Site3: Mediterranean Sea and Black Sea
Complete Mediterranean Sea, including Nile delta, and Black Sea
The Eastern Mediterranean is highly oligotrophic due to phosphorous limitation and the anti-estuarine circulation whereby nutrients are exported at depth and replaced by surface nutrient-poor waters into the basin. Chl-a concentrations ranging from ~0.02 mgm-3 in the Cyprus eddy to 0.2-0.3 mgm-3 during the winter bloom (Groom et al., 2005). The optical properties of the whole of the Mediterranean are anomalous with standard chl-a band ratio algorithms giving erroneously high retrievals: hence, specific regional algorithms have been proposed (e.g. Volpe et al, 2007) and must be used to produce chl-a estimates. Along the Egyptian coast the outflow from the Nile produces a broad band of high suspended particulates and high chl-a: this brighter coastal water is sometimes entrained into oceanic waters by eddies. Similarly, coastal plumes can appear off the Israeli and Lebanese coasts (e.g. Karabashev et al, 2002).
The Black Sea is a virtually enclosed sea with a link to the Aegean through the Sea of Marmara. It has a deep basin and in the north a wide continental shelf both exhibiting dissimilar properties (Chu et al., 2005). It receives freshwater from a number of major rivers and has extensive coccolithophore blooms in Spring that can cover up to 80% of the surface area of the sea (Cokacar et al., 2004). In situ absorption and chlorophyll measurements have been taken in coastal waters off the Crimean peninsula (Dmitriev et al., 2009) and the absorption parameterisation was found to be distinct from other European studies (e.g. Babin et al., 2003).