Demonstration of a new High-Latitude Space Weather Operational Framework: Real-time Assimilative Modeling of the May 2024 Gannon Storm

Advances in modeling, data assimilation, instrumentation, and the growth in real-time observational networks enable the simulation of the ionosphere in three dimensions across wide spatial regions in real time. The focus of this paper is to demonstrate and evaluate the real-time specification of the high-latitude ionosphere throughout storm-time conditions, using the assimilative algorithm H-IDA4D (High latitude Ionospheric Data Assimilation 4D). H-IDA4D is an advanced version of IDA4D, tailored for use in the high-latitudes, that produces 4D time-dependent electron-density maps through variational analysis. The period of interest from May 7 to 14 includes the Gannon storm, with persistent and extreme geomagnetic disturbances, and a prolonged negative phase and a recovery phase. The nowcast reveals dynamical processes driven by convection and precipitation during this extreme storm-time period.

Three ionospheric models (E-CHAIM; IRI-2016; SAMI3) are investigated as background models with H-IDA4D. Real-time (NTRIP) GNSS data are assimilated to generate nowcast specifications. Observational data from the Poker Flat Incoherent Scatter Radar (PFISR) are used to assess and validate the results. The framework is being developed and optimized for use in a real-time operational environment (R2O). Since the focus is the high latitudes, where the dynamics and chemistry can change very quickly, we use a 5-minute modeling + data assimilation cadence and we only ingest near-real-time data that can be automatically processed. Agreement between nowcast products and ground-truth observations is discussed, along with implications of the results and computational requirements for future operational Space Weather programs in the high northern latitudes.