Potential refractive index

From Glossary of Meteorology

potential refractive index

In radio engineering, the refractive index for an atmosphere in which potential temperature and specific humidity are constant with height.

The gradient of potential refractive index depends on the values of potential temperature and specific humidity, but over the range of values commonly encountered in the earth's atmosphere, this gradient does not vary much and is given approximately by
where R is the earth's radius.
See potential refractivity.