An empirical topside electron density model for calculation of absolute ion densities in IRI

An empirical model of the electron density in the topside ionosphere for solar maximum and minimum is introduced. This model is intended for use in combination with the relative ion composition (TTS) model that will be included in the forthcoming version of the IRI code to calculate the absolute ion composition in the topside ionosphere. The validation of the model using satellite data from five different satellites for different altitudes and high and medium solar activity is presented. The proposed model is based on the Langmuir Probe measurements onboard the Atmosphere Explorer satellites for low solar activity and Retarding Potential Analyzer measurements onboard the Intercosmos satellites for high solar activity. Examples of vertical profiles of the absolute density of the most important ions following from the mentioned models are shown.