Multi Eruption Solar Energetic Particle Events Observed with SOHO/ERNE

TL;DR

This study analyzes 333 solar energetic particle events observed by SOHO/ERNE, revealing that most are associated with multiple eruptions, and demonstrates methods to disentangle their effects using energy range, isotope ratios, and anisotropy.

Contribution

It introduces the concept of Multi Eruption SEP events and shows how to identify individual eruptions' effects despite masking in intensity-time profiles.

Findings

Most SEP events involve multiple eruptions.

Multi eruption phenomena can be distinguished using energy range, $^4He/P$ ratio, and anisotropy.

Methods to recover the effects of individual eruptions are proposed.

Abstract

A combination of many Solar energetic particle (SEP) events, each one of which is associated with a single eruption, can create one complex intensity-time profile, that will result in masking the observation of the first injected particles detected near Earth for each participated eruption. We defined such SEP events as Multi Eruption Solar Energetic Particle (MESEP) events. We have investigated the intensity-time profile of 333 solar energetic particle events during the operation time of SOHO mission and studied the associative solar eruptions (CMEs and solar flare) from the starting time of each event till the end. We found that most of the events have multi eruption phenomena which might or might not affect the intensity-time profile. We found that it is possible to know the real effect of some of the eruptions during the whole duration of the event, even if their effect as masked by the first eruption, by studying the widest possible energy range, the $^4He/P$ ratio and the anisotropy.