The solar corona between below 10 solar radii is an important region for early acceleration and transport of solar energetic particles (SEPs) by coronal mass ejection-driven shock waves. There, these waves propagate into a highly variable dynamic medium with steep gradients and rapidly expanding coronal magnetic fields, which modulates the particle acceleration near the shock/wave surfaces, and the way SEPs spread into the heliosphere. In a recently published study (https://doi.org/10.3389/fspas.2022.801429) in the journal Frontiers in Astronomy and Space Sciences (IF 3.494), we have modeled the acceleration of SEPs in global coronal shock events in the corona, as well as their transport to 1 au, based on telescopic observations coupled with dynamic physical models. We first studied the interaction of observed off-limb coronal bright fronts (CBF) with the coronal plasma, based on interactions of geometric shock models with steady-state magnetohydrodynamics (MHD) simulations. We then simulated the SEP acceleration in an analytical diffusive shock acceleration (DSA) model. The simulated fluxes are used as time-dependent inner boundary conditions for modeling the particle transport to 1 au. Resulting flux time series are compared with 1 au observations for validation in the figure below.
Summary of the work on energetic proton acceleration. Panels 1 and 2 show dynamic spectra of the observed and modeled energetic protons at 1 au, for a single SEP event. Panel 3 is a scatter plot showing the statistical relationship between observed and modeled proton power law spectral index. Panel 4 shows the statistical relationship between the event onsets in the observations and simulations.