Geomagnetism and Aeronomy

, Volume 53, Issue 4, pp 441–447 | Cite as

Geomagnetic activity as a reflection of processes in the magnetospheric tail: 1. The source of diurnal and semiannual variations in geomagnetic activity

  • A. A. Danilov
  • G. F. Krymskii
  • G. A. MakarovEmail author


Diurnal and semiannual variations in geomagnetic activity are considered. We prove that there exists an inner magnetospheric source of magnetic activity, which depends on the angle φ between the planes of the magnetotail plasma sheet and the geomagnetic equator. It is shown that diurnal and semiannual variations in magnetic activity result from changes in the value of this angle.


Solar Wind Diurnal Variation Interplanetary Magnetic Field Geomagnetic Activity Plasma Sheet 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Bartels, J., Terrestrial magnetic activity and its relations to solar phenomena, J. Geophys. Res., 1932, vol. 37, pp. 1–52.CrossRefGoogle Scholar
  2. Boller, B.R. and Stolov, H.L., Kelvin-Helmholtz instability and the semiannual variation of geomagnetic activity, J. Geophys. Res., 1970, vol. 75, no. 31, pp. 6073–6084.CrossRefGoogle Scholar
  3. Cortie, A.L., Sunspot and terrestrial magnetic phenomena, 1898–1911: The cause of the annual variation of magnetic disturbances, Mon. Not. R. Astron. Soc., 1912, vol. 73, pp. 52–60.Google Scholar
  4. Danilov, A.A., Statsionarnaya struktura mezhplanetnogo magnitnogo polya i geomagnitnaya aktivnost’ (Stationary Structure of the Interplanetary Magnetic Field and Geomagnetic Activity), Yakutsk: YaNTs SO RAN, 1993.Google Scholar
  5. Danilov, A.A. and Makarov, G.A., Dependence of magnetic activity on the plasma sheet location relative to the geomagnetic equator, Geomagn. Aeron., 2006, vol. 46, pp. 159–165.CrossRefGoogle Scholar
  6. Danilov, A.A. and Sokolov, V.D., Auroral absorption and electric fields in the magnetosphere, Geomagn. Aeron., 2001, vol. 41, pp. 436–444.Google Scholar
  7. Geomagnetic data, IAGA Bull., 1972–1976, no. 32.Google Scholar
  8. Green, C.A., The semiannual variation in the magnetic activity indices Aa and Ap, Planet. Space Sci., 1984, vol. 32, pp. 297–306.CrossRefGoogle Scholar
  9. de La Sayette, P., Empirical simulations for the am annualdiurnal activity, J. Geophys. Res., 2004, vol. 109, p. A07207.CrossRefGoogle Scholar
  10. Lyatsky, W., Newell, P.T., and Hamza, A., Solar illumination as cause of the equinoctial preference for geomagnetic activity, Geophys. Res. Lett., 2001, vol. 28, pp. 2353–2356.CrossRefGoogle Scholar
  11. McIntosh, D.H., On the annual variation of magnetic disturbances, Phil. Trans. R. Soc. London., Ser. A, 1959, vol. 251, pp. 525–552.CrossRefGoogle Scholar
  12. Mishin, V.M. and Shelomentsev, V.V., Artificial and real geomagnetic effects of the IMF sector structure, Issled. Geomagn. Aeron. Fiz. Solntsa, 1975, no. 36, pp. 74–88.Google Scholar
  13. Newell, P.T., Sotirelis, T., Skura, J.P., Meng, C.-I., and Lyatsky, W., Ultraviolet insolation drives seasonal and diurnal space weather variations, J. Geophys. Res., 2002, vol. 107A, p. 1305. doi 10.1029/2001JA000296CrossRefGoogle Scholar
  14. Russell, C.T. and McPherron, R.L., Semiannual variation of geomagnetic activity, J. Geophys. Res., 1973, vol. 78, no. 1, pp. 92–108.CrossRefGoogle Scholar

Copyright information

© Pleiades Publishing, Ltd. 2013

Authors and Affiliations

  • A. A. Danilov
    • 1
  • G. F. Krymskii
    • 1
  • G. A. Makarov
    • 1
    Email author
  1. 1.Shafer Institute of Cosmophysical Research and Aeronomy, Siberian BranchRussian Academy of SciencesYakutskRussia

Personalised recommendations