Space Science Reviews

, Volume 16, Issue 3, pp 347–359 | Cite as

Theory of magnetic pulsations

  • Akira Hasegawa
  • Liu Chen


We present theory of long period (pc 3 to pc 5) magnetic pulsations. It consists of two parts; one (we call type A) deals with a resonant Alfvén wave excitation at a local field line by a monochromatic wave generated at the magnetopause, and the other (we call type B) deals with an excitation of a surface eigenmode by an externally applied impulse at a location with a rapid spatial change of plasma parameter(s).

For the type A pulsations, the theory gives the frequency, the sense and the ellipticity of the polarization and the orientation angle of the major axis as a function of the magnetospheric parameters. In particular, it is shown that the orientation angle of the major axis of the polarization ellipse is a sensitive function of the direction of the wave propagation in longitude and the change of the number density and the magnetic flux density in the radial direction, hence it can be used as an important diagnostic parameter.

In the type B pulsations, the theory gives the excitation frequency and the damping rate of the pulsations using the derived surface eigenmode. Example of an application to the observed magnetic field oscillations at the plasmapause is presented in which the observed frequency and the damping rate are used to estimate the plasmapause density and its radial density gradient.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Barston, E. M.: 1964, Ann. Phys. 29, 282.Google Scholar
  2. Boller, B. R. and Stolov, H. L.: 1970, J. Geophys. Res. 75, 6073.Google Scholar
  3. Burton, R. K., Russel, C. T., and Chappell, C. R.: 1970, J. Geophys. Res. 75, 5582.Google Scholar
  4. Chappell, C. R., Harris, K. K., and Sharp, G. W.: 1970, J. Geophys. Res. 75, 50.Google Scholar
  5. Chen, L. and Hasegawa, A.: 1974a, J. Geophys. Res. 79, 1024.Google Scholar
  6. Chen, L. and Hasegawa, A.: 1974b, J. Geophys. Res. 79, 1033.Google Scholar
  7. Dungey, J. W.: 1955, Proc. Ionosphere Conf., The Physical Society of London, p. 229.Google Scholar
  8. Dungey, J. W.: 1963, in C. De Witt, J. Hieblot, and A. Lebaeu (eds.), The Earth Environment, Gordon and Breach, New York.Google Scholar
  9. Gul'elmi, A. V.: 1974, Space Sci. Rev., this issue, p. 331.Google Scholar
  10. Lanzerotti, L. J., Hasegawa, A., and Tartaglia, N. A.: 1972, J. Geophys. Res. 77, 6731.Google Scholar
  11. Lanzerotti, L. J., Fukunishi, H., Hasegawa, A., and Liu, Chen,: 1973, Phys. Rev Letters 31, 624.Google Scholar
  12. Orr, D.: 1973, J. Atom. Terrest. Phys. 35, 1.Google Scholar
  13. Parker, E. N.: 1958, Phys. Fluids 1, 171.Google Scholar
  14. Radoski, H. R.: 1966, J. Geophys. Res. 71, 1891.Google Scholar
  15. Radoski, H. R.: 1967, J. Geophys. Res. 12, 4026.Google Scholar
  16. Saito, T. and Matsushita, S.: 1967, Planetary Space Sci. 15, 573.Google Scholar
  17. Samson, J. C. and Rostoker, G.: 1972, J. Geophys. Res. 77, 6133.Google Scholar
  18. Samson, J. C., Jacobs, J. A., and Rostoker, G.: 1971, J. Geophys. Res. 76, 3675.Google Scholar
  19. Sedlácek, Z.: 1971, J. Plasma Phys. 5, 239.Google Scholar
  20. Sen, A. K.: 1963, Phys. Fluids 6, 1154.Google Scholar
  21. Southwood, D. J.: 1968, Planetary Space Sci. 16, 587.Google Scholar
  22. Southwood, D. J.: 1974, Planetary Space Sci., to be published.Google Scholar
  23. Watanabe, T.: 1961, Sci. Rep. Tohoku Univ., Ser. 5 1B, 127.Google Scholar

Copyright information

© D. Reidel Publishing Company 1974

Authors and Affiliations

  • Akira Hasegawa
    • 1
  • Liu Chen
    • 1
  1. 1.Bell LaboratoriesMurray HillUSA

Personalised recommendations