- Open Access
Effects of ionospheric damping on MHD wave mode structure
Earth, Planets and Space volume 56, pages e33–e36 (2004)
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.
Allan, W., Phase variation of ULF pulsations along a geomagnetic field line, Planet. Space Sci., 30, 339, 1982.
Allan, W. and F. B. Knox, The effects of finite ionospheric conductivities on axisymmetric toroidal Alfven waves resonances, Planet. Space Sci., 27, 939, 1979.
Baransky, L. N., J. E. Borovkov, M. B. Gokhberg, S. M. Krylov, and V. A. Troitskaya, High resolution method of direct measurement of the magnetic field lines’ eigenfrequencies, Planet. Space Sci., 33, 1369, 1985.
Budnik, F., M. Stellmacher, K.-H. Glassmeier, and S. C. Buchert, Ionospheric conductance distribution and MHD wave structure: Observation and model, Ann. Geophysicae, 16, 140, 1998.
Chappell, C. R., The terrestrial plasma source: A new perspective in solar-terrestrial processes from Dynamics Explorer, Rev. Geophys., 26, 229, 1988.
Chi, P. J. and Russell, An interpretation of the cross-phase spectrum of geomagnetic pulsations by the field line resonance theory, Geophys. Res. Lett., 25, 4445, 1998.
Denton, R. E., M. R. Lessard, R. Anderson, E. G. Miftakhova, and J. W. Hughes, Determining the mass density along magnetic field lines from toroidal eigenfrequencies: Polynomial expansion applied to CRRES data, J. Geophys. Res., 106, 29,915, 2001.
Ellis, P. and D. J. Southwood, Reflection of Alfven waves by nonuniform ionospheres, Planet. Space Sci., 31, 10,717, 1983.
Fujita, S., T. Mizuta, M. Itonaga, A. Yoshikawa, and H. Nakata, Propagation property of transient MHD impulses in the magnetosphere-ionosphere system: The 2D model of the Pi2 pulsation, Geophys. Res. Lett., 28, 2161, 2001.
Hughes, J.W. and D. J. Southwood, The screening of micropulsation signals by the atmosphere and ionosphere, J. Geophys. Res., 81, 3234, 1976.
Lee, D. H. and K. Kim, Compressional MHD waves in the magnetosphere: A new approach, J. Geophys. Res., 104, 12,379, 1999.
Lee, D. H. and R. L. Lysak, Magnetospheric ULF wave coupling in the dipole model: The impulsive excitation, J. Geophys. Res., 94, 17,097, 1989.
Lee, D. H. and Lysak, MHD waves in a three-dimensional dipolar magnetic field: A search for Pi2 pulsations, J. Geophys. Res., 104, 28,691, 1999.
Newton, R. S., D. J. Southwood, and W. Hughes, Damping of geomagnetic pulsations by the ionosphere, Planet. Space Sci., 26, 201, 1978.
Osaki, H., K. Takahashi, H. Fukunishi, T. Nagatsuma, Oya, A. Matsuoka, and D. K. Milling, Pi2 pulsations observed from the Akebono satellite in the plasmasphere, J. Geophys. Res., 103, 17,605–17,615, 1998.
Southwood, D. J. and M. G. Kivelson, Damping standing Alfve’n waves in the magnetosphere, J. Geophys. Res., 106, 10,829, 2001.
Sutcliffe, P. R. and K. Yumoto, On the cavity mode nature of low-latitude Pi 2 pulsations, J. Geophys. Res., 96, 1543, 1991.
Takahashi, K., Ohtani, and B. J. Anderson, Statistical analysis of Pi 2 pulsations observed by the AMPTE CCE spacecraft in the inner magnetosphere, J. Geophys. Res., 100, 21,929, 1995.
Takahashi K., D.-H. Lee, M. Nose’, Anderson, and W. J. Hughes, CRRES electric field study of the radial mode structure of Pi2 pulsations, J. Geophys. Res., 108, 1210, doi:10.1029/2002JA009761, 2003.
Waters, C. L., F. W. Menk, and B. J. Fraser, Low latitude geomagnetic field line resonance: Experiment and modeling, J. Geophys. Res., 99, 17,547, 1995.
Yeoman, T. K. and D. Orr, Phase and spectral power of mid-latitude Pi 2 pulsations: Evidence for a plasmaspheric cavity resonance, Planet. Space Sci., 37, 1367, 1989.
Yoshikawa, A., M. Itonaga, S. Fujita, H. Nakata, and K. Yumoto, Eigenmode analysis of field line oscillations interacting with the ionosphere-atmosphere-solid earth electromagnetic coupled system, J. Geophys. Res., 104, 28,437, 10.1029/1999JA900287, 1999.
About this article
Cite this article
Lee, D.H., Kim, K.H., Denton, R.E. et al. Effects of ionospheric damping on MHD wave mode structure. Earth Planet Sp 56, e33–e36 (2004). https://doi.org/10.1186/BF03352541
- MHD waves
- field line resonance