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Motivated by observations of turbulence in the strongly stratified ocean thermocline, we use direct numerical simulations to investigate the interaction of a sinusoidal shear flow and a large-amplitude internal gravity wave. Despite strong…

Fluid Dynamics · Physics 2023-06-22 Christopher J. Howland , John R. Taylor , C. P. Caulfield

A rigorous theory for the generation of a large-scale magnetic field by random non-helically forced motions of a conducting fluid combined with a linear shear is presented in the analytically tractable limit of low Rm and weak shear. The…

Astrophysics · Physics 2011-12-15 T. Heinemann , J. C. McWilliams , A. A. Schekochihin

Inspired by observations of sunspots embedded in active regions, it is often assumed that large-scale, strong magnetic flux emerges from the Sun's deep interior in the form of arched, cylindrical structures, colloquially known as flux…

Solar and Stellar Astrophysics · Physics 2022-04-28 Bhishek Manek , Christina Pontin , Nicholas Brummell

The nonlinear mean-field dynamo due to a shear-current effect in a nonhelical homogeneous turbulence with a mean velocity shear is discussed. The transport of magnetic helicity as a dynamical nonlinearity is taken into account. The…

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

Magnetic quenching of turbulent thermal diffusivity leads to instability of the large-scale field with the production of spatially isolated regions of enhanced field. This conclusion follows from a linear stability analysis in the framework…

Solar and Stellar Astrophysics · Physics 2019-05-01 Leonid L. Kitchatinov

This article is focused on the dynamics of a rotating electrically conducting fluid in a turbulent state. As inside the Earth's core or in various industrial processes, a flow is altered by the presence of both background rotation and a…

Fluid Dynamics · Physics 2011-04-01 Benjamin F. N. Favier , Fabien S. Godeferd , Claude Cambon

This paper presents the results of the analysis of 3D simulations of solar magneto-convection that include the joint action of the ambipolar diffusion and the Hall effect. Three simulation-runs are compared: one including both ambipolar…

Solar and Stellar Astrophysics · Physics 2021-01-20 E. Khomenko , M. Collados , N. Vitas , P. A. Gonzalez-Morales

We demonstrate that at long times the rate of passive scalar decay in a turbulent, or simply chaotic, flow is dominated by regions (in real space or in inverse space) where mixing is less efficient. We examine two situations. The first is…

Chaotic Dynamics · Physics 2009-11-07 M. Chertkov , V. Lebedev

We examine the role of anisotropic turbulence on the shear instabilities in a stratified flow. Such turbulence is expected to occur in the radiative interiors of stars, due to their differential rotation and their strong stratification, and…

Astrophysics · Physics 2007-05-23 S. Talon , J. -P. Zahn

Initial results from the Madison Dynamo Experiment provide details of the inductive response of a turbulent flow of liquid sodium to an applied magnetic field. The magnetic field structure is reconstructed from both internal and external…

Plasma Physics · Physics 2007-05-23 M. D. Nornberg , E. J. Spence , R. D. Kendrick , C. M. Jacobson , C. B. Forest

The differential rotation of the sun, as deduced from helioseismology, exhibits a prominent radial shear layer near the top of the convection zone wherein negative radial gradients of angular velocity are evident in the low- and…

Astrophysics · Physics 2009-11-07 M. L. DeRosa , P. A. Gilman , J. Toomre

Internal gravity waves excited by overshoot at the bottom of the convection zone can be influenced by rotation and by the strong toroidal magnetic field that is likely to be present in the solar tachocline. Using a simple Cartesian model,…

Solar and Stellar Astrophysics · Physics 2015-05-27 K. B. MacGregor , T. M. Rogers

In a strongly magnetized, magnetically dominated relativistic plasma, Alfv\'enic turbulence can extend to scales much smaller than the particle inertial scales. It leads to an energy cascade somewhat analogous to inertial- or…

Plasma Physics · Physics 2024-04-04 Cristian Vega , Stanislav Boldyrev , Vadim Roytershteyn

We discuss a mean-field theory of generation of large-scale vorticity in a rotating density stratified developed turbulence with inhomogeneous kinetic helicity. We show that the large-scale nonuniform flow is produced due to ether a…

Fluid Dynamics · Physics 2018-06-06 N. Kleeorin , I. Rogachevskii

Geostrophic jets propagating as Alfv\'en waves are shown to arise ina rapidly rotating spherical shell permeated by a magnetic field among the transient motions set up by an impulsive rotation of the inner core. These axially invariant…

Geophysics · Physics 2008-09-22 Dominique Jault

It was recently predicted [J. Phys.: Condens. Matter 18, 11059 (2006)] that turbulence of the electron flow may develop at nonadiabatic nanoscale junctions under appropriate conditions. Here we show that such an effect leads to an…

Other Condensed Matter · Physics 2008-03-24 Neil Bushong , Yuriy Pershin , Massimiliano Di Ventra

For over a century, the Hall effect, a transverse effect under out-of-plane magnetic field or magnetization, has been a cornerstone for magnetotransport studies and applications. Modern theoretical formulation based on the Berry curvature…

Mesoscale and Nanoscale Physics · Physics 2024-12-05 Ayano Nakamura , Shinichi Nishihaya , Hiroaki Ishizuka , Markus Kriener , Yuto Watanabe , Masaki Uchida

We study how anisotropy of turbulent convection affects diffusion of large-scale magnetic fields and the dynamo process on the Sun. The effect of anisotropy is calculated in a mean-field magneto-hydrodynamics framework using the minimal…

Solar and Stellar Astrophysics · Physics 2015-06-16 V. V. Pipin , A. G. Kosovichev

Recently, it has been realized that magnetic plasma turbulence and magnetic field reconnection are inherently related phenomena. Turbulent fluctuations generate regions of a sheared magnetic field that become unstable to the tearing…

Plasma Physics · Physics 2023-01-11 Stanislav Boldyrev , Nuno F. Loureiro

We investigate the radial transport of magnetic flux in a thin accretion disc, the turbulence being modelled by effective diffusion coefficients (viscosity and resistivity). Both turbulent diffusion and advection by the accretion flow…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Jerome Guilet , Gordon I. Ogilvie