What are the meteorological causes of super-refraction in the troposphere?

Answer 1

Refraction in the atmosphere usually refers to the gradual vertical deflection of

light or radio, because of a vertical gradient of refractive index with altitude.

The gradient is usually negative with altitude, so light and radio usually curve

downward at various rates, depending on the magnitude of the gradient.

"Super-refraction" is the label given to the condition wherein the gradient is so

steep that light and radio curve downward along their path more rapidly than the

surface of the earth does, so that the altitude of an initially-horizontal beam

progressively decreases.

Refraction is more pronounced as the temperature increases and humidity decreases

more rapidly with altitude. Super-refraction results when the combined effect of these

two parameters reaches a specific value.

Answer 2

Super-refraction in the troposphere occurs when inversions of temperature and moisture create a refractive index that bends radio waves downward. This bending can lead to signal enhancement or trapping, affecting communication systems. Factors such as high humidity, stable air masses, and thermal inversions can contribute to super-refraction in the atmosphere.