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The multiscale flow structure in the solar convection zone - the coexistence of such features as the granules, mesogranules, supergranules and giant cells - has not yet been properly understood. Here, the possible role of one physical…

Solar and Stellar Astrophysics · Physics 2018-02-15 O. V. Shcheritsa , A. V. Getling , O. S. Mazhorova

Macroscopic gas motions are widespread throughout the solar atmosphere and shearing motions couple to the non--ideal effects, destabilising low frequency fluctuations in the medium. The origin of this non-ideal magnetohydrodynamic…

Solar and Stellar Astrophysics · Physics 2015-06-05 B. P. Pandey , Mark Wardle

We present axisymmetric simulations of the coupled convective and radiative regions in the Sun in order to investigate the angular momentum evolution of the radiative interior. Both hydrodynamic and magnetohydrodynamic models were run. We…

Solar and Stellar Astrophysics · Physics 2015-05-28 T. M. Rogers

Understanding solar turbulent convection and its influence on differential rotation has been a challenge over the past two decades. Current models often overestimate giant convection cells amplitude, leading to an effective Rossby number…

Solar and Stellar Astrophysics · Physics 2025-03-12 Quentin Noraz , Allan Sacha Brun , Antoine Strugarek

A number of observational and theoretical aspects of solar magnetoconvection are considered in this review. We discuss recent developments in our understanding of the small-scale structure of the magnetic field on the solar surface and its…

Solar and Stellar Astrophysics · Physics 2015-12-29 J. M. Borrero , S. Jafarzadeh , M. Schüssler , S. K. Solanki

The eddy viscosity in the solar supergranulation layer is derived from the observed rotational shear by computing theoretical rotation laws for the outermost parts of the solar convection zone using the results from numerical simulations of…

Astrophysics · Physics 2016-08-16 G. Rüdiger , M. Küker

Context: The paradigm of convection in solar-like stars is questioned based on recent solar observations. Aims: The primary aim is to study the effects of surface-driven entropy rain on convection zone structure and flows. Methods:…

Solar and Stellar Astrophysics · Physics 2025-06-11 P. J. Käpylä

Convection in planets and stars is predicted to occur in the "ultimate regime'' of diffusivity-free, rapidly rotating turbulence, in which flows are characteristically unaffected by viscous and thermal diffusion. Boundary layer diffusion,…

Fluid Dynamics · Physics 2025-04-21 Jewel A. Abbate , Yufan Xu , Tobias Vogt , Susanne Horn , Keith Julien , Jonathan M. Aurnou

The propagation of cosmic rays can be described as a diffusive motion in most galactic environments. High-energy gamma-rays measured by Fermi have allowed inference of a gradient in the cosmic-ray density and spectral energy behavior in the…

High Energy Astrophysical Phenomena · Physics 2021-10-14 J. Dörner , P. Reichherzer , L. Merten , J. Becker Tjus , H. Fichtner , M. J. Pueschel , E. G. Zweibel

Three-dimensional numerical simulations of solar surface magnetoconvection using realistic model physics are conducted. The thermal structure of convective motions into the upper radiative layers of the photosphere, the main scales of…

Solar and Stellar Astrophysics · Physics 2015-05-13 Sergey D. Ustyugov

Transport processes are ubiquitous. They are, for example, at the heart of optical flow approaches; or of perfusion imaging, where blood transport is assessed, most commonly by injecting a tracer. An advection-diffusion equation is widely…

Image and Video Processing · Electrical Eng. & Systems 2021-03-30 Peirong Liu , Lin Tian , Yubo Zhang , Stephen R. Aylward , Yueh Z. Lee , Marc Niethammer

Convection and magnetic field generation in the Earth and planetary interiors are driven by both thermal and compositional gradients. In this work numerical simulations of finite-amplitude double-diffusive convection and dynamo action in…

Fluid Dynamics · Physics 2021-01-27 James F. Mather , Radostin D. Simitev

The solar tachocline is a shear layer located at the base of the solar convection zone. The horizontal shear in the tachocline is likely turbulent, and it is often assumed that this turbulence would be strongly anisotropic as a result of…

Solar and Stellar Astrophysics · Physics 2021-01-20 Pascale Garaud

We present the results of a numerical investigation of charged-particle transport across a synthesized magnetic configuration composed of a constant homogeneous background field and a multiscale perturbation component simulating an effect…

Statistical Mechanics · Physics 2007-05-23 Francesco Chiaravalloti , Alexander V. Milovanov , Gaetano Zimbardo

We present a model for diffusion in a molecularly crowded environment. The model consists of random barriers in percolation network. Random walks in the presence of slowly moving barriers show normal diffusion for long times, but anomalous…

Subcellular Processes · Quantitative Biology 2007-06-06 Dietrich Stauffer , Christian Schulze , Dieter W. Heermann

Transport of tracer particles through mesh-like environments such as biological hydrogels and polymer matrices is ubiquitous in nature. These tracers could be passive, such as colloids or active (self-propelled), such as synthetic…

Soft Condensed Matter · Physics 2022-12-08 Praveen Kumar , Rajarshi Chakrabarti

We have studied the importance of the combined effects of rotation, diffusion, and convective overshoot on the p-mode oscillation spectrum and the neutrino flux of the standard solar model. To isolate the various physical affects included…

Astrophysics · Physics 2016-08-30 Brian Chaboyer , P. Demarque , D. B. Guenther , M. H. Pinsonneault

The effects of turbulence on the mixing of gases and dust in the outer Solar nebula are examined using 3-D MHD calculations in the shearing-box approximation with vertical stratification. The turbulence is driven by the magneto-rotational…

Astrophysics · Physics 2009-11-13 N. J. Turner , K. Willacy , G. Bryden , H. W. Yorke

Current models of the solar wind must approximate (or ignore) the small-scale dynamics within the solar atmosphere, however these are likely important in shaping the emerging wave-turbulence spectrum and ultimately heating/accelerating the…

Solar and Stellar Astrophysics · Physics 2022-09-28 Adam J. Finley , Sacha A. Brun , Mats Carlsson , Mikolaj Szydlarski , Viggo Hansteen , Munehito Shoda

Solar flares and coronal mass ejections, the primary space weather disturbances affecting the entire heliosphere and near-Earth environment, mainly emanate from sunspot regions harbouring high degrees of magnetic twist. However, it is not…

Solar and Stellar Astrophysics · Physics 2023-06-01 Shin Toriumi , Hideyuki Hotta , Kanya Kusano