Influence of Coronal Holes on CMEs in Causing SEP Events

TL;DR

This study investigates whether coronal holes influence the ability of coronal mass ejections to generate solar energetic particle events, concluding that no significant effect is observed.

Contribution

It extends previous research by analyzing a larger dataset and incorporating magnetic field extrapolations to confirm the lack of correlation.

Findings

No evident effect of coronal holes on SEP production by CMEs

Analysis of 76 events extending previous studies

Coronal hole parameters do not significantly influence SEP occurrence

Abstract

The issue of the influence of coronal holes (CHs) on coronal mass ejections (CMEs) in causing solar energetic particle (SEP) events is revisited. It is a continuation and extension of our previous work (Shen et al., 2006), in which no evident effect of CHs on CMEs in generating SEPs were found by statistically investigating 56 CME events. This result is consistent with the conclusion obtained by Kahler in 2004. In this paper, we extrapolate the coronal magnetic field, define CHs as the regions consisting of only open magnetic field lines and perform a similar analysis on this issue for totally 76 events by extending the study interval to the end of 2008. Three key parameters, CH proximity, CH area and CH relative position, are involved in the analysis. The new result confirms the previous conclusion that CHs did not show any evident effect on CMEs in causing SEP events.