LF and VLF phase antinomies during solar X-ray flares


  • Giovanni E. Perona


During solar X-ray flares the phases of VLF and LF signals reflected from the ionosphere at grazing incidence often show an opposite behavior, the so-called phase antinomy. Two years of data have been analyzed to show the main characteristics of this phenomenon and, in particular, its seasonal dependence. An explanation of such behavior is sought in terms of changes in the phase of the ionospheric reflection coefficient. Only simple models of electron density distributions with height are numerically analyzed, namely, perturbed exponentials.