Novel ocean tide solutions for application in satellite gravimetry including minor tides

<p>The accuracy of ocean tide models has increased drastically since the launch of Topex/Poseidon and its successors. However, in regions of imperfect altimetry coverage (e.g., polar seas and coastal areas) and for minor tides with small signal-to-noise ratios, unconstrained tidal models provide crucial estimates of tidal variability in both sea-level and ocean bottom pressure that are truly global in spatial coverage.</p> <p>We will present improved results from the unconstrained hydrodynamic barotropic tidal model TiME (Weis et al., 2008) that was enhanced recently with various newly developed features including (i) a rotated grid avoiding the open sea coordinate singularity allowing for global simulations without the need of introducing open ocean boundaries or spherical caps; (ii) a revised scheme for feedbacks of self-attraction and loading on ocean dynamics; (iii) updated bathymetries that also include water column height information in cavities underneath the Antarctic ice-shelves; (iv) the ability to either simulate individual partial tides or transient tidal dynamics by means of full forcing by ephemerides including contributions of the third-order lunisolar potential (Hartmann and Wenzel, 1995). Most recently, (v) a topographic wave drag parametrization following the tensor scheme of Nycander (2005) was incorporated in order to properly represent also this energy dissipation channel in TiME.</p> <p><a name="_GoBack"></a>We will concentrate on results for the principal lunar tide (M2) as well as on estimates of some minor tides that are not routinely included in modern tidal atlases. In a medium term perspective, tidal results from TiME will be considered as background information for the processing of GRACE and GRACE-FO gravity fields as currently explored within the research group NEROGRAV funded by the German Research Foundation.</p>