Detection of small-scale folds at a solar wind reconnection exhaust
File(s)
Author(s)
Mistry, R
Eastwood, JP
Hietala, H
Type
Journal Article
Abstract
Observations of reconnection in the solar wind over the last few years appear to indicate that the majority of large-scale reconnecting current sheets are roughly planar, and that reconnection itself is quasi-steady. Most studies of solar wind exhausts have used spacecraft with large separations and relatively low time cadence ion measurements. Here we present multipoint Cluster observations of a reconnection exhaust and the associated current sheet at ACE and Wind, enabling it to be studied on multiple length scales and at high time resolution. While analysis shows that on large scales the current sheet is planar, detailed measurements using the four closely spaced Cluster spacecraft show that the trailing edge of the reconnection jet is nonplanar with folds orthogonal to the reconnection plane, with length scales of approximately 230 ion inertial lengths. Our findings thus suggest that while solar wind current sheets undergoing reconnection may be planar on large scales, they may also exhibit complex smaller-scale structure. Such structure is difficult to observe and has rarely been detected because exhausts are rapidly convected past the spacecraft in a single cut; there is therefore a limited set of spacecraft trajectories through the exhaust which would allow the nonplanar features to be intercepted. We consider how such nonplanar reconnection current sheets can form and the processes which may have generated the 3-D structure that was observed.
Date Issued
2014-12-12
Date Acceptance
2014-12-09
Citation
Journal of Geophysical Research: Space Physics, 2014, 120 (1), pp.30-42
ISSN
2169-9402
Publisher
American Geophysical Union
Start Page
30
End Page
42
Journal / Book Title
Journal of Geophysical Research: Space Physics
Volume
120
Issue
1
Copyright Statement
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Sponsor
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Grant Number
ST/G00725X/1
ST/K001051/1
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
reconnection
solar wind
exhaust
nonplanar
X line
instability
MAGNETIC RECONNECTION
CURRENT SHEET
CLUSTER
PLASMA
FIELD
INSTABILITY
SPACECRAFT
DISCONTINUITIES
MAGNETOPAUSE
INSTRUMENT
Publication Status
Published