Thin current sheet behind the dipolarization front
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Accepted version
Author(s)
Type
Journal Article
Abstract
We report a unique conjugate observation of fast flows and associated current sheet disturbances in the near-Earth magnetotail by MMS (Magnetospheric Multiscale) and Cluster preceding a positive bay onset of a small substorm at ∼14:10 UT, September 8, 2018. MMS and Cluster were located both at X ∼ −14 RE. A dipolarization front (DF) of a localized fast flow was detected by Cluster and MMS, separated in the dawn-dusk direction by ∼4 RE, almost simultaneously. Adiabatic electron acceleration signatures revealed from the comparison of the energy spectra confirm that both spacecraft encounter the same DF. We analyzed the change in the current sheet structure based on multi-scale multi-point data analysis. The current sheet thickened during the passage of DF, yet, temporally thinned subsequently associated with another flow enhancement centered more on the dawnward side of the initial flow. MMS and Cluster observed intense perpendicular and parallel current in the off-equatorial region mainly during this interval of the current sheet thinning. Maximum field-aligned currents both at MMS and Cluster are directed tailward. Detailed analysis of MMS data showed that the intense field-aligned currents consisted of multiple small-scale intense current layers accompanied by enhanced Hall-currents in the dawn-dusk flow-shear region. We suggest that the current sheet thinning is related to the flow bouncing process and/or to the expansion/activation of reconnection. Based on these mesoscale and small-scale multipoint observations, 3D evolution of the flow and current-sheet disturbances was inferred preceding the development of a substorm current wedge.
Date Issued
2021-10-20
Date Acceptance
2021-10-01
Citation
JGR: Space Physics, 2021, 126 (10), pp.1-19
ISSN
2169-9402
Publisher
American Geophysical Union
Start Page
1
End Page
19
Journal / Book Title
JGR: Space Physics
Volume
126
Issue
10
Copyright Statement
Copyright © 2023 The author(s) This is the peer reviewed version of the following article:Nakamura, R., Baumjohann, W., Nakamura, T. K. M., Panov, E. V., Schmid, D., Varsani, A., et al. (2021). Thin current sheet behind the dipolarization front. Journal of Geophysical Research: Space Physics, 126, e2021JA029518. https://doi.org/10.1029/2021JA029518. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.
Identifier
https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000711498900044&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Astronomy & Astrophysics
bursty bulk flow
Cluster
current sheet
dipolarization front
DRIVEN
ELECTRIC-FIELD
electron acceleration
FLOW-BRAKING
KINETIC BALLOONING/INTERCHANGE INSTABILITY
MAGNETOSPHERE
MAGNETOTAIL
MMS
MODEL
Physical Sciences
RECONNECTION
Science & Technology
Publication Status
Published
Article Number
ARTN e2021JA029518
Date Publish Online
2021-10-11