Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years
The Atlantic meridional overturning circulation (AMOC) is a system of ocean currents that has an essential role in Earth's climate, redistributing heat and influencing the carbon cycle. The AMOC has been shown to be weakening in recent years1; this decline may reflect decadal-scale variability...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.902495 2024-09-15T18:10:13+00:00 Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years Thornalley, David J R Oppo, Delia W Ortega, Pablo Robson, Jon I Brierley, Chris M Davis, Renee Hall, Ian R Moffa-Sanchez, Paola Rose, Neil L Spooner, Peter T Yashayaev, Igor M Keigwin, Lloyd D MEDIAN LATITUDE: 42.371575 * MEDIAN LONGITUDE: -63.934354 * SOUTH-BOUND LATITUDE: 35.466667 * WEST-BOUND LONGITUDE: -74.716667 * NORTH-BOUND LATITUDE: 55.000000 * EAST-BOUND LONGITUDE: -54.816667 2019 application/zip, 22 datasets https://doi.pangaea.de/10.1594/PANGAEA.902495 https://doi.org/10.1594/PANGAEA.902495 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.902495 https://doi.org/10.1594/PANGAEA.902495 CC-BY-4.0: Creative Commons Attribution 4.0 International Access constraints: unrestricted info:eu-repo/semantics/openAccess Woods Hole Oceanographic Institution, Department of Geology & Geophysics Supplement to: Thornalley, David J R; Oppo, Delia W; Ortega, Pablo; Robson, Jon I; Brierley, Chris M; Davis, Renee; Hall, Ian R; Moffa-Sanchez, Paola; Rose, Neil L; Spooner, Peter T; Yashayaev, Igor M; Keigwin, Lloyd D (2018): Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years. Nature, 556(7700), 227-230, https://doi.org/10.1038/s41586-018-0007-4 Atlantic meridional overturning circulation ATLAS A Trans-Atlantic assessment and deep-water ecosystem-based spatial management plan for Europe deep water formation sortable silt subsurface ocean temperatures dataset publication series 2019 ftpangaea https://doi.org/10.1594/PANGAEA.90249510.1038/s41586-018-0007-4 2024-07-24T02:31:21Z The Atlantic meridional overturning circulation (AMOC) is a system of ocean currents that has an essential role in Earth's climate, redistributing heat and influencing the carbon cycle. The AMOC has been shown to be weakening in recent years1; this decline may reflect decadal-scale variability in convection in the Labrador Sea, but short observational datasets preclude a longer-term perspective on the modern state and variability of Labrador Sea convection and the AMOC. Here we provide several lines of palaeo-oceanographic evidence that Labrador Sea deep convection and the AMOC have been anomalously weak over the past 150 years or so (since the end of the Little Ice Age, LIA, approximately AD 1850) compared with the preceding 1,500 years. Our palaeoclimate reconstructions indicate that the transition occurred either as a predominantly abrupt shift towards the end of the LIA, or as a more gradual, continued decline over the past 150 years; this ambiguity probably arises from non-AMOC influences on the various proxies or from the different sensitivities of these proxies to individual components of the AMOC. We suggest that enhanced freshwater fluxes from the Arctic and Nordic seas towards the end of the LIA—sourced from melting glaciers and thickened sea ice that developed earlier in the LIA—weakened Labrador Sea convection and the AMOC. The lack of a subsequent recovery may have resulted from hysteresis or from twentieth-century melting of the Greenland Ice Sheet. Our results suggest that recent decadal variability in Labrador Sea convection and the AMOC has occurred during an atypical, weak background state. Future work should aim to constrain the roles of internal climate variability and early anthropogenic forcing in the AMOC weakening described here. The data presented here is the supporting data for Thornalley et al. 2018 (see details below) and is derived from cores KNR-178-56JPC and KNR-178-48JPC. It includes the mean sortable silt size, details of radiocarbon dating, the % nps and binned sub-surface ... Other/Unknown Material Greenland Ice Sheet Labrador Sea Nordic Seas Sea ice PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(-74.716667,-54.816667,55.000000,35.466667) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
Atlantic meridional overturning circulation ATLAS A Trans-Atlantic assessment and deep-water ecosystem-based spatial management plan for Europe deep water formation sortable silt subsurface ocean temperatures |
spellingShingle |
Atlantic meridional overturning circulation ATLAS A Trans-Atlantic assessment and deep-water ecosystem-based spatial management plan for Europe deep water formation sortable silt subsurface ocean temperatures Thornalley, David J R Oppo, Delia W Ortega, Pablo Robson, Jon I Brierley, Chris M Davis, Renee Hall, Ian R Moffa-Sanchez, Paola Rose, Neil L Spooner, Peter T Yashayaev, Igor M Keigwin, Lloyd D Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years |
