Observation of Magnetic Switchback in the Solar Corona

TL;DR

This paper reports the first observation of a magnetic switchback in the solar corona, providing evidence that interchange reconnection may be its origin and linking it to the source of slow solar wind.

Contribution

It presents the first direct observation of a solar corona switchback and supports interchange reconnection as its formation mechanism.

Findings

First evidence of a switchback in the solar corona

Supports interchange reconnection as the origin

Suggests switchbacks indicate slow solar wind source

Abstract

Switchbacks are sudden, large radial deflections of the solar wind magnetic field, widely revealed in interplanetary space by the Parker Solar Probe. The switchbacks' formation mechanism and sources are still unresolved, although candidate mechanisms include Alfv\'enic turbulence, shear-driven Kelvin-Helmholtz instabilities, interchange reconnection, and geometrical effects related to the Parker spiral. This Letter presents observations from the Metis coronagraph onboard Solar Orbiter of a single large propagating S-shaped vortex, interpreted as first evidence of a switchback in the solar corona. It originated above an active region with the related loop system bounded by open-field regions to the East and West. Observations, modeling, and theory provide strong arguments in favor of the interchange reconnection origin of switchbacks. Metis measurements suggest that the initiation of the switchback may also be an indicator of the origin of slow solar wind.