Dynamic Processes at the Boundary of the Earth's Liquid Core

The investigation of the dynamics of the Earth's magnetic field due to three-dimensional large-scale motion of the inviscid, incompressible, and ideally conducting inhomogeneous rotating fluid, concentrated in liquid Earth’s core. The proposed mathematical model of investigated physical process is a closed system of equations consisting of the equations of hydrodynamics taking into account the Earth's rotation, the Lorentz force and the corresponding equations of magnetic dynamics with the required boundary conditions. The analysis of a mathematical model suitable for calculating three-dimensional movements with high temporal scale and spatial horizontal scale, comparable with radius of the Earth. The main idea of the analysis consists in constructing a scheme of successive approximations, in which the geostrophic approximation is the first step. This method of analysis allows, not limited to heuristic reasonings, to deduce the General geostrophic equations, describing the motion of both homogeneous and heterogeneous electrically conducting rotating fluid. An analytical solution to the system of nonlinear equations modeling the geostrophic motion in a spherical layer of ideal conductive inhomogeneous rotating fluid. Structure analysis presents the fields of the MHD variables allows us to conclude the existence of strong changes in a thin layer adjacent to the boundary with the mantle.