High anthropogenic carbon content in the eastern Mediterranean

This work presents data of dichlorodifluoromethane (CFC-12), dissolved inorganic carbon and total alkalinity from a cruise to the Mediterranean Sea during October-November 2001, with the main focus on the CFC-12 data and on the eastern basin. Using the transit time distribution method, the anthropogenic carbon concentrations in the basin were estimated. Results were cross-checked with a back-calculation technique. The entire water column of the Mediterranean Sea contains anthropogenic CO2, with minimum concentrations of 20.5 mu mol kg(-1) (error range: 16.9-27.1 mu mol kg-1) in the most eastern part of the basin at intermediate depths, where the waters' mean age is > 130 yr. Column inventories of up to 154 mol m (2) (132-179 mol m (2)) are found and a total inventory of 1.7 Pg (1.3-2.1 Pg) of anthropogenic carbon in the Mediterranean Sea was estimated. There is a net flux of 38 Tg yr (1) (30-47 Tg yr (1)) of dissolved inorganic carbon through the Strait of Gibraltar into the Atlantic Ocean and an opposite net flux of 3.5 Tg yr (1) (-1.8-9.2 Tg yr (1)) of anthropogenic carbon into the Mediterranean Sea.