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We investigate the excitation of magnetoacoustic-gravity waves generated from localized pulses in the gas pressure as well as in vertical component of velocity. These pulses are initially launched at the top of the solar photosphere that is…

Solar and Stellar Astrophysics · Physics 2015-06-11 K. Murawski , A. K. Srivastava , J. A. McLaughlin , R. Oliver

The solar tachocline is an internal region of the Sun possessing strong radial and latitudinal shears straddling the base of the convective envelope. Based on helioseismic inversions, the tachocline is known to be thin (less than 5\% of the…

Solar and Stellar Astrophysics · Physics 2023-11-22 Antoine Strugarek , Bernadett Belucz , Allan Sacha Brun , Mausumi Dikpati , Gustavo Guerrero

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

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

We propose a solar dynamo model distributed in the bulk of the convection zone with the toroidal magnetic field the flux concentrated in the near-surface layer. We show that if the boundary conditions at the top of the dynamo region allow…

Solar and Stellar Astrophysics · Physics 2015-05-20 V. V. Pipin , A. G. Kosovichev

We present three-dimensional MHD simulations of buoyant magnetic flux tubes that rise through a stratified model convection zone in the presence of solar rotation. The equations of MHD are solved in the anelastic approximation, and the…

Astrophysics · Physics 2009-10-31 W. P. Abbett , G. H. Fisher , Y. Fan

We present a new insight into the propagation of ion magnetoacoustic and neutral acoustic waves in a magnetic arcade in the lower solar atmosphere. By means of numerical simulations, we aim to: (a) study two-fluid waves propagating in a…

Solar and Stellar Astrophysics · Physics 2021-08-18 Błażej Kuźma , Kris Murawski , Zdzisław E. Musielak , Stefaan Poedts , Dariusz Wójcik

An effect of rotation on a developed turbulent stratified convection is studied. Dependencies of the hydrodynamic helicity, the alpha-tensor and the effective drift velocity of the mean magnetic field on the rate of rotation and an…

Astrophysics · Physics 2009-11-07 N. Kleeorin , I. Rogachevskii

Magnetic field emerges at the surface of the Sun as sunspots and active regions. This process generates a poloidal magnetic field from a rising toroidal flux tube, it is a crucial but poorly understood aspect of the solar dynamo. The…

Solar and Stellar Astrophysics · Physics 2016-07-19 Aaron C. Birch , Hannah Schunker , Douglas C. Braun , Robert Cameron , Laurent Gizon , Björn Löptien , Matthias Rempel

Velocity oscillations "measured" simultaneously at the photosphere and the chromosphere -from time series of spectropolarimetric data in the 10830 A region- of different solar magnetic features allow us to study the properties of wave…

Astrophysics · Physics 2011-02-11 Rebecca Centeno , Manuel Collados , Javier Trujillo Bueno

We investigate numerically Alfv\'en waves propagating along an axisymmetric and non-isothermal solar flux tube embedded in the solar atmosphere. The tube magnetic field is current-free and diverges with height, and the waves are excited by…

Solar and Stellar Astrophysics · Physics 2017-02-08 D. Wójcik , K. Murawski , Z. E. Musielak , P. Konkol , A. Mignone

The influence of the basic rotation on anisotropic and inhomogeneous turbulence is discussed in the context of differential rotation theory. An improved representation for the original turbulence leads to a $\Lam$-effect which complies with…

Astrophysics · Physics 2009-11-11 L. L. Kitchatinov , G. Rüdiger

The Sun's complex dynamics is controlled by buoyancy and rotation in the convection zone and by magnetic forces in the atmosphere and corona. While small-scale solar convection is well understood, the dynamics of large-scale flows in the…

We describe the presence of wavefront dislocations in magnetohydrodynamic waves in stratified stellar atmospheres. Scalar dislocations such as edges and vortices can appear in Alfv\'en waves, as well as in general magneto-acoustic waves. We…

Solar and Stellar Astrophysics · Physics 2015-06-16 A. López Ariste , M. Collados , E. Khomenko

We show that simple 2 and 3-layer flux-transport dynamos, when forced at the top by a poloidal source term, can produce a widely varying amplitude of toroidal field at the bottom, depending on how close the meridional flow speed of the…

Solar and Stellar Astrophysics · Physics 2015-05-28 Peter A. Gilman , Mausumi Dikpati

Can atmospheric waves in planet-hosting solar-like stars substantially resonate to tidal forcing? Substantially at a level of impacting the space weather or even of being dynamo-relevant? In particular, low-frequency Rossby waves, which…

Solar and Stellar Astrophysics · Physics 2023-02-22 G. M. Horstmann , G. Mamatsashvili , A. Giesecke , T. V. Zaqarashvili , F. Stefani

We present a series of radiative MHD simulations addressing the origin and distribution of mixed polarity magnetic field in the solar photosphere. To this end we consider numerical simulations that cover the uppermost 2-6 Mm of the solar…

Solar and Stellar Astrophysics · Physics 2015-06-19 M. Rempel

The simplest interior magnetic field B_i that can explain the observed uniform rotation of the Sun's radiative envelope is an axial dipole stabilized by a deep toroidal field. It can explain the uniform rotation only if confined in the…

Solar and Stellar Astrophysics · Physics 2011-02-21 Toby S. Wood , Michael E. McIntyre

The spectrum of oscillation modes of a star provides information not only about its material properties (e.g. mean density), but also its symmetries. Spherical symmetry can be broken by rotation and/or magnetic fields. It has been…

Solar and Stellar Astrophysics · Physics 2018-04-25 Shyeh Tjing Loi , John C. B. Papaloizou

We investigate an intensification mechanism for the magnetic field near the base of the solar convection zone that does not rely on differential rotation. Such mechanism in addition to differential rotation has been suggested by studies of…

Solar and Stellar Astrophysics · Physics 2015-06-11 H. Hotta , M. Rempel , T. Yokoyama