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Related papers: 3D MHD Modeling of the Impact of Subsurface Strati…

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Various models of solar sub-surface stratification are tested in the global EULAG-MHD solver to simulate diverse regimes of near-surface convective transport. Sub- and superadiabacity are altered at the surface of the model ($ r >…

Solar and Stellar Astrophysics · Physics 2019-11-19 Andrey M. Stejko , Gustavo Guerrero , Alexander G. Kosovichev , Piotr K. Smolarkiewicz

We study the effects of different descriptions of the solar surface convection on the eigenfrequencies of p-modes. 1-D evolution calculations of the whole Sun and 3-D hydrodynamic and magnetohydrodynamic simulations of the current surface…

Solar and Stellar Astrophysics · Physics 2015-06-17 Laurent Piau , Remo Collet , Robert F. Stein , Regner Trampedach , Pierre Morel , Sylvaine Turck-Chieze

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

We investigate the possible development of magnetohydrodynamical instabilities in the EULAG-MHD "millenium simulation" of Passos & Charbonneau (2014). This simulation sustains a large-scale magnetic cycle characterized by solar-like…

Solar and Stellar Astrophysics · Physics 2015-11-11 N. Lawson , A. Strugarek , P. Charbonneau

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…

Helioseismology provides important constraints for the solar dynamo problem. However, the basic properties and even the depth of the dynamo process, which operates also in other stars, are unknown. Most of the dynamo models suggest that the…

Solar and Stellar Astrophysics · Physics 2014-02-11 Alexander G. Kosovichev , Valery V. Pipin , Junwei Zhao

The outer surface layers of the sun show a clear deceleration at low latitudes. This is generally thought to be the result of a strong dominance of vertical turbulent motions associated with strong downdrafts. This strong negative radial…

Astrophysics · Physics 2009-11-13 Axel Brandenburg

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

To explore the physics of large-scale flows in solar-like stars, we perform 3D anelastic simulations of rotating convection for global models with stratification resembling the solar interior. The numerical method is based on an implicit…

Solar and Stellar Astrophysics · Physics 2013-12-10 G. Guerrero , P. K. Smolarkiewicz , A. G. Kosovichev , N. N. Mansour

We present results from numerical modeling of emerging flux regions on the solar surface. The modeling was carried out by means of 3D radiative MHD simulations of the rise of buoyant magnetic flux tubes through the convection zone and into…

Astrophysics · Physics 2009-11-13 M. C. M. Cheung , M. Schuessler , T. D. Tarbell , A. M. Title

The advent of helioseismology has determined in detail the average rotation rate of the Sun as a function of radius and latitude. These data immediately reveal two striking boundary layers of shear in the solar convection zone (CZ): a…

Solar and Stellar Astrophysics · Physics 2019-03-06 Loren I. Matilsky , Bradley W. Hindman , Juri Toomre

Solar p-mode oscillations exhibit a systematic offset towards higher frequencies due to shortcomings in the 1D stellar structure models, especially, the lack of turbulent pressure in the superadiabatic layers just below the optical surface,…

Solar and Stellar Astrophysics · Physics 2016-07-06 Zazralt Magic , Achim Weiss

We report on simulations of mildly turbulent convection in spherical wedge geometry with varying density stratification. We vary the density contrast within the convection zone by a factor of 20 and study the influence of rotation on the…

Solar and Stellar Astrophysics · Physics 2012-04-25 P. J. Käpylä , M. J. Mantere , A. Brandenburg

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

We present results of three dimensional simulations of the uppermost part of the sun, at 3 stages of its evolution. Each model includes physically realistic radiative-hydrodynamics (the Eddington approximation is used in the optically thin…

Astrophysics · Physics 2007-05-23 F. J. Robinson , P. Demarque , S. Sofia , K. L. Chan , Y. -C. Kim , D. B. Guenther

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

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

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

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

The form of the solar meridional circulation is a very important ingredient for mean field flux transport dynamo models. Yet a shroud of mystery still surrounds this large-scale flow, given that its measurement using current helioseismic…

Solar and Stellar Astrophysics · Physics 2015-02-17 Dario Passos , Paul Charbonneau , Mark Miesch
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