
Inner plasma structure of the low‐latitude reconnection layer
Author(s) -
Zhang Q.H.,
Dunlop M. W.,
Lockwood M.,
Lavraud B.,
Bogdanova Y. V.,
Hasegawa H.,
Yang H.G.,
Liu R.Y.,
Hu H.Q.,
Zhang B.C.,
Pu Z.Y.,
Yang Z.W.,
Wang J.,
Taylor M. G. G. T.,
Berchem J.,
Constantinescu D.,
Volwerk M.,
Frey H.,
Fazakerley A. N.,
Shen C.,
Shi J.K.,
Sibeck D.,
Escoubet P.,
Wild J. A.
Publication year - 2012
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2012ja017622
Subject(s) - magnetosheath , magnetopause , magnetic reconnection , physics , magnetosphere , geophysics , current sheet , plasma sheet , interplanetary magnetic field , solar wind , field line , computational physics , plasma , magnetohydrodynamics , quantum mechanics
We report a clear transition through a reconnection layer at the low‐latitude magnetopause which shows a complete traversal across all reconnected field lines during northwestward interplanetary magnetic field (IMF) conditions. The associated plasma populations confirm details of the electron and ion mixing and the time history and acceleration through the current layer. This case has low magnetic shear with a strong guide field and the reconnection layer contains a single density depletion layer on the magnetosheath side which we suggest results from nearly field‐aligned magnetosheath flows. Within the reconnection boundary layer, there are two plasma boundaries, close to the inferred separatrices on the magnetosphere and magnetosheath sides (S sp and S sh ) and two boundaries associated with the Alfvén waves (or Rotational Discontinuities, RD sp and RD sh ). The data are consistent with these being launched from the reconnection site and the plasma distributions are well ordered and suggestive of the time elapsed since reconnection of the field lines observed. In each sub‐layer between the boundaries the plasma distribution is different and is centered around the current sheet, responsible for magnetosheath acceleration. We show evidence for a velocity dispersion effect in the electron anisotropy that is consistent with the time elapsed since reconnection. In addition, new evidence is presented for the occurrence of partial reflection of magnetosheath electrons at the magnetopause current layer.