Role of air–sea fluxes and ocean surface density in the production of deep waters in the eastern subpolar gyre of the North Atlantic
Wintertime convection in the North Atlantic Ocean is a key component of the global climate as it produces dense waters at high latitudes that flow equatorward as part of the Atlantic Meridional Overturning Circulation (AMOC). Recent work has highlighted the dominant role of the Irminger and Iceland...
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ftdoajarticles:oai:doaj.org/article:c912679a9fc24067913b4b9d25d75958 2023-05-15T16:47:32+02:00 Role of air–sea fluxes and ocean surface density in the production of deep waters in the eastern subpolar gyre of the North Atlantic T. Petit M. S. Lozier S. A. Josey S. A. Cunningham 2021-10-01T00:00:00Z https://doi.org/10.5194/os-17-1353-2021 https://doaj.org/article/c912679a9fc24067913b4b9d25d75958 EN eng Copernicus Publications https://os.copernicus.org/articles/17/1353/2021/os-17-1353-2021.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 doi:10.5194/os-17-1353-2021 1812-0784 1812-0792 https://doaj.org/article/c912679a9fc24067913b4b9d25d75958 Ocean Science, Vol 17, Pp 1353-1365 (2021) Geography. Anthropology. Recreation G Environmental sciences GE1-350 article 2021 ftdoajarticles https://doi.org/10.5194/os-17-1353-2021 2022-12-31T07:16:34Z Wintertime convection in the North Atlantic Ocean is a key component of the global climate as it produces dense waters at high latitudes that flow equatorward as part of the Atlantic Meridional Overturning Circulation (AMOC). Recent work has highlighted the dominant role of the Irminger and Iceland basins in the production of North Atlantic Deep Water. Dense water formation in these basins is mainly explained by buoyancy forcing that transforms surface waters to the deep waters of the AMOC lower limb. Air–sea fluxes and the ocean surface density field are both key determinants of the buoyancy-driven transformation. We analyze these contributions to the transformation in order to better understand the connection between atmospheric forcing and the densification of surface water. More precisely, we study the impact of air–sea fluxes and the ocean surface density field on the transformation of subpolar mode water (SPMW) in the Iceland Basin, a water mass that “pre-conditions” dense water formation downstream. Analyses using 40 years of observations (1980–2019) reveal that the variance in SPMW transformation is mainly influenced by the variance in density at the ocean surface. This surface density is set by a combination of advection, wind-driven upwelling and surface fluxes. Our study shows that the latter explains ∼ 30 % of the variance in outcrop area as expressed by the surface area between the outcropped SPMW isopycnals. The key role of the surface density in SPMW transformation partly explains the unusually large SPMW transformation in winter 2014–2015 over the Iceland Basin. Article in Journal/Newspaper Iceland North Atlantic Deep Water North Atlantic Directory of Open Access Journals: DOAJ Articles Ocean Science 17 5 1353 1365 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 |
spellingShingle |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 T. Petit M. S. Lozier S. A. Josey S. A. Cunningham Role of air–sea fluxes and ocean surface density in the production of deep waters in the eastern subpolar gyre of the North Atlantic |
topic_facet |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 |
description |
Wintertime convection in the North Atlantic Ocean is a key component of the global climate as it produces dense waters at high latitudes that flow equatorward as part of the Atlantic Meridional Overturning Circulation (AMOC). Recent work has highlighted the dominant role of the Irminger and Iceland basins in the production of North Atlantic Deep Water. Dense water formation in these basins is mainly explained by buoyancy forcing that transforms surface waters to the deep waters of the AMOC lower limb. Air–sea fluxes and the ocean surface density field are both key determinants of the buoyancy-driven transformation. We analyze these contributions to the transformation in order to better understand the connection between atmospheric forcing and the densification of surface water. More precisely, we study the impact of air–sea fluxes and the ocean surface density field on the transformation of subpolar mode water (SPMW) in the Iceland Basin, a water mass that “pre-conditions” dense water formation downstream. Analyses using 40 years of observations (1980–2019) reveal that the variance in SPMW transformation is mainly influenced by the variance in density at the ocean surface. This surface density is set by a combination of advection, wind-driven upwelling and surface fluxes. Our study shows that the latter explains ∼ 30 % of the variance in outcrop area as expressed by the surface area between the outcropped SPMW isopycnals. The key role of the surface density in SPMW transformation partly explains the unusually large SPMW transformation in winter 2014–2015 over the Iceland Basin. |
format |
Article in Journal/Newspaper |
author |
T. Petit M. S. Lozier S. A. Josey S. A. Cunningham |
author_facet |
T. Petit M. S. Lozier S. A. Josey S. A. Cunningham |
author_sort |
T. Petit |
title |
Role of air–sea fluxes and ocean surface density in the production of deep waters in the eastern subpolar gyre of the North Atlantic |
title_short |
Role of air–sea fluxes and ocean surface density in the production of deep waters in the eastern subpolar gyre of the North Atlantic |
title_full |
Role of air–sea fluxes and ocean surface density in the production of deep waters in the eastern subpolar gyre of the North Atlantic |
title_fullStr |
Role of air–sea fluxes and ocean surface density in the production of deep waters in the eastern subpolar gyre of the North Atlantic |
title_full_unstemmed |
Role of air–sea fluxes and ocean surface density in the production of deep waters in the eastern subpolar gyre of the North Atlantic |
title_sort |
role of air–sea fluxes and ocean surface density in the production of deep waters in the eastern subpolar gyre of the north atlantic |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/os-17-1353-2021 https://doaj.org/article/c912679a9fc24067913b4b9d25d75958 |
genre |
Iceland North Atlantic Deep Water North Atlantic |
genre_facet |
Iceland North Atlantic Deep Water North Atlantic |
op_source |
Ocean Science, Vol 17, Pp 1353-1365 (2021) |
op_relation |
https://os.copernicus.org/articles/17/1353/2021/os-17-1353-2021.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 doi:10.5194/os-17-1353-2021 1812-0784 1812-0792 https://doaj.org/article/c912679a9fc24067913b4b9d25d75958 |
op_doi |
https://doi.org/10.5194/os-17-1353-2021 |
container_title |
Ocean Science |
container_volume |
17 |
container_issue |
5 |
container_start_page |
1353 |
op_container_end_page |
1365 |
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1766037621809610752 |