Vertical electron density profiles from GRACE radio occultation measurements

Abstract

The GNSS radio occultation technique is a powerful tool for retrieving vertical profiles of electron density of the global ionosphere from satellite orbit down to E-layer heights. Thus, ionospheric radio occultation (IRO) measurements onboard CHAMP enabled us to retrieve more than 300,000 vertical electron density profiles since 2001. Continuing the close cooperation between GFZ and DLR in using GRACE IRO data, we could derive more than 60,000 profiles since 2007 so far. This large number of profiles provides a reliable basis for statistical analysis. Here we report results obtained from ionospheric radio occultation (IRO) measurements onboard the GRACE-A satellite in comparison with IRO results from equivalent measurements onboard CHAMP and COSMIC satellites. Considered are ionospheric key parameters such as peak electron density NmF2, height of F2 layer maximum hmF2 and Total Electron Content (TEC). Combining the electron density retrievals of various satellites, there is a great potential for developing and improving global ionospheric models and tomographic reconstructions.