The phenomenon responsible for this is :

Case : Read the passage and answer the question(s).

On a hot sunny day there appear to be a puddle of water on the road at a distance from the viewer. This is called Mirage. The meaning of mirage is an optical illusion which result from refraction of light. A similar phenomenon occurs at sea when a ship is seen far appears to be floating in the air, or in a desert when it appears an oasis at a distance on a hot day.