Related papers: Approaching a realistic force balance in geodynamo…
The equations for fully compressible rotating magnetoconvection are numerically solved in a Cartesian box assuming conditions roughly suitable for the geodynamo. The mean electromotive force describing the generation of mean magnetic flux…
In this thesis, we consider the dynamics of vortices in the easy plane insulating ferromagnet in two dimensions. In addition to the quasiparticle excitations, here spin waves or magnons, this magnetic system admits a family of vortex…
In this paper we discuss a dynamic flux-transport dynamo model that includes the feedback of the induced magnetic field on differential rotation and meridional flow. We consider two different approaches for the feedback: meanfield Lorentz…
We investigate the energy pathways between the velocity and the magnetic fields in a rotating plane layer dynamo driven by Rayleigh-B\'enard convection using direct numerical simulations. The kinetic and magnetic energies are divided into…
The existence of a stably stratified layer underneath the core-mantle boundary (CMB) has been recently revived by corroborating evidences coming from seismic studies, mineral physics and thermal evolution models. Such a layer could find its…
Gyres are central features of large-scale ocean circulation and are involved in transporting tracers such as heat, nutrients, and carbon-dioxide within and across ocean basins. Traditionally, the gyre circulation is thought to be driven by…
The amplification of astrophysical magnetic fields takes place via dynamo instability in turbulent environments. The presence of vorticity is crucial for the dynamo to happen. However, the role of vorticity is not yet fully understood. This…
Motivated by the empirical finding that the known hemispheric rules for the current helicity at the solar surface are not strict, the excitation of small-scale current helicity by the influence of a large-scale helical magnetic background…
We report the results of a magneto-hydrodynamic (MHD) simulation of a convective dynamo in a model solar convective envelope driven by the solar radiative diffusive heat flux. The convective dynamo produces a large-scale mean magnetic field…
The preference for the axial dipole in planetary dynamos is investigated through the analysis of wave motions in spherical dynamo models. Our study focuses on the role of slow magnetostrophic waves, which are generated from localized…
We examine the behaviour of an axisymmetric galactic dynamo model with a radial accretion flow in the disc. We also introduce a vertical magnetic flux through the galactic midplane, to simulate the presence of a large scale magnetic field…
Surface observations indicate that the speed of the solar meridional circulation in the photosphere varies in anti-phase with the solar cycle. The current explanation for the source of this variation is that inflows into active regions…
We generalize the mean field magnetic dynamo to include local evolution of the mean vorticity in addition to the mean magnetic field. The coupled equations exhibit a general mean field dynamo instability that enables the transfer of…
Upper bounds are derived on the amount of magnetic energy that can be generated by dynamo action in collisional and collisionless plasmas with and without external forcing. A hierarchy of mathematical descriptions is considered for the…
We present the results of 3--D nonlinear simulations of magnetic dynamo action by core convection within A-type stars of 2 solar masses, at a range of rotation rates. We consider the inner 30% by radius of such stars, with the spherical…
A multiscale model for real-time simulation of terrain dynamics is explored. To represent the dynamics on different scales the model combines the description of soil as a continuous solid, as distinct particles and as rigid multibodies. The…
High-Velocity Clouds (HVCs) are a major fuel reservoir for star formation in the Galactic disk. Determining their origin and kinematics is thus crucial for understanding Galactic evolution. In this paper, we employ simple test-particle…
The dipole-multipole transition in rapidly rotating dynamos is investigated through the analysis of forced magnetohydrodynamic waves in an unstably stratified fluid. The focus of this study is on the inertia-free limit applicable to…
We investigate how rotating convection responds to the imposition of a latitudinally-varying heat flux at the base of the convective layer. This study is motivated by the solar near-surface shear layer, whose flows are thought to transition…
We seek to quantify the relative contributions of Lorentz forces and aerodynamic drag on the propagation of solar coronal mass ejections (CMEs). We use Graduated Cylindrical Shell (GCS) model fits to a representative set of 38 CMEs observed…