topic_facet |
Atlantic meridional overturning circulation ATLAS A Trans-Atlantic assessment and deep-water ecosystem-based spatial management plan for Europe deep water formation sortable silt subsurface ocean temperatures |
description |
The Atlantic meridional overturning circulation (AMOC) is a system of ocean currents that has an essential role in Earth's climate, redistributing heat and influencing the carbon cycle. The AMOC has been shown to be weakening in recent years1; this decline may reflect decadal-scale variability in convection in the Labrador Sea, but short observational datasets preclude a longer-term perspective on the modern state and variability of Labrador Sea convection and the AMOC. Here we provide several lines of palaeo-oceanographic evidence that Labrador Sea deep convection and the AMOC have been anomalously weak over the past 150 years or so (since the end of the Little Ice Age, LIA, approximately AD 1850) compared with the preceding 1,500 years. Our palaeoclimate reconstructions indicate that the transition occurred either as a predominantly abrupt shift towards the end of the LIA, or as a more gradual, continued decline over the past 150 years; this ambiguity probably arises from non-AMOC influences on the various proxies or from the different sensitivities of these proxies to individual components of the AMOC. We suggest that enhanced freshwater fluxes from the Arctic and Nordic seas towards the end of the LIA—sourced from melting glaciers and thickened sea ice that developed earlier in the LIA—weakened Labrador Sea convection and the AMOC. The lack of a subsequent recovery may have resulted from hysteresis or from twentieth-century melting of the Greenland Ice Sheet. Our results suggest that recent decadal variability in Labrador Sea convection and the AMOC has occurred during an atypical, weak background state. Future work should aim to constrain the roles of internal climate variability and early anthropogenic forcing in the AMOC weakening described here. The data presented here is the supporting data for Thornalley et al. 2018 (see details below) and is derived from cores KNR-178-56JPC and KNR-178-48JPC. It includes the mean sortable silt size, details of radiocarbon dating, the % nps and binned sub-surface ... |
format |
Other/Unknown Material |
author |
Thornalley, David J R Oppo, Delia W Ortega, Pablo Robson, Jon I Brierley, Chris M Davis, Renee Hall, Ian R Moffa-Sanchez, Paola Rose, Neil L Spooner, Peter T Yashayaev, Igor M Keigwin, Lloyd D |
author_facet |
Thornalley, David J R Oppo, Delia W Ortega, Pablo Robson, Jon I Brierley, Chris M Davis, Renee Hall, Ian R Moffa-Sanchez, Paola Rose, Neil L Spooner, Peter T Yashayaev, Igor M Keigwin, Lloyd D |
author_sort |
Thornalley, David J R |
title |
Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years |
title_short |
Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years |
title_full |
Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years |
title_fullStr |
Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years |
title_full_unstemmed |
Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years |
title_sort |
anomalously weak labrador sea convection and atlantic overturning during the past 150 years |
publisher |
PANGAEA |
publishDate |
2019 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.902495 https://doi.org/10.1594/PANGAEA.902495 |
op_coverage |
MEDIAN LATITUDE: 42.371575 * MEDIAN LONGITUDE: -63.934354 * SOUTH-BOUND LATITUDE: 35.466667 * WEST-BOUND LONGITUDE: -74.716667 * NORTH-BOUND LATITUDE: 55.000000 * EAST-BOUND LONGITUDE: -54.816667 |
long_lat |
ENVELOPE(-74.716667,-54.816667,55.000000,35.466667) |
genre |
Greenland Ice Sheet Labrador Sea Nordic Seas Sea ice |
genre_facet |
Greenland Ice Sheet Labrador Sea Nordic Seas Sea ice |
op_source |
Woods Hole Oceanographic Institution, Department of Geology & Geophysics Supplement to: Thornalley, David J R; Oppo, Delia W; Ortega, Pablo; Robson, Jon I; Brierley, Chris M; Davis, Renee; Hall, Ian R; Moffa-Sanchez, Paola; Rose, Neil L; Spooner, Peter T; Yashayaev, Igor M; Keigwin, Lloyd D (2018): Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years. Nature, 556(7700), 227-230, https://doi.org/10.1038/s41586-018-0007-4 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.902495 https://doi.org/10.1594/PANGAEA.902495 |
op_rights |
CC-BY-4.0: Creative Commons Attribution 4.0 International Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1594/PANGAEA.90249510.1038/s41586-018-0007-4 |
_version_ |
1810447815943389184 |