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We investigate the long-term evolution of an initially buoyant magnetic flux tube emerging into a gravitationally-stratified coronal hole environment and report on the resulting oscillations and outflows. We perform 2.5D nonlinear numerical…

Solar and Stellar Astrophysics · Physics 2012-04-02 J. A. McLaughlin , G. Verth , V. Fedun , R. Erdélyi

We report on simulations of turbulent, rotating, stratified, magnetohydrodynamic convection in spherical wedge geometry. An initially small-scale, random, weak-amplitude magnetic field is amplified by several orders of magnitude in the…

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

In the solar atmosphere, the jets are ubiquitous and found to be at various spatia-temporal scales. They are significant to understand energy and mass transport in the solar atmosphere. Recently, the high-speed transition region jets are…

Solar and Stellar Astrophysics · Physics 2016-08-24 Liping Yang , Hardi Peter , Jiansen He , Chuanyi Tu , Linghua Wang , Lei Zhang , Xueshang Feng

Recent observational constraints on the internal structure of Jupiter and Saturn suggest that these planets have ``fuzzy" cores, i.e., gradients of the concentration of heavy elements that might span a large fraction of the planet's radius.…

Earth and Planetary Astrophysics · Physics 2024-10-23 J. R. Fuentes , Bradley W. Hindman , Adrian E. Fraser , Evan H. Anders

Motivated by understanding the dynamics of stellar and planetary interiors, we have performed a set of direct numerical simulations of Boussinesq convection in a rotating full sphere. The domain is internally heated with fixed temperature…

Fluid Dynamics · Physics 2021-05-05 Yufeng Lin , Andrew Jackson

We study the onset of magnetoconvection between two infinite horizontal planes subject to a vertical magnetic field aligned with background rotation. In order to gain insight into the convection taking place in the Earth's tangent cylinder…

Fluid Dynamics · Physics 2014-07-04 Kélig Aujogue , Alban Pothérat , Binod Sreenivasan

Dynamo action in planetary cores has been extensively studied in the context of convectively-driven flows. We show in this letter that mechanical forcings, namely tides, libration and precession, are also able to kinematically sustain a…

Fluid Dynamics · Physics 2018-11-07 K. Sandeep Reddy , Benjamin Favier , Michael Le Bars

Our Sun exhibits strong convective dynamo action which results in magnetic flux bundles emerging through the stellar surface as magnetic spots. Global-scale dynamo action is believed to generate large-scale magnetic structures in the deep…

Solar and Stellar Astrophysics · Physics 2014-03-05 Nicholas J. Nelson , Mark S. Miesch

The problem of the turbulent thermal convection in the Earth's liquid core is considered. Following assumptions on decreasing of the spatial scales due to the rapid rotation, we propose the subgrid model of the eddy diffusivity, which is…

Fluid Dynamics · Physics 2007-05-23 M. Reshetnyak , B. Steffen

The meridional circulation of the Sun, which is observed to be poleward at the surface, should have a return flow at some depth. Since large-scale flows like the differential rotation and the meridional circulation are driven by turbulent…

Solar and Stellar Astrophysics · Physics 2020-08-24 Arnab Rai Choudhuri

Earth-like planets in the habitable zone of low-mass stars undergo strong tidal effects that modify their spin states. These planets are expected to host dense atmospheres that can also play an important role in the spin evolution. On one…

Earth and Planetary Astrophysics · Physics 2024-10-02 E. F. S. Valente , A. C. M. Correia , P. Auclair-Desrotour , M. Farhat , J. Laskar

This paper considers the dominant dynamical, thermal and rotational balances within the solar convection zone. The reasoning is such that: Coriolis forces balance pressure gradients. Background vortex stretching, baroclinic torques and…

Solar and Stellar Astrophysics · Physics 2020-10-30 Geoffrey M. Vasil , Keith Julien , Nicholas A. Featherstone

Using direct numerical simulations of three-dimensional magnetohydrodynamic (MHD) turbulence the spatio-temporal behavior of magnetic field fluctuations is analyzed. Cases with relatively small, medium and large values of a mean background…

Plasma Physics · Physics 2016-12-21 R. Lugones , P. Dmitruk , P. D. Mininni , M. Wan , W. H. Matthaeus

This paper reports positive detections of surface differential rotation on two rapidly rotating cool stars at several epochs, by using stellar surface features (both cool spots and magnetic regions) as tracers of the large scale latitudinal…

Astrophysics · Physics 2009-11-10 J. -F. Donati , A. Collier Cameron , P. Petit

The canonical undestanding of stellar convection has recently been put under doubt due to helioseismic results and global 3D convection simulations. This "convective conundrum" is manifested by much higher velocity amplitudes in simulations…

Solar and Stellar Astrophysics · Physics 2024-12-25 Petri J. Käpylä

In Earth's current climate, moist convective updraft speeds increase with surface warming. This trend suggests that very vigorous convection might be the norm in extremely hot and humid atmospheres, such as those undergoing a runaway…

Earth and Planetary Astrophysics · Physics 2023-01-11 Jacob T. Seeley , Robin D. Wordsworth

Planetary atmospheres are commonly thought to result from the efficient outgassing of cooling magma oceans. During this stage, vigorous convective motions in the molten interior are believed to rapidly transport the dissolved volatiles to…

Earth and Planetary Astrophysics · Physics 2022-09-14 Arnaud Salvador , Henri Samuel

Meridional circulation in stellar convection zones is not generally well observed, but may be critical for MHD dynamos. Coriolis forces from differential rotation (DR) play a large role in determining what the meridional circulation is.…

Solar and Stellar Astrophysics · Physics 2015-06-17 Mausumi Dikpati

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

Stably stratified layers are thought to develop at the top of the liquid metallic cores of many terrestrial planets. We consider the case where the thermal gradient is stable but the compositional gradient is unstable, a situation…

Fluid Dynamics · Physics 2025-11-17 Martin Gray , Celine Guervilly , Graeme Sarson