Cessation and partial reversal of deep water freshening in the northern North Atlantic: observation-based estimates and attribution
International audience Recent decadal salinity changes in the Greenland-Scotland overflow-derived deep waters are quantified using CTD data from repeated hydrographic sections in the Irminger Sea. The Denmark Strait Overflow Water salinity record shows the absence of any net change over the 1980s–20...
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Online Access: | https://hal.archives-ouvertes.fr/hal-00494993 https://doi.org/10.1111/j.1600-0870.2009.00418.x |
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ftccsdartic:oai:HAL:hal-00494993v1 2023-05-15T16:00:40+02:00 Cessation and partial reversal of deep water freshening in the northern North Atlantic: observation-based estimates and attribution Sarafanov, Artem Mercier, Herlé Falina, Anastasia Sokov, Alexey Lherminier, Pascale P.P. Shirshov Institute of Oceanology (SIO) Russian Academy of Sciences Moscow (RAS) Laboratoire de physique des océans (LPO) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) 2010 https://hal.archives-ouvertes.fr/hal-00494993 https://doi.org/10.1111/j.1600-0870.2009.00418.x en eng HAL CCSD Co-Action Publishing info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1600-0870.2009.00418.x hal-00494993 https://hal.archives-ouvertes.fr/hal-00494993 doi:10.1111/j.1600-0870.2009.00418.x ISSN: 0280-6495 EISSN: 1600-0870 Tellus A https://hal.archives-ouvertes.fr/hal-00494993 Tellus A, Co-Action Publishing, 2010, 62 (1), pp.80-90. ⟨10.1111/j.1600-0870.2009.00418.x⟩ [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/article Journal articles 2010 ftccsdartic https://doi.org/10.1111/j.1600-0870.2009.00418.x 2021-10-17T01:58:34Z International audience Recent decadal salinity changes in the Greenland-Scotland overflow-derived deep waters are quantified using CTD data from repeated hydrographic sections in the Irminger Sea. The Denmark Strait Overflow Water salinity record shows the absence of any net change over the 1980s–2000s; changes in the Iceland–Scotland Overflow Water (ISOW) and in the deep water column (σ0 > 27.82), enclosing both overflows, show a distinct freshening reversal in the early 2000s. The observed freshening reversal is a lagged consequence of the persistent ISOW salinification that occurred upstream, in the Iceland Basin, after 1996 in response to salinification of the northeast Atlantic waters entrained into the overflow. The entrainment salinity increase is explained by the earlier documented North Atlantic Oscillation (NAO)-induced contraction of the subpolar gyre and corresponding northwestward advance of subtropical waters that followed the NAO decline in the mid-1990s and continued through the mid-2000s. Remarkably, the ISOW freshening reversal is not associated with changes in the overflow water salinity. This suggests that changes in the NAO-dependent relative contributions of subpolar and subtropical waters to the entrainment south of the Iceland–Scotland Ridge may dominate over changes in the Nordic Seas freshwater balance with respect to their effect on the ISOW salinity. Article in Journal/Newspaper Denmark Strait Greenland Iceland Nordic Seas North Atlantic North Atlantic oscillation Northeast Atlantic Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Greenland Irminger Sea ENVELOPE(-34.041,-34.041,63.054,63.054) Tellus A: Dynamic Meteorology and Oceanography 62 1 80 90 |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
spellingShingle |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography Sarafanov, Artem Mercier, Herlé Falina, Anastasia Sokov, Alexey Lherminier, Pascale Cessation and partial reversal of deep water freshening in the northern North Atlantic: observation-based estimates and attribution |
topic_facet |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
description |
International audience Recent decadal salinity changes in the Greenland-Scotland overflow-derived deep waters are quantified using CTD data from repeated hydrographic sections in the Irminger Sea. The Denmark Strait Overflow Water salinity record shows the absence of any net change over the 1980s–2000s; changes in the Iceland–Scotland Overflow Water (ISOW) and in the deep water column (σ0 > 27.82), enclosing both overflows, show a distinct freshening reversal in the early 2000s. The observed freshening reversal is a lagged consequence of the persistent ISOW salinification that occurred upstream, in the Iceland Basin, after 1996 in response to salinification of the northeast Atlantic waters entrained into the overflow. The entrainment salinity increase is explained by the earlier documented North Atlantic Oscillation (NAO)-induced contraction of the subpolar gyre and corresponding northwestward advance of subtropical waters that followed the NAO decline in the mid-1990s and continued through the mid-2000s. Remarkably, the ISOW freshening reversal is not associated with changes in the overflow water salinity. This suggests that changes in the NAO-dependent relative contributions of subpolar and subtropical waters to the entrainment south of the Iceland–Scotland Ridge may dominate over changes in the Nordic Seas freshwater balance with respect to their effect on the ISOW salinity. |
author2 |
P.P. Shirshov Institute of Oceanology (SIO) Russian Academy of Sciences Moscow (RAS) Laboratoire de physique des océans (LPO) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Sarafanov, Artem Mercier, Herlé Falina, Anastasia Sokov, Alexey Lherminier, Pascale |
author_facet |
Sarafanov, Artem Mercier, Herlé Falina, Anastasia Sokov, Alexey Lherminier, Pascale |
author_sort |
Sarafanov, Artem |
title |
Cessation and partial reversal of deep water freshening in the northern North Atlantic: observation-based estimates and attribution |
title_short |
Cessation and partial reversal of deep water freshening in the northern North Atlantic: observation-based estimates and attribution |
title_full |
Cessation and partial reversal of deep water freshening in the northern North Atlantic: observation-based estimates and attribution |
title_fullStr |
Cessation and partial reversal of deep water freshening in the northern North Atlantic: observation-based estimates and attribution |
title_full_unstemmed |
Cessation and partial reversal of deep water freshening in the northern North Atlantic: observation-based estimates and attribution |
title_sort |
cessation and partial reversal of deep water freshening in the northern north atlantic: observation-based estimates and attribution |
publisher |
HAL CCSD |
publishDate |
2010 |
url |
https://hal.archives-ouvertes.fr/hal-00494993 https://doi.org/10.1111/j.1600-0870.2009.00418.x |
long_lat |
ENVELOPE(-34.041,-34.041,63.054,63.054) |
geographic |
Greenland Irminger Sea |
geographic_facet |
Greenland Irminger Sea |
genre |
Denmark Strait Greenland Iceland Nordic Seas North Atlantic North Atlantic oscillation Northeast Atlantic |
genre_facet |
Denmark Strait Greenland Iceland Nordic Seas North Atlantic North Atlantic oscillation Northeast Atlantic |
op_source |
ISSN: 0280-6495 EISSN: 1600-0870 Tellus A https://hal.archives-ouvertes.fr/hal-00494993 Tellus A, Co-Action Publishing, 2010, 62 (1), pp.80-90. ⟨10.1111/j.1600-0870.2009.00418.x⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1600-0870.2009.00418.x hal-00494993 https://hal.archives-ouvertes.fr/hal-00494993 doi:10.1111/j.1600-0870.2009.00418.x |
op_doi |
https://doi.org/10.1111/j.1600-0870.2009.00418.x |
container_title |
Tellus A: Dynamic Meteorology and Oceanography |
container_volume |
62 |
container_issue |
1 |
container_start_page |
80 |
op_container_end_page |
90 |
_version_ |
1766396678845235200 |