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Related papers: A convection zone dynamo including the effects of …

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We investigate small-scale dynamo action in the solar convection zone through a series of high resolution MHD simulations in a local Cartesian domain with 1$R_\odot$ (solar radius) of horizontal extent and a radial extent from 0.715 to…

Solar and Stellar Astrophysics · Physics 2015-06-23 H. Hotta , M. Rempel , T. Yokoyama

Magnetic field emerges at the surface of the Sun as sunspots and active regions. This process generates a poloidal magnetic field from a rising toroidal flux tube, it is a crucial but poorly understood aspect of the solar dynamo. The…

Solar and Stellar Astrophysics · Physics 2016-07-19 Aaron C. Birch , Hannah Schunker , Douglas C. Braun , Robert Cameron , Laurent Gizon , Björn Löptien , Matthias Rempel

Mean field dynamo theory deals with various mean quantities and does not directly throw any light on the question of existence of flux tubes. We can, however, draw important conclusions about flux tubes in the interior of the Sun by…

Astrophysics · Physics 2008-11-26 Arnab Rai Choudhuri

(abridged) Results from kinematic solar dynamo models employing alpha-effect and turbulent pumping from local convection calculations are presented. We estimate the magnitude of these effects to be around 2-3 m/s. The rotation profile of…

Astrophysics · Physics 2008-11-26 P. J. Käpylä , M. J. Korpi , I. Tuominen

Mean-field dynamo theory has important applications in solar physics and galactic magnetism. We discuss some of the many turbulence effects relevant to the generation of large-scale magnetic fields in the solar convection zone. The…

Solar and Stellar Astrophysics · Physics 2023-11-23 Axel Brandenburg , Detlef Elstner , Youhei Masada , Valery Pipin

Surface observations indicate that the speed of the solar meridional circulation in the photosphere varies in anti-phase with the solar cycle. The current explanation for the source of this variation is that inflows into active regions…

Solar and Stellar Astrophysics · Physics 2017-11-29 D. Passos , M. Miesch , G. Guerrero , P. Charbonneau

Using the non-linear mean-field dynamo models we calculate the magnetic cycle parameters, like the dynamo cycle period, the amplitude of the total magnetic energy, and the Poynting flux luminosity from the surface for the solar analogs with…

Solar and Stellar Astrophysics · Physics 2021-01-27 V. V. Pipin

Context: Observations indicate that the `quiet' solar photosphere outside active regions contains considerable amounts of magnetic energy and magnetic flux, with mixed polarity on small scales. The origin of this flux is unclear. Aims: We…

Astrophysics · Physics 2009-11-13 A. Voegler , M. Schuessler

We study the combined effects of convection and radiative diffusion on the evolution of thin magnetic flux tubes in the solar interior. Radiative diffusion is the primary supplier of heat to convective motions in the lower convection zone,…

Solar and Stellar Astrophysics · Physics 2015-06-03 Maria A. Weber , Yuhong Fan

Solar magnetic fields comprise an 11-year activity cycle, represented by the number of sunspots. The maintenance of such a solar magnetic field can be attributed to fluid motion in the convection zone, i.e. a dynamo. This study conducts the…

Solar and Stellar Astrophysics · Physics 2022-08-24 Ryota Shimada , Hideyuki Hotta , Takaaki Yokoyama

We present three-dimensional MHD simulations of buoyant magnetic flux tubes that rise through a stratified model convection zone in the presence of solar rotation. The equations of MHD are solved in the anelastic approximation, and the…

Astrophysics · Physics 2009-10-31 W. P. Abbett , G. H. Fisher , Y. Fan

The magnetic activity of the Sun, as manifested in the sunspot cycle, originates deep within its convection zone through a dynamo mechanism which involves non-trivial interactions between the plasma and magnetic field in the solar interior.…

Solar and Stellar Astrophysics · Physics 2015-05-13 Dibyendu Nandy

We consider the effects of material flows on the dynamics of toroidal magnetic flux tubes located close to the base of the solar convection zone, initially within the overshoot region. The problem is to find the physical conditions in which…

Solar and Stellar Astrophysics · Physics 2015-05-14 Emre Isik , Volkmar Holzwarth

This study aims at investigating the ability of strong interactions between magnetic field concentrations during their rise through the convection zone to produce complex active regions at the solar surface. To do so, we perform numerical…

Solar and Stellar Astrophysics · Physics 2018-05-02 L. Jouve , A. S. Brun , G. Aulanier

Spherical solar dynamo simulations are performed. Self-consistent, fully compressible magnetohydrodynamic system with a stably stratified layer below the convective envelope is numerically solved with a newly developed simulation code based…

Solar and Stellar Astrophysics · Physics 2015-06-15 Youhei Masada , Kohei Yamada , Akira Kageyama

We present a three-dimensional numerical model for the generation and evolution of the magnetic field in the solar convection zone, in which sunspots are produced and contribute to the cyclic reversal of the large-scale magnetic field. We…

Solar and Stellar Astrophysics · Physics 2018-01-30 Rohit Kumar , Laurène Jouve , Rui F. Pinto , Alexis P. Rouillard

We propose a solar dynamo model distributed in the bulk of the convection zone with the toroidal magnetic field the flux concentrated in the near-surface layer. We show that if the boundary conditions at the top of the dynamo region allow…

Solar and Stellar Astrophysics · Physics 2015-05-20 V. V. Pipin , A. G. Kosovichev

Young solar-type stars rotate rapidly and many are magnetically active; some undergo magnetic cycles similar to the 22-year solar activity cycle. We conduct simulations of dynamo action in rapidly rotating suns with the 3D MHD anelastic…

Solar and Stellar Astrophysics · Physics 2011-03-28 Benjamin P. Brown , Mark S. Miesch , Matthew K. Browning , Allen Sacha Brun , Juri Toomre

Magneto-convection simulations on meso-granule and granule scales near the solar surface are used to study small scale dynamo activity, the emergence and disappearance of magnetic flux tubes, and the formation and evolution of micropores.…

Astrophysics · Physics 2007-05-23 Robert F. Stein , Aake Nordlund

The first results of the solar dynamo model that allows for the diamagnetic effect of inhomogeneous turbulence and the nonlocal alpha-effect due to the rise of magnetic loops are discussed. The nonlocal alpha-effect is not subject to the…

Solar and Stellar Astrophysics · Physics 2015-05-27 L. L. Kitchatinov , S. V. Olemskoy