English

A Catalog of Automatically Identified Multi-Signature ICMEs Observed by Solar Orbiter

Solar and Stellar Astrophysics 2026-07-05 v1

Abstract

In this study, we present a catalog of 138 interplanetary coronal mass ejections (ICMEs) identified using multiple distance-normalized ICME criteria within sliding time windows applied to \textit{Solar Orbiter} in-situ measurements. We observe sub-adiabatic proton cooling, a near-spherical radial density decrease, a steep decline in dynamic pressure indicative of enhanced expansion in the inner heliosphere, and a magnetic-field profile shallower than Parker-spiral expectations. Approximately 55%55\% of the ICMEs are associated with a preceding shock and sheath, while 45%45\% are not. Compared with non-sheath ICMEs, sheath-associated events are 27%\approx27\% longer, 68%\approx68\% more magnetized, 30%\approx30\% faster, 2.6\approx2.6 times hotter, 34%\approx34\% denser, and 2.8\approx2.8 times more over-pressured, while expanding 96%\approx96\% faster and maintaining low plasma β\beta. Expansion speed also scales strongly with ICME size and bulk speed, suggesting that sheath dynamics regulate ejecta expansion. For the 32 ICMEs with Heavy Ion Sensor (HIS) observations, 30%\approx30\% exhibit O7+/O6+1\mathrm{O}^{7+}/\mathrm{O}^{6+}\approx1, whereas Fe-based composition signatures (QFe\langle Q_{\mathrm{Fe}}\rangle, Fe16+/Fe\mathrm{Fe}^{\ge16+}/\mathrm{Fe}, and Fe/O\mathrm{Fe}/\mathrm{O}) identify 50\approx50--65%65\% of events, consistent with lower charge-state enhancements during solar minimum. Superposed epoch analysis reveals enhanced heavy-ion signatures within magnetic-cloud intervals, linking in-situ composition to coronal heating. This catalog provides a robust benchmark for multi-mission studies, machine-learning applications, CME evolution models, and space-weather investigations.

Keywords

Cite

@article{arxiv.2607.04402,
  title  = {A Catalog of Automatically Identified Multi-Signature ICMEs Observed by Solar Orbiter},
  author = {Felix N. Minta and Stefano A. Livi and George C. Ho and Susan T. Lepri and Heather A. Elliott},
  journal= {arXiv preprint arXiv:2607.04402},
  year   = {2026}
}