Switchback-like structures observed by Solar Orbiter

Andrey Fedorov,Vincent Evans,Roberto Livi,Stuart Bale,Virginia Angelini,Alain Barthe,Timothy Horbury,Helen O’Brien,Alexis Rouillard,Roberto Bruno,Philippe Louarn,Lubomir Prech,Justin Kasper,Davin Larson,Swa-Pas, Mag, Sweap, And Fields Teams ,Christopher Owen

doi:10.5194/egusphere-egu21-4996

Abstract

&lt;p&gt;During 27th September 2020 NASA Parker Solar Probe (PSP) and ESA-NASA Solar Orbiter (SolO) have been located around the same Carrington longitude and their latitudinal separation was very small as well. Solar wind plasma and magnetic field data obtained throughout this time interval &amp;#160;allows to consider that sometimes the solar wind, observed by both spacecrafts, originates from the same coronal hole region. Inside these time intervals the SolO radial magnetic field experiences several short variations similar to the &quot;switchbacks&quot; regularly observed by PSP. We used the SolO SWA-PAS proton analyzer data to analyze the ion distribution function variations inside such switchback-like events to understand if such events are really &quot;remains&quot; of the alfvenic structures observed below 60 Rs.&lt;/p&gt;

Highlights

In 1995-1996, during the solar minimum, the Ulysses spacecraft, orbiting at high heliolatitudes, observed numerous radial magnetic field polarity inversions in the fast solar wind that is magnetically mapped to the polar coronal hole
On 27 September 2020, Solar Orbiter sampled a solar wind stream magnetically connected to a southern hemisphere coronal hole
The suprathermal electrons pitch angle distribution and α-particles’ relative speed variations indicate that the magnetic field line was locally folded by 180◦ as a result of velocity shear

Summary

Introduction

In 1995-1996, during the solar minimum, the Ulysses spacecraft, orbiting at high heliolatitudes, observed numerous radial magnetic field polarity inversions (see Balogh et al 1999) in the fast solar wind that is magnetically mapped to the polar coronal hole. The first orbit of NASA’s Parker Solar Probe (PSP) (Fox et al 2016), in November 2018, led to the discovery of a similar, but unexpected feature of the near-Sun solar wind: the presence of frequent and rapid polarity reversals of the radial magnetic field (Bale et al 2019). These reversals, called “switchbacks,” were accompanied by strong fluctuations of the solar wind velocity vector (Kasper et al 2019). The question of whether all such observations relate to the same phenomenon is still open

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Discussion

Conclusion