Río de la Plata Coastal Observatory Station Supporting long-term satellite ocean colour validation and water quality monitoring

Sustained observations in coastal regions (including estuaries and deltas) provide crucial data to understand the impact of human activities (like urbanization, industry, ports and tourism), help monitoring the impacts of natural or anthropogenic hazards, long-term climate change and implement adaptation and mitigation strategies. Remote sensing technology has shown over the last decades to be a cost-effective tool for proving synoptic data for monitoring large scale and long-term water quality. In general, satellite-derived ocean colour products (like chlorophyll-a concentration – Chl-a) work well in oligotrophic open waters, but larger uncertainties are typically found in coastal waters where complex water and aerosol optical properties challenge standard algorithms. Therefore, it is essential to systematically collect in situ radiometric data (water reflectance) and water quality variables to validate satellite-derived products to ensure the quality of satellite-derived parameters useful for monitoring. With this aim, a coastal observatory station (RdP-EsNM) has been established in the turbid waters of the Río de la Plata (Argentina). This large and shallow funnel shaped estuary has large social, ecological and economical importance for Argentina and Uruguay, in which margins their capital cities (Buenos Aires and Montevideo). The RdP-EsNM observatory station is strategically located between a water intake and the active commercial harbour of La Plata city, 60 km south of Buenos Aires city. The site is part of two international and one national network that support long term in situ marine observations. Two autonomous multi- and hyperspectral radiometer systems, HYPSTAR and SeaPRISM within the AERONET-OC and WATERHYPERNETS networks, have been deployed and are currently collecting invaluable data for satellite validation. Furthermore, within the framework of the Argentine Marine Observation Network (ROMA), it’s planned to install a hydro-meteorological station to measure environmental variables like wind intensity and direction, humidity, etc., as well as in-water variables, like turbidity, chlorophyll fluorescence, water temperature, etc. In this work we will present the capabilities of this coastal observatory station to provide unique and sustained oceanic observations for long-term satellite validation and water quality monitoring. A comparison between the two radiometric systems as well as validation of hyperspectral satellite missions including PRISMA, ENMAP and PACE will be presented.