Case studies of multi-day 3He-rich solar energetic particle periods

TL;DR

This study investigates the source regions of long-lasting 3He-rich solar energetic particle events, identifying active region plages and coronal jets as key contributors, and explores how jet occurrence rates influence 3He enrichment.

Contribution

It combines magnetic field modeling and multi-wavelength observations to pinpoint the solar sources of extended 3He-rich SEP events, highlighting the role of coronal jets.

Findings

Long-lasting 3He-rich SEP events originate from single active regions.

Coronal jets are primary sources of ion production in these events.

3He enrichment correlates with the occurrence rate of coronal jets.

Abstract

Context. Impulsive solar energetic particle events in the inner heliosphere show the long-lasting enrichment of 3He. Aims. We study the source regions of long-lasting 3He-rich solar energetic particle (SEP) events Methods. We located the responsible open magnetic field regions, we combined potential field source surface extrapolations (PFSS) with the Parker spiral, and compared the magnetic field of the identified source regions with in situ magnetic fields. The candidate open field regions are active region plages. The activity was examined by using extreme ultraviolet (EUV) images from the Solar Dynamics Observatory (SDO) and STEREO together with radio observations from STEREO and WIND. Results. Multi-day periods of 3He-rich SEP events are associated with ion production in single active region. Small flares or coronal jets are their responsible solar sources. We also find that the 3He enrichment may depend on the occurrence rate of coronal jets.