The Magnetic Mirror Force in Plasma Fluid Models

  1. T. E. Moore,
  2. J. H. Waite Jr.,
  3. T. W. Moorehead and
  4. W. B. Hanson
  1. R. H. Comfort

Published Online: 18 MAR 2013

DOI: 10.1029/GM044p0051

Modeling Magnetospheric Plasma

Modeling Magnetospheric Plasma

How to Cite

Comfort, R. H. (1988) The Magnetic Mirror Force in Plasma Fluid Models, 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/GM044p0051

Author Information

  1. Physics Department, The University of Alabama in Huntsville, Huntsville, Alabama 35899

Publication History

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

ISBN Information

Print ISBN: 9780875900704

Online ISBN: 9781118664414



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


In the past decade, there have been several attempts to include the magnetic mirror force in the equation of motion for a plasma in a fluid formalism. In the process, some confusion has been evident regarding when and how this should be done. This problem has been addressed in the literature, but these treatments appear to have been forgotten or misunderstood. Here we summarize the mathematical arguments so that the physical consequences are readily perceived. It is shown that for an isotropic plasma fluid, in the direction parallel or anti--parallel to a magnetic field, the forces associated with a diverging magnetic field cancel out. Only for anisotropies in the fluid properties does the diverging field influence the plasma dynamics.