Rights statement: Copyright 2008 by the American Geophysical Union.
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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 - Near-Earth substorm features from multiple satellite observations
AU - Lui, A. T. Y.
AU - Volwerk, M.
AU - Dunlop, M. W.
AU - Alexeev, I. V.
AU - Fazakerley, A. N.
AU - Walsh, A. P.
AU - Lester, M.
AU - Grocott, A.
AU - Mouikis, C.
AU - Henderson, M. G.
AU - Kistler, L. M.
AU - Shen, C.
AU - Shi, J. K.
AU - Zhang, T. L.
AU - Rème, H.
N1 - Copyright 2008 by the American Geophysical Union.
PY - 2008/7
Y1 - 2008/7
N2 - We investigate a substorm on 3 October 2004 during which 11 satellites were located in near-Earth magnetotail (XGSM > −10 RE). Double Star 1 (TC-1), Cluster, and LANL-97 satellites were closely aligned in the dawn-dusk direction (<1 RE apart) for this conjunction. After substorm expansion onset, TC-1 observed plasma sheet thinning at X ≈ −5.5 RE and later detected signature of plasma flow shear that may be associated with an auroral arc. Analysis of the dawn-dusk magnetic perturbations from GOES-10 and Polar suggests that these could be caused by a substorm current system consisting of not only the azimuthal closure of field-aligned currents (the substorm current wedge) but also the meridional closure of field-aligned currents. The temporal sequence of substorm activity (particle injection, current disruption, and dipolarization) revealed by these satellites indicates that the substorm expansion activity was initiated close to the Earth and spread later to further downstream distances. Furthermore, TC-1 and Cluster data show that there is no close relationship between some dipolarizations and Earthward plasma flows in the near-Earth region. The overall development of substorm activity is in agreement with the near-Earth initiation model for substorms. A temporal evolution of the magnetic field reconfiguration and plasma boundary motion during this substorm is constructed from these observations.
AB - We investigate a substorm on 3 October 2004 during which 11 satellites were located in near-Earth magnetotail (XGSM > −10 RE). Double Star 1 (TC-1), Cluster, and LANL-97 satellites were closely aligned in the dawn-dusk direction (<1 RE apart) for this conjunction. After substorm expansion onset, TC-1 observed plasma sheet thinning at X ≈ −5.5 RE and later detected signature of plasma flow shear that may be associated with an auroral arc. Analysis of the dawn-dusk magnetic perturbations from GOES-10 and Polar suggests that these could be caused by a substorm current system consisting of not only the azimuthal closure of field-aligned currents (the substorm current wedge) but also the meridional closure of field-aligned currents. The temporal sequence of substorm activity (particle injection, current disruption, and dipolarization) revealed by these satellites indicates that the substorm expansion activity was initiated close to the Earth and spread later to further downstream distances. Furthermore, TC-1 and Cluster data show that there is no close relationship between some dipolarizations and Earthward plasma flows in the near-Earth region. The overall development of substorm activity is in agreement with the near-Earth initiation model for substorms. A temporal evolution of the magnetic field reconfiguration and plasma boundary motion during this substorm is constructed from these observations.
KW - substorm
KW - near-Earth magnetotail
KW - current disruption
U2 - 10.1029/2007JA012738
DO - 10.1029/2007JA012738
M3 - Journal article
VL - 113
JO - Journal of Geophysical Research
JF - Journal of Geophysical Research
SN - 0148-0227
IS - A7
M1 - A07S26
ER -