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2 edition of Prediction of polar motions from air and water excitations. found in the catalog.

Prediction of polar motions from air and water excitations.

Jan Vondrak

Prediction of polar motions from air and water excitations.

by Jan Vondrak

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Published by Dept. of Geodetic Science and Surveying, Ohio State University in Columbus, Ohio .
Written in English


Edition Notes

SeriesReport / Dept. of Geodetic Science and Surveying, Ohio State University -- no.402
ContributionsOhio State University. Department of Geodetic Science and Surveying.
The Physical Object
Pagination60p. ;
Number of Pages60
ID Numbers
Open LibraryOL13792465M

polar motion prediction that uses such a "fixed-period" scheme; it, as far as I know, has remained the only published work on the subject to date. The present paper is an experimental study of the predictability of the polar motion based on a homogeneous BIH data set for the period It will be shown that with a floating-. The polar motion data from which the extrapolation model of the Chandler circle, annual and semiannual ellipses and a bias was computed was equal to one and three years. The increase of the length of polar motion data going into the least-squares extrapolation model increases the polar prediction errors (Kosek et al. b).

Analysis. Polar motion is defined relative to a conventionally defined reference axis, the CIO (Conventional International Origin), being the pole's average location over the year It consists of three major components: a free oscillation called Chandler wobble with a period of about days, an annual oscillation, and an irregular drift in the direction of the 80th meridian west, which. ocean point. These excitations for the length of day and polar motion, given for mass, mass as corrected by IB, and motion, are the basic angular momentum values collected by the SBA and are reviewed in Salstein et al. (; see that paper’s Figs. 1 and 2 for formulas, and sample angular momentum series). The SBA collects such excitation.

  LEWISTON, Maine, Aug. 26, /PRNewswire/ -- If you didn't like last winter, you may want to stop reading right now. The Farmers' Almanac's extended weather forecast is calling for a "Polar. relationship of earthquakes to polar motion. Data produced by classical methods, since , are insufficient to permit accurate prediction of polar motion, to determine the amount or existence of secular drift of the pole, or to'detect the possible effects of earthquakes on polar motion. 'For these and other reasons, the international participants.


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Prediction of polar motions from air and water excitations by Jan Vondrak Download PDF EPUB FB2

Polar motion excitations. Observed polar motion excitations χ 1 and χ 2 are shown in Figs 1(a) and (b) in red curves. AAM and OAM contributions from NCEP reanalysis and ECCO OGCM are in blue and green curves, respectively. Clearly, the atmosphere plays a major role in exciting polar motion, especially in by:   Most recent studies (e.g.

Chen and Wilson, ) conclude that virtually all polar motion in this band is forced by some combination of climate-related mass redistribution (air and water) or relative motion (winds and ocean currents). Yet, when climate series are compared with observed polar motion in detail, coherence is not high at all Author: Clark R.

Wilson, Jianli Chen. [1] Polar motion excitation involves mass redistributions and motions of the Earth system relative to the mantle, as well as the frequency‐dependent rheology of the Earth, where the latter has recently been modeled in the form of frequency‐dependent Love numbers and polar motion transfer functions.

At seasonal and intraseasonal time scales, polar motions are dominated by angular momentum Cited by:   1. Introduction. Polar motion excitation involves the mass redistributions and motions within the Earth system relative to the mantle, as well as the Earth's responses to these perturbations.At seasonal and intra-seasonal time scales, mass redistributions and relative motions are dominated by changes in the Earth's fluid envelopes, namely, the atmosphere, oceans, and continental water Cited by: 6.

The magnitude of the estimates suggests that continental water storage does not account for the unexplained portion of polar motion. A discrepancy in polar motion excitation persists over a broad band of frequencies including the annual frequency, where air and water are the certain cause.

This implies that there are additional polar motion Cited by: 7. Introduction [2] At timescales of a few years and less, Earth's rotational changes (polar motion X and Y and length of day (LOD)) are primarily driven by air and water mass redistribution and movement within the Earth system.

Atmospheric winds and surface pressure changes are considered to be the dominant contributors to LOD variation [e.g., Barnes et al., ; Eubanks et al., ; Hide. Continental hydrological loading, by land water, snow, and ice, is an element that is strongly needed for a full understanding of the excitation of polar motion.

In this study we compute different estimations of hydrological excitation functions of polar motion (Hydrological Angular Momentum - HAM) using various variables from the Global Land Data Assimilation System (GLDAS) models of land. Non-atmospheric polar motion excitations are readily acquired using the differences between ‘observed’ and atmospheric polar motion excitations.

