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Nonideal Electric Field Observed in the Separatrix Region of a Magnetotail Reconnection Event
Author(s) -
Yu Xiancai,
Wang Rongsheng,
Lu Quanming,
Russell Christopher T.,
Wang Shui
Publication year - 2019
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 - 10.1029/2019gl082538
Subject(s) - physics , magnetic reconnection , electron , electric field , separatrix , magnetic field , current sheet , instability , diffusion , geophysics , dissipation , atomic physics , computational physics , magnetohydrodynamics , mechanics , quantum mechanics
Based on the Magnetospheric Multiscale observations in the magnetotail, we present a complete crossing of the current sheet with ongoing magnetic reconnection. The field‐aligned inflowing electrons were observed in both separatrix regions (SRs) and their energy extended up to several times of the thermal energy. Along the SR, a net parallel electrostatic potential was estimated and could be the reason for the inflowing electron streaming. In the northern SR, the electron frozen‐in condition was violated and nonideal electric field was inferred to be caused by the gradient of the electron pressure tensor. The nongyrotropic electron distribution and significant energy dissipation were observed at the same region. The observations indicate that the inner electron diffusion region can extend along the separatrices or some electron‐scale instability can be destabilized in the SR.