Call number:
21/STR 03/01
In:
Scientific technical report
Description / Table of Contents:
Polar motion data is available from the mid-19th century to the present. Based on time series with a variety of sampling intervals (monthly, 0.05-year, 5-day and daily), we have separated the low-frequency terms by low-pass filtering and the Chandler and annual terms by recursive band-pass filtering of the pole coordinates. Using a simple unweighted least-squares fit to the filtered low-frequency terms, the linear trends of the rotation pole were estimated. Assessing the estimates based on intercomparisons, the most reliable trend estimate was found. Using a Fast Fourier Transform, we have computed the prograde, retrograde and total amplitude spectra of the low-frequency part of polar motion in order to reveal the long-periodic signals. The characteristics and time evolution of the Chandler and annual wobbles are described by changes in their parameters (radii, directions and period lengths) over one century.
Type of Medium:
GFZ publications
Pages:
51 S.
Series Statement:
Scientific technical report / Geoforschungszentrum Potsdam 03/01
URL:
http://ebooks.gfz-potsdam.de/pubman/item/escidoc:8596:2/component/escidoc:8595/0301.pdf
Classification:
Geodynamics
Language:
English
Location:
Reading room
Branch Library:
GFZ Library
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