Theory of radio scattering from the aurora

A theory is presented here that explains certain phenomena observed in studies of radio scattering from the aurora. It is postulated that the signals which have been observed are scattered from the leading edges of rapidly advancing columns of ionization created by bundles of incoming auroral protons. Observed fading · spectra and the minimum range effect may be explained in this manner. The rate of advance of the ionized columns has been determined approximately and is of the same order of magnitude as Gartlein has found spectrographically. It is suggested that the columns are on the order of half a meter in diameter. Insufficient data are available to make extensive density calculations.