Analysing Seasonal Characteristics of Residual Ionospheric Errors in Bending Angles Based on Ensembles of Profiles from End- To-End Simulations

Abstract

The Global Navigation Satellite System (GNSS) radio occultation (RO) observation data is widely used for numerical weather prediction (NWP) and global climate monitoring (GCM). However, the residual higher-order ionospheric error (RIE) can still be significant. To further mitigate the RIEs, characterization and quantification of RIEs in bending angles have been performed by using end-to-end simulations. In this study, the seasonal characteristics of the RIEs in bending angles were analyzed by using larger ensembles of profiles from end-to-end simulations. The results indicated that the RIE is a major source of the bending angle in lower mesosphere and upper stratosphere (LMUS), and its bias has a clear negative tendency that in line with our previous studies. The preliminary analysis showed that, globally the average bias and standard deviation of RIEs changed slightly, while regionally they changed obviously. For the northern hemisphere middle latitude (NHM) region, the largest average bias and standard deviation of RIEs happened in summer, while the smallest ones happened in winter. This study helps to inform future RIE mitigation schemes for ensuring benchmark quality stratospheric RO data.