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Climate Excitation of Polar Motion
2002Recently, Gross (2000) demonstrated that the Chandler wobble may be excited by a combination of oceanic and atmospheric processes during 1985–1996 using observational records and a general ocean circulation model. Aoyama and Naito (2001) suggest that the atmospheric wind and pressure variations by themselves maintain a major part of the observed ...
E. W. Leuliette, J. M. Wahr
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On the Excitation and Damping of the Polar Motion
Publications of the Astronomical Society of Japan, 1965Abstract In the present paper, the excitation and damping of the polar motion are treated as a series of stochastic process, and the damping coefficient and constants concerning to the excitation of the polar motion are determined. The damping .coefficient thus determined is 0.320 (year–1), which is very close to that obtained by WALKER ...
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Excitation of polar motion by earthquake displacement field
Chinese Astronomy and Astrophysics, 1982Abstract We discuss the excitation of polar motion by earthquake displacement field. Instead of the usual static equilibrium equations in the literature, we use an improved set as given in /1/, which guarantee continuity at the core-mantle boundary. We take the parameter values of three earthquakes from /2/.
null Song Guo-xuan +2 more
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Polar motion excitation – A broad-band perspective
Journal of Geodynamics, 2012Abstract Many recent studies of polar motion have demonstrated that climate-related variations (air and water motion and mass redistribution) provide the dominant source of polar motion excitation over virtually the entire band of frequencies that can be studied with modern space geodetic data.
Clark R. Wilson, Jianli Chen
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Regional Atmospheric Angular Momentum Contributions to Polar Motion Excitation
Journal of Geophysical Research: Solid Earth, 1998We focus on a regional analysis of equatorial components of the effective atmospheric angular momentum (EAAM) functions that measure the excitation of polar motion. These functions are computed from National Centers for Environmental Prediction and National Center for Atmospheric Research (NCEP/NCAR) reanalysis data both globally and in 108 geographic ...
Jolanta Nastula, David Salstein
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Air and Water Contributions to Polar Motion Excitation
1990Modern space-geodetic observations show that the Earth’s polar motion occurs over a broad range of frequencies from below the Chandler frequency at fractions of a cycle per year (cpy), up to tens of cycles per year. Across this entire frequency band, the excitation sources for polar motion are only partially understood.
Clark R. Wilson, John Kuehne
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Regional contributions to the atmospheric excitation of rapid polar motions
Journal of Geophysical Research: Atmospheres, 1989Daily fields of surface pressure produced by the National Meteorological Center during 1981–1985 are used to identify the sectors of the globe over which changes in atmospheric mass contribute most importantly to the excitation of intraseasonal variations in the Earth's polar axis.
David A. Salstein, Richard D. Rosen
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Hydrological excitation of polar motion
2008First harmonics of the gravity field (C21 and S21), derived from the Gravity Recovery and Climate Experiment (GRACE), and processed at different institutes, are used to determine thehydrological equatorial excitation function of polar motion. For that purpose time-variable gravity field solutions are made tidal free and free from modelled non-tidal ...
Seoane, Lucia +3 more
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On Some Properties of the Excitation and Damping of the Polar Motion
Publications of the Astronomical Society of Japan, 1972Abstract Values of the Chandlerian period and the damping coefficient of the polar motion are calculated for ten year intervals from 1900.0 to 1970.0, using a method developed by Sekiguchi (1966). The damping coefficient varies between 0.074 and 0.008 year−1 through this period, and is correlative with the variation of the Chandlerian ...
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On the Excitation of Short-Term Variations in the Length of the Day and Polar Motion
Geophysical Surveys, 1984Variations in the distribution of mass within the atmosphere and changes in the pattern of winds produce fluctuations in all three components of the angular momentum of the atmosphere on time-scales upwards of a few days. It has been shown that variations in the axial component of atmospheric angular momentum during the Special Observing Periods in the
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