Observation of Magnetic Switchback in the Solar Corona

Daniele Telloni, Gary P. Zank, Marco Stangalini, Cooper Downs, Haoming Liang, Masaru Nakanotani, Vincenzo Andretta, Ester Antonucci, Luca Sorriso-Valvo, Laxman Adhikari, Lingling Zhao, Raffaele Marino, Roberto Susino, Catia Grimani, Raffaella D'Amicis, Denise Perrone, Roberto Bruno, Francesco Carbone, Salvatore Mancuso, Marco Romoli, Vania Da Deppo, Silvano Fineschi, Petr Heinzel, John D. Moses, Giampiero Naletto, Gianalfredo Nicolini, Daniele Spadaro, Luca Teriaca, David Berghmans, Frédéric Auchère, Regina Aznar Cuadrado, Lakshmi P. Chitta, Louise Harra, Emil Kraaikamp, David M. Long, Sudip Mandal, Susanna Parenti, Gabriel Pelouze, Hardi Peter, Luciano Rodriguez, Udo Schühle, Conrad Schwanitz, Phil J. Smith, Cis Verbeeck, Andrei N. Zhukov

Published 2022-06-07Version 1

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.