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Exploring shallow sunspot formation by using Implicit Large-eddy simulations

Published online by Cambridge University Press:  12 September 2017

F. J. Camacho ,
G. Guerrero ,
P. K. Smolarkiewicz ,
A. G. Kosovichev  and
N. N. Mansour
F. J. Camacho*
Affiliation:
Universidade Federal de Minas Gerais, Av. Pres. Antônio Carlos, 6627 - Pampulha Belo Horizonte - MG, Brazil
G. Guerrero*
Affiliation:
Universidade Federal de Minas Gerais, Av. Pres. Antônio Carlos, 6627 - Pampulha Belo Horizonte - MG, Brazil
P. K. Smolarkiewicz
Affiliation:
European Centre for Medium-Range Weather Forecasts, Reading RG2 9AX, UK email: smolar@ecmwf.int
A. G. Kosovichev
Affiliation:
New Jersey Institute of Technology, Newark, NJ 07103, USA email: alexander.g.kosovichev@njit.edu
N. N. Mansour
Affiliation:
NASA, Ames Research Center, Moffet Field, Mountain View, CA, USA email: nagi.n.mansour@nasa.gov
*
*email: camacho@fisica.ufmg.br
**email: guerrero@fisica.ufmg.br
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Abstract

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The mechanism by which sunspots are generated at the surface of the sun remains unclear. In the current literature two types of explanations can be found. The first one is related to the buoyant emergence of toroidal magnetic fields generated at the tachocline. The second one states that active regions are formed, from initially diffused magnetic flux, by MHD instabilities that develop in the near-surface layers of the Sun. Using the anelastic MHD code EULAG we address the problem of sunspot formation by performing implicit large-eddy simulations of stratified magneto-convection in a domain that resembles the near-surface layers of the Sun. The development of magnetic structures is explored as well as their effect on the convection dynamics. By applying a homogeneous magnetic field over an initially stationary hydrodynamic convective state, we investigate the formation of self-organized magnetic structures in the range of the initial magnetic field strength, 0.01 < B0/Beq < 0.5, where Beq is the characteristic equipartition field strength.

Keywords

convectionEULAG-MHDILESturbulencesunspots
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 12 , Symposium S328: Living Around Active Stars , October 2016 , pp. 117 - 119
Copyright
Copyright © International Astronomical Union 2017 

References

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