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Convective turbulent motions in the solar interior, as well as the mean flows resulting from them, determine the evolution of the solar magnetic field. With the aim to get a better understanding of these flows we study anelastic rotating…

Solar and Stellar Astrophysics · Physics 2015-06-12 G. Guerrero , P. K. Smolarkiewicz , A. Kosovichev , N. Mansour

Context: We study the impact of two-dimensional spherical shells on compressible convection. Realistic profiles for density and temperature from a one-dimensional stellar evolution code are used to produce a model of a large stellar…

Solar and Stellar Astrophysics · Physics 2016-10-05 J. Pratt , I. Baraffe , T. Goffrey , C. Geroux , M. Viallet , D. Folini , T. Constantino , M. Popov , R. Walder

(abridged) Context: Late-type stars such as the Sun rotate differentially due to the interaction of turbulent convection and rotation. Aims: The aim of the study is to investigate the effects of the thermal Prandtl number on the transition…

Solar and Stellar Astrophysics · Physics 2023-01-18 Petri J. Käpylä

It has recently been recognized that the convective velocities achieved in the current solar convection simulations might be over-estimated. The newly-revealed effects of the prevailing small-scale magnetic field within the convection zone…

Solar and Stellar Astrophysics · Physics 2017-12-27 Y. Bekki , H. Hotta , T. Yokoyama

The Sun is the most constrained and well-studied of all stars. As a consequence, the physical ingredients entering solar models are used as a reference to study all other stars observed in the Universe. However, our understanding of the…

This study considers the onset of stress-free Boussinesq thermal convection in rotating spherical shells with aspect ratio $\eta=r_i/r_o=0.9$ ($r_i$ and $r_o$ being the inner and outer radius), Prandtl numbers ${\rm Pr}…

Solar and Stellar Astrophysics · Physics 2018-05-16 F. Garcia , F. R. N. Chambers , A. L. Watts

We present a three-dimensional model of rotating convection combined with a simplified corona in spherical coordinates. The motions in the convection zone generate a large-scale magnetic field that gets sporadically ejected into the outer…

Solar and Stellar Astrophysics · Physics 2012-07-17 Jörn Warnecke , Petri J. Käpylä , Maarit. J. Mantere , Axel Brandenburg

We present a new mechanism for generation of large-scale magnetic field by thermal convection which does not involve the alpha-effect. We consider weakly nonlinear perturbations of space-periodic steady convective magnetic dynamos in a…

Fluid Dynamics · Physics 2015-12-01 Roman Chertovskih , Vladislav Zheligovsky

Horizontally extended turbulent convection, termed mesoscale convection in natural systems, remains a challenge to investigate in both experiments and simulations. This is particularly so for very low molecular Prandtl numbers as in stellar…

Fluid Dynamics · Physics 2022-09-09 Ambrish Pandey , Dmitry Krasnov , Katepalli R. Sreenivasan , Jörg Schumacher

Stellar activity and planetary magnetospheres are powered by an underlying dynamo mechanism generated by magnetoconvection coupled with rotation. In astrophysical contexts, magnetoconvection typically occurs in parameter regimes that are…

Solar and Stellar Astrophysics · Physics 2025-12-03 Giuseppina Nigro

It is shown that in presence of URCA shell pulsational energy losses due to neutrino emission and nonequilibrium beta heating are much less than energy losses by excitation of short-wavelength acoustic waves. Convective motion in presence…

Astrophysics · Physics 2007-05-23 G. S. Bisnovatyi-Kogan

Magnetic reconnection in the quiet Sun is a phenomenon that is consistently observed, and it has recently become feasible to simulate via 3D numerical models of realistically stratified and convection-driven reconnection. We aim to…

Solar and Stellar Astrophysics · Physics 2022-12-21 Rebecca Robinson , Mats Carlsson , Guillaume Aulanier

We present a numerical study of double-diffusive convection characterized by a stratification unstable to thermal convection while at the same time a mean molecular weight (or solute concentration) difference between top and bottom…

Fluid Dynamics · Physics 2019-06-28 Florian Zaussinger , Friedrich Kupka

In local helioseismology numerical simulations of wave propagation are useful to model the interaction of solar waves with perturbations to a background solar model. However, the solution to the equations of motions include convective modes…

Solar and Stellar Astrophysics · Physics 2010-02-11 H. Schunker , R. Cameron , L. Gizon

The interaction of magnetic fields and stratified convection was studied in the context of the solar and late type stellar dynamos by using numerical 3D MHD simulations. The topology of stratified asymmetric and over-turning convection…

Astrophysics · Physics 2007-05-23 Bertil Dorch , Aake Nordlund

We discuss the turbulent structure and dynamics of the upper solar convection zone using a 3D radiative hydrodynamic simulation model at 45 degrees latitude. The model reveals the self-formation of meridional flows, the leptocline, and the…

Solar and Stellar Astrophysics · Physics 2025-02-04 Irina N. Kitiashvili , Alan A. Wray

A simplified model for stellar and planetary convection is derived for the magnitude of the rms velocity, degree of superadiabaticity, and characteristic length scale with Rossby number as well as with thermal and viscous diffusivities.…

Solar and Stellar Astrophysics · Physics 2018-11-13 Kyle Augustson , Stéphane Mathis

Core convection and dynamo activity deep within rotating A-type stars of 2 solar masses are studied with 3--D nonlinear simulations. Our modeling considers the inner 30% by radius of such stars, thus capturing within a spherical domain the…

Astrophysics · Physics 2008-11-26 Allan Sacha Brun , Matthew K. Browning , Juri Toomre

Rayleigh-Benard convection in a rotating spherical shell provides a simplified model for convective dynamics of planetary and stellar interiors. In this study, we build more than 200 numerical models of rotating convection in a spherical…

Fluid Dynamics · Physics 2025-08-14 Wei Fan , Qi Wang , Yufeng Lin

A physically consistent model of magnetic field generation by convection in a rotating spherical shell with a minimum of parameters is applied to the Sun. Despite its unrealistic features the model exhibits a number of properties resembling…

Solar and Stellar Astrophysics · Physics 2015-06-04 R. D. Simitev , F. H. Busse