Ionospheric Radio Occultation as a tool for model validation

Abstract

Understanding and forecasting the variability of the solar-terrestrial environment is crucial to prevent the risks of space weather events on technologies like terrestrial and satellite-based communication and navigation systems. This requires the development and improvement of Ionosphere-Thermosphere (IT) modeling techniques. Model validation shows the model's performance and indicates if the model error is affected by the solar cycle, daily or seasonal variability and if there are bias in it. But, there is no standard set of validation tools or reference datasets yet that can be used in the IT domain. Ionospheric Radio Occultation (IRO) is a promising technique in reconstructing the ionospheric electron density profiles in a broad range of heights and global coverage. IRO data from the COSMIC2 mission is used here to demonstrate its quality for validating IT models. Electron density profiles obtained from models like the International Reference Ionosphere (IRI) and the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIEGCM) are compared against IRO data. A set of validation and statistical methods is applied for different conditions (geomagnetically quiet and active) and periods (daily, seasonal variations). The results from this study aim to establish the most significant validation metrics and find the temporal dependencies that are most important in IT model validation.