Tidal station displacements

Abstract

Theoretical modeling of the station displacements produced by tidal deformations of the Earth due to lunisolar gravitational forces is a necessary part of the analysis of space geodetic data. To attain the accuracies demanded by the precision of the data, a generalized version of the Love number formalism has to be used wherein the classical Love and Shida numbers are replaced by sets of Love number parameters with values that depend on the frequency of the tidal excitation. This paper presents theoretical expressions for the contributions from the various Love number parameters to the station displacement vector and a scheme for efficient computation of these contributions, taking into account the frequency dependence of these parameters as well as the imaginary parts that are present when the effects of mantle anelasticity are taken into account. A brief discussion of the permanent tide which arises from the zero frequency component of the tide-generating potential is included.