_attribution_description: English: Sequence of Fata morgana of Farallon Islands show how Fata Morgana is changing constantly. The last two frames were photographed few hours after the first frames. Around sunset time the air is getting cooler, while the ocean might be a little bit warmer after a hot day. The lower the difference in the temperatures the lower inversion, and the mirage shown in the last two frames is not as complex as the mirage photographed around noon.
context_page_description: A Fata Morgana is a complex form of superior mirage that is seen in a narrow band right above the horizon. It is an Italian term named after 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 deaths.
  Fata Morgana mirages significantly distort the object or objects on which they are based, often such that the object is completely unrecognizable. A Fata Morgana may be seen on land or at sea, in polar regions, or in deserts. It may involve almost any kind of distant object, including boats, islands, and the coastline.
  Often, a Fata Morgana changes rapidly. The mirage comprises several inverted and erect images that are stacked on top of one another. Fata Morgana mirages also show alternating compressed and stretched zones.
  The 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.
context_section_description: A Fata Morgana is most commonly seen in polar regions, especially over large sheets of ice that have a uniform low temperature. It may, however, be observed in almost any area. In polar regions the Fata Morgana phenomenon is observed on relatively cold days. In deserts, over oceans, and over lakes, however, a Fata Morgana may 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 may be observed from any altitude within the Earth's atmosphere, from sea level up to mountaintops, and even including the view from airplanes.
  A Fata Morgana may 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 may 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 a 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 so complex as a 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 images here, through a telephoto lens.
  Gabriel Gruber (1740–1805) and Tobias Gruber (1744–1806), who observed Fata Morgana above Lake Cerknica, were the first to study it in a laboratory setting.
caption: A sequence of a Fata Morgana of the Farallon Islands as seen from San Francisco
exif: {"Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop Elements 2.0", "Image DateTime": "2008:12:02 12:16:57", "Image ExifOffset": "164", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "302", "Thumbnail JPEGInterchangeFormatLength": "4010", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "1400", "EXIF ExifImageLength": "1101"}