Global Simulation of Auroral Arcs

  1. S.-I. Akasofu and
  2. J.R. Kan
  1. Akira Miura1 and
  2. Tetsuya Sato2

Published Online: 26 MAR 2013

DOI: 10.1029/GM025p0321

Physics of Auroral Arc Formation

Physics of Auroral Arc Formation

How to Cite

Miura, A. and Sato, T. (1981) Global Simulation of Auroral Arcs, in Physics of Auroral Arc Formation (eds S.-I. Akasofu and J.R. Kan), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM025p0321

Author Information

  1. 1

    Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90024

  2. 2

    Institute for Fusion Theory, Hiroshima University, Hiroshima 730, Japan

Publication History

  1. Published Online: 26 MAR 2013
  2. Published Print: 1 JAN 1981

ISBN Information

Print ISBN: 9780875900506

Online ISBN: 9781118664360

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Keywords:

  • Auroras—Addresses, essays, lectures

Summary

Numerical simulation of global formation of auroral arcs is performed for a three-dimensional coupled ionosphere-magnetosphere system. Under the presence of the stationary convection electric field, the field-aligned current driven by the polarization and drift of the ionospheric conductivity enhancement is shown to be responsible for the feedback instability (Sato, 1978) of the shear Alfvén wave. The simulation result demonstrates the dynamic process of auroral arc formation, in which an ionospheric perturbation nearly resonant with the magnetospheric Alfvén wave (toroidal mode) can grow eventually into auroral arcs. Many of the important characteristics of quiet auroral arcs are demonstrated, and the overall distribution of auroras is shown to depend critically on the stationary state of the auroral oval characterized by the large-scale Birkeland current, the electric field, and the electron density distribution.