Magnetic structure, dipole reversals, and 1/f noise in resistive MHD spherical dynamos

A parametric study of the magnetic dipole behavior in resistive incompressible magnetohydrodynamics inside a rotating sphere is performed, using direct numerical simulations and considering Reynolds and Ekman numbers as controlling parameters. The tendency is to obtain geodynamolike magnetic dipole...

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Autores principales: Fontana, M., Mininni, P.D., Dmitruk, P.
Formato: JOUR
Materias:
Magnetic structure
Reynolds number
Spheres
Controlling parameters
Ekman numbers
Incompressible magnetohydrodynamics
Long term memory
Lower frequencies
Magnetic dipole
Parametric study
Rotating spheres
Magnetohydrodynamics
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_2469990X_v3_n12_p_Fontana
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_2469990X_v3_n12_p_Fontana2023-10-03T16:41:26Z Magnetic structure, dipole reversals, and 1/f noise in resistive MHD spherical dynamos Fontana, M. Mininni, P.D. Dmitruk, P. Magnetic structure Reynolds number Spheres Controlling parameters Ekman numbers Incompressible magnetohydrodynamics Long term memory Lower frequencies Magnetic dipole Parametric study Rotating spheres Magnetohydrodynamics A parametric study of the magnetic dipole behavior in resistive incompressible magnetohydrodynamics inside a rotating sphere is performed, using direct numerical simulations and considering Reynolds and Ekman numbers as controlling parameters. The tendency is to obtain geodynamolike magnetic dipole reversal regimes for sufficiently small Ekman and large Reynolds numbers. The typical dipole latitude obtained in the reversal regime is around 40-(with respect to the rotation axis of the sphere). A statistical analysis of waiting times between dipole reversals is also performed, obtaining a non-Poissonian distribution of waiting times, indicating long-term memory effects. We also report the presence of a 1/f frequency power spectrum in the magnetic dipole time series, which also shows a tendency to grow toward lower frequencies as the Ekman number is decreased. © 2018 American Physical Society. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_2469990X_v3_n12_p_Fontana
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Magnetic structure
Reynolds number
Spheres
Controlling parameters
Ekman numbers
Incompressible magnetohydrodynamics
Long term memory
Lower frequencies
Magnetic dipole
Parametric study
Rotating spheres
Magnetohydrodynamics
spellingShingle Magnetic structure
Reynolds number
Spheres
Controlling parameters
Ekman numbers
Incompressible magnetohydrodynamics
Long term memory
Lower frequencies
Magnetic dipole
Parametric study
Rotating spheres
Magnetohydrodynamics
Fontana, M.
Mininni, P.D.
Dmitruk, P.
Magnetic structure, dipole reversals, and 1/f noise in resistive MHD spherical dynamos
topic_facet Magnetic structure
Reynolds number
Spheres
Controlling parameters
Ekman numbers
Incompressible magnetohydrodynamics
Long term memory
Lower frequencies
Magnetic dipole
Parametric study
Rotating spheres
Magnetohydrodynamics
description A parametric study of the magnetic dipole behavior in resistive incompressible magnetohydrodynamics inside a rotating sphere is performed, using direct numerical simulations and considering Reynolds and Ekman numbers as controlling parameters. The tendency is to obtain geodynamolike magnetic dipole reversal regimes for sufficiently small Ekman and large Reynolds numbers. The typical dipole latitude obtained in the reversal regime is around 40-(with respect to the rotation axis of the sphere). A statistical analysis of waiting times between dipole reversals is also performed, obtaining a non-Poissonian distribution of waiting times, indicating long-term memory effects. We also report the presence of a 1/f frequency power spectrum in the magnetic dipole time series, which also shows a tendency to grow toward lower frequencies as the Ekman number is decreased. © 2018 American Physical Society.
format JOUR
author Fontana, M.
Mininni, P.D.
Dmitruk, P.
author_facet Fontana, M.
Mininni, P.D.
Dmitruk, P.
author_sort Fontana, M.
title Magnetic structure, dipole reversals, and 1/f noise in resistive MHD spherical dynamos
title_short Magnetic structure, dipole reversals, and 1/f noise in resistive MHD spherical dynamos
title_full Magnetic structure, dipole reversals, and 1/f noise in resistive MHD spherical dynamos
title_fullStr Magnetic structure, dipole reversals, and 1/f noise in resistive MHD spherical dynamos
title_full_unstemmed Magnetic structure, dipole reversals, and 1/f noise in resistive MHD spherical dynamos
title_sort magnetic structure, dipole reversals, and 1/f noise in resistive mhd spherical dynamos
url http://hdl.handle.net/20.500.12110/paper_2469990X_v3_n12_p_Fontana
work_keys_str_mv AT fontanam magneticstructuredipolereversalsand1fnoiseinresistivemhdsphericaldynamos
AT mininnipd magneticstructuredipolereversalsand1fnoiseinresistivemhdsphericaldynamos
AT dmitrukp magneticstructuredipolereversalsand1fnoiseinresistivemhdsphericaldynamos
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