Ocean color satellite products have been used to estimate Chl-a trends in European Seas. The work aim is to develop a new indicator based on ocean colour data for the European Environment Agency (EEA). The new indicator, called CSI023 (+), produced from satellite ocean colour products from the MyOcean Marine Core Service (www.myocean.eu) has been defined and calculated.
CSI023 (+) is intended to complement the EEA CSI023 indicator for eutrophication, which is based on chlorophyll-a (Chl-a) in-situ observations. Validation of ocean colour products has been carried out by comparison with observations of the Eionet EEA database, and it is believed that such validation should continue in the future, perhaps with a dedicated data collection exercise.
In our analysis we used both global and regional (adjusted to specific regional Mediterranean Sea conditions) ocean colour products, but more regional and sub-regional products are recommended for the future.
The analysis has revealed the potential of ocean colour as a CSI023 (+) indicator: large-scale, and in some cases even local-scale, changes appear to be captured by the satellite images even if in general the ocean color products underestimate the Chl-a values. CSI023 (+) shows decreasing Chl-a concentrations throughout the Black Sea, in the Eastern Mediterranean Sea, in the southern part of the Western Mediterranean, in the English Channel and in the north part of the North Sea, whereas large areas with increasing trends are observed in the Bay of Biscay, in the North East Atlantic regions of Ireland and UK, in the northern part of the North Sea and in the Baltic Sea.
Not all the information from ocean colour has been used yet because CSI023 (+) uses summer mean values for analogy with classical CSI023, for the future it is suggested to use the full daily resolution of satellite chl-a estimates.
Keywords: Ocean colour; Chlorophyll-a; European Seas; Trend estimation
Biography: Giovanni Coppini holds a Phd in Environmental Sciences from the University of Bologna from 2010. Since 2003 is working as Technologist at the National Group of Operational Oceanography of INGV, he is responsible of the group that develop environmental applications such as oil spill forecasting and environmental indicators.