|Sunset Mirage over the Baltic Sea imaged at Rowy, Poland by Robert Tyszek of Warsaw. Images ©Robert Tyszek, shown with permission.
A strong temperature inversion, consisting of abnormally warm air overlaying cooler air, is present over the sea. Its upper boundary can be seen where the upper solar image is cut off. The sun's rays are refracted and curved as they pass between the air layers of different temperature and density to produce a ducted mock-mirage sunset. There are at least three solar images - all equally "real". The upper one is upright and descending and within the inversion layer one image is inverted and rising whilst the third is upright and setting.