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Related papers: Solar overshoot region and small-scale dynamo with…

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We investigate small-scale dynamo action in the solar convection zone through a series of high resolution MHD simulations in a local Cartesian domain with 1$R_\odot$ (solar radius) of horizontal extent and a radial extent from 0.715 to…

Solar and Stellar Astrophysics · Physics 2015-06-23 H. Hotta , M. Rempel , T. Yokoyama

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

In an attempt to understand the properties of convective energy transport in the solar convection zone, a numerical model has been constructed for turbulent flows in a compressible, radiation-coupled, non-magnetic, gravitationally…

Astrophysics · Physics 2007-05-23 Yong -Cheol Kim , Peter A. Fox , Sabatino Sofia , Pierre Demarque

We study convective overshooting by means of local 3D convection calculations. Using a mixing length model of the solar convection zone (CZ) as a guide, we determine the Coriolis number (Co), which is the inverse of the Rossby number, to be…

Astrophysics · Physics 2015-06-24 P. J. Käpylä , M. J. Korpi , M. Stix , I. Tuominen

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

We present numerical simulations of hydrodynamic overshooting convection in local Cartesian domains. We find that a substantial fraction of the lower part of the convection zone (CZ) is stably stratified according to the Schwarzschild…

The theory of the solar/stellar activity cycles is presented, based on the mean-field concept in magnetohydrodynamics. A new approach to the formulation of the electromotive force and the theory of differential rotation and meridional…

Astrophysics · Physics 2017-02-22 Günther Rüdiger , Rainer Arlt

We present numerical simulations of convective overshoot in a two-dimensional model of the solar equatorial plane. The simulated domain extends from 0.001 R_sun to 0.93 R_sun, spanning both convective and radiative regions. We show that…

Astrophysics · Physics 2008-11-26 Tamara M. Rogers , Gary A. Glatzmaier

In this Letter we present a seismological detection of a rising motion of magnetic flux in the shallow convection zone of the Sun, and show estimates of the emerging speed and its decelerating nature. In order to evaluate the speed of…

Solar and Stellar Astrophysics · Physics 2015-06-15 Shin Toriumi , Stathis Ilonidis , Takashi Sekii , Takaaki Yokoyama

Flux-dominated solar dynamo models have demonstrated to reproduce the main features of the large scale solar magnetic cycle, however the use of a solar like differential rotation profile implies in the the formation of strong toroidal…

Astrophysics · Physics 2009-11-13 G. A. Guerrero , E. M. de G. Dal Pino

(abridged) Context: Rotation is thought to influence the size of convective eddies and the efficiency of convective energy transport in the deep convection zones of stars. Rotationally constrained convection has been invoked to explain the…

Solar and Stellar Astrophysics · Physics 2023-10-20 Petri J. Käpylä

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

Motivated by the dynamics in the deep interiors of many stars, we study the interaction between overshooting convection and the large-scale poloidal fields residing in radiative zones. We have run a suite of 3D Boussinesq numerical…

Solar and Stellar Astrophysics · Physics 2021-02-24 Lydia Korre , Nicholas H. Brummell , Pascale Garaud , Celine Guervilly

The meridional circulation plays an essential role in determining the basic mechanism of the dynamo action in case the of a low eddy diffusivity. Flux-transport dynamos with strong return flow and a deep stagnation point are discussed in…

Solar and Stellar Astrophysics · Physics 2015-06-03 Alfio Bonanno

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

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

We present a model for the lower overshoot layer of the Sun, based on the realistic solar stratification, without the use of a "mixing-length" parameter, by solving the system of Reynolds momentum equations using the closure formalism of…

Astrophysics · Physics 2009-11-10 D. Marik , K. petrovay

Downflows with high velocities occur in the transition region above many sunspots; however, how these signatures evolve over short time-scales in both spatial and spectral terms is still unknown. In this article, we investigate the…

Solar and Stellar Astrophysics · Physics 2020-08-26 C. J. Nelson , S. Krishna Prasad , M. Mathioudakis

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

Turbulent convection models are thought to be good tools to deal with the convective overshooting in the stellar interior. However, they are too complex to be applied in calculations of stellar structure and evolution. In order to…

Solar and Stellar Astrophysics · Physics 2013-07-16 Q. S. Zhang , Y. Li
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