Radial Evolution of ICME-Associated Particle Acceleration Observed by Solar Orbiter and ACE

On 2022 March 10, a coronal mass ejection (CME) erupted from the Sun, resulting in Solar Orbiter observations at 0.45 au of both dispersive solar energetic particles arriving prior to the interplanetary CME (ICME) and locally accelerated particles near the ICME-associated shock structure as it passe...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2024-10
Main Authors: Walker, Malik H, Allen, Robert C, Li, Gang, Ho, George C, Mason, Glenn M, Rodriguez-Pacheco, Javier, Wimmer-Schweingruber, Robert F, Kouloumvakos, Athanasios
Format: Article
Language:English
Subjects:
Advanced Composition Explorer
Composition
Coronal mass ejection
Energetic particles
Particle acceleration
Radiation counters
Solar corona
Spacecraft
Spectra
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:On 2022 March 10, a coronal mass ejection (CME) erupted from the Sun, resulting in Solar Orbiter observations at 0.45 au of both dispersive solar energetic particles arriving prior to the interplanetary CME (ICME) and locally accelerated particles near the ICME-associated shock structure as it passed the spacecraft on 2022 March 11. This shock was later detected on 2022 March 14 by the Advanced Composition Explorer (ACE), which was radially aligned with Solar Orbiter, at 1 au. Ion composition data from both spacecraft -- via the Solar Orbiter Energetic Particle Detector/ Suprathermal Ion Spectrograph (EPD/SIS) and the Ultra Low Energy Isotope Spectrometer (ULEIS) on ACE -- allows for in-depth analysis of the radial evolution of species-dependent ICME shock-associated acceleration processes for this event. We present a study of the ion spectra observed at 0.45 and 1 au during both the gradual solar energetic particle (SEP) and energetic storm particle (ESP) phases of the event. We find that the shapes of the spectra seen at each spacecraft have significant differences that were likely caused by varying shock geometry: Solar Orbiter spectra tend to lack spectral breaks, and the higher energy portions of the ACE spectra have comparable average flux to the Solar Orbiter spectra. Through an analysis of rigidity effects on the spectral breaks observed by ACE, we conclude that the 1 au observations were largely influenced by a suprathermal pool of \(\mathrm{He}^{+}\) ions that were enhanced due to propagation along a stream interaction region (SIR) that was interacting with the ICME at times of observation.
ISSN:2331-8422