Field-Aligned Currents and Magnetospheric Convection–A Comparison Between MHD Simulations and Observations

  1. T. E. Moore,
  2. J. H. Waite Jr.,
  3. T. W. Moorehead and
  4. W. B. Hanson
  1. Raymond J. Walker1 and
  2. Tatsuki Ogino2

Published Online: 18 MAR 2013

DOI: 10.1029/GM044p0039

Modeling Magnetospheric Plasma

Modeling Magnetospheric Plasma

How to Cite

Walker, R. J. and Ogino, T. (1988) Field-Aligned Currents and Magnetospheric Convection–A Comparison Between MHD Simulations and Observations, in Modeling Magnetospheric Plasma (eds T. E. Moore, J. H. Waite, T. W. Moorehead and W. B. Hanson), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM044p0039

Author Information

  1. 1

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

  2. 2

    Research Institute of Atmospherics, Nagoya University, Toyokawa, Japan

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1988

ISBN Information

Print ISBN: 9780875900704

Online ISBN: 9781118664414

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Keywords:

  • Space plasmas—Mathematical models;
  • Magnetosphere—Mathematical models;
  • Ionosphere—Mathematical models

Summary

Recently we have simulated the interaction between the solar wind and the earth's magnetosphere by using a time-dependent three-dimensional magnetohydrodynamic (MHD) model. We have used this model to investigate the magnetospheric configuration as a function of the interplanetary magnetic field (IMF) direction when it was in the y-z plane in geocentric solar magnetospheric coordinates. The model results show four types of convection cells. They are the large global convection cells, the tail lobe cells, the high-latitude polar cap cells, and the low-latitude cells. There are also four main field-aligned current systems: two systems at subpolar cap latitudes, the region 1 and 2 currents, and two current systems in the polar cap region, the tail region 1 currents and the polar cap currents. The polar cap currents evolve into the polar cusp currents when we rotate the IMF from northward to southward. The polar cap convection pattern and the distribution of field-aligned currents are determined by the location of magnetopause reconnection, which is determined by the IMF direction. Recent polar cap observations are consistent with the model results. For northward IMF, we have made direct comparisons between MAGSAT observations and the MHD simulation and found good agreement between the model current distributions and the observations. We also found good agreement between the current patterns from the simulation and polar cap currents observed on S3-2 for southward IMF. Finally we compared the polar cap convection patterns observed on Atmosphere Explorer C and Dynamics Explorer 2 for both northward and southward IMF with the model and again found reasonable agreement.