液核自由运动的变分方法

VARIATIONAL APPROACH TO FREE MOTION IN THE EARTH’S FLUID OUTER CORE

从流体静力平衡地球的弹性 -引力运动动量方程出发 ,以角动量方程控制弹性地幔、液态外核和弹性内核之间的相对转动 ,在球对称近似下考虑了地幔和内核对液核边界扰动的形变响应 ,并以此作为液核边界运动的约束条件 .根据地球简正模对称性的一般特征 ,建立了自转、非黏性。

This study is based on the elasto gravitational motion equations for a hydrostatic equilibrium Earth. The relative rotation among the solid elastic mantle, the fluid outer core and the solid elastic inner core is governed by the angular momentum equation. The deformation response of the mantle and inner core to the core dynamics, generated by the perturbations on the boundaries of the fluid outer core, is considered on the assumption of the spherical symmetry. This response is employed to constrain the movement on the boundaries of the fluid outer core. Based on the general symmetrical characteristics of the Earth’s eigenmodes, the variational principle of free oscillations in a rotating, inviscid and elliptically stratified fluid outer core is developed and the corresponding functional is deduced.