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The aim of this article is to study how the differential rotation of solar-like stars is influenced by rotation rate and mass in presence of magnetic fields generated by a convective dynamo. We use the ASH code to model the convective…

Solar and Stellar Astrophysics · Physics 2016-09-21 J. Varela , A. Strugarek , A. S. Brun

We present evidence for finite magnetic helicity density in the heliosphere and numerical models thereof, and relate it to the magnetic field properties of the dynamo in the solar convection zone. We use simulations and solar wind data to…

Solar and Stellar Astrophysics · Physics 2012-08-03 Jörn Warnecke , Axel Brandenburg , Dhrubaditya Mitra

Convection in the solar interior is thought to comprise structures on a spectrum of scales. This conclusion emerges from phenomenological studies and numerical simulations, though neither covers the proper range of dynamical parameters of…

Solar and Stellar Astrophysics · Physics 2015-06-05 Shravan Hanasoge , Thomas L. Duvall , Katepalli R. Sreenivasan

We simulate the rise through the upper convection zone and emergence through the solar surface of initially uniform, untwisted, horizontal magnetic flux with the same entropy as the non-magnetic plasma that is advected into a domain 48 Mm…

Solar and Stellar Astrophysics · Physics 2015-05-14 R. F. Stein , A. Lagerfjärd , Å. Nordlund , D. Georgobiani

Stellar dynamos are driven by complex couplings between rotation and turbulent convection, which drive global-scale flows and build and rebuild stellar magnetic fields. When stars like our sun are young, they rotate much more rapidly than…

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

In this paper, we present a model for the effects of the tachocline on the differential rotation in the solar convection zone. The mathematical technique relies on the assumption that entropy is nearly constant ("well-mixed") in isorotation…

Solar and Stellar Astrophysics · Physics 2015-05-19 Steven A. Balbus , Henrik N. Latter

Solar-type stars exhibit a rich variety of magnetic activity. Seeking to explore the convective origins of this activity, we have carried out a series of global 3D magnetohydrodynamic (MHD) simulations with the anelastic spherical harmonic…

Solar and Stellar Astrophysics · Physics 2015-06-12 Nicholas J. Nelson , Benjamin P. Brown , A. Sacha Brun , Mark S. Miesch , Juri Toomre

We use three-dimensional direct numerical simulations of the helically forced magnetohydrodynamic equations in spherical shell segments in order to study the effects of changes in the geometrical shape and size of the domain on the growth…

Astrophysics · Physics 2010-01-15 Dhrubaditya Mitra , Reza Tavakol , Axel Brandenburg , David Moss

This paper provides a brief overview of dynamo scaling relationships for the degree of equipartition between magnetic and kinetic energies. Three basic approaches are adopted to explore these scaling relationships, with a first look at two…

Solar and Stellar Astrophysics · Physics 2017-01-11 Kyle Augustson , Stéphane Mathis , Allan Sacha Brun

We perform idealised numerical simulations of magnetic buoyancy instabilities in a model of the solar tachocline. We introduce a simplified model of magnetic flux pumping in an upper layer (the convection zone), and study the effects of its…

Solar and Stellar Astrophysics · Physics 2015-06-04 Adrian J. Barker , Lara J. Silvers , Michael R. E. Proctor , Nigel O. Weiss

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

Convectively driven dynamos with rotation generating magnetic fields on scales large compared with the scale of the turbulent eddies are being reviewed. It is argued that such fields can be understood as the result of an alpha effect.…

Solar and Stellar Astrophysics · Physics 2011-08-19 A. Brandenburg , P. J. Käpylä , M. J. Korpi

Several recent advances in turbulent dynamo theory are reviewed. High resolution simulations of small-scale and large-scale dynamo action in periodic domains are compared with each other and contrasted with similar results at low magnetic…

Solar and Stellar Astrophysics · Physics 2012-07-10 Axel Brandenburg , Dmitry Sokoloff , Kandaswamy Subramanian

The heat transfer behavior of convection-driven dynamos in a rotating plane layer between two parallel plates, heated from below and cooled from the top, is investigated. At a fixed rotation rate (Ekman Number, $E=10^{-6}$) and fluid…

Fluid Dynamics · Physics 2022-06-08 Souvik Naskar , Anikesh Pal

A putative temporally varying circulation-free magnetic-field configuration is inferred in an equatorial segment of the solar convection zone from the helioseismologically inferred angular-velocity variation, assuming that the predominant…

Solar and Stellar Astrophysics · Physics 2015-06-11 H. M. Antia , S. M. Chitre , D. O. Gough

(abridged) Results from kinematic solar dynamo models employing alpha-effect and turbulent pumping from local convection calculations are presented. We estimate the magnitude of these effects to be around 2-3 m/s. The rotation profile of…

Astrophysics · Physics 2008-11-26 P. J. Käpylä , M. J. Korpi , I. Tuominen

The surprising thinness of the solar tachocline is still not understood with certainty today. Among the numerous possible scenarios suggested to explain its radial confinement, one hypothesis is based on Maxwell stresses that are exerted by…

Solar and Stellar Astrophysics · Physics 2017-04-26 R. Barnabé , A. Strugarek , P. Charbonneau , A. S. Brun , J. -P. Zahn

In this paper, we investigate a simple model where two, initially unconnected, flux systems are forced to interact in response to the imposed boundary driving by solving the non-ideal 3D MHD equations numerically. The reconnection rate of…

Astrophysics · Physics 2007-05-23 K. Galsgaard , C. Parnell

Kilogauss-strength magnetic fields are often observed in intergranular lanes at the photosphere in the quiet Sun. Such fields are stronger than the equipartition field $B_e$, corresponding to a magnetic energy density that matches the…

Astrophysics · Physics 2009-11-13 P. J. Bushby , S. M. Houghton , M. R. E. Proctor , N. O. Weiss
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