North Atlantic Synthesis Group: Mike Fasham1, Hugh Ducklow2, Emilio Fernandez 3, Véronique Garçon4*, W. Glenn Harrison5, Wolfgang Koeve6, Roy Lowry7, Laurent Mémery8 and David Siegel9

1SOC/NERC, Southampton, 2VIMS, Gloucester Point, USA, UK, 3University of Vigo, Vigo, Spain, 4LEGOS/CNRS, Toulouse, France, Tel: +33561332957, Fax: +33561253205, E-mail: veronique.garcon@cnes.fr, 5Bedford Institute of Oceanography, Dartmouth, Canada, 6MARUM, University of Bremen, Bremen, Germany, 7BODC, Prenton, UK, 8LODYC/CNRS, Paris, France and 9University of California, Santa Barbara, USA

 

Large scale biogeochemical diagnostics: the North Atlantic carbon machinery

 

The North Atlantic is of key importance to the oceans regulation of climate and to its control of the global carbon cycle. Deep water formation occurs at subpolar latitudes driving the deep water conveyor belt circulation. As a major component of the physico-chemical solubility pump, this basin constitutes the largest ocean sink for atmospheric CO2 in the Northern Hemisphere on average taking up about 0.7 ±0.1 Pg C/yr. Over large provinces, changes in atmospheric forcing drive strong fluctuations in the depth of mixing, the nutrient input and the mean light level in the upper ocean. As a consequence, the North Atlantic spring bloom is one of the largest mass greening observed on Earth. We investigate the different routes followed by the carbon uptaken at the air-sea interface: the production and transformation of organic matter in the surface ocean and twilight zone, its transport within the ocean, and its exchange at the boundaries with margins and sediments. Large scale observational constraints are used along these paths in the ocean interior to explain the basin distribution pattern and magnitude of carbon burial in the North Atlantic.