Vestnik KRAUNC. Fiz.-Mat. Nauki. 2022. vol. 41. no. 4. pp. 107–119. ISSN 2079-6641

Contents of this issue

Read Russian Version US Flag

MSC 65N80

Research Article

Dynamics of generation modes changes in magnetic field depending on the oscillation frequency of the \alpha -effect suppression process by field energy in the \alpha\Omega -dynamo model

O. V. Sheremetyeva

Institute of Cosmophysical Research and Radio Wave Propagation, FEB RAS, 684034 Kamchatka region, Elizovskiy district, Paratunka, Mirnaya str., 7, Russia

E-mail: sheremeteva@ikir.ru

This article considers a \alpha\Omega -dynamo large-scale model in a low-mode approximation. The intensity of the \alpha -effect is regulated by a process with hereditarity properties, depending on the energy of the magnetic field. The nature of the process impact is determined by an alternating kernel function with a variable damping frequency and a constant damping coefficient equal to 0.1. Based on the results of numerical simulation of the magnetic field generation modes, the boundaries for the values of the model parameters are determined for which there are no oscillations in the velocity field of a viscous liquid or they are insignificant. The results of magnetic field generation modes simulation at various damping frequency values are displayed on the phase plane of the control parameters. These parameters contain information about large-scale and turbulent generators. The paper investigates the question about the dynamics of changes in the pattern on the phase plane depending on the value of the damping frequency and the waiting time. A comparison is made with the results obtained earlier for the constant intensity of the \alpha -effect and for the intensity, the change of which is determined by the process with exponential kernel.

Key words: low-mode dynamo model, \alpha\Omega -dynamo, \alpha -effect, magnetic field, reversals.

DOI: 10.26117/2079-6641-2022-41-4-107-119

Original article submitted: 29.11.2022

Revision submitted: 06.12.2022

For citation. Sheremetyeva O. V. Dynamics of generation modes changes in magnetic field depending on the oscillation frequency of the \alpha -effect suppression process by field energy in the \alpha\Omega -dynamo model. Vestnik KRAUNC. Fiz.-mat. nauki. 2022, 41: 4, 107-119. DOI: 10.26117/2079-6641-2022-41-4-107-119

Competing interests. The author declare that there is no conflicts of interest regarding authorship and publication.

Contribution and Responsibility. The author is solely responsible for providing the final version of the article in print. The final version of the manuscript was approved by the author.

The content is published under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/deed.ru)

© Sheremetyeva O. V., 2022

Funding. The work was carried out within the framework of the state assignment on the topic Physical processes in the system of near space and geospheres under solar and lithospheric influences (No. AAAA-A21-121011290003-0).

References

  1. Vodinchar G. M., Parovik R. I., Perezhogin A. S., Sheremetyeva O. V. Simulation of physical processes and systems in institute of cosmophysical research and radio wave propagation FEB RAS [Raboty po modelirovaniyu fizicheskih processov i sistem v institute kosmofizicheskih issledovanij i rasprostraneniya radiovoln DVO RAN], History of Science and Engineering [Istoriya nauki i tehniki], 2017, 8, 100-112. (In Russian)
  2. Vodinchar G. M. Using Modes of Free Oscillation of a Rotating Viscous Fluid in the Large-Scale Dinamo, Bulletin KRASEC. Phys. & Math. Sci., 2013, 2(7), 33-42. (In Russian) DOI: 10.18454/2079-6641-2013-7-2-33-42
  3. Feschenko L. K., Vodinchar G. M. Reversals in the large-scale \alpha\Omega-dynamo with memory, Nonlinear Processes in Geophysics, 2015, 22: 4, 361-369 DOI: 10.5194/npg-22-361-2015
  4. Vodinchar G. M., Feshchenko L. K. Model of geodynamo dryven by six-jet convection in the Earth’s core, Magnetohydrodynamics, 2016, 52:1, 287-300.
  5. Godomskaya A. N., Sheremetyeva O. V. Reversals in the low-mode model dynamo with \alpha\Omega-generators, E3S Web of Conferences, 2018, 62, 02016. DOI: 10.1051/ e3sconf/20186202016
  6. Sheremetyeva O. V., Godomskaya A. N. Modelling the magnetic field generation modes in the low-mode model of the \alpha\Omega-dynamo with varying intensity of the \alpha-effect, Bulletin of the South Ural State University, Series <Mathematical Modelling, Programming & Computer Software>, 2021, vol. 14, no. 2, pp. 27-38 (In Russian DOI: 10.14529/mmp210203).
  7. Sheremetyeva O.V. Modes of magnetic field generation in the low-mode \alpha\Omega-dynamo model with dynamic regulation of the α-effect by the field energy. Vestnik KRAUNC. Fiz.-mat. nauki.
    2021, 37:4, 92-103 (In Russian DOI: 10.26117/2079-6641-2021-37-4-92-103).
  8. Godomskaya A. N., Sheremetyeva O. V. The modes of magnetic field generation in a low-mode model of \alpha\Omega-dynamo with α-generator varying intensity regulated by a function with an alternating kernel, EPJ Web of Conferences, 2021, 254, 02015. DOI:10.1051/epjconf/202125402015
  9. Parker, E.N. Hydromagnetic dynamo models, Astrophys. J., 1955, 122, 293-314.
  10. Steenbek M., Krause F. Zur Dynamotheorie stellarer und planetarer Magnetfelder I. Berechnung sonnen¨ahnlicher Wechselfeldgeneratoren, Astron.Nachr., 1969, 291, 49-84.
  11. Zeldovich Ya. B., Rusmaikin A. A., Sokoloff D. D. Magnetic fields in astrophysics. The Fluid Mechanics of Astrophysic and Geophysics. Gordon and Breach: New York, 1983, 382.
  12. Krause F., R¨adler K.H. Mean-filed magnetohydrodynamics and dynamo theory. Pergamon Press: Oxford, 1980, 271.
  13. Sokoloff D. D., Nefedov S. N. A small-mode approximation in the stellar dynamo problem, Num. Meth. Prog., 2007, 8:2, 195-204 (In Russian http://mi.mathnet.ru/vmp485).
  14. Merril R. T., McElhinny M. W., McFadden P. L. The Magnetic Field of the Earth: Paleomagnetism, the Core, and the Deep Mantle. Academic Press: London, 1996, 531.
  15. Gledzer E. B., Dolzhanskiy F. V., Obukhov A. M. Sistemy gidrodinamicheskogo tipa i ikh primenenie [Hydrodynamic Type Systems and Their Application]. Nauka: Moscow, 1981, 368 (In Russian).
  16. Vodinchar G. M. Baza dannyh <Parametry sobstvennyh mod svobodnyh kolebanij MGD polej v yadre Zemli> [Database <Parameters of natural modes of normal oscillations of MHD fields in the Earth’s core>], 2019620054, 2019 (In Russian).
  17. Vodinchar G. M., Feshenko L. K. Biblioteka programm dlya issledovaniya <Malomodovoj modeli geodinamo> [Library of programs for researching <Low-mode geodynamo model> <LowModedGeodinamoModel>], 50201100092, 2011 (In Russian).

Sheremetyeva Olga Vladimirovna – PhD (Tech.), Research Scientist, Laboratory of Physical Process Modeling, Institute of Cosmophysical Research and Radio Wave Propagation FEB RAS, Paratunka, Kamchatka, Russia, ORCID 0000-0001-9417-9731.