A data-driven physics-based transport model of solar energetic particles accelerated by coronal mass ejection shocks propagating through the solar coronal and heliospheric magnetic fields

TL;DR

This paper introduces a data-driven, physics-based model for simulating the injection, acceleration, and propagation of solar energetic particles caused by CME shocks, integrating MHD data and advanced stochastic techniques.

Contribution

The paper presents a novel 5D focus transport model that combines MHD-driven plasma data with stochastic simulation to accurately predict SEP events.

Findings

Model reproduces multi-spacecraft SEP observations without flux normalization.

Single CME shock explains widespread SEP event at multiple spacecraft.

Accurately simulates SEP propagation using real CME data.

Abstract

In an effort to develop computational tools for predicting radiation hazards from solar energetic particles (SEPs), we have created a data-driven physics-based particle transport model to calculate the injection, acceleration and propagation of SEPs from coronal mass ejection (CME) shocks traversing through the solar corona and interplanetary magnetic fields. The model runs on an input of corona and heliospheric plasma and magnetic field configuration from an MHD model driven by solar photospheric magnetic field measurements superposed with observed CME shocks determined from coronagraph images. Using several advanced computation techniques involving stochastic simulation and integration, it rigorously solves the time-dependent 5-dimensional focus transport equation in the phase space that includes pitch-angle scattering, diffusion across magnetic field line, and particle acceleration by CME shocks. We apply the model to the 2011 November 3 CME event. The calculation results reproduce multi-spacecraft SEP observations reasonably well without normalization of particle flux. This circumsolar SEP event seen by spacecraft at Earth, STEREO-A and STEREO-B at widely separated longitudes can be explained by diffusive shock acceleration by a single CME shock with a moderate speed.