Love numbers for a rotating spheroidal Earth: new definitions and numerical values

Abstract

For an oceanless, elastic, spheroidal, rotating and nutating Earth, we present new definitions for the latitude-dependent Love numbers and gravimetric constant which are free of certain drawbacks of the definitions currently in use, and make the computation of quantities of observational interest simpler and more direct. Numerical values, computed for an Earth model characterized by "modified PREM" parameters, are also presented. This model is designed to have the value estimated from VLBI data for the eigenfrequency of the Nearly Diurnal Free Wobble (NDFW), and assures thus an accurate representation of the NDFW resonance in the Earth tides. To achieve current and future accuracy goals, the Love number values used must fully correspond to the definitions employed-a requirement not consistently met in some existing programs for analysis of space-geodetic data.