https://www.theguardian.com/science/2021/mar/05/ship-hovering-above-sea-cornwall-optical-illusion
The effect is an example of an optical illusion known as a superior mirage. Such illusions are reasonably common in the Arctic but can also happen in UK winters when the atmospheric conditions are right, though they are very rare.
The illusion is caused by a meteorological phenomenon called a temperature inversion. Normally, the air temperature drops with increasing altitude, making mountaintops colder than the foothills. But in a temperature inversion, warm air sits on top of a band of colder air, playing havoc with our visual perception. The inversion in Cornwall was caused by chilly air lying over the relatively cold sea with warmer air above.
The effect is an example of an optical illusion known as a superior mirage. Such illusions are reasonably common in the Arctic but can also happen in UK winters when the atmospheric conditions are right, though they are very rare.
The illusion is caused by a meteorological phenomenon called a temperature inversion. Normally, the air temperature drops with increasing altitude, making mountaintops colder than the foothills. But in a temperature inversion, warm air sits on top of a band of colder air, playing havoc with our visual perception. The inversion in Cornwall was caused by chilly air lying over the relatively cold sea with warmer air above.