<P> Heat haze is not related to the atmospheric phenomenon of haze . </P> <P> A superior mirage occurs when the air below the line of sight is colder than the air above it . This unusual arrangement is called a temperature inversion, since warm air above cold air is the opposite of the normal temperature gradient of the atmosphere . Passing through the temperature inversion, the light rays are bent down, and so the image appears above the true object, hence the name superior . Superior mirages are in general less common than inferior mirages, but, when they do occur, they tend to be more stable, as cold air has no tendency to move up and warm air has no tendency to move down . </P> <P> Superior mirages are quite common in polar regions, especially over large sheets of ice that have a uniform low temperature . Superior mirages also occur at more moderate latitudes, although in those cases they are weaker and tend to be less smooth and stable . For example, a distant shoreline may appear to tower and look higher (and, thus, perhaps closer) than it really is . Because of the turbulence, there appear to be dancing spikes and towers . This type of mirage is also called the Fata Morgana or hafgerdingar in the Icelandic language . </P> <P> A superior mirage can be right - side up or upside down, depending on the distance of the true object and the temperature gradient . Often the image appears as a distorted mixture of up and down parts . </P>

Which of these is not an example of convection