Locations and mechanisms of ocean ventilation in the high-latitude North Atlantic in an eddy-permitting ocean model
A substantial fraction of the deep ocean is ventilated in the high-latitude North Atlantic. Consequently, the region plays a crucial role in transient climate change through the uptake of carbon dioxide and heat. However, owing to the Lagrangian nature of the process, many aspects of deep Atlantic O...
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fttriple:oai:gotriple.eu:10670/1.or44ky 2023-05-15T16:29:58+02:00 Locations and mechanisms of ocean ventilation in the high-latitude North Atlantic in an eddy-permitting ocean model Macgilchrist, Graeme A. Johnson, Helen L. Marshall, David P. Lique, Camille Thomas, Matthew Jackson, Laura C. Wood, Richard A. 2020-01-01 https://doi.org/10.1175/JCLI-D-20-0191.1 https://archimer.ifremer.fr/doc/00646/75833/76825.pdf https://archimer.ifremer.fr/doc/00646/75833/ en eng American Meteorological Society doi:10.1175/JCLI-D-20-0191.1 10670/1.or44ky https://archimer.ifremer.fr/doc/00646/75833/76825.pdf https://archimer.ifremer.fr/doc/00646/75833/ other Archimer, archive institutionnelle de l'Ifremer Journal Of Climate (0894-8755) (American Meteorological Society), 2020-12 , Vol. 33 , N. 23 , P. 10113-10131 envir geo Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ 2020 fttriple https://doi.org/10.1175/JCLI-D-20-0191.1 2023-01-22T18:15:25Z A substantial fraction of the deep ocean is ventilated in the high-latitude North Atlantic. Consequently, the region plays a crucial role in transient climate change through the uptake of carbon dioxide and heat. However, owing to the Lagrangian nature of the process, many aspects of deep Atlantic Ocean ventilation and its representation in climate simulations remain obscure. We investigate the nature of ventilation in the high latitude North Atlantic in an eddy-permitting numerical ocean circulation model using a comprehensive set of Lagrangian trajectory experiments. Backwards-in-time trajectories from a model-defined ‘North Atlantic DeepWater’ (NADW) reveal the locations of subduction from the surface mixed layer at high spatial resolution. The major fraction of NADW ventilation results from subduction in the Labrador Sea, predominantly within the boundary current (̴ 60% of ventilated NADW volume) and a smaller fraction arising from open ocean deep convection (̴ 25%). Subsurface transformations — due in part to the model’s parameterization of bottom-intensified mixing—facilitate NADWventilation, such that water subducted in the boundary current ventilates all of NADW, not just the lighter density classes. There is a notable absence of ventilation arising from subduction in the Greenland-Iceland-Norwegian Seas, due to the re-entrainment of those waters as they move southward. Taken together, our results emphasize an important distinction between ventilation and dense water formation in terms of the location where each takes place, and their concurrent sensitivities. These features of NADW ventilation are explored to understand how the representation of high-latitude processes impacts properties of the deep ocean in a state-of-the-science numerical simulation. Text Greenland Iceland Labrador Sea NADW North Atlantic Unknown Greenland Journal of Climate 33 23 10113 10131 |
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envir geo Macgilchrist, Graeme A. Johnson, Helen L. Marshall, David P. Lique, Camille Thomas, Matthew Jackson, Laura C. Wood, Richard A. Locations and mechanisms of ocean ventilation in the high-latitude North Atlantic in an eddy-permitting ocean model |
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envir geo |
description |
A substantial fraction of the deep ocean is ventilated in the high-latitude North Atlantic. Consequently, the region plays a crucial role in transient climate change through the uptake of carbon dioxide and heat. However, owing to the Lagrangian nature of the process, many aspects of deep Atlantic Ocean ventilation and its representation in climate simulations remain obscure. We investigate the nature of ventilation in the high latitude North Atlantic in an eddy-permitting numerical ocean circulation model using a comprehensive set of Lagrangian trajectory experiments. Backwards-in-time trajectories from a model-defined ‘North Atlantic DeepWater’ (NADW) reveal the locations of subduction from the surface mixed layer at high spatial resolution. The major fraction of NADW ventilation results from subduction in the Labrador Sea, predominantly within the boundary current (̴ 60% of ventilated NADW volume) and a smaller fraction arising from open ocean deep convection (̴ 25%). Subsurface transformations — due in part to the model’s parameterization of bottom-intensified mixing—facilitate NADWventilation, such that water subducted in the boundary current ventilates all of NADW, not just the lighter density classes. There is a notable absence of ventilation arising from subduction in the Greenland-Iceland-Norwegian Seas, due to the re-entrainment of those waters as they move southward. Taken together, our results emphasize an important distinction between ventilation and dense water formation in terms of the location where each takes place, and their concurrent sensitivities. These features of NADW ventilation are explored to understand how the representation of high-latitude processes impacts properties of the deep ocean in a state-of-the-science numerical simulation. |
format |
Text |
author |
Macgilchrist, Graeme A. Johnson, Helen L. Marshall, David P. Lique, Camille Thomas, Matthew Jackson, Laura C. Wood, Richard A. |
author_facet |
Macgilchrist, Graeme A. Johnson, Helen L. Marshall, David P. Lique, Camille Thomas, Matthew Jackson, Laura C. Wood, Richard A. |
author_sort |
Macgilchrist, Graeme A. |
title |
Locations and mechanisms of ocean ventilation in the high-latitude North Atlantic in an eddy-permitting ocean model |
title_short |
Locations and mechanisms of ocean ventilation in the high-latitude North Atlantic in an eddy-permitting ocean model |
title_full |
Locations and mechanisms of ocean ventilation in the high-latitude North Atlantic in an eddy-permitting ocean model |
title_fullStr |
Locations and mechanisms of ocean ventilation in the high-latitude North Atlantic in an eddy-permitting ocean model |
title_full_unstemmed |
Locations and mechanisms of ocean ventilation in the high-latitude North Atlantic in an eddy-permitting ocean model |
title_sort |
locations and mechanisms of ocean ventilation in the high-latitude north atlantic in an eddy-permitting ocean model |
publisher |
American Meteorological Society |
publishDate |
2020 |
url |
https://doi.org/10.1175/JCLI-D-20-0191.1 https://archimer.ifremer.fr/doc/00646/75833/76825.pdf https://archimer.ifremer.fr/doc/00646/75833/ |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Iceland Labrador Sea NADW North Atlantic |
genre_facet |
Greenland Iceland Labrador Sea NADW North Atlantic |
op_source |
Archimer, archive institutionnelle de l'Ifremer Journal Of Climate (0894-8755) (American Meteorological Society), 2020-12 , Vol. 33 , N. 23 , P. 10113-10131 |
op_relation |
doi:10.1175/JCLI-D-20-0191.1 10670/1.or44ky https://archimer.ifremer.fr/doc/00646/75833/76825.pdf https://archimer.ifremer.fr/doc/00646/75833/ |
op_rights |
other |
op_doi |
https://doi.org/10.1175/JCLI-D-20-0191.1 |
container_title |
Journal of Climate |
container_volume |
33 |
container_issue |
23 |
container_start_page |
10113 |
op_container_end_page |
10131 |
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1766019683841998848 |