A refraction effect that causes distant objects to appear elongated vertically. Although there is normally a decrease in air density with height, when this is far more rapid than normal (i.e. there is a sharp increase in temperature with height), rays of light from the top of the object undergo considerably greater refraction than those from the bottom, and appear to come from higher in the sky. Sometimes incorrectly called looming. The opposite effect is known as stooping. See also mirage.
Subjects: Meteorology and Climatology.