Research article | Highlight paper |
| 21 Oct 2022
Exceptional freshening and cooling in the eastern subpolar North Atlantic caused by reduced Labrador Sea surface heat loss
Alan D. Fox,Patricia Handmann,Christina Schmidt,Neil Fraser,Siren Rühs,Alejandra Sanchez-Franks,Torge Martin,Marilena Oltmanns,Clare Johnson,Willi Rath,N. Penny Holliday,Arne Biastoch,Stuart A. Cunningham,and Igor Yashayaev
Ocean Dynamics Department, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
now at: Climate Change Research Centre and the Australian Centre for Excellence in Antarctic Science, University of New South Wales, Sydney, NSW, Australia
In this paper, a new hypothesis is put forward to explain the remarkable freshening of the Subpolar North Atlantic that peaked in 2016. The hypothesis emphasizes the increased surface circulation in the Labrador Sea region, following a reduction in heat loss to the atmosphere during the period 2000-2013. This new hypothesis, supported by the analysis of a very high resolution ocean model, contrasts with other studies that concluded to an overwhelming role of the reduced Atlantic Meridional Overturning Circulation in the freshening. In the present study, the AMOC decline is shown to account for not more than 27% of the freshening.
Overall, this paper points out that surface properties of the Subpolar North Atlantic Ocean, which are important for European climate, cannot be understood in terms of AMOC variability only, but rather depend on the horizontal circulation at the ocean surface and on regional air-sea exchanges.
In this paper, a new hypothesis is put forward to explain the remarkable freshening of the...
Observations of the eastern subpolar North Atlantic in the 2010s show exceptional freshening and cooling of the upper ocean, peaking in 2016 with the lowest salinities recorded for 120 years. Using results from a high-resolution ocean model, supported by observations, we propose that the leading cause is reduced surface cooling over the preceding decade in the Labrador Sea, leading to increased outflow of less dense water and so to freshening and cooling of the eastern subpolar North Atlantic.
Observations of the eastern subpolar North Atlantic in the 2010s show exceptional freshening and...
