Potential links between surging ice sheets, circulation changes and the Dansgaard Oeschger cycles in the Irminger Sea, 60-18 kyr.
Surface and deepwater paleoclimate records in Irminger Sea core SO82-5 (59°N, 31°W) and Icelandic Sea core PS2644 (68°N, 22°W) exhibit large fluctuations in thermohaline circulation (THC) from 60 to 18 calendar kyr B.P., with a dominant periodicity of 1460 years from 46 to 22 calendar kyr B.P., matc...
Published in: | Paleoceanography |
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Format: | Article in Journal/Newspaper |
Language: | English |
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2000
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Online Access: | https://research.vu.nl/en/publications/9bef35ae-bb3b-498c-bfea-22448dae4cb3 https://doi.org/10.1029/1999PA000464 https://research.vu.nl/ws/files/1713946/131868.pdf |
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ftvuamstcris:oai:research.vu.nl:publications/9bef35ae-bb3b-498c-bfea-22448dae4cb3 2024-06-23T07:52:21+00:00 Potential links between surging ice sheets, circulation changes and the Dansgaard Oeschger cycles in the Irminger Sea, 60-18 kyr. van Krefeld-Alfane, S. Sarntheim, M. Erlenkeuser, S. Grootes, P. Jung, S.J.A. Nadeau, M.J. Pflaumann, U. Voelker, A. 2000 application/pdf https://research.vu.nl/en/publications/9bef35ae-bb3b-498c-bfea-22448dae4cb3 https://doi.org/10.1029/1999PA000464 https://research.vu.nl/ws/files/1713946/131868.pdf eng eng https://research.vu.nl/en/publications/9bef35ae-bb3b-498c-bfea-22448dae4cb3 info:eu-repo/semantics/openAccess van Krefeld-Alfane , S , Sarntheim , M , Erlenkeuser , S , Grootes , P , Jung , S J A , Nadeau , M J , Pflaumann , U & Voelker , A 2000 , ' Potential links between surging ice sheets, circulation changes and the Dansgaard Oeschger cycles in the Irminger Sea, 60-18 kyr. ' , Paleoceanography , vol. 15 , no. 4 , pp. 425-442 . https://doi.org/10.1029/1999PA000464 /dk/atira/pure/sustainabledevelopmentgoals/life_below_water name=SDG 14 - Life Below Water article 2000 ftvuamstcris https://doi.org/10.1029/1999PA000464 2024-06-12T23:57:46Z Surface and deepwater paleoclimate records in Irminger Sea core SO82-5 (59°N, 31°W) and Icelandic Sea core PS2644 (68°N, 22°W) exhibit large fluctuations in thermohaline circulation (THC) from 60 to 18 calendar kyr B.P., with a dominant periodicity of 1460 years from 46 to 22 calendar kyr B.P., matching the Dansgaard-Oeschger (D-O) cycles in the Greenland Ice Sheet Project 2 (GISP2) temperature record [Grootes and Stuiver, 1997]. During interstadials, summer sea surface temperatures (SST su ) in the Irminger Sea averaged to 8°C, and sea surface salinities (SSS) averaged to ∼36.5, recording a strong Irminger Current and Atlantic THC. During stadials, SST su dropped to 2°-4°C, in phase with SSS drops by ∼1-2. They reveal major meltwater injections along with the East Greenland Current, which turned off the North Atlantic deepwater convection and hence the heat advection to the north, in harmony with various ocean circulation and ice models. On the basis of the IRD composition, icebergs came from Iceland, east Greenland, and perhaps Svalbard and other northern ice sheets. However, the southward drifting icebergs were initially jammed in the Denmark Strait, reaching the Irminger Sea only with a lag of 155-195 years. We also conclude that the abrupt stadial terminations, the D-O warming events, were tied to iceberg melt via abundant seasonal sea ice and brine water formation in the meltwater-covered northwestern North Atlantic. In the 1/1460-year frequency band, benthic δ 18 O brine water spikes led the temperature maxima above Greenland and in the Irminger Sea by as little as 95 years. Thus abundant brine formation, which was induced by seasonal freezing of large parts of the northwestern Atlantic, may have finally entrained a current of warm surface water from the subtropics and thereby triggered the sudden reactivation of the THC. In summary, the internal dynamics of the east Greenland ice sheet may have formed the ultimate pacemaker of D-O cycles. Article in Journal/Newspaper Denmark Strait East Greenland east greenland current Greenland Greenland Ice Sheet Project Ice Sheet Iceland North Atlantic Sea ice Svalbard Vrije Universiteit Amsterdam (VU): Research Portal Greenland Irminger Sea ENVELOPE(-34.041,-34.041,63.054,63.054) Svalbard Paleoceanography 15 4 425 442 |
institution |
Open Polar |
collection |
Vrije Universiteit Amsterdam (VU): Research Portal |
op_collection_id |
ftvuamstcris |
language |
English |
topic |
/dk/atira/pure/sustainabledevelopmentgoals/life_below_water name=SDG 14 - Life Below Water |
spellingShingle |
/dk/atira/pure/sustainabledevelopmentgoals/life_below_water name=SDG 14 - Life Below Water van Krefeld-Alfane, S. Sarntheim, M. Erlenkeuser, S. Grootes, P. Jung, S.J.A. Nadeau, M.J. Pflaumann, U. Voelker, A. Potential links between surging ice sheets, circulation changes and the Dansgaard Oeschger cycles in the Irminger Sea, 60-18 kyr. |
