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Intense Electric Fields and Electron‐Scale Substructure Within Magnetotail Flux Ropes as Revealed by the Magnetospheric Multiscale Mission
Author(s) -
Stawarz J. E.,
Eastwood J. P.,
Genestreti K. J.,
Nakamura R.,
Ergun R. E.,
Burgess D.,
Burch J. L.,
Fuselier S. A.,
Gershman D. J.,
Giles B. L.,
Le Contel O.,
Lindqvist P.A.,
Russell C. T.,
Torbert R. B.
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl079095
Subject(s) - physics , magnetic reconnection , vortex , electron , magnetic flux , electric field , magnetic field , flux (metallurgy) , particle acceleration , computational physics , geophysics , mechanics , nuclear physics , materials science , quantum mechanics , metallurgy
Three flux ropes associated with near‐Earth magnetotail reconnection are analyzed using Magnetospheric Multiscale observations. The flux ropes are Earthward propagating with sizes from ∼3 to 11 ion inertial lengths. Significantly different axial orientations are observed, suggesting spatiotemporal variability in the reconnection and/or flux rope dynamics. An electron‐scale vortex, associated with one of the most intense electric fields ( E ) in the event, is observed within one of the flux ropes. This E is predominantly perpendicular to the magnetic field ( B ); the electron vortex is frozen‐in with E × B drifting electrons carrying perpendicular current and causing a small‐scale magnetic enhancement. The vortex is ∼16 electron gyroradii in size perpendicular to B and potentially elongated parallel to B . The need to decouple the frozen‐in vortical motion from the surrounding plasma implies a parallel E at the structure's ends. The formation of frozen‐in electron vortices within reconnection‐generated flux ropes may have implications for particle acceleration.