Vittorio Canuto and Armando Howard, NASA/GISS
Since tidal energy is quite large (of the order of terawatts), it is imperative to account for it in modeling the mixing properties of any realistic ocean model. The underlying physical picture is that this additional source of energy will help lift cold waters from the ocean bottom, thus producing a cooler surface temperature vis a vis one without tidal energy. Tidal waves are viewed as breaking on rough topography thus increasing vertical local mixing. Several measurements have indeed shown that there are large bottom enhancements of the vertical diffusivity. We have extended the GISS mixing model so as to include bottom tidal mixing and results will be presented from the runs of a GFDL ocean code. Work is in progress to insert this new mixing model into the HYCOM code at GISS.