Open AccessTidal terms in universal time: Effects of zonal winds and mantle Q
Author(s) -
Merriam J. B.
Publication year - 1984
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/jb089ib12p10109
Subject(s) - nutation , earth's rotation , dissipation , geology , physics , series (stratigraphy) , ocean tide , geodesy , rotation (mathematics) , geophysics , angular momentum , atmospheric sciences , classical mechanics , geometry , mathematics , thermodynamics , paleontology , astronomy
The zonal response coefficient κ is studied, and some improvements in its determination are made. First, the reprocessing of the Bureau International de l'Heure data with the 1980 International Astronomical Union nutation series is found to result in improved estimates of κ. Second, a time series of the angular momentum of the atmosphere is found to have power in the tidal bands, and it is demonstrated that removing the atmospheric influence from the rotation data leads to better estimates of κ. The frequency dependence of κ due to finite dissipation in the earth is computed, and the observations are subsequently shown to limit the allowable models of dissipation. If Q varies with frequency σ, as Q∼σ α , then the M f and M m terms in UT place an upper bound of about 1/3 on α. Finally, dynamic ocean tide models are studied, and it is concluded that the rotation data cannot distinguish between these and an equilibrium tide.