Distributions of oxygen and carbon stable isotopes and CFC-12 in the water masses of the Southern Ocean at 30°E from South Africa to Antarctica: results of the CIVA1 cruiseReportar como inadecuado




Distributions of oxygen and carbon stable isotopes and CFC-12 in the water masses of the Southern Ocean at 30°E from South Africa to Antarctica: results of the CIVA1 cruise - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

1 LPCM - Laboratoire de Physique et Chimie Marines 2 LODYC - Laboratoire d-océanographie dynamique et de climatologie

Abstract : This study presents oceanic distributions of stable isotopes δ18O of water and δ13C of ΣCO2 and CFC-12 from samples collected during the CIVA1 cruise February-March 1993, across the Southern Ocean, along a meridian section at 30°E, from South Africa 44°S to Antarctica 70°S. The isotopic measurements show important variations between the subantarctic surface waters with low δ18O–high δ13C values and the antarctic surface waters with very low δ18O–low δ13C values. The surface distributions of δ13C values follow the major frontal oceanic structures; the vertical distribution shows the progressive upwelling from the subantarctic zone to the antarctic divergence of 13C-depleted CO2 derived from remineralization of organic matter. Along the Antarctic continental shelf, between 2500 and 4000 m, a core of water with δ18O values close to −0.1‰ is associated with a relative maximum in CFC-12 concentration, although this core is not detected by its temperature and salinity parameters. This water mass, which corresponds to recently formed deep water, may originate from the eastward extension of the Weddell gyre or from bottom waters coming from the East and formed near Prydz Bay.

Keywords : CFC-12 13C 18O Stable isotopes Austral Ocean





Autor: Anne-Sophie Archambeau - Catherine Pierre - Alain Poisson - Bernard Schauer -

Fuente: https://hal.archives-ouvertes.fr/



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