Climate-Driven Changes in the Ocean's Ventilation Pathways and Time Scales Diagnosed From Transport Matrices
We diagnose changes in the decadal-mean ocean transport over the 21st century as simulated by the ACCESS-1.3 model under RCP8.5 forcing. A matrix formulation of advection-diffusion is used to quantify transport into the ocean interior and from the interior back to the surface. We compute the ocean v...
Published in: | Journal of Geophysical Research: Oceans |
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American Geophysical Union (AGU)
2020
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Online Access: | http://hdl.handle.net/1959.4/unsworks_72722 https://unsworks.unsw.edu.au/bitstreams/aa93c06e-ad0b-45f0-bce2-ce98e73d0e0f/download https://doi.org/10.1029/2020JC016414 |
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ftunswworks:oai:unsworks.library.unsw.edu.au:1959.4/unsworks_72722 2024-05-19T07:32:26+00:00 Climate-Driven Changes in the Ocean's Ventilation Pathways and Time Scales Diagnosed From Transport Matrices Holzer, M Chamberlain, MA Matear, RJ 2020-10-01 application/pdf http://hdl.handle.net/1959.4/unsworks_72722 https://unsworks.unsw.edu.au/bitstreams/aa93c06e-ad0b-45f0-bce2-ce98e73d0e0f/download https://doi.org/10.1029/2020JC016414 unknown American Geophysical Union (AGU) http://hdl.handle.net/1959.4/unsworks_72722 https://unsworks.unsw.edu.au/bitstreams/aa93c06e-ad0b-45f0-bce2-ce98e73d0e0f/download https://doi.org/10.1029/2020JC016414 open access https://purl.org/coar/access_right/c_abf2 CC-BY-NC-ND https://creativecommons.org/licenses/by-nc-nd/4.0/ free_to_read urn:ISSN:2169-9275 urn:ISSN:2169-9291 Journal of Geophysical Research: Oceans, 125, 10 13 Climate Action 14 Life Below Water anzsrc-for: 0404 Geophysics anzsrc-for: 0405 Oceanography anzsrc-for: 0406 Physical Geography and Environmental Geoscience journal article http://purl.org/coar/resource_type/c_6501 2020 ftunswworks https://doi.org/10.1029/2020JC016414 2024-04-24T01:04:00Z We diagnose changes in the decadal-mean ocean transport over the 21st century as simulated by the ACCESS-1.3 model under RCP8.5 forcing. A matrix formulation of advection-diffusion is used to quantify transport into the ocean interior and from the interior back to the surface. We compute the ocean volumes last ventilated at the surface, as well as the volumes next reexposed to the atmosphere, per unit area, and the distributions of water in transit between key ventilation regions. We find that for the 2090s circulation, Antarctic Bottom Water formation and Antarctic ventilation have collapsed but are compensated by increased mode water formation and ventilation at the poleward edge of the southern subtropical gyres. Reexposure of deep water back to the atmosphere in the Antarctic Southern Ocean is also reduced but compensated by enhanced reexposure in the subpolar Southern Ocean. Labrador Sea ventilation is suppressed, while there is increased ventilation in the eastern subpolar Atlantic. The 2090s surface-to-surface interbasin transport is much more sluggish than that of the 1990s, with 30–40% reduced volume flow rates. For transport from last ventilation in the subpolar North Atlantic to next ventilation in the tropical Eastern Pacific, the 2090s residence-time distribution has a ∼40% longer mode with much more slowly decaying tails and correspondingly lagged path densities. The 2090s mean times since last ventilation, as well as the mean times to reexposure are older in the Antarctic Southern Ocean and elsewhere progressively with depth, by up to ∼1,000 years in the abyss. Article in Journal/Newspaper Antarc* Antarctic Labrador Sea North Atlantic Southern Ocean UNSW Sydney (The University of New South Wales): UNSWorks Journal of Geophysical Research: Oceans 125 10 |
institution |
Open Polar |
collection |
UNSW Sydney (The University of New South Wales): UNSWorks |
op_collection_id |
ftunswworks |
language |
unknown |
topic |
13 Climate Action 14 Life Below Water anzsrc-for: 0404 Geophysics anzsrc-for: 0405 Oceanography anzsrc-for: 0406 Physical Geography and Environmental Geoscience |
