Long-Term (2001-2011) Temperature, Salinity and Chlorophyll-a Variations at a Southeastern Coastal Site of the Black Sea

Long-term measurements of temperature, salinity and chlorophyll-a concentration at a coastal site off Trabzon in the southeastern Black Sea document their monthly-to-interannual variabilities during 2001-2011. The data point to a general trend of warming with either negligible or absence of the Cold Intermediate Layer except for the relatively cold period of 2002-2004. The warming trend appears to be a continuation of the one started during the early 1990s. The data further documents enhanced anticyclonic type mesoscale features of the circulation system and its impacts on the local startification characteristics in terms of ventilation of the subsurface waters. The surface chlorophyll measurements show a rather sporadic relatively high plankton production events identified by the values greater than 2.0 mg m(-3). More importantly, relatively high chlorophyll concentrations prevail below the surface mixed layer up to 50 m depth throughouit the years. The mesoscale physical processes occasionally spread this productivity well below the euphotic zone and support biological production at oxygen deficient waters of the upper layer water column. The data further point to quasi-lateral, most likely isopycnal, intrusions and ventilation of subsurface waters