Atmospheric perspective – also called aerial perspective – is the effect you get when far away objects take on the colors of atmospheric haze.

http://www.arthints.com/what-is-atmospheric-perspective/


aerial perspective, also called atmospheric perspective ,  method of creating the illusion of depth

http://www.britannica.com/EBchecked/topic/7229/aerial-perspective

Aatmospheric perspective is when objects appear lighter as they get farther away