Gravity, bathymetry, and Mesoscale

ocean circulation from altimetry Over the last 15 years, satellite altimetry has enhanced our understanding of marine gravity, seafloor bathymetry and ocean circulation. The shape of the ocean’s surface is determined by the Earth’s gravity field. Bumps and wiggles in the time-averaged sea surface height measured by altimetry can tell us where the gravity field is particularly large or small [Sandwell and Smith, 1997]. In turn, the gravity field has been used to estimated the depth of the ocean. Anomalies in the gravity field are associated with seafloor ridges and troughs (as well as with differing densities of crustal material), so altimetric gravity estimates allow us to estimate ocean depth in regions not measured during past ship surveys [Smith and Sandwell, 1997]. Finally, since the Earth’s gravity field is essentially constant over local time scales, variations in sea surface height from one satellite pass to the next tell u