õhkupeeglid

Õhkupeeglid, also known as superior mirages, are optical phenomena that occur when light rays bend upwards due to temperature inversions in the atmosphere. This bending creates the illusion that an object, such as a ship or a distant coastline, is floating above its actual position. These mirages are most commonly observed over bodies of water, particularly in cold regions, where a layer of cold air can sit above warmer air.

The formation of an õhkupeegel relies on the difference in refractive index between air layers of different temperatures. Light travels slower in denser, colder air than in less dense, warmer air. When light rays pass from a warmer layer to a colder layer at a shallow angle, they bend upwards, following the curvature of the Earth. The observer's eye then perceives these bent rays as if they originated from a higher point in the sky, creating the mirage.

Õhkupeeglid can manifest in various forms, including inverted images below the real object or duplicated images above it. The appearance and intensity of the mirage depend on the specific atmospheric conditions, such as the temperature gradient and the distance of the observer from the object. While often associated with maritime settings, õhkupeeglid can also occur over land under similar temperature inversion conditions, though they are less frequently observed and recognized. These natural optical illusions have historically contributed to tales of phantom islands and flying ships.