Model description of electron density in the middle ionosphere

In this paper, we present and discuss results of a comparison between model calculations of electron density (N) at ionospheric heights of 120-200 km and experimental data obtained in a number of geographic points during various solar activity levels in different seasons under quiet and disturbed conditions. The calculations have been made using the authors' semiempiri-cal model (SEM) that provides a general relation of N with thermospheric neutral gas characteristics and solar activity index. The data given in this paper suggest that in most cases the SEM calculations accord well with the experiment (the difference between them is within 10-20 %). Hence the authors assume that the comparison results presented here bear witness to a high degree of universality of the model under discussion