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RCM‐E simulation of substorm growth phase arc associated with large‐scale adiabatic convection
Author(s) -
Yang Jian,
Wolf Richard A.,
Toffoletto Frank R.,
Sazykin Stanislav
Publication year - 2013
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 - 10.1002/2013gl058253
Subject(s) - substorm , arc (geometry) , convection , breakup , adiabatic process , geophysics , geology , phase (matter) , magnetic field , physics , mechanics , geometry , thermodynamics , mathematics , magnetosphere , quantum mechanics
Substorm auroral breakup often occurs on a longitudinally elongated arc at the end of a growth phase. We present an idealized high‐resolution simulation with the Rice Convection Model‐Equilibrium (RCM‐E) to investigate how large‐scale adiabatic convection under equilibrium conditions can give rise to an auroral arc. We find that a thin arc that maps to the magnetic transition region at r ~ 8 R E emerges in the late growth phase. The simulation implies that the arc in the premidnight sector is associated with a sheet of additional region 1 sense field‐aligned current (FAC) just poleward of the main region 2 FAC, while the arc in the postmidnight sector is associated with the poleward portion of the main upward region 2 FAC. Explanations for the location and the thickness of the arc are proposed, based on the simulation.