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Magneto-Coriolis (QG-MC) waves are considered an important part of the rapid dynamics of the Earth's outer core. The detailed characteristics of these waves are however still under scrutiny. In this study we explore the sensibility of the…

Geophysics · Physics 2025-05-09 Olivier Barrois , Julien Aubert

Ground observatory and satellite-based determinations of temporal variations in the geomagnetic field probe a decadal to annual time scale range where Earth's core slow, inertialess convective motions and rapidly propagating,…

Geophysics · Physics 2021-02-15 Julien Aubert , Nicolas Gillet

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

Motivated by recent observations of rapid (interannual) signals in the geomagnetic data, and by advances in numerical simulations approaching the Earth's outer core conditions, we present a study on the dynamics of hydromagnetic waves…

Geophysics · Physics 2024-10-24 Olivier Barrois , Julien Aubert

The secular variation of the geomagnetic field suggests that there are anticyclonic polar vortices in the Earth's core. Under the influence of a magnetic field, the polar azimuthal flow is thought to be produced by one or more coherent…

Geophysics · Physics 2023-10-11 Debarshi Majumder , Binod Sreenivasan

Alfv\'en waves propagate in electrically conducting fluids in the presence of a magnetic field. Their reflection properties depend on the ratio between the kinematic viscosity and the magnetic diffusivity of the fluid, also known as the…

Geophysics · Physics 2012-10-17 Nathanaël Schaeffer , Dominique Jault , Philippe Cardin , Marie Drouard

We suggest a mechanism of energy transformation from fast magnetosonic waves propagating across a magnetic field to Alfv{\'e}n waves propagating along the field. The mechanism is based on {\it swing wave-wave interaction} [T.V.…

Astrophysics · Physics 2009-11-07 T. v. Zaqarashvili , B. Roberts

Torsional Alfv\'en waves are promising candidates for transport of energy across different layers of the solar atmosphere and have been theoretically predicted for decades. Previous detections of Alfv\'en waves so far have however mostly…

Solar and Stellar Astrophysics · Physics 2020-01-15 P. Kohutova , E. Verwichte , C. Froment

We consider torsional Alfv\'en waves which may be excited in Jupiter's metallic hydrogen region. These axisymmetric zonal flow fluctuations have previously been examined for incompressible fluids in the context of Earth's liquid iron core.…

Earth and Planetary Astrophysics · Physics 2019-05-29 Kumiko Hori , Robert J. Teed , Chris A Jones

The predominant force balance in rapidly rotating planetary cores is between Coriolis, pressure, buoyancy and Lorentz forces. This magnetostrophic balance leads to a Taylor state where the spatially averaged azimuthal Lorentz force is…

Earth and Planetary Astrophysics · Physics 2015-06-16 Robert J. Teed , Chris A. Jones , Steven M. Tobias

Using advanced numerical magneto-hydrodynamic simulations of the magnetised solar photosphere, including non-grey radiative transport and a non-ideal equation of state, we analyse plasma motions in photospheric magnetic vortices. We…

Solar and Stellar Astrophysics · Physics 2015-06-17 S. Shelyag , P. S. Cally , A. Reid , M. Mathioudakis

In-situ observations in the Earth's and Saturn's magnetosheaths and in the solar wind reveal the presence of Alfv\'en vortices as intermittent structures in the range of scales from fluid lengths down to few ion lengths. The density and the…

Plasma Physics · Physics 2020-04-16 Dusan Jovanovic , Olga Alexandrova , Milan Maksimovic , Milivoj Belic

A weak turbulence theory is derived for magnetohydrodynamics under rapid rotation and in the presence of a large-scale magnetic field. The angular velocity $\Omega_0$ is assumed to be uniform and parallel to the constant Alfv\'en speed…

Geophysics · Physics 2015-06-19 Sebastien Galtier

We solve for waves in an isothermal, stratified medium with a magnetic field that points along a direction perpendicular to that of gravity and varies exponentially in the direction of gravity. We find exact analytical solutions for two…

Solar and Stellar Astrophysics · Physics 2022-06-17 B. Tripathi , Dhrubaditya Mitra

We perform nonlinear general relativistic ideal magnetohydrodynamic simulations of poloidal magnetic fields in rotating polytropic neutron stars. We have three primary goals: i) to understand the nature of magnetohydrodynamic instabilities…

Solar and Stellar Astrophysics · Physics 2012-03-19 Paul D. Lasky , Burkhard Zink , Kostas D. Kokkotas

The recently suggested swing interaction between fast magnetosonic and Alfv\'en waves (2002) is generalized to inhomogeneous media. We show that the fast magnetosonic waves propagating across an applied non-uniform magnetic field can…

Astrophysics · Physics 2007-05-23 B. M. Shergelashvili , T. V. Zaqarashvili , S. Poedts , B. Roberts

We investigate the evolution and origin of small-scale chromospheric swirls by analyzing numerical simulations of the quiet solar atmosphere, using the radiative magnetohydrodynamic code CO$5$BOLD. We are interested in finding their…

Inertial waves propagate in homogeneous rotating fluids, and constitute a challenging and simplified case study for the broader class of inertio-gravity waves, present in all geophysical and astrophysical media, and responsible for…

Fluid Dynamics · Physics 2014-02-12 Anna Rabitti , Leo R. M. Maas

The recently suggested swing interaction between fast magnetosonic and Alfven waves (Zaqarashvili and Roberts 2002) is generalized to inhomogeneous media. We show that the fast magnetosonic waves propagating across an applied non-uniform…

Astrophysics · Physics 2014-10-13 B. M. Shergelashvili , T. V. Zaqarashvili , S. Poedts , B. Roberts

We introduce a quasi-geostrophic model of core dynamics, which aims at describing core processes on geomagnetic secular variation timescales. It extends the formalism of Alfv\'en torsional oscillations by incorporating non-zonal motions.…

Geophysics · Physics 2016-11-27 Elisabeth Canet , Alexandre Fournier , Dominique Jault
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