English
Related papers

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

200 papers

The operation of the solar global dynamo appears to involve many dynamical elements. Self-consistent MHD simulations which realistically incorporate all of these processes are not yet computationally feasible, though some elements can now…

Astrophysics · Physics 2008-11-26 Allan Sacha Brun , Mark S. Miesch , Juri Toomre

We present a series of radiative MHD simulations addressing the origin and distribution of mixed polarity magnetic field in the solar photosphere. To this end we consider numerical simulations that cover the uppermost 2-6 Mm of the solar…

Solar and Stellar Astrophysics · Physics 2015-06-19 M. Rempel

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 carry out non-rotating high-resolution calculations of the solar global convection, which resolve convective scales of less than 10 Mm. To cope with the low Mach number conditions in the lower convection zone, we use the reduced speed of…

Solar and Stellar Astrophysics · Physics 2015-06-18 H. Hotta , M. Rempel , T. Yokoyama

We demonstrate that a magneto-convection simulation incorporating essential physical processes governing solar surface convection exhibits turbulent small-scale dynamo action. By presenting a derivation of the energy balance equation and…

Solar and Stellar Astrophysics · Physics 2010-04-23 Jonathan Pietarila Graham , Robert Cameron , Manfred Schuessler

We report the results of a magneto-hydrodynamic (MHD) simulation of a convective dynamo in a model solar convective envelope driven by the solar radiative diffusive heat flux. The convective dynamo produces a large-scale mean magnetic field…

Solar and Stellar Astrophysics · Physics 2014-06-18 Yuhong Fan , Fang Fang

Understanding the complex interactions between convection, magnetic fields, and rotation is key to modeling the internal dynamics of the Sun and stars. Under rotational influence, compressible convection forms prograde-propagating…

Solar and Stellar Astrophysics · Physics 2025-11-26 Yuto Bekki

One of the key questions in solar physics that remains to be answered concerns the strength and the distribution of the magnetic fields at the base of the convection zone. The flux tube dynamics requires that toroidal fields of strength as…

Astrophysics · Physics 2007-05-23 Alberto Bigazzi , Alexander A. Ruzmaikin

We carry out high resolution calculations of the solar overshoot region with unprecedentedly realistic parameters, especially the small energy flux compared with $\rho c^3_\mathrm{s}$, where $\rho$ and $c_\mathrm{s}$ are density and speed…

Solar and Stellar Astrophysics · Physics 2017-07-19 H. Hotta

Magnetic fields are usually observed in the quiet Sun as small-scale elements that cover the entire solar surface (the `salt and pepper' patterns in line-of-sight magnetograms). By using 3D radiative MHD numerical simulations we find that…

Solar and Stellar Astrophysics · Physics 2015-08-19 I. N. Kitiashvili , A. G. Kosovichev , N. N. Mansour , A. A. Wray

Regions of quiet Sun generally exhibit a complex distribution of small-scale magnetic field structures, which interact with the near-surface turbulent convective motions. Furthermore, it is probable that some of these magnetic fields are…

Solar and Stellar Astrophysics · Physics 2015-06-18 Paul J. Bushby , Benjamin Favier

In the quiet Sun, magnetic fields are usually observed as small-scale magnetic elements, `salt and pepper', covering the entire solar surface. By using 3D radiative MHD numerical simulations we demonstrate that these fields are a result of…

Solar and Stellar Astrophysics · Physics 2013-12-05 I. N. Kitiashvili , A. G. Kosovichev , N. N. Mansour , A. A. Wray

The global-scale dynamo action achieved in a simulation of a Sun-like star rotating at thrice the solar rate is assessed. The 3-D MHD Anelastic Spherical Harmonic (ASH) code, augmented with a viscosity minimization scheme, is employed to…

Solar and Stellar Astrophysics · Physics 2015-03-17 Kyle Augustson , Sacha Brun , Mark Miesch , Juri Toomre

Solar modelling has long been split into ''internal'' and ''surface'' modelling, because of the lack of tools to connect the very different scales in space and time, as well as the widely different environments and dominating physical…

Solar and Stellar Astrophysics · Physics 2022-11-18 Andrius Popovas , Åke Nordlund , Mikolaj Szydlarski

A magnetic flux tube may be considered both as a separate body and as a confined field. As a field, it is affected both by the cyclonic convection ($\alpha$-effect) and differential rotation ($\Omega$-effect). As a body, the tube…

Astrophysics · Physics 2007-05-23 L. H. Li , S. Sofia

Numerical MHD simulations play increasingly important role for understanding mechanisms of stellar magnetism. We present simulations of convection and dynamos in density-stratified rotating spherical fluid shells. We employ a new 3D…

Solar and Stellar Astrophysics · Physics 2015-09-03 Radostin D. Simitev , Alexander G. Kosovichev , Friedrich H. Busse

We present a comprehensive radiative magnetohydrodynamic simulation of the quiet Sun and large solar active regions. The 197 Mm wide simulation domain spans from 18 (10) Mm beneath the photosphere to 113 Mm in the solar corona. Radiative…

Solar and Stellar Astrophysics · Physics 2022-10-12 Feng Chen , Matthias Rempel , Yuhong Fan

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

Three-dimensional magnetohydrodynamical large eddy simulations of solar surface convection using realistic model physics is conducted. The effects of magnetic fields on thermal structure of convective motions into radiative layers, the…

Astrophysics · Physics 2007-05-23 Sergey Ustyugov

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
‹ Prev 1 2 3 10 Next ›