SA44B-07 - An updated assimilative CHAIM for near-real-time ionospheric specification: assessing its real-world performance

The Assimilative Canadian High Arctic Ionospheric Model (A-CHAIM) is a near-real-time data assimilation model of ionospheric plasma density above 45 degrees North geomagnetic magnetic latitude. The model assimilates data from ground-based GNSS receivers, ionosondes, and the JASON altimeter satellites, using a particle filter technique. The model has recently been refined, building on two years of nearly continuous operation since 2019. In this study we will use the observation files gathered by the operational system to run the refined A-CHAIM data assimilation model and examine its performance during the May 12, 2021, Kp 7 geomagnetic storm. The modeling and forecasting ability of A-CHAIM will be evaluated by comparing the assimilation to in-situ measurements of topside electron density from the DMSP and Swarm satellites, as well as to manually-scaled ionograms from the Canadian High Arctic Ionospheric Network (CHAIN), ahead of updating the core A-CHAIM system with the refined model.