| Abstract: | Measurements of the principal ion species of the F1- and F2- regions have been used to develop an empirical model of the ion composition for altitudes between 150 and 500 km. The species measured by the S3-1 satellite include N+, O+, N2+, NO+ and O2+. The data were obtained near the minimum of the solar cycle, thus limited information on the ionospheric variation with solar flux is available. However, the range of latitude, altitude, local time and geomagnetic activity does provide a useful basis for modeling the F-region. The ion composition measurements have been used to provide a model for relative ion composition which is compatible with the total ion density from the International Reference Ionosphere model. |
