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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Inner plasma structure of the low-latitude reconnection layer
AU - Zhang, Q. -H.
AU - Dunlop, M. W.
AU - Lockwood, M.
AU - Lavraud, B.
AU - Bogdanova, Y. V.
AU - Hasegawa, H.
AU - Yang, H-G.
AU - Liu, R. -Y.
AU - Hu, H. -Q.
AU - Zhang, B. -C.
AU - Pu, Z. -Y.
AU - Yang, Z. -W.
AU - Wang, J.
AU - Taylor, M. G. G. T.
AU - Berchem, J.
AU - Constantinescu, D.
AU - Volwerk, M.
AU - Frey, H.
AU - Fazakerley, A. N.
AU - Shen, C.
AU - Shi, J. -K.
AU - Sibeck, D.
AU - Escoubet, P.
AU - Wild, J. A.
PY - 2012/8/3
Y1 - 2012/8/3
N2 - 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 Alfven waves (or Rotational Discontinuities, RDsp and RDsh). 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.
AB - 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 Alfven waves (or Rotational Discontinuities, RDsp and RDsh). 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.
KW - magnetic reconnection
KW - THEMIS
U2 - 10.1029/2012JA017622
DO - 10.1029/2012JA017622
M3 - Journal article
VL - 117
SP - -
JO - Journal of Geophysical Research
JF - Journal of Geophysical Research
SN - 0148-0227
M1 - A08205
ER -