Large-scale control of the retroflection of the Labrador Current

Abstract The Labrador Current transports cold, relatively fresh, and well-oxygenated waters within the subpolar North Atlantic and towards the eastern American continental shelf. The relative contribution of these waters to either region depends on the eastward retroflection of the Labrador Current...

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Bibliographic Details
Published in:Nature Communications
Main Authors: Mathilde Jutras, Carolina O. Dufour, Alfonso Mucci, Lauryn C. Talbot
Format: Article in Journal/Newspaper
Language:English
Published: Nature Portfolio 2023
Subjects:
Q
Online Access:https://doi.org/10.1038/s41467-023-38321-y
https://doaj.org/article/4bcde0b858c648ef8769d417ab446d86
Description
Summary:Abstract The Labrador Current transports cold, relatively fresh, and well-oxygenated waters within the subpolar North Atlantic and towards the eastern American continental shelf. The relative contribution of these waters to either region depends on the eastward retroflection of the Labrador Current at the Grand Banks of Newfoundland. Here, we develop a retroflection index based on the pathway of virtual Lagrangian particles and show that strong retroflection generally occurs when a large-scale circulation adjustment, related to the subpolar gyre, accelerates the Labrador Current and shifts the Gulf Stream northward, partly driven by a northward shift of the wind patterns in the western North Atlantic. Starting in 2008, a particularly strong northward shift of the Gulf Stream dominates the other drivers. A mechanistic understanding of the drivers of the Labrador Current retroflection should help predict changes in the water properties in both export regions, and anticipate their impacts on marine life and deep-water formation.