Evaluation of two sites for Ocean Color Validation in the Turbid waters of the Río de la Plata (Argentina)

DOGLIOTTI, A.I.; GOSSN, J.I; VANHELLEMONT, Q.; RUDDICK, K.

Workshop; Sentinel-3 for Science 2015; 2015

The Río de la Plata (RdP) is a large-scale andshallow funnel-shape estuary which drains the second largest basin in South America. The river carries a large amount ofsuspended particulate and dissolved organic matter and high values of suspendedparticulate matter have been reported in this region. Mean values range from100 to 300 g m−3 and extreme concentrations up to 400 g m−3,representing a challenge and an ideal scenario to test atmospheric correctionalgorithm performance. Strong efforts have been put into the collection offield measurements making the RdP an international site for ocean color (OC)validation of current and future OC missions, like S3-OLCI and the futureArgentina-Brazil ocean color mission SABIA-Mar. Measurements of opticalproperties have been carried out from a fixed pontoon since 2012 and from shipssince November 2013 in the upper part of the RdP estuary (Buenos Aires,Argentina). This provides a basis for setting up an automatic measuring system,for example combining radiometry from a AERONET-OC system with  continuously measuring in-water sensors, to obtainhigh-frequency and high-quality data for validation of satellite products and specificallytest atmospheric correction algorithms in turbid waters. With the aim ofchoosing the location to setup such an autonomous validation site in the RdP, twopossible sites are here characterized in terms of temporal and spatialvariability of optical properties based on information from high (Landsat-8/OLI)and medium (MODIS/Aqua) spatial resolution satellite sensors and available insitu data. The capability of estimating turbidity using the 1020 nm OLCIband, which is also measured by the CIMEL instrument used in the AERONET-OCnetwork, is also analyzed.