Waves

Waves in a medium are the direct result of periodic perturbations. The basic modes of waves are classified by their restoring forces, which in a non-viscous, perfectly conducting plasma are gravity, pressure, and magnetism. As well as acting individually, these may act in three sets of pairs or all at once. This section contains a brief summary of the general dispersion relation for each mode of wave, followed by a qualitative description of the multi-force modes. For a more detailed description the reader is referred to any MHD textbook (e.g., Priest 1982, Choudhuri 1998) or Stein & Leibacher (1974).