Articles | Volume 18, issue 5
https://doi.org/10.5194/os-18-1507-2022
https://doi.org/10.5194/os-18-1507-2022
Research article
 | Highlight paper
 | 
21 Oct 2022
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

Viewed

Total article views: 4,540 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
3,200 1,271 69 4,540 60 55
  • HTML: 3,200
  • PDF: 1,271
  • XML: 69
  • Total: 4,540
  • BibTeX: 60
  • EndNote: 55
Views and downloads (calculated since 11 Apr 2022)
Cumulative views and downloads (calculated since 11 Apr 2022)

Viewed (geographical distribution)

Total article views: 4,540 (including HTML, PDF, and XML) Thereof 4,172 with geography defined and 368 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Latest update: 13 Jun 2024
Download
Co-editor-in-chief
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.
Short summary
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.