DOMINANT TIMESCALES OF OPTICAL VARIABILITY IN SURFACE BLACK SEA WATERS

Coastal oceans and transitional waters are heavily impacted by anthropogenic activities and climate change effects. The Black Sea represents a system long under pressure from anthropogenic impacts such as deforestation, pollution from industry and agriculture, overfishing and introduction of exotic species, which have brought enclosed marine ecosystems close to collapse in the recent past. While the Black Sea is on a road towards recovery, current and emerging pressures could jeopardise this trend. In work supported through of the DOORS (Developing Optimal and Open Research Support for the Black Sea) project, we show novel approaches to study marine ecosystems using satellite-derived products applied on the Black Sea. Water color in this system is primarily influenced by colored dissolved organic matter, phytoplankton and suspended sediments. Optical water type (OWT) classification of remote sensing water color products aims to categorize water parcels with differing properties, thus allowing quantification over time of variations in spectral properties associated with water quality metrics. The OWT analysis scheme developed in the EU H2020 CERTO project, building on OC-CCI, uses fuzzy c-means OWT classes designed for characterization of transitional waters. Using the novel MOving Standard deviation Saturation (MOSS) approach on OWT data, we examine dynamics of Black Sea surface water parcels through their persistency, transience and variability over time. Patterns observed from the satellite data are compared with results from Black Sea modelling studies.