An electromagnetic calculation of ionospheric conductance that seems to override the field line integrated conductivity

Using a rigorous solution for the electromagnetic fluid equations, it is found that they do not predict the electric-field-mapping that is usually expected, and that even if they did, the ionospheric conductance would have a significantly smaller value. In fact, these equations predict wavelike effects on all transverse scales investigated, which are partially associated with short parallel wavelengths, and partially associated with the interaction of multiple modes. It is also found that the electrostatic-wave theory that is used, for example, to derive the spectrum of incoherent scatter, will likely produce unphysical results if extended to transverse scales longer than about one hundred meters. By way of comparison, the new solution is a steady-state solution and thus has benefits that are complimentary to those of time-domain simulations: it computes the ionospheric conductance and electric field mapping, but it cannot compute the time evolution that eventually produces these effects. Also, although the signal is 3-dimensional, the background ionosphere is assumed horizontally uniform. Hence, while the new solution should be useful for evaluating the efficacy of time-domain simulations, it cannot replace them for the complex and evolving events that usually attract our attention. Rather, the results are best understood as baseline, fundamental results that inform our thinking broadly.