Mixed Source Region Signatures Inside Magnetic Switchback Patches Inferred by Heavy Ion Diagnostics

TL;DR

This study investigates the heavy ion properties of magnetic switchback patches near the Sun, finding no distinctive compositional signatures and suggesting their formation involves interchange reconnection or shear-driven processes.

Contribution

It provides new insights into the formation of magnetic switchback patches by analyzing heavy ion diagnostics and linking in-situ solar wind observations with coronal source regions.

Findings

Switchback patches lack unique heavy ion signatures compared to surrounding solar wind.

Both patches and ambient wind show a mix of fast and slow wind qualities.

Results suggest formation in coronal hole boundary wind involving interchange reconnection or shear processes.

Abstract

Since Parker Solar Probe's (Parker's) first perihelion pass at the Sun, large amplitude Alfv\'en waves grouped in patches have been observed near the Sun throughout the mission. Several formation processes for these magnetic switchback patches have been suggested with no definitive consensus. To provide insight to their formation, we examine the heavy ion properties of several adjacent magnetic switchback patches around Parker's 11th perihelion pass capitalizing on a spacecraft lineup with Solar Orbiter where each samples the same solar wind streams over a large range of longitudes. Heavy ion properties (Fe/O, C$^{6+}$/C$^{5+}$, O$^{7+}$/O$^{6+}$) related to the wind's coronal origin, measured with Solar Orbiter can be linked to switchback patch structures identified near the Sun with Parker. We find that switchback patches do not contain distinctive ion and elemental compositional signatures different than the surrounding non-switchback solar wind. Both the patches and ambient wind exhibit a range of fast and slow wind qualities, indicating coronal sources with open and closed field lines in close proximity. These observations and modeling indicate switchback patches form in coronal hole boundary wind and with a range of source region magnetic and thermal properties. Furthermore, the heavy ion signatures suggest interchange reconnection and/or shear driven processes may play a role in their creation.