Abstract
A critical analysis of existing theories of the magnetospheric resonator for fast magnetosonic waves is performed. A new variant of the theory is suggested, according to which the near-Earth part of the plasma sheet plays the role of the resonator. It is shown that the magnetosonic wave is locked inside this region over its entire boundaries. The eigen frequencies of resonator modes are in a good agreement with observed values (0.8, 1.3, 1.9, 2.6, 3.4, ... MHz), both when estimated in the order of magnitude and when calculated exactly in the context of a simple model.
Similar content being viewed by others
References
McClay, J.F., On Resonant Modes of a Cavity and the Dynamical Properties of Micropulsations, Planet. Space Sci., 1970, vol. 18, pp. 1673–1682.
Southwood, D.J.. and Kivelson, M.G., The Effect of Parallel Inhomogeneity of Magnetospheric Hydromagnetic Wave Coupling, J. Geophys. Res., 1986, vol. 91, pp. 6871–6877.
Kivelson, M.G.. and Southwood, D.J., Coupling of Global Magnetospheric MHD Eigenmodes to Field Line Resonances, J. Geophys. Res., 1986, vol. 91, pp. 4345–4351.
Ruohoniemi, J.M., Greenwald, R.A., and Baker, K.B., HF Radar Observations of Pc5 Field Line Resonances in the Midnight/Early Morning MLT Sector, J. Geophys. Res., 1991, vol. 96, pp. 15697–1571.
Samson, J.C. and Harrold, B.G., Field Line Resonances Associated with Waveguides in the Magnetosphere, Geophys. Res. Lett., 1992, vol. 19, pp. 441–444.
Mathie, R.A., Menk, F.W., Mann, I.R., and Orr, D., Discrete Field Line Resonances and the Alfven Continuum in the Outer Magnetosphere, Geophys. Res. Lett., 1999, vol. 26, pp. 659–662.
Wanliss, J.A., Rankin, R., and Samson, J.C., Field Line Resonances in a Stretched Magnetotail: CANOPUS Optical and Magnetometer Observations, J. Geophys. Res., 2002, vol. 107, pp. SMP9-1–SMP9-12.
Leonovich, A.S. and Mazur, V.A., Why Do Ultra-Low-Frequency MHD Oscillations with a Discrete Spectrum Exist in the Magnetosphere?, Annal. Geophys., 2005, vol. 23, pp. 1075–1079.
Lee, D.-H.. and Lysak, R.L., Magnetospheric ULF Wave Coupling in the Dipole Model: The Impulsive Excitation, J. Geophys. Res., 1989, vol. 94, pp. 17097–17109.
Lee, D.-H.. and Lysak, R.L., Monochromatic ULF Wave Excitation Coupling in the Dipole Magnetosphere, J. Geophys. Res., 1991, vol. 96, pp. 5811–5823.
Leonovich, A.S. and Mazur, V.A., Structure of Magnetosonic Eigenoscillations of an Axisymmetric Magnetosphere, J. Geophys. Res., 2000, vol. 105, pp. 27707–27716.
Allan, W., White, S.P., and Poulter, E.M., Impulse-Excited Hydromagnetic Cavity and Field Line Resonance in the Magnetosphere, Planet. Space Sci., 1986, vol. 34, pp. 371–380.
Zhu, X. and Kivelson, M.G., Global Mode ULF Pulsations in a Magnetosphere with a Nonmonotonic Alfven Velocity Profile, J. Geophys. Res., 1989, vol. 94, pp. 1479–1485.
Lee, D.-H. and Lysak, R.L, Numerical Studies on ULF Wave Structures in the Dipole Model, in Solar Wind Sources of Magnetospheric Ultra-Low-Frequency Waves, vol. 81 of Geophys. Monogr. Ser., Engebretson, M.J., Takahashi, K., and Scholer, M., Eds., Washington, D.C.: AGU, 1994, pp. 293–297.
Leonovich, A.S. and Mazur, V.A., On the Spectrum of Magnetosonic Eigenoscillations of an Axisymmetric Magnetosphere, J. Geophys. Res., 2001, vol. 106, pp. 3919–3928.
Harrold, B.G.. and Samson, J.C., Standing ULF Modes of the Magnetosphere: A Theory, Geophys. Res. Lett., 1992, vol. 19, pp. 1811–1814.
Samson, J.C. and Rankin, R., The Coupling of Solar Wind Energy to MHD Cavity Modes, Waveguide Modes, and Field Line Resonances in the Earth’s Magnetosphere, in Solar Wind Sources of Magnetospheric Ultra-Low-Frequency Waves, vol. 81 of Geophys. Monogr. Ser., Engebretson, M.J., Takahashi, K., and Scholer, M., Eds., Washington, D.C.: AGU, 1994, pp. 253–264.
Siskoe, G.L., Resonant Compressional Waves in the Geomagnetic Tail, J. Geophys. Res., 1969, vol. 74, pp. 6482–6486.
Borovsky, J.E., Thomsen, M.F., Elphic, R.C., Cayton, T.E., and McComac, D.J., The Transport of Plasma Sheet Material from the Distant Tail to Geosynchronous Orbit, J. Geophys. Res., 1998, vol. 103, pp. 20297–20331.
Shabanskii, V.P., Yavleniya v oklozemnom prostranstve (Phenomena in the Near-Earth Space), Moscow: Nauka, 1972.
Antonova, E.E., Radial Pressure Gradients in the Earth’s Magnetosphere and Amplitude of the D st Variation, Geomagn. Aeron., 2001, vol. 41, pp. 148–156.
Author information
Authors and Affiliations
Additional information
Original Russian Text © A.S. Leonovich, V.A. Mazur, 2008, published in Kosmicheskie Issledovaniya, 2008, Vol. 46, No. 4, pp. 336–343.