A new electron density model of the plasmasphere for operational 3 applications and services

Abstract

The Earth's plasmasphere contributes essentially to total electron content (TEC) measurements 10 from ground or satellite platforms. Furthermore, as an integral part of space weather, associated 11 plasmaspheric phenomena must be addressed in conjunction with ionosphere weather monitoring by 12 operational space weather services. For supporting space weather services and mitigation of propagation 13 errors in Global Navigation Satellite Systems (GNSS) applications we have developed the empirical 14 Neustrelitz plasmasphere model (NPSM). The model consists of an upper L shell dependent part and a lower 15 altitude dependent part, both described by specific exponential decays. Here the McIllwain parameter L 16 defines the geomagnetic field lines in a centered dipole model for the geomagnetic field. The coefficients of 17 the developed approaches are successfully fitted to numerous electron density data derived from dual 18 frequency GPS measurements on-board the CHAMP satellite mission from 2000 to 2005. The data are 19 utilized for fitting up to the L shell L = 3 because a previous validation has shown a good agreement with 20 IMAGE/RPI measurements up to this value. Using the solar radio flux index F10.7 as the only external 21 parameter, the operation of the model is robust, with 40 coefficients fast and sufficiently accurate to be used 22 as a background model for estimating TEC or electron density profiles in near real time GNSS applications 23 and services. In addition to this, the model approach is sensitive to ionospheric coupling resulting in 24 anomalies such as the Nighttime Winter Anomaly and the related Mid-Summer Nighttime Anomaly and 25 even shows a slight plasmasphere compression of the dayside plasmasphere due to solar wind pressure. 26 Modelled electron density and TEC values agree with estimates reported in the literature in similar cases.