Lefèvre Nathalie auteur aut IRD Mejia C. auteur aut IRD Khvorostyanov D. auteur aut IRD Beaumont L. auteur aut IRD Koffi U. auteur aut IRD text journalArticle eng text/pdf reformatted digital access The carbon system in the eastern tropical Atlantic remains poorly known. The variability and drivers of the carbon system are assessed using surface dissolved inorganic carbon (DIC), alkalinity (TA) and fugacity of CO2 (fCO2) measured in the 12° N-12° S, 12° W-12° E region from 2005 to 2019. A relationship linking DIC to temperature, salinity and year has been determined, with salinity being the strongest predictor. The seasonal variations of DIC, ranging from 80 to 120 Mu mol kg-1, are more important than the year-to-year variability that is less than 50 Mu mol kg-1 over the 2010-2019 period. DIC and TA concentrations are lower in the northern part of the basin where surface waters are fresher and warmer. Carbon supply dominates over biological carbon uptake during the productive upwelling period from July to September. The lowest DIC and TA are located in the Congo plume. The influence of the Congo is still observed at the mooring at 6° S, 8° E as shown by large salinity and chlorophyll variations. Nevertheless, this site is a source of CO2 emissions into the atmosphere. specialized ATLANTIQUE ZONE TROPICALE 032 2 1 126-148 2021 2673-1924 https://www.documentation.ird.fr/hor/fdi:010091421 10.3390/oceans2010008 2673-1924 [F B010091421] https://www.documentation.ird.fr/hor/fdi:010091421 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2024-08/010091421.pdf IRD - Base Horizon / Pleins textes 2024-06-20 2025-02-24 fdi:010091421 fre