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TitreThe Holocene Labrador Current: changing linkages to atmospheric and oceanographic forcing factors
AuteurRashid, H; Piper, D J W; Lazar, K B; McDonald, K; Saint-Ange, F
SourcePaleoceanography vol. 32, issue 5, 2017 p. 498-510, https://doi.org/10.1002/2016PA003051
Année2017
Séries alt.Secteur des sciences de la Terre, Contribution externe 20150471
ÉditeurWiley-Blackwell
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1002/2016PA003051
Mediapapier; en ligne; numérique
Formatspdf
Lat/Long OENS-110.0000 30.0000 80.0000 40.0000
Sujetsanalyse granulométriques; carottes de sédiment marin; paléocourants; vitesses de fluage; géologie marine
Illustrationslocation maps; tables; graphs
ProgrammeLa géoscience pour les développements extracôtiers de la côte est, Géoscience en mer
Diffusé2017 05 23
Résumé(disponible en anglais seulement)
The role of Labrador Current (LC) in providing freshwater to the North Atlantic and hence modulating the Atlantic meridional overturning circulation (AMOC) has been debated with very few data. This study provides the first data on the relative speed of the LC for the past 9.2 ka using mean size of the sortable silt of sediments as a proxy from a midshelf basin in the western Labrador Sea. LC speed progressively intensified from 9.2 to 5 ka, during which two meltwater events had minor influence. The LC was fastest between 5 ka and 3.1 ka and gradually weakened after 3.1 ka. The mean size of the sortable silt data shows overall covariations with similar existing data from deepwater areas of the greater North Atlantic, suggesting an overarching link that modulates changes in both the near-surface and deep North Atlantic. A dynamical link between the LC and AMOC vigor is hypothesized in which high meltwater discharge in the Labrador Sea oriented the subpolar gyre (SPG) more north-south (meridional), weakening the SPG and thus decelerating the upper limb of the AMOC. Conversely, reduction in LC transport during the late Holocene, due to the greater export of sea ice, oriented the SPG more east-west.
Résumé(Résumé en langage clair et simple, non publié)
Le présent article décrit les changements de vitesse du courant du Labrador qui se sont déroulés au cours des 9 000 dernières années. L¿étude met en lumière les questions se rapportant aux futurs changements du courant du Labrador compte tenu du réchauffement planétaire.
GEOSCAN ID297804