Lana Erofeeva (Oregon State University, USA); Richard Ray (NASA/GSFC, USA); Gary Egbert (Oregon State University, United States)

A significant update of the latest in the TPXO series of barotropic ocean tide models is in development. The newest version, "TPXO10", has undergone significant improvements which reduced the error of the 1/6-deg resolution hydrodynamic (non-data-assimilating) prior model from about 12cm root-mean-square (rms) to 3cm rms in deep water for the main semidiurnal constituent, M2. Prior errors are reduced for all the other constituents as well. The primary improvements in the model are the result of a revised estimate and handling of bottom topography which may be interpreted as effectively doubling the model resolution. Other improvements include the used of a revised baroclinic wave drag, inclusion of the atmospherically-forced S2 tide, and validation against a new dataset of M2 tidal currents inferred from ocean surface drifters. The forthcoming data-assimilative model will use a larger altimeter dataset than previous versions of TPXO. All these factors together anticipate improvements to the current suite of tidal constituents as well as the inclusion of new, smaller, constituents not previously estimated via data assimilation.