Cross-slope variations of dissolved organic carbon in the Gulf of Cadiz, NE Atlantic Ocean (February 1998)

Our observations at a traverse of Cadiz in February 1998 indicated dissolve d organic carbon (DOC) concentrations ranging from 61 to 89 mu M C within t he Spanish Shelf Water, from 48 to 64 mu M C within the North Atlantic Surf ace Water, and from 49 to 55 mu M C within the North Atlantic Central Water . Moreover. according to temperature and salinity data, the shallow core of the Mediterranean outflow was also identified deeper than 350 m depth with DOC concentrations between 52 and 58 mu M C. The data suggest that DOC dis tribution at the traverse of the Gulf of Cadiz was controlled by outputs of degraded particles transported within along-slope descending shelf waters and also by features of the circulation in the Gulf of Cadiz. An estimate o f organic carbon transport suggests that ca 1.34 to 2.68 x 10(2) mol C s(-1 ) were transported within the shallow core of Mediterranean outflow. This a mount of DOC was 2 orders of magnitude less than that calculated within the Mediterranean outflow in the Strait of Gibraltar for the summer and autumn seasons. These processes might partly regulate the biogeochemistry of the shallow core of the Mediterranean outflow along the Iberian coast.