Topside ionosphere and plasmasphere: Use of NeQuick in connection with Gallagher plasmasphere model

The NeQuick ionospheric electron density model has a very simple topside formulation, which allows taking into account the electron content up to 20,000 km. In the present work, the Gallagher model has been used in connection with NeQuick to provide a more realistic representation of the electron concentration distribution in the plasmasphere. An analysis of the impact of the proposed modification in low geomagnetic latitudes (±40°) on modeled vertical total electron content has been performed for different levels of solar activity, season, and universal time. In addition, GPS vertical total electron content values obtained from seven IGS (International GPS Service) station data have been compared with the NeQuick and NeQuick+Gallagher vertical total electron content values, confirming the importance of including a plasmaspheric formulation in the NeQuick model.