Some Spectral Characteristics of the Radio Refractivity in the Surface Layer of the Atmosphere

Abstract
Experimental data suggest that the spectral density of the radio refractivity, N, exhibits a strong dependence on stability (Richardson's number, Ri) at the low frequency range and a weak dependence on stability at the high frequency range. Furthermore, the average spectral decay of N was found to be in reasonably good agreement with the “−5/3” law; however, significant departures from this law were observed depending upon the frequency range considered. In fact, systematically smaller spectral decays were observed at low frequencies and larger decays at high frequencies.