spellingShingle |
13 Climate Action 14 Life Below Water anzsrc-for: 0404 Geophysics anzsrc-for: 0405 Oceanography anzsrc-for: 0406 Physical Geography and Environmental Geoscience Holzer, M Chamberlain, MA Matear, RJ Climate-Driven Changes in the Ocean's Ventilation Pathways and Time Scales Diagnosed From Transport Matrices |
topic_facet |
13 Climate Action 14 Life Below Water anzsrc-for: 0404 Geophysics anzsrc-for: 0405 Oceanography anzsrc-for: 0406 Physical Geography and Environmental Geoscience |
description |
We diagnose changes in the decadal-mean ocean transport over the 21st century as simulated by the ACCESS-1.3 model under RCP8.5 forcing. A matrix formulation of advection-diffusion is used to quantify transport into the ocean interior and from the interior back to the surface. We compute the ocean volumes last ventilated at the surface, as well as the volumes next reexposed to the atmosphere, per unit area, and the distributions of water in transit between key ventilation regions. We find that for the 2090s circulation, Antarctic Bottom Water formation and Antarctic ventilation have collapsed but are compensated by increased mode water formation and ventilation at the poleward edge of the southern subtropical gyres. Reexposure of deep water back to the atmosphere in the Antarctic Southern Ocean is also reduced but compensated by enhanced reexposure in the subpolar Southern Ocean. Labrador Sea ventilation is suppressed, while there is increased ventilation in the eastern subpolar Atlantic. The 2090s surface-to-surface interbasin transport is much more sluggish than that of the 1990s, with 30–40% reduced volume flow rates. For transport from last ventilation in the subpolar North Atlantic to next ventilation in the tropical Eastern Pacific, the 2090s residence-time distribution has a ∼40% longer mode with much more slowly decaying tails and correspondingly lagged path densities. The 2090s mean times since last ventilation, as well as the mean times to reexposure are older in the Antarctic Southern Ocean and elsewhere progressively with depth, by up to ∼1,000 years in the abyss. |
format |
Article in Journal/Newspaper |
author |
Holzer, M Chamberlain, MA Matear, RJ |
author_facet |
Holzer, M Chamberlain, MA Matear, RJ |
author_sort |
Holzer, M |
title |
Climate-Driven Changes in the Ocean's Ventilation Pathways and Time Scales Diagnosed From Transport Matrices |
title_short |
Climate-Driven Changes in the Ocean's Ventilation Pathways and Time Scales Diagnosed From Transport Matrices |
title_full |
Climate-Driven Changes in the Ocean's Ventilation Pathways and Time Scales Diagnosed From Transport Matrices |
title_fullStr |
Climate-Driven Changes in the Ocean's Ventilation Pathways and Time Scales Diagnosed From Transport Matrices |
title_full_unstemmed |
Climate-Driven Changes in the Ocean's Ventilation Pathways and Time Scales Diagnosed From Transport Matrices |
title_sort |
climate-driven changes in the ocean's ventilation pathways and time scales diagnosed from transport matrices |
publisher |
American Geophysical Union (AGU) |
publishDate |
2020 |
url |
http://hdl.handle.net/1959.4/unsworks_72722 https://unsworks.unsw.edu.au/bitstreams/aa93c06e-ad0b-45f0-bce2-ce98e73d0e0f/download https://doi.org/10.1029/2020JC016414 |
genre |
Antarc* Antarctic Labrador Sea North Atlantic Southern Ocean |
genre_facet |
Antarc* Antarctic Labrador Sea North Atlantic Southern Ocean |
op_source |
urn:ISSN:2169-9275 urn:ISSN:2169-9291 Journal of Geophysical Research: Oceans, 125, 10 |
op_relation |
http://hdl.handle.net/1959.4/unsworks_72722 https://unsworks.unsw.edu.au/bitstreams/aa93c06e-ad0b-45f0-bce2-ce98e73d0e0f/download https://doi.org/10.1029/2020JC016414 |
op_rights |
open access https://purl.org/coar/access_right/c_abf2 CC-BY-NC-ND https://creativecommons.org/licenses/by-nc-nd/4.0/ free_to_read |
op_doi |
https://doi.org/10.1029/2020JC016414 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
125 |
container_issue |
10 |
_version_ |
1799470482498519040 |