Study of height and tidal currents from in-situ data, models and satellite altimetry over the Argentine Continental Shelf
Event: 2020 Ocean Surface Topography Science Team Meeting (virtual)
Session: Tides, internal tides and high-frequency processes
Presentation type: Type Forum
Satellite altimetry measurements have become an essential dataset for many oceanographic and climate applications. Close to the coast their use is restricted because of several factors that limit their accuracy. Tidal correction must be done with precision in regions of microtidal regimes. One of such regions is the Argentine Continental Shelf. There, the evaluation of tidal models becomes particularly important in order to avoid aliasing the sea level anomaly. With the objective of expanding the knowledge of the tides in the study region, the amplitudes and phases of the main tidal constituents are extracted from four global tidal models (FES2014, EOT11, TPX09 and GOT410), three regional models (Simionato, SMARA and Palma) and from a satellite altimetry product (CTOH) and compared with the harmonics of four bottom pressure recorders and four tide gauges obtained at different sites between 38° S and 52° S. In order to evaluate the performance of each model, the Root Sum Square (RSS) of the misfit of the common set of the five tidal constituents solved by the models (M2, N2, S2, O1, K1) is calculated. FES2014 is the model that performs the best overall, except in Puerto Madryn. The analysis was also carried out for five subregions defined as coastline, continental shelf, continental slope, north and south 42° S. The results indicate that FES2014 compares more favorably than the rest of the models with an RSS < 1.2 cm over the shelf, slope and north regions and less than 14.5 cm considering all regions, except Puerto Madryn. In the coastline and south of 42° S regions, the Palma model achieves the best performance with an RSS< 18.0 cm. Three series of in-situ current measurements obtained on the shelf were also analyzed. The ellipses associated with tidal currents compared favorably with those estimated by the global model FES2014, especially in the south. For the M2 constituent, the difference in amplitude is of the order of 3% in most cases, and the difference in the direction of the semi-major axis does not exceed 16°.