MMS observations of electron-scale filamentary currents in the reconnection exhaust and near the X line
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
We report Magnetospheric Multiscale observations of macroscopic and electron-scale current layers in asymmetric reconnection. By intercomparing plasma, magnetic, and electric field data at multiple crossings of a reconnecting magnetopause on 22 October 2015, when the average interspacecraft separation was ~10km, we demonstrate that the ion and electron moments are sufficiently accurate to provide reliable current density measurements at 30ms cadence. These measurements, which resolve current layers narrower than the interspacecraft separation, reveal electron-scale filamentary Hall currents and electron vorticity within the reconnection exhaust far downstream of the X line and even in the magnetosheath. Slightly downstream of the X line, intense (up to 3μA/m2) electron currents, a super-Alfvénic outflowing electron jet, and nongyrotropic crescent shape electron distributions were observed deep inside the ion-scale magnetopause current sheet and embedded in the ion diffusion region. These characteristics are similar to those attributed to the electron dissipation/diffusion region around the X line.
Date Issued
2016-06-05
Date Acceptance
2016-06-03
Citation
Geophysical Research Letters, 2016, 43 (12), pp.6060-6069
ISSN
0094-8276
Publisher
American Geophysical Union
Start Page
6060
End Page
6069
Journal / Book Title
Geophysical Research Letters
Volume
43
Issue
12
Copyright Statement
© 2016 American Geophysical Union. All Rights Reserved.
Sponsor
Science and Technology Facilities Council (STFC)
Grant Number
ST/K001051/1
Subjects
Meteorology & Atmospheric Sciences
MD Multidisciplinary
Publication Status
Published