CONICET | Buscador de Institutos y Recursos Humanos

The objective of this work is to evaluate satellite altimetry data and its corrections terms in a complex coastalenvironment. Satellite altimetry data are compared with data obtained from a bottom pressure recorder deployedduring 22 months. The instrument is moored at 1 km from the coast in San Matias Gulf, Argentina, at only 38mfrom the nominal intersection of satellite tracks 52 (descending) and 189 (ascending) of Jason 2. Data obtainedfrom the bottom pressure recorder are therefore ideal to test coastal satellite altimetry products. Correlationbetween the two datasets is 0.9 (95% CL) when no corrections are applied to the altimeter data, until a distanceof 3 km to the coast for track 189, and 10 km for track 52. Results show that both sea bias and ionospherecorrections reduce the correlation between altimetry and in-situ data near the coast: a correlation value of 0.9 isfound at a distance from the coast of 7 km (track 189) and 13 km (track 52). Tide correction also reduces thecorrelation between the two datasets along the tracks. Eight global models were considered, and the one withlower root sum square of the difference considering the first 11 amplitude and phase constants is FES2012 (0.84cm). Finally two retracking algorithms were considered: a classic Brown model (MLE4) and a more recentdeveloped method: ALES (Adaptive Leading Edge Subwaveform Retracker). Both ALES and MLE4 show similarcorrelation with in-situ data when applied to satellite altimetry data for distances larger than 10km from the coast,obtaining a correlation factor of 0.9 (95% CL). ALES has the ability to recover more data close to the coast,especially for the ascending track 189 (the one that has a transition from ocean to land), up to 3km from thecoast. We conclude that satellite data from Jason 2 can adequately represent the sea level variability as close as3 km from the coast depending on the relative motion of the satellite to the coast and the corrections used.