Ionospheric model validation using COSMIC 2 - Preliminary results

Abstract

Space weather events (SWE) that result in geomagnetic storms influence electromagnetic wave propagation in the Earth's ionosphere and atmosphere, affecting communications, navigation, and positioning. Forecasting the state of the upper atmosphere and conditions following SWE is one of the key aspects to protect the current high technological society. However, accurately representing the thermosphere-ionosphere (TI) system is challenging due to its complex interactions with the lower atmosphere and the magnetosphere that are challenging to correctly represent. SWE events have often been poorly observed which can lead to uncertain conclusions about these phenomena. TI modeling is essential for understanding the complex coupling interactions between thermosphere and ionosphere to predict and mitigate SWE effects and their impacts. Model validation is crucial to assess the capabilities of these models and to develop new modelling techniques. It assesses the performance of the models and identifies errors which can be caused by factors such as the solar cycle, daily or seasonal variability and other biases. So far, there is no standard set of validation tools or reference datasets that can be used in the TI domain. In this work Ionospheric radio occultation data (electron density) from the COSMIC2 mission serves as the basis for validating two models, (1) the International Reference Ionosphere (IRI) and (2) the Thermosphere-Ionosphere Electrodynamics General Circulation Model (TIEGCM). A set of verification and statistical methods is applied to evaluate these models under geomagnetically quiet conditions. The outcome of this study is an initial model validation framework that employs different statistics and metrics, allowing the comparison of model performances.