Geophysical Research Letters

Can oceanic submesoscale processes be observed with satellite altimetry?



[1] High-resolution (2 km and hourly) observations of surface currents from High-Frequency Radars are analyzed in terms of sea level anomalies (SLA) and compared with data from two satellite altimeter ground tracks. Purpose is to investigate whether ocean submesoscale processes can be observed with satellite altimetry. Our results highlight two major problems that must be overcome before being able to resolve submesoscale processes with altimetry: (i) signal contamination from high-frequency motions and in particular from incoherent internal tides (near-inertial oscillations have no effect on SLA), and (ii) measurement noise which prevents the computation of accurate cross-track currents on scales equation image (10 km). The latter may be overcome by future satellite altimeter missions, but the former will require taking into account the effect of mesoscale variability on internal tide propagation in regions where internal tides are significant.