topic_facet |
/dk/atira/pure/sustainabledevelopmentgoals/life_below_water name=SDG 14 - Life Below Water |
description |
Surface and deepwater paleoclimate records in Irminger Sea core SO82-5 (59°N, 31°W) and Icelandic Sea core PS2644 (68°N, 22°W) exhibit large fluctuations in thermohaline circulation (THC) from 60 to 18 calendar kyr B.P., with a dominant periodicity of 1460 years from 46 to 22 calendar kyr B.P., matching the Dansgaard-Oeschger (D-O) cycles in the Greenland Ice Sheet Project 2 (GISP2) temperature record [Grootes and Stuiver, 1997]. During interstadials, summer sea surface temperatures (SST su ) in the Irminger Sea averaged to 8°C, and sea surface salinities (SSS) averaged to ∼36.5, recording a strong Irminger Current and Atlantic THC. During stadials, SST su dropped to 2°-4°C, in phase with SSS drops by ∼1-2. They reveal major meltwater injections along with the East Greenland Current, which turned off the North Atlantic deepwater convection and hence the heat advection to the north, in harmony with various ocean circulation and ice models. On the basis of the IRD composition, icebergs came from Iceland, east Greenland, and perhaps Svalbard and other northern ice sheets. However, the southward drifting icebergs were initially jammed in the Denmark Strait, reaching the Irminger Sea only with a lag of 155-195 years. We also conclude that the abrupt stadial terminations, the D-O warming events, were tied to iceberg melt via abundant seasonal sea ice and brine water formation in the meltwater-covered northwestern North Atlantic. In the 1/1460-year frequency band, benthic δ 18 O brine water spikes led the temperature maxima above Greenland and in the Irminger Sea by as little as 95 years. Thus abundant brine formation, which was induced by seasonal freezing of large parts of the northwestern Atlantic, may have finally entrained a current of warm surface water from the subtropics and thereby triggered the sudden reactivation of the THC. In summary, the internal dynamics of the east Greenland ice sheet may have formed the ultimate pacemaker of D-O cycles. |
format |
Article in Journal/Newspaper |
author |
van Krefeld-Alfane, S. Sarntheim, M. Erlenkeuser, S. Grootes, P. Jung, S.J.A. Nadeau, M.J. Pflaumann, U. Voelker, A. |
author_facet |
van Krefeld-Alfane, S. Sarntheim, M. Erlenkeuser, S. Grootes, P. Jung, S.J.A. Nadeau, M.J. Pflaumann, U. Voelker, A. |
author_sort |
van Krefeld-Alfane, S. |
title |
Potential links between surging ice sheets, circulation changes and the Dansgaard Oeschger cycles in the Irminger Sea, 60-18 kyr. |
title_short |
Potential links between surging ice sheets, circulation changes and the Dansgaard Oeschger cycles in the Irminger Sea, 60-18 kyr. |
title_full |
Potential links between surging ice sheets, circulation changes and the Dansgaard Oeschger cycles in the Irminger Sea, 60-18 kyr. |
title_fullStr |
Potential links between surging ice sheets, circulation changes and the Dansgaard Oeschger cycles in the Irminger Sea, 60-18 kyr. |
title_full_unstemmed |
Potential links between surging ice sheets, circulation changes and the Dansgaard Oeschger cycles in the Irminger Sea, 60-18 kyr. |
title_sort |
potential links between surging ice sheets, circulation changes and the dansgaard oeschger cycles in the irminger sea, 60-18 kyr. |
publishDate |
2000 |
url |
https://research.vu.nl/en/publications/9bef35ae-bb3b-498c-bfea-22448dae4cb3 https://doi.org/10.1029/1999PA000464 https://research.vu.nl/ws/files/1713946/131868.pdf |
long_lat |
ENVELOPE(-34.041,-34.041,63.054,63.054) |
geographic |
Greenland Irminger Sea Svalbard |
geographic_facet |
Greenland Irminger Sea Svalbard |
genre |
Denmark Strait East Greenland east greenland current Greenland Greenland Ice Sheet Project Ice Sheet Iceland North Atlantic Sea ice Svalbard |
genre_facet |
Denmark Strait East Greenland east greenland current Greenland Greenland Ice Sheet Project Ice Sheet Iceland North Atlantic Sea ice Svalbard |
op_source |
van Krefeld-Alfane , S , Sarntheim , M , Erlenkeuser , S , Grootes , P , Jung , S J A , Nadeau , M J , Pflaumann , U & Voelker , A 2000 , ' Potential links between surging ice sheets, circulation changes and the Dansgaard Oeschger cycles in the Irminger Sea, 60-18 kyr. ' , Paleoceanography , vol. 15 , no. 4 , pp. 425-442 . https://doi.org/10.1029/1999PA000464 |
op_relation |
https://research.vu.nl/en/publications/9bef35ae-bb3b-498c-bfea-22448dae4cb3 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/1999PA000464 |
container_title |
Paleoceanography |
container_volume |
15 |
container_issue |
4 |
container_start_page |
425 |
op_container_end_page |
442 |
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1802643632085270528 |