The carbonic system distribution and fluxes in the NE Atlantic during Spring 1991

The potential of the North Atlantic as a sink for atmospheric CO(2) was investigated by studying the carbonic system using data obtained during the spring of 1991. The air-sea flux of CO(2) was related to chlorophyll and other environmental variables, and the regeneration of carbon in the mid-ocean studied by examining vertical sections representative of the study area. Poor correlations were found between pCO, and chlorophyll throughout much of the study area, although a good correlation was found along 16 degrees W. The highest air-sea fluxes of CO(2) were calculated for areas where chlorophyll was highest (45 degrees 13'N, 16 degrees 04'W), and where the greatest wind speeds occurred (47 degrees 51'N, 28 degrees 18'W). The mean CO(2) flux from the atmosphere to the ocean during the study period (May) was calculated as 0.65 mmol m(-2)d(-1), which compares well with other studies. Regression equations were developed to predict total inorganic carbon from nutrients; errors were typically less than 1 mu mol kg(-1). Regeneration of carbon in the mid-ocean occurred in two principal stages: 0-1000m and>2300m. Regeneration in the upper zone was dominated by soft tissue carbon (86%), with skeletal carbon( calcite) contributing only 14%. The fraction of regenerated carbon of skeletal origin increased to 51% in the > 2300m zone.