Comparison of the IRI-2007 Model Topside Electron Density with CHAMP and COSMIC/Formosat-3 Data

Kurzfassung

Reported are results of a comparison of the four topside electron density model options of the IRI-2007 model with data obtained from the CHAMP and the COSMIC/Formosat-3 satellite missions. Starting from 2001 we have collected on average 15 tomographic reconstructions of the topside electron density every day using GPS data of the zenith-viewing antenna onboard CHAMP. These data sets form the basis of a comparative study with the IRI-2007 model topside. While this long-term data basis enables us to study solar cycle dependent effects in the upper ionosphere/plasmasphere, the electron density profiles derived from COSMIC/Formosat-3 GPS radio occultation offer an up to now unprecedented temporal and spatial resolution with up to 2500 profiles per day. As more and more of the COSMIC satellites approach their design orbits in about 800km height, it becomes possible to compare the upper part of the COSMIC radio occultation electron density profiles to the IRI-2007 topside electron density