Dependence of Frequency Power Law Exponent of Ionospheric Radiowave Absorption on Solar Zenith Angle

43-46study of the effect of the solar zenth angle on the frequency power law exponent derived from simultaneous vertical incidence multifrequency ionospheric absorption measurements available from a number of low and midlatitude stations has shown that the exponent, in fact, increases when deviative absorption becomes relatively more significant compared to nondeviative absorption. A numerical simulation using a double x-Chapman type absorbing zone yielded results identical to the experimental observation. It is suggested that in the formula L = A/(f+fL)m (solar zenith angle constant), widely used in such studies, neither A nor m remains independent of the solar zenith angle