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Plasmoid formation and evolution in a numerical simulation of a substorm
Author(s) -
Slinker S. P.,
Fedder J. A.,
Lyon J. G.
Publication year - 1995
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 - 10.1029/95gl00300
Subject(s) - plasmoid , substorm , geophysics , magnetosphere , earth's magnetic field , magnetosheath , physics , solar wind , field line , interplanetary magnetic field , electric field , magnetohydrodynamics , geology , magnetic field , magnetic reconnection , magnetopause , quantum mechanics
Plasmoids are thought to occur as a consequence of the formation of a near‐Earth neutral line during the evolution of a geomagnetic substorm. Using a 3D, global MHD simulation of the interaction of the Earth's magnetosphere with the solar wind, we initiate a substorm by a southward turning of the Interplanetary Magnetic Field (IMF) after a long period of steady northward field. A large plasmoid is formed and ejected. We show field line maps of its shape and relate its formation time to the progress of the substorm as indicated by the cross polar potential. Because of the large region of closed field in the magnetotail at the time of the substorm, this plasmoid is longer in axial dimension than is typically observed. We compare the simulation results with the type of satellite observations which have been used to argue for the existence of plasmoids or of traveling compression regions (TCRs) in the lobes or magnetosheath. The simulation predicts that plasmoid passage would result in a strong signal in the cross tail electric field.