Solar Orbiter observations of an ion-scale flux rope confined to a bifurcated solar wind current sheet
File(s)Orbiter_Fluxrope_v11_final.pdf (1.69 MB)
Accepted version
Author(s)
Type
Journal Article
Abstract
Context. Flux ropes in the solar wind are a key element of heliospheric dynamics and particle acceleration. When associated with
current sheets, the primary formation mechanism is magnetic reconnection and flux ropes in current sheets are commonly used as
tracers of the reconnection process.
Aims. Whilst flux ropes associated with reconnecting current sheets in the solar wind have been reported, their occurrence, size
distribution, and lifetime are not well understood.
Methods. Here we present and analyse new Solar Orbiter magnetic field data reporting novel observations of a flux rope confined to
a bifurcated current sheet in the solar wind. Comparative data and large-scale context is provided by Wind.
Results. The Solar Orbiter observations reveal that the flux rope, which does not span the current sheet, is of ion scale, and in a
reconnection formation scenario, existed for a prolonged period of time as it was carried out in the reconnection exhaust. Wind is also
found to have observed clear signatures of reconnection at what may be the same current sheet, thus demonstrating that reconnection
signatures can be found separated by as much as ∼ 2 000 Earth radii, or 0.08 au.
Conclusions. The Solar Orbiter observations provide new insight into the hierarchy of scales on which flux ropes can form, and show
that they exist down to the ion scale in the solar wind. The context provided by Wind extends the spatial scale over which reconnection
signatures have been found at solar wind current sheets. The data suggest the local orientations of the current sheet at Solar Orbiter
and Wind are rotated relative to each other, unlike reconnection observed at smaller separations; the implications of this are discussed
with reference to patchy vs. continuous reconnection scenarios.
current sheets, the primary formation mechanism is magnetic reconnection and flux ropes in current sheets are commonly used as
tracers of the reconnection process.
Aims. Whilst flux ropes associated with reconnecting current sheets in the solar wind have been reported, their occurrence, size
distribution, and lifetime are not well understood.
Methods. Here we present and analyse new Solar Orbiter magnetic field data reporting novel observations of a flux rope confined to
a bifurcated current sheet in the solar wind. Comparative data and large-scale context is provided by Wind.
Results. The Solar Orbiter observations reveal that the flux rope, which does not span the current sheet, is of ion scale, and in a
reconnection formation scenario, existed for a prolonged period of time as it was carried out in the reconnection exhaust. Wind is also
found to have observed clear signatures of reconnection at what may be the same current sheet, thus demonstrating that reconnection
signatures can be found separated by as much as ∼ 2 000 Earth radii, or 0.08 au.
Conclusions. The Solar Orbiter observations provide new insight into the hierarchy of scales on which flux ropes can form, and show
that they exist down to the ion scale in the solar wind. The context provided by Wind extends the spatial scale over which reconnection
signatures have been found at solar wind current sheets. The data suggest the local orientations of the current sheet at Solar Orbiter
and Wind are rotated relative to each other, unlike reconnection observed at smaller separations; the implications of this are discussed
with reference to patchy vs. continuous reconnection scenarios.
Date Issued
2021-12-14
Date Acceptance
2021-08-18
Citation
Astronomy & Astrophysics, 2021, 656 (A27), pp.1-8
ISSN
0004-6361
Publisher
EDP Sciences
Start Page
1
End Page
8
Journal / Book Title
Astronomy & Astrophysics
Volume
656
Issue
A27
Copyright Statement
© ESO 2021.
Sponsor
Science and Technology Facilities Council (STFC)
Identifier
https://www.aanda.org/component/article?access=doi&doi=10.1051/0004-6361/202140949
Grant Number
ST/N000692/1
Subjects
Astronomy & Astrophysics
0201 Astronomical and Space Sciences
Publication Status
Published
Date Publish Online
2021-08-20