Solar System Research

, Volume 53, Issue 4, pp 254–260 | Cite as

Collapse and Recovery of the Magnetic Field During Reversals

  • M. Yu. ReshetnyakEmail author


The process of polarity reversal of a magnetic dipole is considered using the two-dimensional model of the mean-field with random α-effect. The correlation of the sequence of fluctuations of α and the evolution of a magnetic dipole is investigated. It was shown that during fluctuations, which subsequently lead to inversions of the magnetic field, the dynamo system can switch to the mode of frequent changes in the dipole polarity with a lowered magnetic field, as well as to the temporal damping mode. Since the characteristic decay and generation times are different, a temporary asymmetry of the magnetic field arises during the reversal: the time of reduction of the magnetic dipole is several times longer than its growth time. The asymmetry for the geomagnetic field over the last five inversions is 4 : 1, which is close to the simulation results.


mean-field dynamo fluctuations of the alpha effect 



This work was supported by the Russian Scientific Foundation (project 19-47-04110).


  1. 1.
    Anufriev, A.P., Reshetnyak, M.Yu., and Sokolov, D.D., Evaluation of the dynamo number in the model of the turbulent α-effect for the liquid core of the Earth, Geomagn. Aeron., 1997, vol. 37, no. 5, pp. 141–146.Google Scholar
  2. 2.
    Braginskii, S.I., An almost axially symmetric model of the Earth’s hydromagnetic dynamo, Geomagn. Aeron., 1978, vol. 18, no. 2, pp. 340–351.ADSGoogle Scholar
  3. 3.
    Braginsky, S.I., Magnetic waves in the core of the Earth, Geophys. Astrophys. Fluid Dyn., 1980, vol. 14, pp. 189–208.ADSCrossRefGoogle Scholar
  4. 4.
    Glatzmaier, G.A., Coe, R.S., Hongre, L., and Roberts, P.H., The role of the Earth’s mantle in controlling the frequency of geomagnetic reversals, Nature, 1999, vol. 401, pp. 885–890.ADSCrossRefGoogle Scholar
  5. 5.
    Gubbins, D., The distinction between geomagnetic excursions and reversals, Geophys. J. Int., 1999, vol. 137, pp. F1–F3.CrossRefGoogle Scholar
  6. 6.
    Hoyng, P., Helicity fluctuations in mean field theory: an explanation for the variability of the solar cycle? Astron. Astrophys., 1993, vol. 272, pp. 321–339.ADSMathSciNetGoogle Scholar
  7. 7.
    Jacobs, J.A., Reversals of the Earth’s Magnetic Field, Cambridge: Cambridge Univ. Press, 1994.CrossRefGoogle Scholar
  8. 8.
    Krause, F. and Rädler, K.-H., Mean-Field Magnetohydrodynamics and Dynamo Theory, Oxford: Pergamon, 1980.zbMATHGoogle Scholar
  9. 9.
    Mori, N., Schmitt, D., Wicht, J., Ferriz-Mas, A., Mouri, H., Nakamichi, A., and Morikawa, M., Domino model for geomagnetic field reversals, Phys. Rev. E, 2013, vol. 87, p. 012 108.CrossRefGoogle Scholar
  10. 10.
    Reshetnyak, M.Yu., Parker’s model in geodynamo, Magnetohydrodynamics, 2016a, vol. 52, no. 1, pp. 181–190.CrossRefGoogle Scholar
  11. 11.
    Reshetnyak, M.Yu., Growth of the inner core in the mean-field dynamo model, Russ. J. Earth Sci., 2016b, vol. 16, p. ES6003.CrossRefGoogle Scholar
  12. 12.
    Reshetnyak, M.Yu., Tuning of the mean-field geodynamo model, Izv., Phys. Solid Earth, 2017a, vol. 53, no. 4, pp. 581–587.CrossRefGoogle Scholar
  13. 13.
    Reshetnyak, M.Yu., Time asymmetry of magnetic field variations in dynamo models, Geomagn. Aeron. (Engl. Transl.), 2017b, vol. 57, no. 3, pp. 369–374.Google Scholar
  14. 14.
    Reshetnyak, M.Yu. and Hejda, P., Heat flux modulation in Domino dynamo model, Open J. Geol. B, 2013, vol. 3, no. 2, pp. 55–59.ADSCrossRefGoogle Scholar
  15. 15.
    Reshetnyak, M.Yu. and Pavlov, V.E., Evolution of the dipole geomagnetic field. Observations and models, Geomagn. Aeron. (Engl. Transl.), 2016, vol. 56, no. 1, pp. 110–124.Google Scholar
  16. 16.
    Roberts, P.H. and King, E.M., On the genesis of the Earth’s magnetism, Rep. Prog. Phys., 2013, vol. 76, p. 096 801.CrossRefGoogle Scholar
  17. 17.
    Valet, J.-P., Meynadier, L., and Guyodo, Y., Geomagnetic dipole strength and reversal rate over the past two million years, Nature, 2005, vol. 435, pp. 802–805.ADSCrossRefGoogle Scholar
  18. 18.
    Zieger, L.B. and Constable, C.G., Asymmetry in growth and decay of the geomagnetic dipole, Earth Planet. Sci. Lett., 2011, vol. 312, pp. 300–304.ADSCrossRefGoogle Scholar

Copyright information

© Pleiades Publishing, Inc. 2019

Authors and Affiliations

  1. 1.Institute of Physics of the Earth, Russian Academy of SciencesMoscowRussia
  2. 2.Institute of Terrestrial Magnetism, Ionosphere, and Radiowave Propagation, Russian Academy of SciencesMoscowRussia

Personalised recommendations