Sampling the mesoscale ocean surface currents with various satellite altimeter configurations

Ten-day composites of maximum cross correlation (MCC) ocean surface current vectors from 1 km spatial resolution advanced very high resolution radiometer (AVHRR) thermal infrared images are used to simulate the ocean surface current retrieval capabilities of three satellite altimeter configurations over a large California coastal region. Ground track positions of the nadir sampling TOPEX/Poseidon (TP; now the Jason-1) satellite altimeters are used to compute the cross track components of the corresponding MCC vectors for a ten-day composite period. Next, the TP and Jason-1 "tandem mission" sampling is simulated for the same region and temporal sample. Finally, a similar approach is used to simulate the current retrievals from the proposed wide swath ocean altimeter (WSOA), which will have the capability to retrieve both along and cross track components of the surface velocity over a spatial swath rather than just nadir sampling. Visual comparisons of raw vector fields and through differences and wavenumber spectra from optimally interpolated (OI) currents from the "simulated altimetry" with the corresponding MCC fields demonstrates that the combined coverage from Jason and TOPEX results in a better representation of the currents than that of Jason alone and that the retrieved currents from the WSOA altimeter provide an even greater improvement over the tandem mapping of the TP and Jason-1 altimeters.