# Sources of Solar Energetic Particles

## TL;DR

This review revises the traditional understanding of solar energetic particle acceleration, highlighting recent evidence that supports a unified mechanism involving turbulence and reconnection during solar flares and CMEs.

## Contribution

It introduces a revised model supported by recent MHD simulations, suggesting a common acceleration process for flares and CMEs involving current sheet formation and turbulence.

## Key findings

- Formation of current sheets in erupting magnetic structures
- Turbulent reconnection as a key acceleration process
- Unified mechanism for flare and CME-driven shock acceleration

## Abstract

Solar Energetic Particles (SEP) are an integral part of the physical processes related with Space Weather. We present a review for the acceleration mechanisms related to the explosive phenomena (flares and/or CMEs) inside the solar corona. For more than 40 years, the main 2D cartoon representing our understanding of the explosive phenomena inside the solar corona remained almost unchanged. The acceleration mechanisms related to solar flares and CMEs also remained unchanged and were part of the same cartoon. In this review, we revise the standard cartoon and present evidence from recent global MHD simulations that supports the argument that explosive phenomena will lead to the spontaneous formation of current sheets in different parts of the erupting magnetic structure. The evolution of the large scale current sheets and their fragmentation will lead to strong turbulence and turbulent reconnection during solar flares and turbulent shocks. In other words, the acceleration mechanism in flares and CME-driven shocks may be the same, and their difference will be the overall magnetic topology, the ambient plasma parameters, and the duration of the unstable driver.