J. T. Farrar (Woods Hole Oceanographic Institution, USA)

Several models are presented for the sea-surface height (SSH) signature of the interior-ocean internal-wave continuum. Most are based on the Garrett-Munk internal-wave model. One is derived from the frequency spectrum of dynamic height from mooring observations. The different models are all plausibly consistent with accepted dynamical and semi-empirical spectral descriptions of the climatological interval-wave field in the interior ocean, but they result in different proportionalities between interior and SSH spectral energy levels. The differences arise in part from differences in the representation of near-surface stratification, and a major source of uncertainty for all the models comes from inadequately constrained assumptions about the energy in the low-vertical-mode internal-wave field. Most of these models suggest that the SSH signature of the internal-wave continuum will exceed the anticipated noise level of SSH measurements from the Surface Water and Ocean Topography (SWOT) wide-swath satellite altimeter. Temporal variability of internal-wave energy levels and the internal-wave directional spectrum are less well characterized but will also be consequential for the observability of internal-wave signals in SWOT data. We conclude that the SSH signature of the internal-wave continuum will likely exceed the anticipated noise level of SSH measurements from SWOT, at least in some times and places.