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Related papers: Quasi-geostrophic convection-driven dynamos in a t…

200 papers

In a previous paper, Oruba, Soward & Dormy (J.Fluid Mech., vol.818, 2017, pp.205-240) considered the primary quasi-steady geostrophic (QG) motion of a constant density fluid of viscosity $\nu$ that occurs during linear spin-down in a…

Fluid Dynamics · Physics 2020-03-18 L. Oruba , A. M. Soward , E. Dormy

A three-dimensional (3D) MHD model is applied to simulate the evolution of a large-scale magnetic field in a barred galaxy possessing a gaseous halo extending to about 2.8 kpc above the galactic plane. As the model input we use a…

Astrophysics · Physics 2009-11-07 K. Otmianowska-Mazur , D. Elstner , M. Soida , M. Urbanik

Among planetary dynamos, the magnetic field of Saturn stands out in its exceptional level of axisymmetry. One of its peculiar features is that the magnetic dipole mode is tilted with respect to the planetary rotation axis by only $\approx…

Earth and Planetary Astrophysics · Physics 2022-04-06 Rakesh K. Yadav , Hao Cao , Jeremy Bloxham

We performed 2D and full 3D magnetohydrodynamic simulations of disk accretion to a rotating star with an aligned or misaligned dipole magnetic field. We investigated the rotational equilibrium state and derived from simulations the ratio…

The transport induced by ocean mesoscale eddies remains unresolved in most state-of-the-art climate models and needs to be parameterized instead. The natural scale separation between the forcing and the emergent turbulent flow calls for a…

Fluid Dynamics · Physics 2023-05-31 Julie Meunier , Benjamin Miquel , Basile Gallet

Quasi-particle picture in a magnetic field is pursued for dynamical spin and charge correlation functions of the one-dimensional supersymmetric t-J model with inverse-square interaction. With use of exact diagonalization and the asymptotic…

Strongly Correlated Electrons · Physics 2009-10-31 Yasuhiro Saiga , Yoshio Kuramoto

Some of the small-scale solar magnetic flux can be attributed to a small-scale dynamo (SSD) operating in the near-surface convection. The SSD fields have consequences for solar granular convection, basal flux, as well as chromospheric…

The mechanism by which the Earth's magnetic field is generated is thought to be thermal convection in the metallic liquid iron core. Computational considerations previously restricted most numerical simulations to a regime where the…

Geophysics · Physics 2017-01-17 Andrey Sheyko , Christopher Finlay , Jean Favre , Andrew Jackson

Density inhomogeneities are ubiquitous in space and astrophysical plasmas, in particular at contact boundaries between different media. They often correspond to regions that exhibits strong dynamics on a wide range of spatial and temporal…

Plasma Physics · Physics 2021-08-04 F. Lavorenti , P. Henri , F. Califano , S. Aizawa , N. André

Hydrodynamic and magnetohydrodynamic numerical studies of a mechanically forced two-vortex flow inside a sphere are reported. The simulations are performed in the intermediate regime between the laminar flow and developed turbulence where a…

Fluid Dynamics · Physics 2015-05-14 K. Reuter , F. Jenko , A. Tilgner , C. B. Forest

Context: Large-scale magnetic fields resulting from hydromagnetic dynamo action may differ substantially in their time dependence. Cyclic field variations, characteristic for the solar magnetic field, are often explained by an important…

Solar and Stellar Astrophysics · Physics 2015-05-27 M. Schrinner , L. Petitdemange , E. Dormy

Within the resistive magnetohydrodynamic model, high-Lundquist number reconnection layers are unstable to the plasmoid instability, leading to a turbulent evolution where the reconnection rate can be independent of the underlying…

Plasma Physics · Physics 2019-09-04 A. Stanier , W. Daughton , A. Le , X. Li , R. Bird

The observed surface dynamics of Jupiter and Saturn is dominated by a banded system of zonal winds. Their depth remains unclear but they are thought to be confined to the very outer envelopes where hydrogen remains molecular and the…

Earth and Planetary Astrophysics · Physics 2013-06-27 Lúcia D. V. Duarte , Thomas Gastine , Johannes Wicht

We analyse the anisotropy of homogeneous turbulence in an electrically conducting fluid submitted to a uniform magnetic field, for low magnetic Reynolds number, in the quasi- static approximation. We interpret disagreeing previous…

Fluid Dynamics · Physics 2012-07-23 B. F. N. Favier , F. S. Godeferd , C. Cambon , A. Delache , W. J. T. Bos

Using the magnetohydrodynamic (MHD) description, we develop a nonlinear dynamo model that couples the evolution of the large scale magnetic field with turbulent dynamics of the plasma at small scale by electromotive force (e.m.f.) in the…

Earth and Planetary Astrophysics · Physics 2011-09-29 Giuseppina Nigro , Pierlugi Veltri

The planet Mercury possesses a small but highly dynamic magnetosphere in which the role and dynamics of electrons are still largely unknown. We aim at modeling the global dynamics of solar wind electrons impinging on Mercury's…

Large-scale planetary or stellar magnetic fields generated by a dynamo effect are mostly attributed to flows forced by buoyancy forces in electrically conducting fluid layers. However, these large-scale fields may also be controlled by…

Solar and Stellar Astrophysics · Physics 2015-06-22 David Cébron , Rainer Hollerbach

We study plasmons in a rectangular two-dimensional (2D) electron system in the vicinity of a planar metal electrode (gate) and in the presence of a perpendicular uniform magnetic field, using Maxwell's equations and neglecting retardation…

Mesoscale and Nanoscale Physics · Physics 2024-07-24 D. A. Rodionov , I. V. Zagorodnev

The dynamo effect is the most popular candidate to explain the non-primordial magnetic fields of astrophysical objects. Although many systematic studies of parameters have already been made to determine the different dynamical regimes…

Fluid Dynamics · Physics 2020-07-14 Mélissa D. Menu , Ludovic Petitdemange , Sébastien Galtier

We present a three-dimensional model of rotating convection combined with a simplified corona in spherical coordinates. The motions in the convection zone generate a large-scale magnetic field that gets sporadically ejected into the outer…

Solar and Stellar Astrophysics · Physics 2012-07-17 Jörn Warnecke , Petri J. Käpylä , Maarit. J. Mantere , Axel Brandenburg