Basin-scale tracer replacement timescales in a one-degree global OGCM
This study investigates basin-scale tracer replacement timescales of the two polar oceans and the Atlantic, Indian, and Pacific Oceans using a one-degree global ocean-sea ice model that represents oceans under the largest Antarctic ice shelves, the Filchner-Ronne and Ross Ice Shelf (FRIS and RIS). A...
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Online Access: | http://dx.doi.org/10.3389/fmars.2023.1308728 https://www.frontiersin.org/articles/10.3389/fmars.2023.1308728/full |
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crfrontiers:10.3389/fmars.2023.1308728 2024-02-11T09:57:54+01:00 Basin-scale tracer replacement timescales in a one-degree global OGCM Kusahara, Kazuya Tatebe, Hiroaki Japan Society for the Promotion of Science Ministry of Education, Culture, Sports, Science and Technology 2023 http://dx.doi.org/10.3389/fmars.2023.1308728 https://www.frontiersin.org/articles/10.3389/fmars.2023.1308728/full unknown Frontiers Media SA https://creativecommons.org/licenses/by/4.0/ Frontiers in Marine Science volume 10 ISSN 2296-7745 Ocean Engineering Water Science and Technology Aquatic Science Global and Planetary Change Oceanography journal-article 2023 crfrontiers https://doi.org/10.3389/fmars.2023.1308728 2024-01-26T09:56:18Z This study investigates basin-scale tracer replacement timescales of the two polar oceans and the Atlantic, Indian, and Pacific Oceans using a one-degree global ocean-sea ice model that represents oceans under the largest Antarctic ice shelves, the Filchner-Ronne and Ross Ice Shelf (FRIS and RIS). After a long spin-up with present-day surface boundary conditions, we confirm that the model has a typical representation of wind-driven and thermohaline circulations in one-degree ocean models. We use virtual passive tracers placed in the five oceans and examine the behavior of the passive tracers to estimate the tracer replacement timescales and pathways of the basin-scale ocean waters. Replacement timescales in the polar oceans (114 years for the Southern Ocean and 109 years for the Arctic Ocean) are found to be shorter than those in the three oceans (217 years for the Atlantic Ocean, 163 years for the Indian Ocean, and 338 years for the Pacific Ocean). The Southern Ocean tracer has two clear pathways to the Northern Hemisphere: the surface route in the Atlantic Ocean and the bottom route in the Pacific and Indian Oceans. This surface route is a rapid conduit to transport the Southern Ocean signal to the North Atlantic and Arctic Oceans. The Atlantic Ocean tracer is transported to both polar regions along the North Atlantic Current and the Antarctic Circumpolar Current (ACC). The tracer experiments clearly demonstrate that Atlantic Meridional Overturning Circulation (AMOC) plays a vital role in transporting the water masses in the Atlantic and Arctic Oceans to the Southern Ocean. The southward flow of the AMOC at the intermediate depths carries the northern waters to the ACC region, and then the water spreads over the Southern Ocean along the eastward-flowing ACC. The decay timescales of water in the ice-shelf cavities exposed to the water outside the Southern Ocean are estimated to be approximately 150 years for both the FIRS and RIS. The decay timescales in the Antarctic coastal region are short at the surface and ... Article in Journal/Newspaper Antarc* Antarctic Arctic Arctic Ocean Ice Shelf Ice Shelves north atlantic current North Atlantic Ross Ice Shelf Sea ice Southern Ocean Frontiers (Publisher) Arctic Antarctic Southern Ocean The Antarctic Arctic Ocean Ross Ice Shelf Pacific Indian Frontiers in Marine Science 10 |
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Open Polar |
collection |
Frontiers (Publisher) |
op_collection_id |
crfrontiers |
language |
unknown |
topic |
Ocean Engineering Water Science and Technology Aquatic Science Global and Planetary Change Oceanography |
spellingShingle |
