Fujian Baota geographic photography

A mirage is a natural phenomenon caused by the refraction of light. Also referred to as a mirage, it is a virtual image formed by the refraction of light reflected by objects on the earth through the atmosphere.

Mirages often appear on the sea and in the desert. Mirage is the result of light refraction along a straight line in gas layers with different densities. There are many kinds of mirage, which can be divided into Shanghai mirage, Xiahai mirage and seaside mirage according to their position relative to the original objects. According to its symmetrical relationship with the original object, it can be divided into positive, lateral, positive and negative; According to the color, it can be divided into colored mirage and colorless mirage.

Mirages are closely related to the geographical location, geophysical conditions and meteorological characteristics of those places at a specific time. The abnormal distribution of temperature is the meteorological condition for the formation of most mirage.

In summer, the humidity of seawater is relatively low during the day, especially on the sea surface where cold water flows, and the water temperature is even lower. The air in the lower layer is affected by the water temperature, which is colder than the air in the upper layer, so there is an abnormal phenomenon of cooling and heating (under normal circumstances, it is cooling and heating, with an average increase of 100 m and a temperature drop of about 0.6℃). Because the air pressure in the lower layer is high and the temperature is lower than that in the upper layer, the difference between the density under the air layer and the density under the air layer is extremely significant.