The existence of viscosity, thermal conductivity, and electrical resistivity results in the dissipation of energy in MHD waves; the wave energy is consequently absorbed and the wave amplitude progressively attenuated. Dissipation mechanisms cause the amplitude of the waves to vary slowly over a large scale length L. When L is greater than the wavelength λ, WKB solutions can be obtained to compare the absorption rates for the three modes of MHD waves. Among the three dissipation mechanisms, thermal diffusion plays the dominant role, while electrical resistivity has negligible effects.
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