1990 Fiscal Year Final Research Report Summary
Tidal Interaction of the Earth and the Moon and the Lunar Origin
| Project/Area Number |
01540225
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Astronomy
|
|---|
| Research Institution | National Astronomical Observatory, Division of Earth Rotation |
|---|
Principal Investigator |
OOE Masatugu National Astronomical Observatory, Earth Rotation Division, professor, 地球回転研究系, 教授 (00088783)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TAMURA Yoshiaki National Astronomical Observatory, Earth Rotation Division, Assistant Researcher, 地球回転研究系, 助手 (90150002)
SATO Kachishige National Astronomical Observatory, Earth Rotation Division, Assistant Researcher, 地球回転研究系, 助手 (80150001)
SASAKI Hisashi National Astronomical Observatory, Mizusawa Astrogeodynamics Observatory, Associ, 水沢観測センター, 助教授 (20088785)
KINOSHITA Hiroshi National Astronomical Observatory, Astrometry and Celestial Mechanics Division,, 位置力学研究系, 教授 (00012857)
|
|---|
| Project Period (FY) |
1989 – 1990
|
| Keywords | Configuration of Oceans / Ocean Tide model / Tidal Torque / Earth Rotation / Lunar Orbit / Dynamical Evolution |
|---|
| Research Abstract |
Ocean dynamics is extremely important in the study of the Earth-Moon system.
Phase delays in oceanic and solid tides generate torques to perturb the orbital motion of the Moon and the Earth's rotation. At the present day, the ratio between the torques of the oceanic and the solid tide is about 10:1.
The oceanic tide is affected by friction in the oceans and also by the shapes of boundaries. Ocean dynamics seems to be functional to the frequencies of the tidal waves and also is affected by the Earth's spin velocity through the Coriori force.
Many works have been performed by hydrologists since earlier time. We investigated effects of the eddy viscosity and the linear and/or non-linear friction terms in the hydrodynamic equations of one-layered ocean models and showed several experiences in the numerical simulation of ocean tide. Tidal models obtained by the present study were compared with current accurate models.
The distribution of the oceans affects the tidal bulge to remarkable extents. We investigated these effects using a Permian and a Canbrian continental model. Corresponding to the much earlier era, we used more simple and idealized continent models.
The effects of the tidal torques were computed by Lagrangian Planetary equations.
Rigorous formulas were used to take account the eccentricity and the inclination of the orbit and also the prefessional motions in the estimation of the orbital evolution.
Obtained results after these procedures would set bounds to the past variations of the lunar orbit and the Earth's rotation. Simulation studies of the evolution of the Earth-Moon system were presented.
|
Research Products
(8 results)
