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How large is the retrograde annual wobble?
Author(s) -
King N. E.,
Agnew Duncan Carr
Publication year - 1991
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/91gl01882
Subject(s) - speed wobble , polar motion , geodesy , geodetic datum , geology , coda , excitation , seismology , physics , earth's rotation , classical mechanics , quantum mechanics
We compare recent measurements of polar motion (wobble) made by space‐geodetic methods with older optical measurements. Multitaper spectra of these data show that the retrograde (clockwise) annual wobble is much larger in the older data than the newer data, implying systematic errors in the older techniques. Two additional analyses show evidence for a small retrograde motion in the newer data, which appears to be consistent between data types. This implies that the excitation of the retrograde wobble must be about half of the prograde excitation. None of the available estimates of the excitation shows full agreement with these observations.