Evaluating predicted diurnal and semidiurnal tidal variations in polar motion with GPS‐based observations

• DOI: 10.1002/2016jb013125
• Publication Date: 2016-06-13T02:02:43Z
• Authors: Shailen D. Desai; Aurore E. Sibois
• Keywords: Libration (molecule); Polar motion; Ocean tide

Abstract We evaluate models for the predicted diurnal and semidiurnal tidal variations in polar motion using observations based upon Global Positioning System (GPS). The GPS‐based are composed of 10 year continuous time series estimates with 15 min temporal resolution. Predicted effects account contributions from ocean tide angular momentum libration. consider two effects, both which have their heritage so‐called TPXO hydrodynamic heights currents that assimilate satellite altimetry, example, Egbert et al. (1994) Erofeeva (2002). When considering libration we use model Mathews Bretagnon (2003). Of considered this study, best consistency is achieved predictions most recent (version 8) TPXO‐based together effects. This combination demonstrates closure budget between at level less than 10, 2, 5 µas prograde diurnal, semidiurnal, retrograde motion, respectively. also demonstrate inconsistency older model, currently recommended by International Earth Rotation Service.