Ocean Engineering Water Science and Technology Aquatic Science Global and Planetary Change Oceanography Kusahara, Kazuya Tatebe, Hiroaki Basin-scale tracer replacement timescales in a one-degree global OGCM |
topic_facet |
Ocean Engineering Water Science and Technology Aquatic Science Global and Planetary Change Oceanography |
description |
This study investigates basin-scale tracer replacement timescales of the two polar oceans and the Atlantic, Indian, and Pacific Oceans using a one-degree global ocean-sea ice model that represents oceans under the largest Antarctic ice shelves, the Filchner-Ronne and Ross Ice Shelf (FRIS and RIS). After a long spin-up with present-day surface boundary conditions, we confirm that the model has a typical representation of wind-driven and thermohaline circulations in one-degree ocean models. We use virtual passive tracers placed in the five oceans and examine the behavior of the passive tracers to estimate the tracer replacement timescales and pathways of the basin-scale ocean waters. Replacement timescales in the polar oceans (114 years for the Southern Ocean and 109 years for the Arctic Ocean) are found to be shorter than those in the three oceans (217 years for the Atlantic Ocean, 163 years for the Indian Ocean, and 338 years for the Pacific Ocean). The Southern Ocean tracer has two clear pathways to the Northern Hemisphere: the surface route in the Atlantic Ocean and the bottom route in the Pacific and Indian Oceans. This surface route is a rapid conduit to transport the Southern Ocean signal to the North Atlantic and Arctic Oceans. The Atlantic Ocean tracer is transported to both polar regions along the North Atlantic Current and the Antarctic Circumpolar Current (ACC). The tracer experiments clearly demonstrate that Atlantic Meridional Overturning Circulation (AMOC) plays a vital role in transporting the water masses in the Atlantic and Arctic Oceans to the Southern Ocean. The southward flow of the AMOC at the intermediate depths carries the northern waters to the ACC region, and then the water spreads over the Southern Ocean along the eastward-flowing ACC. The decay timescales of water in the ice-shelf cavities exposed to the water outside the Southern Ocean are estimated to be approximately 150 years for both the FIRS and RIS. The decay timescales in the Antarctic coastal region are short at the surface and ... |
author2 |
Japan Society for the Promotion of Science Ministry of Education, Culture, Sports, Science and Technology |
format |
Article in Journal/Newspaper |
author |
Kusahara, Kazuya Tatebe, Hiroaki |
author_facet |
Kusahara, Kazuya Tatebe, Hiroaki |
author_sort |
Kusahara, Kazuya |
title |
Basin-scale tracer replacement timescales in a one-degree global OGCM |
title_short |
Basin-scale tracer replacement timescales in a one-degree global OGCM |
title_full |
Basin-scale tracer replacement timescales in a one-degree global OGCM |
title_fullStr |
Basin-scale tracer replacement timescales in a one-degree global OGCM |
title_full_unstemmed |
Basin-scale tracer replacement timescales in a one-degree global OGCM |
title_sort |
basin-scale tracer replacement timescales in a one-degree global ogcm |
publisher |
Frontiers Media SA |
publishDate |
2023 |
url |
http://dx.doi.org/10.3389/fmars.2023.1308728 https://www.frontiersin.org/articles/10.3389/fmars.2023.1308728/full |
geographic |
Arctic Antarctic Southern Ocean The Antarctic Arctic Ocean Ross Ice Shelf Pacific Indian |
geographic_facet |
Arctic Antarctic Southern Ocean The Antarctic Arctic Ocean Ross Ice Shelf Pacific Indian |
genre |
Antarc* Antarctic Arctic Arctic Ocean Ice Shelf Ice Shelves north atlantic current North Atlantic Ross Ice Shelf Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Arctic Arctic Ocean Ice Shelf Ice Shelves north atlantic current North Atlantic Ross Ice Shelf Sea ice Southern Ocean |
op_source |
Frontiers in Marine Science volume 10 ISSN 2296-7745 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3389/fmars.2023.1308728 |
container_title |
Frontiers in Marine Science |
container_volume |
10 |
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1790593450332127232 |