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Related papers: Dipolar dynamos in stratified systems

200 papers

(abidged) Context: Stellar convection zones are characterized by vigorous high-Reynolds number turbulence at low Prandtl numbers. Aims: We study the dynamo and differential rotation regimes at varying levels of viscous, thermal, and…

Solar and Stellar Astrophysics · Physics 2017-02-22 P. J. Käpylä , M. J. Käpylä , N. Olspert , J. Warnecke , A. Brandenburg

We investigate and quantify the effect of stratification on the stability time of a stably stratified rest state for the 2D inviscid Boussinesq system on $\mathbb{R}^2$. As an important consequence, we obtain stability of the steady state…

Analysis of PDEs · Mathematics 2025-11-20 Catalina Jurja , Haram Ko

Convection is ubiquitous in stellar and planetary interiors where it likely plays an integral role in the generation of magnetic fields. As the interiors of these objects remain hidden from direct observation, numerical models of convection…

Solar and Stellar Astrophysics · Physics 2026-01-22 Brandon J. Lazard , Nicholas A. Featherstone , Jonathan M. Aurnou

Understanding the stability of the magnetic field in radiation zones is of crucial importance for various processes in stellar interior like mixing, circulation and angular momentum transport. The stability properties of a star containing a…

Solar and Stellar Astrophysics · Physics 2015-05-30 Alfio Bonanno , Vadim Urpin

A layered system of two-dimensional planes containing fermionic polar molecules can potentially realize a number of exotic quantum many-body states. Among the predictions, are density-wave instabilities driven by the anisotropic part of the…

Quantum Gases · Physics 2015-03-18 N. T. Zinner , G. M. Bruun

Recent work by Mitra et al. (2014) has shown that in strongly stratified forced two-layer turbulence with helicity and corresponding large-scale dynamo action in the lower layer, a magnetic field occurs in the upper layer in the form of…

Solar and Stellar Astrophysics · Physics 2015-06-03 Sarah Jabbari , Axel Brandenburg , Nathan Kleeorin , Dhrubaditya Mitra , Igor Rogachevskii

The elastic interaction between kinks (and antikinks) within domain walls plays a pivotal role in shaping the domain structure, and their dynamics. In bulk materials, kinks interact as elastic monopoles, dependent on the distance between…

Mesoscale and Nanoscale Physics · Physics 2024-11-04 John J R Scott , Guangming Lu , Brian J. Rodriguez , Ian MacLaren , Ekhard K. H. Salje , Miryam Arredondo

We perform direct numerical simulations of the equations of magnetohydrodynamics with external random forcing and in the presence of gravity. The domain is divided into two parts: a lower layer where the forcing is helical and an upper…

Solar and Stellar Astrophysics · Physics 2014-10-20 Dhrubaditya Mitra , A. Brandenburg , N. Kleeorin , I. Rogachevskii

It has been recently shown numerically that a small-scale dynamo (SSD) instability could be possible in solar-like low magnetic Prandtl number plasmas. It has been proposed that the presence of SSD can potentially have a significant impact…

Solar and Stellar Astrophysics · Physics 2025-04-09 Jörn Warnecke , Maarit J. Korpi-Lagg , Matthias Rheinhard , Mariangela Viviani , Ameya Prabhu

Resistive tearing instabilities are common in fluids that are highly electrically conductive and carry strong currents. We determine the effect of stable stratification on the tearing instability under the Boussinesq approximation. Our…

Fluid Dynamics · Physics 2024-11-20 Scott J. Hopper , Toby S. Wood , Paul J. Bushby

In this manuscript, we consider the $3$D Boussinesq equations for stably stratified fluids with the horizontal viscosity and thermal diffusivity and investigate the large time behavior of the solutions. Making use of the anisotropic…

Analysis of PDEs · Mathematics 2024-10-14 Mikihiro Fujii , Yang Li

We consider the 2D Boussinesq equations with a velocity damping term in a strip $\mathbb{T}\times[-1,1]$, with impermeable walls. In this physical scenario, where the \textit{Boussinesq approximation} is accurate when density/temperature…

Analysis of PDEs · Mathematics 2018-10-02 Angel Castro , Diego Córdoba , Daniel Lear

We present results from simulations of rotating magnetized turbulent convection in spherical wedge geometry representing parts of the latitudinal and longitudinal extents of a star. Here we consider a set of runs for which the density…

Solar and Stellar Astrophysics · Physics 2013-11-19 Petri J. Käpylä , Maarit. J. Mantere , Elizabeth Cole , Jörn Warnecke , Axel Brandenburg

Analyses of recent helioseismic data have produced ample evidence for substantial dynamical variation of the differential rotation within the solar convection zone. Given the inevitable difficulties in resolving the precise nature of…

Astrophysics · Physics 2009-11-10 Eurico Covas , David Moss , Reza Tavakol

In classical mechanics, solutions can be classified according to their stability. Each of them is part of the possible trajectories of the system. However, the signatures of unstable solutions are hard to observe in an experiment, and most…

Pattern Formation and Solitons · Physics 2021-05-05 Jaime Cisternas , Paula Mellado , Felipe Urbina , Cristóbal Portilla , Miguel Carrasco , Andrés Concha

We report the results of three-dimensional numerical simulations of convection-driven dynamos in relatively thin rotating spherical shells that show a transition from an strong non-oscillatory dipolar magnetic field to a weaker regularly…

Fluid Dynamics · Physics 2011-02-08 R. D. Simitev , F. H. Busse , A. G. Kosovichev

In the paper we study the helicity density patterns which can result from the emerging bipolar regions. Using the relevant dynamo model and the magnetic helicity conservation law we find that the helicity density pattern around the bipolar…

Solar and Stellar Astrophysics · Physics 2021-02-17 V. V. Pipin

Surface magnetic fields have a strong impact on stellar mass loss and rotation and, as a consequence, on the evolution of massive stars. In this work we study the influence of an evolving dipolar surface fossil magnetic field with an…

Solar and Stellar Astrophysics · Physics 2019-03-27 Z. Keszthelyi , G. Meynet , C. Georgy , G. A. Wade , V. Petit , A. David-Uraz

This paper examines the stability threshold at high Reynolds numbers $\textbf{Re}$ for the three-dimensional Boussinesq equations with rotation on the domain $\Omega=\{(x,\,y,\,z)\in \mathbb{T} \times \mathbb{R} \times \mathbb{T}\}$ around…

Analysis of PDEs · Mathematics 2026-02-12 Wenting Huang , Zekai Luo , Ying Sun , Xiaojing Xu

The outer areas of Jupiter and Saturn have multiple zonal winds, reaching the high latitudes, that penetrate deep into the planets' interiors, as suggested by gravity measurements. These characteristics are replicable in numerical…

Earth and Planetary Astrophysics · Physics 2024-02-02 Paula N. Wulff , Ulrich R. Christensen , Wieland Dietrich , Johannes Wicht