A Simple Theory on the Dynamical Effects of a Stratified Fluid Core upon Nutational Motion of the Earth
A Simple Theory on the Dynamical Effects of a Stratified Fluid Core upon Nutational Motion of the Earth
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DOI：
10.1007/978-94-010-9568-6_27
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
T. Sasao;S. Okubo;M. Saito
中科院分区：
文献类型：
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作者：
T. Sasao;S. Okubo;M. Saito
Molodensky（1961）关于分层流体外核对章动和地球日潮汐动力学效应的理论在一个新的可能更简单的基础上得到了重建。一个与莫洛坚斯基的理论相当的理论是基于两个关于整个地球和流体外核的角动量平衡的线性方程，这两个方程与庞加莱（1910）的著名方程的不同之处仅在于存在由于整个地球和流体外核的变形而产生的惯性积。惯性积由四个参数表征，这四个参数对于每个地球模型都很容易通过通常的固体潮方程计算。两个参数之间存在互易关系。Adams-Wiliamson条件不是该理论的必要前提。计算了三种地球模型的章动振幅和潮汐重力因子。定性地将耗散核幔耦合引入到理论中。所得方程的形式与Sasao，Okamoto和Sakai（1977）的方程相同。导出了地月系统由于核幔摩擦引起的长期变化公式，作为理论内在一致性的证据。
The theory of Molodensky (1961) on dynamical effects of a stratified fluid outer core upon nutations and diurnal Earth tides is reconstructed on a new and probably much simpler ground. A theory equivalent to Molodensky's is well represented on the basis of two linear equations for angular-momentum balance of the whole Earth and the fluid outer core, which differ from the well-known equations of Poincaré (1910) only in the existence of products of inertia due to deformations of the whole Earth and fluid outer core. The products of inertia are characterized by four parameters which are easily computed for every Earth model by the usual Earth tide equations. A reciprocity relation exists between two of the parameters. The Adams-Wiliamson condition is not a necessary premise of the theory. Amplitudes of nutations and tidal gravity factors are computed for three Earth models. A dissipative core-mantle coupling is introduced into the theory qualitatively. The resulting equations are expressed in the same form as those of Sasao, Okamoto and Sakai (1977). Formulae for secular changes in the Earth-Moon system due to the core-mantle friction are derived as evidences of internal consistency of the theory.