Sabine1, Christopher L., R. A. Feely1, K. Lee2, R. Wanninkhof3, R.M. Key4, T.-H. Peng3, F. Millero5, J. Bullister1, A. Kozyr6, N. Gruber7, and M.F. Lamb1

1NOAA/PMEL, 7600 Sand Point Way NE, Seattle, WA, 98115 USA, E-mail: Sabine@pmel.noaa.gov Tel: 206-526-4809; Fax: 206-526-6744, 2School of Environ. Science and Engineering, Pohang, South Korea, 3NOAA/AOML, Miami, FL, USA, 4AOS Program, Princeton University, Princeton, NJ, USA, 5University of Miami/ RSMAS, Miami, FL, USA, 6Carbon Dioxide Information Analysis Center, ORNL, Oak Ridge, TN, USA and 7IGPP & Dept. of Atm. Sciences, UCLA, Los Angeles, CA, USA

 

Global Estimates of Anthropogenic CO2

 

Working with international investigators, JGOFS synthesis and modeling project researchers have compiled a global ocean data set of 67 WOCE/JGOFS/NOAA global survey cruises that provide approximately 72,000 unique sample locations analyzed for at least two carbon parameters. Significant advances have been made in separating the anthropogenic component from the large background of ocean dissolved inorganic carbon (DIC) during the JGOFS era. Using the ΔC* approach, we estimate the global inventory of anthropogenic CO2 in the oceans to be 110±13 Pg C for a nominal year of 1994. High inventories are generally observed in the mid-latitudes, with the lowest inventories in the high latitude Southern Ocean and near the Equator. Roughly 25% of the total inventory of anthropogenic carbon is found in the North Atlantic. The high inventory regions are associated with convergence zones, where waters with relatively high anthropogenic concentrations are moving into the ocean's interior. The low inventory waters are associated with general regions of upwelling, where waters with low anthropogenic concentrations are brought near the surface. The high latitude Southern Ocean generally has very low anthropogenic CO2 inventories and very shallow penetration. The southern hemisphere mode and intermediate waters at around 40-50°S, on the other hand, contain the largest inventories of anthropogenic CO2. Over 56% of the total anthropogenic CO2 inventory is stored in the Southern Hemisphere. These data-based distributions compare well with results from the large number of global ocean carbon models that participated in the Ocean Carbon-cycle Model Intercomparison Project (OCMIP).