Simulation of solar energetic particle events originated from coronal mass ejection shocks with a data-driven physics-based transport model

TL;DR

This paper presents a data-driven physics-based model to simulate solar energetic particle events from CME shocks, improving prediction accuracy for SEP hazards by comparing simulations with multiple spacecraft observations.

Contribution

It introduces a novel model that incorporates real magnetic field and CME data to simulate SEP events, enhancing predictive capabilities over previous models.

Findings

Model matches observed SEP intensity profiles well below 40 MeV.

Discrepancies occur at higher energies and specific events, overestimating proton flux.

Transport effects cause differences between modeled and observed intensities at some spacecraft.

Abstract

Solar energetic particle (SEP) events are associated with coronal mass ejections (CMEs) and/or solar flares. SEPs travel through the corona and interplanetary space to reach Earth, posing a radiation hazard to spacecraft and astronauts working in space and the electronics on spacecraft. Due to the distinct magnetic field configuration and solar eruption kinematic properties associated with each event, the utilization of a data-driven model becomes essential for predicting SEP hazards. In this study, we use a developed model that utilizes photospheric magnetic field measurements and CME shock observations as inputs to simulate several historical SEP events associated with fast CME speeds (>700 km/s). The model includes an SEP source term aligned with the theory of diffusive shock acceleration by the CME shock. The performance of the model is accessed by comparing simulations and observations of SEP intensity time profiles at SOHO, ACE, STEREO-A and STEREO-B. The results generally matched observations well, particularly for protons below 40.0 MeV. However, discrepancies arose for higher-energy protons, notably for the events on 2011 March 7 and 2014 February 25, where the simulation tended to overestimate the proton flux . At STEREO-A, the modeled proton intensities for the SEP events on 2013 April 11 and 2011 March 7 display a very different behavior compared to observations because of the efficient transport in longitude caused by the weak magnetic field.