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Title: Vortices at the magnetic equator generated by hybrid Alfvén resonant waves

We performed three-dimensional magnetohydrodynamic simulations of shear Alfvén waves in a full field line system with magnetosphere-ionosphere coupling and plasma non-uniformities. Feedback instability of the Alfvén resonant modes showed various nonlinear features under the field line cavities: (i) a secondary flow shear instability occurs at the magnetic equator, (ii) trapping of the ionospheric Alfvén resonant modes facilitates deformation of field-aligned current structures, and (iii) hybrid Alfvén resonant modes grow to cause vortices and magnetic oscillations around the magnetic equator. Essential features in the initial brightening of auroral arc at substorm onsets could be explained by the dynamics of Alfvén resonant modes, which are the nature of the field line system responding to a background rapid change.
Authors:
 [1]
  1. National Institute of Polar Research, Midori-cho 10-3, Tachikawa, Tokyo 190-8518 (Japan)
Publication Date:
OSTI Identifier:
22408009
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 1; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ALFVEN WAVES; COMPUTERIZED SIMULATION; DEFORMATION; EARTH MAGNETOSPHERE; EQUATOR; IONOSPHERE; MAGNETIC FIELDS; MAGNETOHYDRODYNAMICS; NONLINEAR PROBLEMS; OSCILLATIONS; PLASMA; RESONANCE; SHEAR; THREE-DIMENSIONAL CALCULATIONS; VORTICES