10:00 〜 10:15
[PPS03-05] THE EARTH ORIENTATION PARAMETERS AND THE VARIATION OF THE SECOND ZONAL HARMONIC OF THE GEOPOTENTIAL
キーワード：the rotary-oscillatory processes, secular variations, stochastic fluctuations, geopotential
The study of the time variations of the geopotential as a result of the rotary-oscillatory processes of the Earth motion is of a significant natural-sciences and practical interest. Oscillations of the Earth′s inertia tensor components depend on many factors, among them the mechanical and physical parameters of the planet, the motions of tide-forming bodies, and the observed large-scale phenomena in nature. Time-dependent variations of these and other factors (regular and irregular oscillations, stochastic fluctuations, secular variations) affect the Earth rotary-oscillatory processes and the rotational parameters of the planet. The dynamic processes of the Earth orientation parameters (EOP) in turn have an effect on its figure and lead to the fluctuations of the gravitation field. Observed variations of the EOP, the variations of the Earth′s gravitational field and oscillations in the large-scale geophysical events appear to be in a considerable correlation.An amplitude-frequency analysis of the rotary-oscillatory Earth motion under the action of gravitational-tidal perturbing torques from the Sun and the Moon is carried out using the classical mechanics' methods. The simulation results of the oscillatory process in the motion of the Earth pole and the variations of the second zonal harmonic of the geopotential are studied. Based on the dynamic Euler-Liouville equations expressions for amplitude and phase of the Earth pole oscillations are obtained. A comparison of the spectral power densities of the time series between the Earth pole coordinates and the variations of the gepotential is carried out. A functional dependence of the aforementioned component of the geopotential from the amplitude and phase of the Earth′s pole oscillatory process is shown.