Publications des scientifiques de l'IRD

Stoens A., Menkès Christophe, Radenac Marie-Hélène, Dandonneau Yves, Grima N., Eldin Gérard, Mémery L., Navarette C., André Jean-Michel, Moutin T., Raimbault P. (1999). The coupled physical-new production system in the equatorial Pacific during the 1992-1995 El Nino. In : Dandonneau Yves (ed.). Biogeochemical conditions in the equatorial Pacific in late 1994. Journal of Geophysical Research, 104 (C2), p. 3323-3339. ISSN 0148-0227.

Titre du document
The coupled physical-new production system in the equatorial Pacific during the 1992-1995 El Nino
Année de publication
1999
Type de document
Article
Auteurs
Stoens A., Menkès Christophe, Radenac Marie-Hélène, Dandonneau Yves, Grima N., Eldin Gérard, Mémery L., Navarette C., André Jean-Michel, Moutin T., Raimbault P.
In
Dandonneau Yves (ed.), Biogeochemical conditions in the equatorial Pacific in late 1994
Source
Journal of Geophysical Research, 1999, 104 (C2), p. 3323-3339 ISSN 0148-0227
We investigate the coupling between the physics and new production variability during the period April 1992 to June 1995 in the equatorial Pacific via two cruises and simulations. The simulations are provided by a high-resolution Ocean General Circulation Model forced with satellite-derived weekly winds and coupled to a nitrate transport model in which biology acts as a nitrate sink. The cruises took place in September-October 1994 and sampled the western Pacific warm pool and the upwelling region further east. The coupled model reproduces these contrasted regimes. In the oligotrophic warm pool the upper layer is fresh, and nitrate-depleted, and the new production is low. In contrast, the upwelling waters are colder, and saltier with higher nitrate concentrations, and the new production is higher. Along the equator the Eastern edge of the warm pool marked by a sharp salinity front, also coincides with a "new production front". Consistent with the persistent eastward surface currents during the second half of 1994, these fronts undergo huge eastward displacement at the time of the cruises. The warm/fresh poll and oligotrophic region has an average new production of 0.9 mmol NO3/m2/d, which is almost balanced by horizontal advection from the central Pacific and by vertical advection of richer water from the nitrate reservoir below. In contrast, the upwelling mesotrophic region shows average new production of 2.1 mmol NO3/m2/d and the strong vertical nitrate input by the equatorial upwelling is balanced by the losses, through westward advection and meridional divergence of nitrate rich waters, and by the biological sink. (Résumé d'auteur)
Plan de classement
Milieux physico-chimique [032MILPHY]
Descripteurs
OCEAN ; CYCLE BIOGEOCHIMIQUE ; PRODUCTION BIOLOGIQUE ; VARIABILITE ; DYNAMIQUE DE L'EAU ; UPWELLING ; EL NINO ; TEMPERATURE ; SALINITE ; NITRATE ; CHLOROPHYLLE ; BIOMASSE ; FLUX ; MODELISATION
Localisation
Fonds IRD [F A010017695]
Identifiant IRD
fdi:010017697
Contact