Simulated Real-Time Testing of the Prototype Implementation of the SOFIE Model: The 2025 Space Weather Prediction Testbed Exercise

Abstract: The CLEAR Space Weather Center of Excellence's solar energetic particle (SEP) prediction model, SOlar wind with FIeld lines and Energetic particles (SOFIE), was run and evaluated on-site during the Space Weather Prediction Testbed (SWPT) exercise at NOAA's Space Weather Prediction Center (SWPC) in May 2025. As a physics-based SEP simulation and prediction model, SOFIE simulates the acceleration and transport of energetic particles in the coronal mass ejection (CME) driven shock in the solar corona and inner heliosphere. It has been validated against historical events. However, questions remain regarding whether a physics-based model, traditionally considered computationally expensive, could meet operational needs. The SWPT exercise offered a valuable opportunity to evaluate SOFIE's performance under simulated real-time conditions. Interactive feedback during the exercise from SWPC forecasters, SRAG console operators, CCMC personnel, and M2M SWAO analysts led to significant strategic improvements in the model setup to meet operational requirements. The resolution of the simulation domain was optimized by combining a coarser background grid with higher-resolution regions along the CME path and facing toward Earth, reducing computational cost without compromising accuracy. In this work, we present the operational performance of SOFIE and its capability to predict SEP fluxes significantly faster than real time. SOFIE was able to complete a 4-day SEP simulation within 5 hours on a supercomputer with 1,000 CPU cores during the SWPT exercise. This marks a critical milestone in demonstrating both the robustness and operational usefulness of SOFIE to support future human space exploration.