Anthropogenic carbon distributions in the Atlantic Ocean: data-based estimates from the Arctic to the Antarctic

Abstract

Abstract. Five of the most recent observational methods to estimate anthropogenic CO2 (Cant) are applied to a high-quality dataset from five representative sections of the Atlantic Ocean extending from the Arctic to the Antarctic. Between latitudes 60° N–40° S all methods give similar spatial distributions and magnitude of Cant. Conversely, large discrepancies are found in the Southern Ocean and Nordic Seas. The differences in the Southern Ocean have a significant impact on the anthropogenic carbon inventories. The calculated total inventories of Cant for the Atlantic referred to 1994 range from 48 to 67 Pg (1015 g) of carbon, with an average of 54±8 Pg C, which is higher than previous estimates. These results, both the detailed Cant distributions and extrapolated inventories, will help to validate biogeochemical ocean models and coupled climate-carbon models.