Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Earth's Inner Core dynamics induced by the Lorentz force   Seismic studies indicate that the Earth's inner core has a complex structure
and exhibits a strong elastic anisotropy with a cylindrical symmetry. Among the
various models which have been proposed to explain this anisotropy, one class
of models considers the effect of the Lorentz force associated with the
magnetic field diffused within the inner core. In this paper we extend previous
studies and use analytical calculations and numerical simulations to predict
the geometry and strength of the flow induced by the poloidal component of the
Lorentz force in a neutrally or stably stratified growing inner core, exploring
also the effect of different types of boundary conditions at the inner core
boundary (ICB). Unlike previous studies, we show that the boundary condition
that is most likely to produce a significant deformation and seismic anisotropy
is impermeable, with negligible radial flow through the boundary. Exact
analytical solutions are found in the case of a negligible effect of buoyancy
forces in the inner core (neutral stratification), while numerical simulations
are used to investigate the case of stable stratification. In this situation,
the flow induced by the Lorentz force is found to be localized in a shear layer
below the ICB, which thickness depends on the strength of the stratification,
but not on the magnetic field strength. We obtain scaling laws for the
thickness of this layer, as well as for the flow velocity and strain rate in
this shear layer as a function of the control parameters, which include the
magnitude of the magnetic field, the strength of the density stratification,
the viscosity of the inner core, and the growth rate of the inner core. We find
that the resulting strain rate is probably too small to produce significant
texturing unless the inner core viscosity is smaller than about $10^{12}$ Pa.s.

10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph