Validation of Ionospheric Models at Mid- and High-Latitudes: Climatological Performance of WACCM-X (SD) and TIE-GCM in foF2

Accurate modelling of the high-latitude ionosphere-thermosphere system is critical to understanding the impacts of space weather on modern technology, such as communications and navigation systems. At low and mid latitudes, both physics-based and empirical models are well-developed and capture the variability of the ionosphere to a good degree of accuracy. At high latitudes, however, the complex chemistry and dynamics due to interactions with the solar wind and magnetosphere, added to lack of observations, presents challenges to such models. This study evaluates the climatological performance of the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM), the Whole Atmosphere Community Climate Model with thermosphere and ionosphere extensions (WACCM-X), and the Empirical Canadian High Arctic Ionospheric Model (E-CHAIM) for the period 1950 – 2022. Model outputs are compared to observational foF2 data from the high-latitude Resolute Bay ionosonde and the mid-latitude Chilton ionosonde to assess the limitations of models in reproducing the variability of the high-latitude ionosphere. Preliminary results from TIE-GCM and WACCM-X exhibit strong winter anomaly behaviour at all times of day at high latitude, which is not present in observational data. An equinoctial asymmetry is also present, with elevated electron densities in March compared to September, even during low solar activity. In contrast, E-CHAIM shows significantly better agreement with observations, more accurately reproducing seasonal and solar cycle trends. These findings highlight the need for improved representation of high-latitude processes in physics-based models.