Coupling of eastern and western subpolar North Atlantic: salt transport in the Irminger Current ...

Salt transport in the Irminger Current and thus the coupling between eastern and western subpolar North Atlantic plays an important role for climate variability across a wide range of time scales. High-resolution ocean modeling and observations indicate that 5 salinities in the eastern subpolar Nort...

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Bibliographic Details
Main Authors: Sandø, A. B., Stocker, Thomas, Born, Andreas
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus 2013
Subjects:
Online Access:https://dx.doi.org/10.7892/boris.57889
http://boris.unibe.ch/57889/
Description
Summary:Salt transport in the Irminger Current and thus the coupling between eastern and western subpolar North Atlantic plays an important role for climate variability across a wide range of time scales. High-resolution ocean modeling and observations indicate that 5 salinities in the eastern subpolar North Atlantic decrease with enhanced circulation of the North Atlantic subpolar gyre (SPG). This has led to the perception that a stronger SPG also transports less salt westward. In this study, we analyze a regional ocean model and a comprehensive global coupled climate model, and show that a stronger SPG transports more salt in the Irminger Current irrespective of lower salinities in its 10 source region. The additional salt converges in the Labrador Sea and the Irminger Basin by eddy transports, increases surface salinity in the western SPG, and favors more intense deep convection. This is part of a positive feedback mechanism with potentially large implications for climate variability and predictability. ...