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  • E-Letter
  • Open Access

Effects of ionospheric damping on MHD wave mode structure

Earth, Planets and Space201456:BF03352541

  • Received: 19 June 2004
  • Accepted: 21 October 2004
  • Published:


We calculate the mode structure of magnetospheric MHD waves on a meridional plane. We have added the effect of ionospheric dissipation to the three-dimensional dipole field MHD model of Lee and Lysak (1999); this model allows a realistic Alfven speed profile for the plasmasphere and realistic boundary conditions at the outer boundaries that vary with respect to local time. Using power spectra and plots of spatial mode structure, we show that the two-dimensional transverse modes on the dipolar meridian are strongly affected by ionospheric damping, but the compressional modes are not. The location of field line resonances spreads wide as the damping increases, but the compressional mode structure remains stable.

Key words

  • MHD waves
  • magnetosphere
  • ionosphere
  • field line resonance