Publications des scientifiques de l'IRD

Messias M.J., Andrié Chantal, Mémery L., Mercier H. (1999). Tracing the North Atlantic deep water through the Romanche and Chain fracture zones with chlorofluoromethanes. Deep Sea Research : Part 1, 46, p. 1247-1278. ISSN 0967-0637.

Titre du document
Tracing the North Atlantic deep water through the Romanche and Chain fracture zones with chlorofluoromethanes
Année de publication
1999
Type de document
Article
Auteurs
Messias M.J., Andrié Chantal, Mémery L., Mercier H
Source
Deep Sea Research : Part 1, 1999, 46, p. 1247-1278 ISSN 0967-0637
Chlorofluoromethanes (CFMs) F-11 and F-12 were measured during August 1991 and November 1992 in the Romanche and Chain Fracture Zones in the equatorial Atlantic. The CFM distributions showed the two familiar signatures of the more recently ventilated North Atlantic Deep Water (NADW) seen in the Deep Western Boundary Current (DWBC). The upper maximum is centered around 1600 m at the level of the Upper North Atlantic Deep Water (UNADW) and the deeper maximum around 3800 m at level of the Lower North Atlantic Deep Water (LNADW). These observations suggest a bifurcation at the western boundary, some of the NADW spreading eastward with the LNADW entering the Romanche and the Chain Fracture Zones. The upper core (sigma1.5 = 34.70 kg/m3) was observed eastward as far as 5°W. The deep CFM maximum (sigma4 = 45.87 kg/m3), associated with an oxygen maximum, decreased dramatically at the sills of the Romanche Fracture Zone : east of the sills, the shape of the CFM profiles reflects mixing and deepening of isopycnals. Mean apparent water "ages" computed from the F-11/F-12 ratio are estimated. Near the bottom, no enrichment in CFMs is detected at the entrance of the fracture zones in the cold water mass originating from the Antarctic Bottom Water flow. (Résumé d'auteur)
Plan de classement
Dynamique des eaux [032DYNEAU]
Descripteurs
CIRCULATION PROFONDE ; COURANT MARIN ; COMPOSE ORGANOCHLORE ; GAZ DISSOUS ; DISTRIBUTION SPATIALE ; BASSIN OCEANIQUE ; DYNAMIQUE DE L'EAU ; MASSE D'EAU ; CHROMATOGRAPHIE EN PHASE GAZEUSE ; PROFIL VERTICAL ; CORRELATION NUMERIQUE ; TEMPERATURE ; SALINITE ; PROFONDEUR ; OXYGENE DISSOUS ; MESURE ; TRACEUR OCEANIQUE
Description Géographique
ATLANTIQUE EQUATORIAL
Localisation
Fonds IRD [F B010023734]
Identifiant IRD
fdi:010023734
Contact