A subtropical fate awaited freshwater discharged from glacial Lake Agassiz
The 8.2 kyr event is the largest abrupt climatic change recorded in the last 10,000 years, and is widely hypothesized to have been triggered by the release of thousands of kilometers cubed of freshwater into the North Atlantic Ocean. Using a high-resolution (1/6°) global, ocean-ice circulation model...
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Online Access: | http://www.osti.gov/servlets/purl/1159310 https://www.osti.gov/biblio/1159310 https://doi.org/10.1029/2010GL046011 |
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ftosti:oai:osti.gov:1159310 2023-07-30T03:59:22+02:00 A subtropical fate awaited freshwater discharged from glacial Lake Agassiz Condron, Alan Winsor, Peter 2022-05-20 application/pdf http://www.osti.gov/servlets/purl/1159310 https://www.osti.gov/biblio/1159310 https://doi.org/10.1029/2010GL046011 unknown http://www.osti.gov/servlets/purl/1159310 https://www.osti.gov/biblio/1159310 https://doi.org/10.1029/2010GL046011 doi:10.1029/2010GL046011 54 ENVIRONMENTAL SCIENCES 2022 ftosti https://doi.org/10.1029/2010GL046011 2023-07-11T08:57:55Z The 8.2 kyr event is the largest abrupt climatic change recorded in the last 10,000 years, and is widely hypothesized to have been triggered by the release of thousands of kilometers cubed of freshwater into the North Atlantic Ocean. Using a high-resolution (1/6°) global, ocean-ice circulation model we present an alternative view that freshwater discharged from glacial Lake Agassiz would have remained on the continental shelf as a narrow, buoyant, coastal current, and would have been transported south into the subtropical North Atlantic. The pathway we describe is in contrast to the conceptual idea that freshwater from this lake outburst spread over most of the sub-polar North Atlantic, and covered the deep, open-ocean, convection regions. This coastally confined freshwater pathway is consistent with the present-day routing of freshwater from Hudson Bay, as well as paleoceanographic evidence of this event. In this study, using a coarse-resolution (2.6°) version of the same model, we demonstrate that the previously reported spreading of freshwater across the sub-polar North Atlantic results from the inability of numerical models of this resolution to accurately resolve narrow coastal flows, producing instead a diffuse circulation that advects freshwater away from the boundaries. To understand the climatic impact of freshwater released in the past or future (e.g. Greenland and Antarctica), the ocean needs to be modeled at a resolution sufficient to resolve the dynamics of narrow, coastal buoyant flows. Other/Unknown Material Antarc* Antarctica Greenland Hudson Bay North Atlantic SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Glacial Lake ENVELOPE(-129.463,-129.463,58.259,58.259) Greenland Hudson Hudson Bay Geophysical Research Letters 38 3 n/a n/a |
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Open Polar |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
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ftosti |
language |
unknown |
topic |
54 ENVIRONMENTAL SCIENCES |
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54 ENVIRONMENTAL SCIENCES Condron, Alan Winsor, Peter A subtropical fate awaited freshwater discharged from glacial Lake Agassiz |
topic_facet |
54 ENVIRONMENTAL SCIENCES |
description |
The 8.2 kyr event is the largest abrupt climatic change recorded in the last 10,000 years, and is widely hypothesized to have been triggered by the release of thousands of kilometers cubed of freshwater into the North Atlantic Ocean. Using a high-resolution (1/6°) global, ocean-ice circulation model we present an alternative view that freshwater discharged from glacial Lake Agassiz would have remained on the continental shelf as a narrow, buoyant, coastal current, and would have been transported south into the subtropical North Atlantic. The pathway we describe is in contrast to the conceptual idea that freshwater from this lake outburst spread over most of the sub-polar North Atlantic, and covered the deep, open-ocean, convection regions. This coastally confined freshwater pathway is consistent with the present-day routing of freshwater from Hudson Bay, as well as paleoceanographic evidence of this event. In this study, using a coarse-resolution (2.6°) version of the same model, we demonstrate that the previously reported spreading of freshwater across the sub-polar North Atlantic results from the inability of numerical models of this resolution to accurately resolve narrow coastal flows, producing instead a diffuse circulation that advects freshwater away from the boundaries. To understand the climatic impact of freshwater released in the past or future (e.g. Greenland and Antarctica), the ocean needs to be modeled at a resolution sufficient to resolve the dynamics of narrow, coastal buoyant flows. |
author |
Condron, Alan Winsor, Peter |
author_facet |
Condron, Alan Winsor, Peter |
author_sort |
Condron, Alan |
title |
A subtropical fate awaited freshwater discharged from glacial Lake Agassiz |
title_short |
A subtropical fate awaited freshwater discharged from glacial Lake Agassiz |
title_full |
A subtropical fate awaited freshwater discharged from glacial Lake Agassiz |
title_fullStr |
A subtropical fate awaited freshwater discharged from glacial Lake Agassiz |
title_full_unstemmed |
A subtropical fate awaited freshwater discharged from glacial Lake Agassiz |
title_sort |
subtropical fate awaited freshwater discharged from glacial lake agassiz |
publishDate |
2022 |
url |
http://www.osti.gov/servlets/purl/1159310 https://www.osti.gov/biblio/1159310 https://doi.org/10.1029/2010GL046011 |
long_lat |
ENVELOPE(-129.463,-129.463,58.259,58.259) |
geographic |
Glacial Lake Greenland Hudson Hudson Bay |
geographic_facet |
Glacial Lake Greenland Hudson Hudson Bay |
genre |
Antarc* Antarctica Greenland Hudson Bay North Atlantic |
genre_facet |
Antarc* Antarctica Greenland Hudson Bay North Atlantic |
op_relation |
http://www.osti.gov/servlets/purl/1159310 https://www.osti.gov/biblio/1159310 https://doi.org/10.1029/2010GL046011 doi:10.1029/2010GL046011 |
op_doi |
https://doi.org/10.1029/2010GL046011 |
container_title |
Geophysical Research Letters |
container_volume |
38 |
container_issue |
3 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1772810151830487040 |