Relationship between EIT Post Eruption Arcades, Coronal Mass Ejections, Coronal Neutral Line and Magnetic Clouds

TL;DR

This study investigates the relationships between the orientations of coronal mass ejections, magnetic clouds, eruption arcades, and the coronal neutral line, revealing correlations that improve understanding of CME and magnetic cloud configurations.

Contribution

It provides new observational evidence linking CME, MC, arcade, and CNL orientations, highlighting the alignment patterns and possible axis rotations of ejecta.

Findings

Good correlation between EIT arcade axes and halo CME elongations.

Alignment of MC axes with the coronal neutral line.

Eruptions with aligned orientations tend to have CNL co-aligned with them.

Abstract

There is observational evidence that the elongation of an Earth directed coronal mass ejection (CME) may indicate the orientation of the underlying erupting flux rope. In this study, we compare orientations of CMEs, MCs, eruption arcades and coronal neutral line (CNL). We report on good correlations between i) the directions of the axial field in EIT arcades and the elongations of halo CMEs and ii) the tilt of the CNL and MC axis orientations. We found that majority of the eruptions that had EIT arcades, CMEs and MCs similarly oriented also had the CNL co-aligned with them. To the contrary, those events that showed no agreement between orientations of the EIT arcades, CMEs and MCs, had their MCs aligned with the coronal neutral line. We speculate that the axis of the ejecta may be rotated in such a way that it is locally aligns itself with the heliospheric current sheet.