Magnetic structure of Coronal Mass Ejections

TL;DR

This paper models the magnetic structures of coronal mass ejections (CMEs), exploring force-free expansions, ionization changes, and stable magnetic cloud configurations to better understand their dynamics and internal processes.

Contribution

It introduces models of CME magnetic structures including force-free expansions, ionization effects from resistive dissipation, and stable magnetic cloud configurations without surface currents.

Findings

Expansion maintains force-free fields but causes complex internal velocities.

Resistive dissipation during expansion alters ion charge states.

Stable magnetic clouds can undergo reconnection upon expansion.

Abstract

We present several models of the magnetic structure of solar coronal mass ejections (CMEs). First, we model CMEs as expanding force-free magnetic structures. While keeping the internal magnetic field structure of the stationary solutions, expansion leads to complicated internal velocities and rotation, while the field structures remain force-free. Second, expansion of a CME can drive resistive dissipation within the CME changing the ionization states of different ions. We fit in situ measurements of ion charge states to the resistive spheromak solutions. Finally, we consider magnetic field structures of fully confined stable magnetic clouds containing both toroidal and poloidal magnetic fields and having no surface current sheets. Expansion of such clouds may lead to sudden onset of reconnection events.