Contribution of water vapor monomer resonances to fluctuations of refraction and absorption for submillimeter through centimeter wavelengths

Atmospheric fluctuations in temperature, humidity, and total pressure cause fluctuations in the absorption and refraction of electromagnetic waves. We consider only the absorption and refraction fluctuations caused by variations in the width and strength of water monomer resonances. We differentiate the absorption coefficient and refractive index with respect to temperature, humidity, and total pressure in order to obtain the coefficients that relate the fluctuations in absorption and refraction to these atmospheric parameters. The resulting coefficients as well as the absorption coefficient and the refractivity are calculated by summing over all water vapor infrared resonances and are displayed graphically. In the limit of low frequencies, these calculated coefficients are in good agreement with the formula for radio wave refractive index. The effects of turbulent fluctuations in total pressure are usually negligible.