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Related papers: Coronal influence on dynamos

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The solar dynamo and the solar Global internal Magnetic Structure (GMS) appear to be a thin ($\sim$2 Mm thick) structure near ($\sim$1 Mm below) the solar surface. Evidence for these properties are found from the amplitude of the torsional…

Solar and Stellar Astrophysics · Physics 2017-12-05 T. R. Jarboe , T. E. Benedett , C. J. Everson , C. J. Hansen , A. C. Hossack , K. D. Morgan , B. A. Nelson , J. M. Penna , D. A. Sutherland

We investigate the change in stellar magnetic topology across the fully-convective boundary and its effects on coronal properties. We consider both the magnitude of the open flux that influences angular momentum loss in the stellar wind and…

Solar and Stellar Astrophysics · Physics 2012-07-11 Pauline Lang , Moira Jardine , Jean-Francois Donati , Julien Morin , Aline Vidotto

To understand solar and stellar dynamos combining local and global numerical modelling with long-term observations is a challenging task: even with state of the art computational methods and resources, the stellar parameter regime remains…

Solar and Stellar Astrophysics · Physics 2021-02-08 M. Viviani , A. Prabhu , J. Warnecke , L. Duarte , J. Pekkilä , M. Rheinhardt , M. J. Käpylä

This paper reviews our growing understanding of the physics behind coronal heating (in open-field regions) and the acceleration of the solar wind. Many new insights have come from the last solar cycle's worth of observations and theoretical…

Solar and Stellar Astrophysics · Physics 2010-02-02 Steven R. Cranmer , John L. Kohl , Mari Paz Miralles , Adriaan A. van Ballegooijen

The dynamo mechanism, responsible for the solar magnetic activity, is still an open problem in astrophysics. Different theories proposed to explain such phenomena have failed in reproducing the observational properties of the solar…

Solar and Stellar Astrophysics · Physics 2020-09-30 G Guerrero

The structure of electric current and magnetic helicity in the solar corona is closely linked to solar activity over the 11-year cycle, yet is poorly understood. As an alternative to traditional current-free "potential field"…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. R. Yeates , J. A. Constable , P. C. H. Martens

2.5-dimensional magnetohydrodynamic (MHD) simulations are performed with high spatial resolution in order to distinguish between competing models of the coronal heating problem. A single coronal loop powered by Alfv\'{e}n waves excited in…

Solar and Stellar Astrophysics · Physics 2016-08-24 Takuma Matsumoto

The hemispheric pattern of solar filaments is considered in the context of the global magnetic field of the solar corona. In recent work Mackay and van Ballegooijen have shown how, for a pair of interacting magnetic bipoles, the observed…

Astrophysics · Physics 2009-11-13 A. R. Yeates , D. H. Mackay , A. A. van Ballegooijen

We consider a fluid dynamo model generated by the flow on both sides of a moving layer. The magnetic permeability of the layer is larger than that of the flow. We show that there exists an optimum value of magnetic permeability for which…

Fluid Dynamics · Physics 2014-11-04 Johann Herault , François Pétrélis

Advanced 3D radiative MHD simulations now reproduce many properties of the outer solar atmosphere. When including a domain from the convection zone into the corona, a hot chromosphere and corona are self-consistently maintained. Here we…

Solar and Stellar Astrophysics · Physics 2015-10-07 Viggo Hansteen , Nuno Guerreiro , Bart De Pontieu , Mats Carlsson

How and where are coronal loops rooted in the solar lower atmosphere? The details of the magnetic environment and its evolution at the footpoints of coronal loops are crucial to understanding the processes of mass and energy supply to the…

We present a numerical study of dynamo action in a conducting fluid encased in a metallic spherical shell. Motions in the fluid are driven by differential rotation of the outer metallic shell, which we refer to as "the wall". The two…

Fluid Dynamics · Physics 2014-01-08 Celine Guervilly , Toby S. Wood , Nicholas H. Brummell

One of the greatest challenges in solar physics is understanding the heating of the Sun's corona. Most theories for coronal heating postulate that free energy in the form of magnetic twist/stress is injected by the photosphere into the…

Solar and Stellar Astrophysics · Physics 2019-09-25 Kalman J. Knizhnik , Spiro K. Antiochos , James A. Klimchuk , C. Richard DeVore

We analyze direct numerical simulations of large-scale dynamos in inhomogeneous nonhelically driven rotating turbulence with and without shear. The forcing is modulated so that the turbulent intensity peaks in the middle of the…

Plasma Physics · Physics 2025-05-02 Axel Brandenburg , Ethan T. Vishniac

Stars of sufficiently low mass are convective throughout their interiors, and so do not possess an internal boundary layer akin to the solar tachocline. Because that interface figures so prominently in many theories of the solar magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-20 Matthew Browning

The plasma thermodynamics in the solar upper atmosphere, particularly in the corona, are dominated by the magnetic field, which controls the flow and dissipation of energy. The relative lack of knowledge of the coronal vector magnetic field…

Solar and Stellar Astrophysics · Physics 2016-06-29 N. E. Raouafi , P. Riley , S. Gibson , S. Fineschi , S. K. Solanki

We give a short introduction to the subject and review advances in understanding the basic ingredients of the mean-field dynamo theory. The discussion includes the recent analytic and numerical work in developments for the mean…

Solar and Stellar Astrophysics · Physics 2015-06-12 V. V. Pipin

We present direct numerical simulations of dynamo action in a forced Roberts flow. The behavior of the dynamo is followed as the mechanical Reynolds number is increased, starting from the laminar case until a turbulent regime is reached.…

Fluid Dynamics · Physics 2015-06-26 P. D. Mininni , D. C. Montgomery

We focus on the connection between the internal dynamo magnetic field and the stellar wind. If the star has a cyclic dynamo, the modulations of the magnetic field can affect the wind, which in turn can back-react on the boundary conditions…

Solar and Stellar Astrophysics · Physics 2021-03-31 Barbara Perri , Allan Sacha Brun , Antoine Strugarek , Victor Réville

The origin and evolution of the magnetic helicity in the solar corona are not well understood. For instance, the magnetic helicity of an active region is often about $10^{42}$ Mx$^2$ ($10^{26}$ Wb$^{2}$), but the observed processes whereby…

Solar and Stellar Astrophysics · Physics 2009-11-13 S. Regnier
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