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Related papers: A two-layer $\alpha\omega$ dynamo model, and its i…

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We present results from a model for magnetic flux generation and transport in cool stars and a qualitative comparison of models with observations. The method combines an alpha-omega dynamo at the base of the convection zone, buoyant rise of…

Solar and Stellar Astrophysics · Physics 2015-06-03 Emre Işık

It has recently been shown that a significant slowdown of many stars can be attributed to the emergence of a strong magnetic field within the radiative region, where heat is transferred through radiation in a stably stratified layer. Here,…

Fluid Dynamics · Physics 2023-11-30 Florentin Daniel , Ludovic Petitdemange , Christophe Gissinger

To understand the generation of the Earth's and planetary magnetic fields, we investigate numerically the combined effect of precession and convection on the dynamo action in a spherical shell. The convection alone, the precession alone and…

Earth and Planetary Astrophysics · Physics 2016-08-24 Xing Wei

We explore the influence of geometry variations on the structure and the time-dependence of the magnetic field that is induced by kinematic $\alpha^{2}$ dynamos in a finite cylinder. The dynamo action is due to an anisotropic $\alpha$…

Geophysics · Physics 2009-05-12 R. Avalos-Zuñiga , M. Xu , F. Stefani , G. Gerbeth , F. Plunian

With the development of condensed-matter physics and nanotechnology, attention has turned to the fields near and on surfaces that result from interactions between electric dipole radiation and mesoscale structures. It is hoped that studying…

Optics · Physics 2022-01-07 Qiang Sun , Evert Klaseboer

Magnetic field generation on scales large compared with the scale of the turbulent eddies is known to be possible via the so-called $\alpha$ effect when the turbulence is helical and if the domain is large enough for the $\alpha$ effect to…

Solar and Stellar Astrophysics · Physics 2013-11-18 Simon Candelaresi , Axel Brandenburg

We quantify possible differences between turbulent dynamo action in the Sun and the dynamo action studied in idealized simulations. For this purpose we compare Fourier-space shell-to-shell energy transfer rates of three incrementally more…

Solar and Stellar Astrophysics · Physics 2011-07-08 R. Moll , J. Pietarila Graham , J. Pratt , R. H. Cameron , W. -C. Müller , M. Schüssler

The alpha effect is known to be an indispensable energy source of the poloidal magnetic field in the sun or planet. However, the alpha effect is quenched as the magnetic field grows due to the conservation of magnetic helicity. With these…

Solar and Stellar Astrophysics · Physics 2020-08-05 Kiwan Park

Using simple kinematics, we propose a general theory of linear wave interactions between the interfacial waves of a two dimensional (2D), inviscid, multi-layered fluid system. The strength of our formalism is that one does not have to…

Fluid Dynamics · Physics 2017-04-05 Anirban Guha , Firdaus E. Udwadia

Although it is widely accepted that photospheric motions provide the energy source and that the magnetic field must play a key role in the process, the detailed mechanisms responsible for heating the Sun's corona and accelerating the solar…

Solar and Stellar Astrophysics · Physics 2016-01-12 Roberto Lionello , Marco Velli , Cooper Downs , Jon A. Linker , Zoran Mikić

Long-term variations of solar activity, including the Grand minima, are believed to result from temporal variations of dynamo parameters. The simplest approximation of dynamo waves is applied to show that cyclic variations of the parameters…

Solar and Stellar Astrophysics · Physics 2015-08-06 Leonid Kitchatinov , Alexander Nepomnyashchikh

Collective coupling between dipoles can dramatically modify the optical response of a medium. Such effects depend strongly on the geometry of the medium and the polarization of the light. Using a classical coupled dipole model, here we…

Atomic Physics · Physics 2016-10-26 R. J. Bettles , S. A. Gardiner , C. S. Adams

At small but supercritical Rayleigh numbers, simulations of dynamos in spherical shells often separate into two broad regimes characterised either by their relative magnetic field strength (weak/strong) or by their dominant force balance…

Fluid Dynamics · Physics 2026-03-18 Luke J. Gostelow , Robert J. Teed

We investigate dynamo action in three-dimensional numerical simulations of turbulent spherical Couette flows. Close to the onset of dynamo action, the magnetic field exhibits an intermittent behavior, characterized by a series of short…

Fluid Dynamics · Physics 2013-04-24 Raphaël Raynaud , Emmanuel Dormy

One obvious feature of the solar cycle is its variation from one cycle to another. In this article, we review the dynamo models for the long-term variations of the solar cycle. By long-term variations, we mean the cycle modulations beyond…

Solar and Stellar Astrophysics · Physics 2023-07-05 Bidya Binay Karak

A series of kinetic phenomena in metallic multilayers has been considered. The kinetic properties of multilayers differ essentially from the properties of both massive metals and thin films. One of the main reasons of that is the influence…

Statistical Mechanics · Physics 2010-06-09 L. V. Dekhtyaruk , Yu. A. Kolesnichenko , V. G. Peschansky

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

Plasma models, consisting of advection-diffusion Partial Differential Equations coupled with chemical reactions, are widely adopted to describe corona, streamers and dielectric barrier discharges. However, the complex geometry of the…

Plasma Physics · Physics 2025-12-10 Beatrice Crippa , Anna Scotti , Andrea Villa

A new simple dynamo model for stellar activity cycle is proposed. By considering an inhomogeneous mean flow effect on turbulence, it is shown that turbulent cross helicity (velocity--magnetic-field correlation) should enter the expression…

Solar and Stellar Astrophysics · Physics 2016-06-22 Nobumitsu Yokoi , Dieter Schmitt , Valery Pipin , Fujihiro Hamba

The diffusion and low vibrational motions of adsorbates on surfaces can be well described by a purely stochastic model, the so-called interacting single adsorbate model, for low-moderate coverages (\theta \lesssim 0.12). Within this model,…

Statistical Mechanics · Physics 2010-02-16 R. Martinez-Casado , A. S. Sanz , G. Rojas-Lorenzo , S. Miret-Artes