Extreme space weather events, including major solar flares, solar energetic particle events, and severe geomagnetic storms, pose significant risks to space‑ and ground‑based infrastructure. Their rarity but potentially high impact highlights the limitations of current monitoring, modelling, and forecasting capabilities, especially for extreme or poorly observed scenarios. Strengthening resilience requires advanced modelling approaches supported by sustained, near‑real‑time observations across the near‑Earth environment.
This session focuses on the combined use of space weather missions, instrumentation, and models to observe, understand, and predict extreme events and their effects on the heliosphere, magnetosphere, ionosphere, thermosphere, auroral regions, and radiation belts. Continuous and timely measurements are essential to capture event initiation and evolution, quantify environmental impacts, and provide robust boundary conditions and validation data for physics‑based and data‑driven models.
We have welcomed contributions showcasing the capabilities of current and upcoming missions and instruments measuring plasma properties, electromagnetic fields, radiation, and atmospheric response. Particular emphasis is placed on how these observations enable near‑real‑time situational awareness, support data assimilation, and help close critical observational gaps during severe events through coordinated multi‑mission strategies and hosted payloads.
The session also addresses advances in space weather modelling and forecasting, including physics‑based modelling, machine‑learning approaches, and hybrid techniques. We promote contributions evaluating model performance during extreme events, identifying key physical and observational limitations, and proposing paths to improved predictive skill. Topics include uncertainty quantification, extreme‑event benchmarks, and translating model outputs into actionable information for operational and pre‑operational services.
By bringing together instrument developers, mission teams, modellers, and forecasters, this session aims to strengthen the connection between observations and models and to advance end‑to‑end capabilities for monitoring and forecasting extreme space weather.