内核地球自转动力学理论的研究进展(Ⅰ)—理论基础

The researchful progress on dynamical theory of Inner core Earth rotation (Ⅰ) —theoretical foundation

地球固体内核(SIC)和地球其余部分之间的引力和压力的耦合作用引起了一个力矩,从而对地球的章动运动产生影响.由于SIC的转动惯量和整体地球转动惯量相比是非常小的,因此可以认为SIC的动力学效应只是导致一个新的章动本征模,其频率与自由核章动(FCN)相差不太远,且对地球章动产生了一个微弱的共振影响.本文在文献〔1〕理论的基础上,对内核地球自转动力学理论进行了更加深入和详细的研究,顾及到高阶引潮力位的影响,介绍了研究内核地球自转的基本假设和定义,引潮力位的复数球函数表示,复数矢量球函数的基本理论等.

Gravitational and pressure couplings between the solid inner core (SIC) and the rest of the Earth give rise to torques through which the inner core influences the nutational motion of the Earth. In view of the very small magnitude of the moment of inertia of SIC relative to that of the the Earth as a whole, one expects from physical considerations that inclusion of SIC in the dynamics should lead to a new nutational normal mode with a natural frequency not too far from that of the free core nutation (FCN), and to an associated weak resonance in the amplitude of forced nutations. Based on theory of literature \, the dynamical theory of the inner core Earth rotation had been lucubrated in particular, and some errors in which had been corrected, and considering influence of high order Tide-Generating Potential (TGP) on Earth rotation. This text introduced definitions, basic assumptions and approximations on dynamical theory of inner Earth model, and the expression of TGP with complex spherical harmonic function, and the basic theory of complex vector spherical harmonic function, and so forth.