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Related papers: Magnetic field distribution in the quiet Sun: a si…

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Recent studies have demonstrated that in fully developed turbulence, the effective magnetic pressure of a large-scale field (non-turbulent plus turbulent contributions) can become negative. In the presence of strongly stratified turbulence,…

Solar and Stellar Astrophysics · Physics 2013-10-07 Axel Brandenburg , Nathan Kleeorin , Igor Rogachevskii

The Earth's magnetic field is generated by dynamo action driven by convection in the outer core. For numerical reasons, inertial and viscous forces play an important role in geodynamo models; however, the primary dynamical balance in the…

Earth and Planetary Astrophysics · Physics 2016-06-08 David W. Hughes , Fausto Cattaneo

We compare horizontal velocities, vertical magnetic fields and evolution of trees of fragmenting granules (TFG, also named families of granules) derived in the quiet Sun at disk center from observations at solar minimum and maximum of the…

Solar and Stellar Astrophysics · Physics 2018-04-11 J. M. Malherbe , T. Roudier , R. Stein , Z. Frank

Stellar convection in the presence of magnetic field affects the emergent intensity, as well as the structure and evolution of cool main-sequence dwarfs. We aim to understand the effect of faculae-like field strengths on near-surface…

The purpose of this work was to obtain diffusion coefficient for the magnetic angular momentum transport and material transport in a rotating solar model. We assumed that the transport of both angular momentum and chemical elements caused…

Astrophysics · Physics 2008-05-26 W. M. Yang , S. L. Bi

The rotation-activity relationship of G-type stars results from surface magnetic fields emerging from the interior. How the magnetic flux and its emergence rate scale with rotation rate are not well understood, both observationally and…

Solar and Stellar Astrophysics · Physics 2026-05-18 Emre Isik , Sami K. Solanki , Natalie A. Krivova , Alexander I. Shapiro

We demonstrate that the radial magnetic-field component at the outer boundary of the sunspot penumbra is about 550 Mx cm$^{-2}$ independent of the sunspot area and the maximum magnetic field in the umbra. The mean magnetic-field intensity…

Solar and Stellar Astrophysics · Physics 2022-10-26 V. N. Obridko , M. M. Katsova , D. D. Sokoloff , B. D. Shelting , I. M. Livshits

The coronal magnetic field above a particular photospheric region will vanish at a certain number of points, called null points. These points can be found directly in a potential field extrapolation or their density can be estimated from…

Astrophysics · Physics 2009-11-13 D. W. Longcope , C. E. Parnell

We review recent insights into the dynamics of the solar convection zone obtained from global numerical simulations, focusing on two recent developments in particular. The first is quasi-cyclic magnetic activity in a long-duration dynamo…

Solar and Stellar Astrophysics · Physics 2015-05-20 Mark S. Miesch , Benjamin P. Brown , Matthew K. Browning , Allan Sacha Brun , Juri Toomre

In the past, spectropolarimetric data from Hinode/SP has been employed to infer the distribution of the magnetic field vector in the quiet Sun. While some authors have found predominantly horizontal magnetic fields, others favor an…

Solar and Stellar Astrophysics · Physics 2015-05-20 J. M. Borrero , P. Kobel

The emergence of minimally structured (uniform and horizontal) magnetic field from a depth of 20 Mm has been simulated. The field emerges first in a mixed polarity pepper and salt pattern, but then collects into separate, unipolar…

Solar and Stellar Astrophysics · Physics 2015-03-18 Robert F. Stein , Anders Lagerfjärd , Åke Nordlund , Dali Georgobiani

Three kinds of magnetic couplings in the quiet solar atmosphere are highlighted and discussed, all fundamentally connected to the Lorentz force. First the coupling of the convecting and overshooting fluid in the surface layers of the Sun…

Solar and Stellar Astrophysics · Physics 2015-05-13 O. Steiner

Context: The presence of a turbulent magnetic field in the quiet Sun has been unveiled observationally using different techniques. The magnetic field is quasi-isotropic and has field strengths weaker than 100G. It is pervasive and may host…

Solar and Stellar Astrophysics · Physics 2016-11-26 A. López Ariste , A. Sainz Dalda

The Sun, aside from its eleven year sunspot cycle is additionally subject to long term variation in its activity. In this work we analyse a solar-like convective dynamo simulation, containing approximately 60 magnetic cycles, exhibiting…

Solar and Stellar Astrophysics · Physics 2017-10-11 Frederick A. Gent , Maarit J. Käpylä , Jörn Warnecke

In the mean field approximation of the relativistic $\sigma$-$\omega$-$\rho$ model, the magnetic fields are incorporated, and its influence on the properties of n-p-e neutron star matter are studied. When the strength of the magnetic field…

Astrophysics · Physics 2008-11-26 W. Chen , P. Q. Zhang , L. G. Liu

Small-scale magnetic flux emergence in the quiet Sun is crucial for maintaining solar magnetic activity. On the smallest scales studied so far, namely within individual granules, two mechanisms have been identified: emergence in tiny…

Solar and Stellar Astrophysics · Physics 2025-03-05 S. M. Díaz-Castillo , C. E. Fischer , F. Moreno-Insertis , S. L. Guglielmino , R. Ishikawa , S. Criscuoli

The Universe at present is highly magnetized, with fields of the order of a few 10^-5 G and coherence lengths larger than 10 kpc in typical galaxies like the Milky Way. We propose that the magnetic field was amplified to this values already…

Astrophysics of Galaxies · Physics 2015-06-17 Jennifer Schober , Dominik R. G. Schleicher , Ralf S. Klessen

The existence of a turbulent small-scale solar surface dynamo is likely, considering existing numerical and laboratory experiments, as well as comparisons of a small-scale dynamo in MURaM simulations with Hinode observations. We find the…

Solar and Stellar Astrophysics · Physics 2010-03-19 Jonathan Pietarila Graham , Sanja Danilovic , Manfred Schuessler

Aims. In this paper we analyse numerically the propagation and dispersion of acoustic waves in the solar-like sub-photosphere with localised non-uniform magnetic field concentrations, mimicking sunspots with various representative magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-13 S. Shelyag , S. Zharkov , V. Fedun , R. Erdelyi , M. J. Thompson

We review (i) observations and numerical simulations of vortical flows in the solar atmosphere and (ii) measurements of the horizontal magnetic field in quiet Sun regions. First, we discuss various manifestations of vortical flows and…

Solar and Stellar Astrophysics · Physics 2012-02-21 O. Steiner , R. Rezaei