Electric and magnetic spectra from MHD to electron scales in the magnetosheath
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Published version
Author(s)
Matteini, L
Alexandrova, O
Chen, CHK
Lacombe, C
Type
Journal Article
Abstract
We investigate the transition of the turbulence from large to kinetic scales using Cluster observations. Simultaneous spectra of magnetic and electric fields in the Earth's magnetosheath from magnetohydrodynamic (MHD) to electron scales are presented for the first time. While the two spectra have approximatively similar behaviour in the fluid-MHD regime, they show different trends in the kinetic range. As the magnetic field spectrum steepens at ion scales, the electric field spectrum is characterized by a shallower power law continuing down to electron scales. Such an evolution is consistent with theoretical expectations, assuming that the turbulence is dominated by highly oblique k-vectors and that between ion and electron scales the electric field is governed by the non-ideal terms in the generalized Ohm's law. This leads to an expected linear increase of the electric-to-magnetic ratio of fluctuations, consistent with observations presented here. The influence of local whistler wave activity on electron-scale spectra is also discussed.
Date Issued
2017-04-01
Date Acceptance
2016-12-02
Citation
Monthly Notices of the Royal Astronomical Society, 2017, 466 (1), pp.945-951
ISSN
0035-8711
Publisher
Oxford University Press
Start Page
945
End Page
951
Journal / Book Title
Monthly Notices of the Royal Astronomical Society
Volume
466
Issue
1
Copyright Statement
© 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Sponsor
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Grant Number
ST/N003748/1
ST/N000692/1
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
magnetic fields
MHD
plasmas
turbulence
solar wind
SOLAR-WIND TURBULENCE
RESOLUTION HYBRID SIMULATIONS
CLUSTER OBSERVATIONS
FIELD FLUCTUATIONS
PLASMA TURBULENCE
KINETIC SCALES
PROTON SCALES
ANISOTROPY
INSTABILITIES
DEPENDENCE
Astronomy & Astrophysics
0201 Astronomical and Space Sciences
Publication Status
Published
Date Publish Online
2016-12-09