Holocene North Atlantic Overturning in an atmosphere-ocean-sea ice model compared to proxy-based reconstructions
Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 30 (2015): 1503–1524, doi:10.1002/2015PA002828. Climate and ocean circulation...
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/7808 2023-05-15T16:28:41+02:00 Holocene North Atlantic Overturning in an atmosphere-ocean-sea ice model compared to proxy-based reconstructions Blaschek, Michael Renssen, Hans Kissel, Catherine Thornalley, David J. R. 2015-11-24 https://hdl.handle.net/1912/7808 en_US eng John Wiley & Sons https://doi.org/10.1002/2015PA002828 Paleoceanography 30 (2015): 1503–1524 https://hdl.handle.net/1912/7808 doi:10.1002/2015PA002828 Paleoceanography 30 (2015): 1503–1524 doi:10.1002/2015PA002828 Holocene Paleoclimate modeling AMOC Sortable silt δ13C Magnetic susceptibility Article 2015 ftwhoas https://doi.org/10.1002/2015PA002828 2022-05-28T22:59:30Z Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 30 (2015): 1503–1524, doi:10.1002/2015PA002828. Climate and ocean circulation in the North Atlantic region changed over the course of the Holocene, partly because of disintegrating ice sheets and partly because of an orbital-induced insolation trend. In the Nordic Seas, this impact was accompanied by a rather small, but significant, amount of Greenland ice sheet melting. We have employed the EMIC LOVECLIM and compared our model simulations with proxy-based reconstructions of δ13C, sortable silt, and magnetic susceptibility (κ) used to infer changes in past ocean circulation over the last 9000 years. The various reconstructions exhibit different long-term evolutions suggesting changes in either the overturning of the Atlantic in total or of subcomponents of the ocean circulation, such as the overflow waters across the Greenland-Scotland ridge. Thus, the question arises whether these reconstructions are consistent with each other or not. A comparison with model results indicates that δ13C, employed as an indicator of overturning, agrees well with the long-term evolution of the modeled Atlantic meridional overturning circulation (AMOC). The model results suggest that different long-term trends in subcomponents of the AMOC, such as Iceland-Scotland overflow water, are consistent with proxy-based reconstructions and allow some of the reconstructions to be reconciled with the modeled and reconstructed (from δ13C) AMOC evolution. We find a weak early Holocene AMOC, which recovers by 7 kyr B.P. and shows a weak increasing trend of 88 ± 1 mSv/kyr toward present, with relatively low variability on centennial to millennial timescales. European Community's 7th Framework Program Grant Number: FP7/2007-2013; Marie-Curie Actions Grant Number: 238111 2016-05-24 Article in Journal/Newspaper Greenland Greenland-Scotland Ridge Ice Sheet Iceland Nordic Seas North Atlantic Sea ice Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Greenland Paleoceanography 30 11 1503 1524 |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Holocene Paleoclimate modeling AMOC Sortable silt δ13C Magnetic susceptibility |
spellingShingle |
Holocene Paleoclimate modeling AMOC Sortable silt δ13C Magnetic susceptibility Blaschek, Michael Renssen, Hans Kissel, Catherine Thornalley, David J. R. Holocene North Atlantic Overturning in an atmosphere-ocean-sea ice model compared to proxy-based reconstructions |
topic_facet |
Holocene Paleoclimate modeling AMOC Sortable silt δ13C Magnetic susceptibility |
description |
Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 30 (2015): 1503–1524, doi:10.1002/2015PA002828. Climate and ocean circulation in the North Atlantic region changed over the course of the Holocene, partly because of disintegrating ice sheets and partly because of an orbital-induced insolation trend. In the Nordic Seas, this impact was accompanied by a rather small, but significant, amount of Greenland ice sheet melting. We have employed the EMIC LOVECLIM and compared our model simulations with proxy-based reconstructions of δ13C, sortable silt, and magnetic susceptibility (κ) used to infer changes in past ocean circulation over the last 9000 years. The various reconstructions exhibit different long-term evolutions suggesting changes in either the overturning of the Atlantic in total or of subcomponents of the ocean circulation, such as the overflow waters across the Greenland-Scotland ridge. Thus, the question arises whether these reconstructions are consistent with each other or not. A comparison with model results indicates that δ13C, employed as an indicator of overturning, agrees well with the long-term evolution of the modeled Atlantic meridional overturning circulation (AMOC). The model results suggest that different long-term trends in subcomponents of the AMOC, such as Iceland-Scotland overflow water, are consistent with proxy-based reconstructions and allow some of the reconstructions to be reconciled with the modeled and reconstructed (from δ13C) AMOC evolution. We find a weak early Holocene AMOC, which recovers by 7 kyr B.P. and shows a weak increasing trend of 88 ± 1 mSv/kyr toward present, with relatively low variability on centennial to millennial timescales. European Community's 7th Framework Program Grant Number: FP7/2007-2013; Marie-Curie Actions Grant Number: 238111 2016-05-24 |
format |
Article in Journal/Newspaper |
author |
Blaschek, Michael Renssen, Hans Kissel, Catherine Thornalley, David J. R. |
author_facet |
Blaschek, Michael Renssen, Hans Kissel, Catherine Thornalley, David J. R. |
author_sort |
Blaschek, Michael |
title |
Holocene North Atlantic Overturning in an atmosphere-ocean-sea ice model compared to proxy-based reconstructions |
title_short |
Holocene North Atlantic Overturning in an atmosphere-ocean-sea ice model compared to proxy-based reconstructions |
title_full |
Holocene North Atlantic Overturning in an atmosphere-ocean-sea ice model compared to proxy-based reconstructions |
title_fullStr |
Holocene North Atlantic Overturning in an atmosphere-ocean-sea ice model compared to proxy-based reconstructions |
title_full_unstemmed |
Holocene North Atlantic Overturning in an atmosphere-ocean-sea ice model compared to proxy-based reconstructions |
title_sort |
holocene north atlantic overturning in an atmosphere-ocean-sea ice model compared to proxy-based reconstructions |
publisher |
John Wiley & Sons |
publishDate |
2015 |
url |
https://hdl.handle.net/1912/7808 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Greenland-Scotland Ridge Ice Sheet Iceland Nordic Seas North Atlantic Sea ice |
genre_facet |
Greenland Greenland-Scotland Ridge Ice Sheet Iceland Nordic Seas North Atlantic Sea ice |
op_source |
Paleoceanography 30 (2015): 1503–1524 doi:10.1002/2015PA002828 |
op_relation |
https://doi.org/10.1002/2015PA002828 Paleoceanography 30 (2015): 1503–1524 https://hdl.handle.net/1912/7808 doi:10.1002/2015PA002828 |
op_doi |
https://doi.org/10.1002/2015PA002828 |
container_title |
Paleoceanography |
container_volume |
30 |
container_issue |
11 |
container_start_page |
1503 |
op_container_end_page |
1524 |
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1766018368963346432 |