3 Oceanic Angular Momentum Excitations. The OAM excitations can be computed using velocities of ocean currents, sea level, temperature, salinity and ocean bottom pressure, estimated from OGCMs.

The new Release (RL06) Gravity Recovery and Climate Experiment (GRACE) gravity field solutions are evaluated by converting them into equatorial effective angular momentum functions (so-called excitation functions) for polar motion and comparing these to respective time series based on space-geodetic observations (geodetic excitation).

The same is performed for the older RL05. The real-time estimation of polar motion (PM) is needed for the navigation of Earth satellite and interplanetary spacecraft. However, it is impossible to have real-time information due to the complexity of the measurement model and data processing.

Various prediction methods have been developed. However, the accuracy of PM prediction is still not satisfactory even for a few days in the. Finally, GRACE-based excitations reveal the possible influence of water storage variations in exciting polar motion around the frequency of 3 cycles per year.

View Show abstract. The main aim of this study is to show the influence of variables from different hydrological processes including evapotranspiration, runoff, snowmelt and soil moisture, on polar motion excitations.

Nastula J, Pasnicka M, Kolaczek B () Comparison of the geophysical excitations of polar motion from the period: – Acta Geophys 59(3)– CrossRef Google Scholar Quinn K, Ponte RM () Estimating weights for the use of time-dependent gravity recovery and climate experiment data in constraining ocean models.

and form an important component of polar motion excitations (24). The variations in polar motion induced by polar ice sheets, global GICs, and TWS are shown in Fig. Because the pole excitations are related to the degree 2 order 1 spherical harmonic (SH) coefficients of L(q, l, t), c 1(t)andc 2(t) are greatly sensitive to mass changes occur.

Polar motion. The motion of the rotation axis of the earth relative to the crust has three major components. A free oscillation with period about days (Chandler wobble) and an annual oscillation forced by the seasonal displacement of air and water masses, beating which each other, give the characteristic pulsating shape of the motion, represented in Figure 1 (dots at 5-day intervals).

Air Quality Satellites D.A., Atmospheric excitation of polar motion. In Polar Motion: Historical and scientific problems, ASP Conference Series, International Astronomical Union Efforts to assess dynamic forecasts of the atmospheric polar motion excitations have demonstrated positive skill out to at least 10 days for the.

Chen J, Wilson C. Hydrological excitations of polar motion, – Geophys J Int. ; (3)– doi: /jXx. [Google Scholar] Chin TM, Gross RS, Dickey JO.

Modeling and forecast of the polar motion excitation functions for short-term polar motion prediction. *denotes the report is not available as an original bound copy, but a photo-copy can be provided.

Habana, Nlingilili, Gravity Recovery by Kinematic State Vector Perturbation from Satellite-to-Satellite Tracking for GRACE-like Orbits over Long Arcs [pdf], vi+ pp., January ; Yang, Junjun, Seafloor Topography Estimation from Gravity Gradients [pdf], viii+ pp., December The polar motion considered at time scale larger that 10 year, namely the low-frequency pole, has an irregular drift in the direction to 80 deg.

West, shown in Figure 5. Figure 1: Polar motion since with day prediction in Yellow Figure 2: x and y pole coordinates from to. Matter-equatorial Matter-axial Motion-equatorial Motion-axial This tool allows you to compute the excitation functions of the Earth rotation χ 1, χ 2, χ 3 (according to the "Euler-Liouville" formalism) and to compare them to the geophysical excitation functions, as far as these later ones are available.

There are irregulär variations or disturbances of polar motions in El Niiio epochs, too. They are related to the transfer of perturbations of Atmospheric Angular Momentum (AAM) into correlations between geodetic and atmospheric excitation functions of polar motion (Kosek et al. b, ).Combining TWS excitations with cryospheric signals greatly reduces the variance of a fit to the amplitude and direction of polar motion: The reconstructed motion has 83 ± 23% magnitude and is within ° ± ° of the observed (detrended) polar motion ( mas/year along ° East longitude).An excitation of the OH-stretch νOH of water has unique disruptive effects on the local hydrogen bonding.

The disruption is not an immediate vibrational predissociation, which is frequently the case with hydrogen-bonded clusters, but instead is a delayed disruption caused by a burst of energy from a vibrationally excited water molecule.

The disruptive effects are the result of a fragile.