# Acceleration and propagation of Solar Energetic Particles

## TL;DR

This paper reviews the mechanisms, observations, and forecasting methods of Solar Energetic Particles, emphasizing their acceleration during solar flares and Coronal Mass Ejections, and their impact on space weather and Earth.

## Contribution

It provides a comprehensive review of SEP acceleration, transport, and forecasting, integrating recent observational data and modeling approaches.

## Key findings

- Both flare and CME shock acceleration contribute to SEP populations.
- Transport effects significantly influence SEP propagation to Earth.
- Current forecasting tools incorporate multiple acceleration mechanisms.

## Abstract

Solar Energetic Particles (SEPs) are an important component of Space Weather, including radiation hazard to humans and electronic equipment, and the ionisation of the Earth's atmosphere. We review the key observations of SEPs, our current understanding of their acceleration and transport, and discuss how this knowledge is incorporated within Space Weather forecasting tools. Mechanisms for acceleration during solar flares and at shocks driven by Coronal Mass Ejections are discussed, as well as the timing relationships between signatures of solar eruptive events and the detection of SEPs in interplanetary space. Evidence on how the parameters of SEP events are related to those of the parent solar activity is reviewed and transport effects influencing SEP propagation to near-Earth locations are examined. Finally, the approaches to forecasting Space Weather SEP effects are discussed. We conclude that both flare and CME shock acceleration contribute to Space Weather relevant SEP populations and need to be considered within forecasting tools.