A role for icebergs in the 8.2 ka climate event

We investigate the potential role of icebergs in the 8.2 ka climate event, using a coupled climate model equipped with an iceberg component. First, we evaluate the effect of a large iceberg discharge originating from the decaying Laurentide ice sheet on ocean circulation, compared to a release of an...

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Published in:Climate Dynamics
Main Authors: Wiersma, Ane P., Jongma, Jochem I.
Format: Article in Journal/Newspaper
Language:English
Published: Springer 2010
Subjects:
Online Access:https://archimer.ifremer.fr/doc/00496/60749/65152.pdf
https://doi.org/10.1007/s00382-009-0645-1
https://archimer.ifremer.fr/doc/00496/60749/
id ftarchimer:oai:archimer.ifremer.fr:60749
record_format openpolar
spelling ftarchimer:oai:archimer.ifremer.fr:60749 2023-05-15T16:30:01+02:00 A role for icebergs in the 8.2 ka climate event Wiersma, Ane P. Jongma, Jochem I. 2010-08 application/pdf https://archimer.ifremer.fr/doc/00496/60749/65152.pdf https://doi.org/10.1007/s00382-009-0645-1 https://archimer.ifremer.fr/doc/00496/60749/ eng eng Springer https://archimer.ifremer.fr/doc/00496/60749/65152.pdf doi:10.1007/s00382-009-0645-1 https://archimer.ifremer.fr/doc/00496/60749/ info:eu-repo/semantics/openAccess restricted use Climate Dynamics (0930-7575) (Springer), 2010-08 , Vol. 35 , N. 2-3 , P. 535-549 8.2 ka event Climate modeling Icebergs Laurentide ice sheet Hudson Strait Holocene Heinrich events text Publication info:eu-repo/semantics/article 2010 ftarchimer https://doi.org/10.1007/s00382-009-0645-1 2021-09-23T20:32:46Z We investigate the potential role of icebergs in the 8.2 ka climate event, using a coupled climate model equipped with an iceberg component. First, we evaluate the effect of a large iceberg discharge originating from the decaying Laurentide ice sheet on ocean circulation, compared to a release of an identical volume of freshwater alone. Our results show that, on top of the freshwater effect, a large iceberg discharge facilitates sea-ice growth as a result of lower sea-surface temperatures induced by latent heat of melting. This causes an 8% increased sea-ice cover, 5% stronger reduction in North Atlantic Deep Water production and 1A degrees C lower temperature in Greenland. Second, we use the model to investigate the effect of a hypothetical two-stage lake drainage, which is suggested by several investigators to have triggered the 8.2 ka climate event. To account for the final collapse of the ice-dam holding the Laurentide Lakes we accompany the secondary freshwater pulse in one scenario with a fast 5-year iceberg discharge and in a second scenario with a slow 100-year iceberg discharge. Our experiments show that a two-stage lake drainage accompanied by the collapsing ice-dam could explain the anomalies observed around the 8.2 ka climate event in various climate records. In addition, they advocate a potential role for icebergs in the 8.2 ka climate event and illustrate the importance of latent heat of melting in the simulation of climate events that involve icebergs. Our two-stage lake drainage experiments provide a framework in the discussion of two-stage lake drainage and ice sheet collapse. Article in Journal/Newspaper Greenland Hudson Strait Ice Sheet North Atlantic Deep Water North Atlantic Sea ice Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Greenland Hudson Hudson Strait ENVELOPE(-70.000,-70.000,62.000,62.000) Climate Dynamics 35 2-3 535 549
institution Open Polar
collection Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer)
op_collection_id ftarchimer
language English
topic 8.2 ka event
Climate modeling
Icebergs
Laurentide ice sheet
Hudson Strait
Holocene
Heinrich events
spellingShingle 8.2 ka event
Climate modeling
Icebergs
Laurentide ice sheet
Hudson Strait
Holocene
Heinrich events
Wiersma, Ane P.
Jongma, Jochem I.
A role for icebergs in the 8.2 ka climate event
topic_facet 8.2 ka event
Climate modeling
Icebergs
Laurentide ice sheet
Hudson Strait
Holocene
Heinrich events
description We investigate the potential role of icebergs in the 8.2 ka climate event, using a coupled climate model equipped with an iceberg component. First, we evaluate the effect of a large iceberg discharge originating from the decaying Laurentide ice sheet on ocean circulation, compared to a release of an identical volume of freshwater alone. Our results show that, on top of the freshwater effect, a large iceberg discharge facilitates sea-ice growth as a result of lower sea-surface temperatures induced by latent heat of melting. This causes an 8% increased sea-ice cover, 5% stronger reduction in North Atlantic Deep Water production and 1A degrees C lower temperature in Greenland. Second, we use the model to investigate the effect of a hypothetical two-stage lake drainage, which is suggested by several investigators to have triggered the 8.2 ka climate event. To account for the final collapse of the ice-dam holding the Laurentide Lakes we accompany the secondary freshwater pulse in one scenario with a fast 5-year iceberg discharge and in a second scenario with a slow 100-year iceberg discharge. Our experiments show that a two-stage lake drainage accompanied by the collapsing ice-dam could explain the anomalies observed around the 8.2 ka climate event in various climate records. In addition, they advocate a potential role for icebergs in the 8.2 ka climate event and illustrate the importance of latent heat of melting in the simulation of climate events that involve icebergs. Our two-stage lake drainage experiments provide a framework in the discussion of two-stage lake drainage and ice sheet collapse.
format Article in Journal/Newspaper
author Wiersma, Ane P.
Jongma, Jochem I.
author_facet Wiersma, Ane P.
Jongma, Jochem I.
author_sort Wiersma, Ane P.
title A role for icebergs in the 8.2 ka climate event
title_short A role for icebergs in the 8.2 ka climate event
title_full A role for icebergs in the 8.2 ka climate event
title_fullStr A role for icebergs in the 8.2 ka climate event
title_full_unstemmed A role for icebergs in the 8.2 ka climate event
title_sort role for icebergs in the 8.2 ka climate event
publisher Springer
publishDate 2010
url https://archimer.ifremer.fr/doc/00496/60749/65152.pdf
https://doi.org/10.1007/s00382-009-0645-1
https://archimer.ifremer.fr/doc/00496/60749/
long_lat ENVELOPE(-70.000,-70.000,62.000,62.000)
geographic Greenland
Hudson
Hudson Strait
geographic_facet Greenland
Hudson
Hudson Strait
genre Greenland
Hudson Strait
Ice Sheet
North Atlantic Deep Water
North Atlantic
Sea ice
genre_facet Greenland
Hudson Strait
Ice Sheet
North Atlantic Deep Water
North Atlantic
Sea ice
op_source Climate Dynamics (0930-7575) (Springer), 2010-08 , Vol. 35 , N. 2-3 , P. 535-549
op_relation https://archimer.ifremer.fr/doc/00496/60749/65152.pdf
doi:10.1007/s00382-009-0645-1
https://archimer.ifremer.fr/doc/00496/60749/
op_rights info:eu-repo/semantics/openAccess
restricted use
op_doi https://doi.org/10.1007/s00382-009-0645-1
container_title Climate Dynamics
container_volume 35
container_issue 2-3
container_start_page 535
op_container_end_page 549
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