01 Stage
Background solar wind & connectivity
AWSoM-R + SA-MHD
Time-dependent corona + inner heliosphere driven by near-real-time GONG magnetograms, with Stream-Aligned MHD providing accurate sun-to-spacecraft magnetic connectivity.
Physics-based SEP simulation tool
SOFIE — Solar Wind with Field Lines and Energetic Particles
SOFIE couples the real-time solar wind, CME initiation, shock-driven particle acceleration, and interplanetary transport into a single end-to-end simulation chain — producing forecasts of SEP flux, spectrum, and timing at any heliospheric vantage point.
The Pipeline
Sun-to-spacecraft, in four coupled stages
Each stage feeds the next. The same simulation produces the background solar wind, propagates the CME shock, accelerates particles, and tracks them through the structured heliosphere to the observer.
02 Stage
CME initiation
EEG
EEG flux-rope insertion at the active region drives a self-consistent CME and shock.
03 Stage
Particle acceleration
M-FLAMPA / MITTENS
Diffusive shock acceleration along a population of Lagrangian magnetic field lines.
04 Stage
Interplanetary transport
Transport
Particles propagate through the structured heliosphere to any observer location.
Underlying components
Built on the CLEAR modeling stack
SOFIE integrates four physics-based modeling components developed at the University of Michigan and delivered to the community:
- AWSoM-R Real-time solar wind
- SA-MHD Magnetic connectivity
- EEG CME initiation
- M-FLAMPA / MITTENS Particle acceleration & transport
See Components of CLEAR for full descriptions of each module.
Forecast products
What SOFIE produces
Time–intensity profiles
Full rise → peak → decay of SEP flux at any heliospheric vantage point.
Energy spectra
Spectrum from a few MeV up to >100 MeV — not just an integrated intensity.
Onset, peak, end timing
Quantitative prediction of when the event begins, peaks, and ends at the observer.
Multi-point simulation outputs
Simulated SEP flux at any longitude in the inner heliosphere — Earth, Moon, Mars, and deep-space spacecraft.
Validation
Tested against historical events and operational testbeds
SOFIE has been validated against historical SEP events and exercised in NOAA SWPC's 2025 Artemis II Space Weather Prediction Testbed (April 29 – May 8, 2025), alongside other interagency forecasting tools.
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Historical SEP events validation
Application of SOFIE to multiple historical SEP events, demonstrating end-to-end forecasting capability across event types.
Zhao et al. 2024, Space Weather 22, e2023SW003729
DOI: 10.1029/2023SW003729 → -
2013 April 11 SEP event
Physics-based simulation reproducing the observed time-intensity profile and energy spectrum from a well-studied historical event.
Liu et al. 2025, ApJ 985, 82
DOI: 10.3847/1538-4357/adc4e3 → -
2025 NOAA SWPC Testbed exercise
Simulated real-time testing of the SOFIE prototype during the inaugural NOAA Space Weather Prediction Testbed (April 29 – May 8, 2025) — interagency exercise simulating radiation-storm scenarios for Artemis II.
Liu et al. 2025 (submitted), Space Weather
arXiv: 2511.09716 →
Status
From research prototype to operational forecast
SOFIE is currently a research-grade prototype that has been exercised in operational testbeds. The CLEAR team is preparing a real-time operational version for delivery through the Community Coordinated Modeling Center (CCMC).
During Artemis II, SOFIE prototype runs support NASA situational awareness for solar radiation events alongside other CLEAR forecasting tools.