Lefèvre Nathalie auteur aut IRD Diverrès Denis auteur aut IRD Gallois Francis auteur aut IRD text journalArticle eng text/pdf born digital access Underway fCO(2) has been measured from two merchant ships sailing from France to French Guyana and France to Brazil, and during two zonal cruises from Africa to French Guyana. In the western Tropical Atlantic, the strongest undersaturation is associated with the Amazon discharge near 55 degrees W. In the 5 degrees S-10 degrees N, 65-35 degrees W region, the carbon system is strongly correlated to salinity and robust empirical relationships could be determined. This region is a sink of CO2 in May-June during the high-flow period of the Amazon river. The eastward propagation of Amazon waters is observed when the retroflection of the North Brazil Current takes place. In August 2008, freshwater is observed as far as 40 degrees W when the North Equatorial Counter Current is quite strong. The Amazon plume, defined as salinities less than 34.9, is a sink of CO2 of 0.96 mmol m-2 d-1. Further east, near 27 degrees W, CO2 undersaturation is recorded thoughout the year between 5 degrees N and 8 degrees N. This is caused by the high precipitation associated with the presence of the intertropical convergence zone (ITCZ). Removing the temperature effect leads to low (high) fCO(2) associated with low (high) salinities in boreal summer (winter), which is consistent with the seasonal migration of the ITCZ. specialized 032 62 5 595-607 2010 0280-6509 https://www.documentation.ird.fr/hor/fdi:010052863 10.1111/j.1600-0889.2010.00475.x 0280-6509 [F B010052863] https://www.documentation.ird.fr/hor/fdi:010052863 https://www.documentation.ird.fr/intranet/publi/2010/11/010052863.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2010-12-03 2017-08-23 fdi:010052863 fre