Publications des scientifiques de l'IRD

Maamaatuaiahutapu K., Provost C., Andrié Chantal, Vigan X. (1999). Origin and ages of mode waters in the Brazil-Malvinas confluence region during austral winter 1994. Journal of Geophysical Research, 104 (C9), p. 21,051-21,061. ISSN 0148-0227.

Titre du document
Origin and ages of mode waters in the Brazil-Malvinas confluence region during austral winter 1994
Année de publication
1999
Type de document
Article
Auteurs
Maamaatuaiahutapu K., Provost C., Andrié Chantal, Vigan X.
Source
Journal of Geophysical Research, 1999, 104 (C9), p. 21,051-21,061 ISSN 0148-0227
The ventilation of the main thermocline associated with the formation of Subtropical Mode Water (STMW) and Subantarctic Mode Water (SAMW) within the Brazil/Malvinas Confluence region is investigated using satellite data, hydrographic data, and dissolved CFCs as transient tracers. During the winter of 1994, two types of STMW were observed. Both types, 26.24 sigma theta and 26.46 sigma theta were formed within the warm pool of the South Atlantic Central Water (SACW). The SAMW is found on the 27.10 sigma theta density surface. This surface lies in the minimum salinity layer of the Antarctic Intermediate Water (AAIW). The mode waters are dated using CFC ratios. To our knowledge, this is the first estimate of the age of the mode waters in the region using the CFC-113:CFC-11 ratio method. The lighter STMW was being formed during the cruise. The heavier STMW was found to be 6 plus or minus 3 years old and is thought to have circulated in the subtropical gyre without losing its primary properties. The SAMW, or the lightest AAIW has an age of 3 plus or minus 2 years. This water is very young compared with the oldest (10 plus or minus 5 years) and heaviest component of the AAIW; which circulates within the subropical gyre. The formation of the STMW in the confluence region is dependent on the southward extension of the Brazil Current. (Résumé d'auteur)
Plan de classement
Dynamique des eaux [032DYNEAU]
Descripteurs
COURANT MARIN ; VARIATION SAISONNIERE ; CIRCULATION OCEANIQUE ; MASSE D'EAU ; DYNAMIQUE DE L'EAU ; THERMOCLINE ; TELEDETECTION SPATIALE ; HYDROGRAPHIE ; PROFIL VERTICAL ; COMPOSE ORGANOCHLORE ; GAZ DISSOUS ; TEMPERATURE DE SURFACE ; DENSITE ; SALINITE ; CIRCULATION THERMOHALINE ; FACTEUR CLIMATIQUE ; OXYGENE DISSOUS ; TRACEUR OCEANIQUE
Description Géographique
ATLANTIQUE SUD
Localisation
Fonds IRD [F B010023730]
Identifiant IRD
fdi:010023730
Contact