相关论文: Parker's model in geodynamo
Choosing a simple class of flows, with characteristics that may be present in the Earth's core, we study the ability to generate a magnetic field when the flow is permitted to oscillate periodically in time. The flow characteristics are…
Using a one-dimensional $\alpha\omega$-dynamo model appropriate to galaxies, we study the possibility of dynamo action driven by a stochastic alpha effect and shear. To determine the field evolution, one needs to examine a large number of…
Though generated deep inside the convection zone, the solar magnetic field has a direct impact on the Earth space environment via the Parker spiral. It strongly modulates the solar wind in the whole heliosphere, especially its latitudinal…
Magnetic geodesics describe the trajectory of a particle in a Riemannian manifold under the influence of an external magnetic field. In this article, we use the heat flow method to derive existence results for such curves. We first…
The self-consistent two-fluid model of the pulsar magnetosphere is considered. We concentrate on the case of vanishingly small inertia of the particles. Our approach allows to obtain the realistic particle distributions sustaining the…
Parameters of magnetic activity on the solar type stars depend on the properties of the dynamo processes operating in stellar convection zones. We apply nonlinear mean-field axisymmetric $\alpha^2\Omega$ dynamo models to calculate of the…
Magnetic helicity effects are discussed in laboratory and astrophysical settings. First, dynamo action in Taylor-Green flows is discussed for different boundary conditions. However, because of the lack of scale separation with respect to…
The structure of geomagnetism is very complex, and there are still some problems left in magnetohydrodynamics (MHD) simulations. Recently, the macro spin model has been suggested. This is the idea that geomagnetism is described by…
Context: dynamo action in giant planets and rapidly rotating stars leads to a broad variety of magnetic field geometries including small scale multipolar and large scale dipole-dominated topologies. Previous dynamo models suggest that…
The evolution of large-scale magnetic fields in disk galaxies is investigated numerically. The gasdynamical simulations in a disk perturbed by spiral or bar potential are incorporated into the kinematic calculations of induction equations…
The theory of planetary dynamos and its applications to observed phenomena of planetary magnetism are outlined. It is generally accepted that convection flows driven by thermal or compositional buoyancy are the most likely source for the…
We study the magnetic geodesic flows on 2-surfaces having an additional first integral which is independent of the Hamiltonian at a fixed energy level. The following two cases are considered: when there exists a quadratic in momenta…
We investigate the build-up of the galactic dynamo and subsequently the origin of a magnetic driven outflow. We use a setup of an isolated disc galaxy with a realistic circum-galactic medium (CGM). We find good agreement of the galactic…
We present 3D global kinetic pulsar magnetosphere models, where the charged particle trajectories and the corresponding electromagnetic fields are treated self-consistently. For our study, we have developed a cartesian 3D relativistic…
We explore the effect of some simple perturbations on three chaotic models proposed to describe large scale solar behavior via the solar dynamo theory: the Lorenz and the Rikitake systems, and a Van der Pol-Duffing oscillator. Planetary…
We show that hemispherical dynamos can result from weak equatorial symmetry breaking of the flow in the interior of planets and stars. Using a model of spherical dynamo, we observe that the interaction between a dipolar and a quadrupolar…
In this paper we discuss the sign of helicity in the $\alpha$-$\Omega$ dynamo and propose a wave-$\Omega$ model in which the $\alpha$ effect in the geodynamo is induced by helical wave but not helical flow as in the solar dynamo. We then…
In this study, we investigate preferences of dipolar magnetic structure from a seed magnetic field in the rapidly rotating spherical shell dynamo models. In this study, we set up a realistic model to show the effect of the Lorentz force in…
The nonlocal alpha-effect of Babcock-Leighton type is not prone to the catastrophic quenching due to conservation of magnetic helicity. This is shown with a dynamo model, which jointly applies the nonlocal alpha-effect, the diamagnetic…
A theory of two-dimensional plasma evolution with Beltrami-like flow and field due to baroclinic effect has been presented. Particular solution of the nonlinear two-fluid equations is obtained. This simple model can explain the generation…