English
Related papers

Related papers: Efficient small-scale dynamo in solar convection z…

200 papers

We present the first results from three-dimensional spherical shell simulations of magnetic dynamo action realized by turbulent convection penetrating downward into a tachocline of rotational shear. This permits us to assess several…

Astrophysics · Physics 2011-02-11 Matthew Browning , Mark S. Miesch , Allan Sacha Brun , Juri Toomre

One of the main theories for heating of the solar corona is based on the idea that solar convection shuffles and tangles magnetic field lines to make many small-scale current sheets that, via reconnection, heat coronal loops. Tiwari et al…

Solar and Stellar Astrophysics · Physics 2025-05-08 V. Aparna , Sanjiv K. Tiwari , Ronald L. Moore , Navdeep K. Panesar , Brian Welsch , Bart De Pontieu , Aimee Norton

Recent analysis of the helioseismic observations indicate that the previously observed surface torsional oscillations extend significantly downwards into the solar convection zone. In an attempt to understand these oscillations, we study…

Astrophysics · Physics 2007-05-23 Eurico Covas , Reza Tavakol , David Moss , Andrew Tworkowski

In this work, we study and quantify properties of strong-field small-scale convection and compare observed properties with those predicted by numerical simulations. We analyze spectropolarimetric 630.25 nm data from a unipolar ephemeral…

Solar and Stellar Astrophysics · Physics 2015-05-19 G. Narayan , G. B. Scharmer

Stars of sufficiently low mass are convective throughout their interiors, and so do not possess an internal boundary layer akin to the solar tachocline. Because that interface figures so prominently in many theories of the solar magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-20 Matthew Browning

We study dynamo action in a convective layer of electrically-conducting, compressible fluid, rotating about the vertical axis. At the upper and lower bounding surfaces, perfectly-conducting boundary conditions are adopted for the magnetic…

Solar and Stellar Astrophysics · Physics 2011-11-23 Benjamin F. N. Favier , Paul J. Bushby

It has been recently shown numerically that a small-scale dynamo (SSD) instability could be possible in solar-like low magnetic Prandtl number plasmas. It has been proposed that the presence of SSD can potentially have a significant impact…

Solar and Stellar Astrophysics · Physics 2025-04-09 Jörn Warnecke , Maarit J. Korpi-Lagg , Matthias Rheinhard , Mariangela Viviani , Ameya Prabhu

We assess the global-scale dynamo action achieved in a simulation of a sun-like star rotating at three times the solar rate. The 3-D MHD Anelastic Spherical Harmonic code, using slope-limited diffusion, is employed to capture convection and…

Solar and Stellar Astrophysics · Physics 2013-11-01 Kyle Augustson , Allan Sacha Brun , Mark Steven Miesch , Juri Toomre

Some of the small-scale solar magnetic flux can be attributed to a small-scale dynamo (SSD) operating in the near-surface convection. The SSD fields have consequences for solar granular convection, basal flux, as well as chromospheric…

Results of realistic simulations of solar surface convection on the scale of supergranules (96 Mm wide by 20 Mm deep) are presented. The simulations cover only 10% of the geometric depth of the solar convection zone, but half its pressure…

Astrophysics · Physics 2008-11-05 R. F. Stein , A. Nordlund , D. Georgobiani , D. Benson , W. Schaffenberger

We carry out a magneto-hydrodynamic (MHD) simulation of convective dynamo in the rotating solar convective envelope driven by the solar radiative diffusive heat flux. The simulation is similar to that reported in Fan & Fang (2014) but with…

Solar and Stellar Astrophysics · Physics 2016-01-12 Yuhong Fan , Fang Fang

We present the results of 3--D nonlinear simulations of magnetic dynamo action by core convection within A-type stars of 2 solar masses, at a range of rotation rates. We consider the inner 30% by radius of such stars, with the spherical…

Astrophysics · Physics 2009-11-10 Matthew Browning , Allan Sacha Brun , Juri Toomre

In this article we review small-scale dynamo processes that are responsible for magnetic field generation on scales comparable to and smaller than the energy carrying scales of turbulence. We provide a review of critical observation of…

Solar and Stellar Astrophysics · Physics 2023-07-19 Matthias Rempel , Tanayveer Bhatia , Luis Bellot Rubio , Maarit J. Korpi-Lagg

We obtain lower limits on the amplitude of convective velocities in the deep solar convection zone based only on the observed properties of the differential rotation and meridional circulation together with simple and robust dynamical…

Solar and Stellar Astrophysics · Physics 2015-06-05 Mark S. Miesch , Nicholas A. Featherstone , Matthias Rempel , Regner Trampedach

We present a radiative magnetohydrodynamics simulation of the formation of an Active Region on the solar surface. The simulation models the rise of a buoyant magnetic flux bundle from a depth of 7.5 Mm in the convection zone up into the…

Solar and Stellar Astrophysics · Physics 2015-05-19 M. C. M. Cheung , M. Rempel , A. M. Title , M. Schüssler

This paper describes a series of 3D simulations of shallow inefficient convection in the outer layers of the Sun. The computational domain is a closed box containing the convection-radiation transition layer, located at the top of the solar…

Astrophysics · Physics 2009-11-07 F. J. Robinson , P. Demarque , L. H. Li , S. Sofia , Y. -C. Kim , K. L. Chan , D. B. Guenther

Most large-scale planetary magnetic fields are thought to be driven by low Rossby number convection of a low magnetic Prandtl number fluid. Here kinematic dynamo action is investigated with an asymptotic, rapidly rotating dynamo model for…

Geophysics · Physics 2016-12-14 Michael A. Calkins , Louie Long , David Nieves , Keith Julien , Steven M. Tobias

A comprehensive understanding of the solar magnetic cycle requires detailed modeling of the solar interior including the maintenance and variation of large scale flows (differential rotation and meridional flow), the solar dynamo and the…

Solar and Stellar Astrophysics · Physics 2010-10-29 M. Rempel

The goal of this research is to investigate how magnetic field affects the dynamics of granular convection and excitation of solar oscillations by means of realistic numerical simulations. We have used a 3D, compressible, non-linear…

Astrophysics · Physics 2008-05-27 L. Jacoutot , A. G. Kosovichev , A. Wray , N. N. Mansour

The question of possible small-scale dynamo action in the surface layers of the Sun is revisited with realistic 3D MHD simulations. As in other MHD problems, dynamo action is found to be a sensitive function of the magnetic Prandtl number…

Solar and Stellar Astrophysics · Physics 2015-06-11 I. Thaler , H. C. Spruit