Fates of paleo Antarctic Bottom Water during the early Eocene ― based on a Lagrangian analysis of IPSL‐CM5A2 climate model simulations
Both deepwater formation and the obduction processes converting dense deepwater to lighter surface water are the engine for the global meridional overturning circulation (MOC). Their spatio‐temporal variations effectively modify the ocean circulation and related carbon cycle, which affects climate e...
Published in: | Paleoceanography and Paleoclimatology |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Geophysical Union (AGU)
2021
|
Subjects: | |
Online Access: | https://archimer.ifremer.fr/doc/00663/77556/79448.pdf https://archimer.ifremer.fr/doc/00663/77556/79449.docx https://doi.org/10.1029/2019PA003845 https://archimer.ifremer.fr/doc/00663/77556/ |
id |
ftarchimer:oai:archimer.ifremer.fr:77556 |
---|---|
record_format |
openpolar |
spelling |
ftarchimer:oai:archimer.ifremer.fr:77556 2023-05-15T13:47:36+02:00 Fates of paleo Antarctic Bottom Water during the early Eocene ― based on a Lagrangian analysis of IPSL‐CM5A2 climate model simulations Zhang, Yurui Grima, Nicolas Huck, Thierry 2021-01 application/pdf https://archimer.ifremer.fr/doc/00663/77556/79448.pdf https://archimer.ifremer.fr/doc/00663/77556/79449.docx https://doi.org/10.1029/2019PA003845 https://archimer.ifremer.fr/doc/00663/77556/ eng eng American Geophysical Union (AGU) https://archimer.ifremer.fr/doc/00663/77556/79448.pdf https://archimer.ifremer.fr/doc/00663/77556/79449.docx doi:10.1029/2019PA003845 https://archimer.ifremer.fr/doc/00663/77556/ info:eu-repo/semantics/openAccess restricted use Paleoceanography And Paleoclimatology (2572-4517) (American Geophysical Union (AGU)), 2021-01 , Vol. 36 , N. 1 , P. e2019PA003845 (24p.) the early Eocene paleo-Antarctic Bottom Water Lagrangian analysis deepwater obduction Equtorial and tropical upwelling Ekman pumping text Publication info:eu-repo/semantics/article 2021 ftarchimer https://doi.org/10.1029/2019PA003845 2021-09-23T20:36:34Z Both deepwater formation and the obduction processes converting dense deepwater to lighter surface water are the engine for the global meridional overturning circulation (MOC). Their spatio‐temporal variations effectively modify the ocean circulation and related carbon cycle, which affects climate evolution throughout geological time. Using early‐Eocene bathymetry and enhanced atmospheric CO2 concentration, the IPSL‐CM5A2 climate model has simulated a well‐ventilated Southern Ocean associated with a strong anticlockwise MOC. To trace the fates of these paleo Antarctic Bottom Water (paleo‐AABW), we conducted Lagrangian analyses using these IPSL‐CM5A2 model results and tracking virtual particles released at the lower limb of the MOC, defined as an initial section at 60°S below 1900m depth. Diagnostic analysis of these particles trajectories reveals that most paleo‐AABW circulates back to the Southern Ocean through either the initial section (43%) or the section above (31%); the remaining (>25%) crossing the base of the mixed layer mostly in tropical regions (up to half). The majority of water parcels ending in the mixed layer experience negative density transformations, intensified in the upper 500m and mostly occurring in tropical upwelling regions, with a spatial pattern consistent with the wind‐driven Ekman pumping, largely determined by the Eocene wind stress and continental geometry. In the same way as present‐day North Atlantic Deep Water upwells in the Southern Ocean, our results suggest that the strong tropical and equatorial upwelling during the Eocene provides an efficient pathway from the abyss to the surface, but at much higher temperature, with potential implications for the oceanic carbon cycle. Article in Journal/Newspaper Antarc* Antarctic North Atlantic Deep Water North Atlantic Southern Ocean Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Antarctic Southern Ocean Paleoceanography and Paleoclimatology 36 1 |
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 |
the early Eocene paleo-Antarctic Bottom Water Lagrangian analysis deepwater obduction Equtorial and tropical upwelling Ekman pumping |
spellingShingle |
the early Eocene paleo-Antarctic Bottom Water Lagrangian analysis deepwater obduction Equtorial and tropical upwelling Ekman pumping Zhang, Yurui Grima, Nicolas Huck, Thierry Fates of paleo Antarctic Bottom Water during the early Eocene ― based on a Lagrangian analysis of IPSL‐CM5A2 climate model simulations |
topic_facet |
the early Eocene paleo-Antarctic Bottom Water Lagrangian analysis deepwater obduction Equtorial and tropical upwelling Ekman pumping |
description |
Both deepwater formation and the obduction processes converting dense deepwater to lighter surface water are the engine for the global meridional overturning circulation (MOC). Their spatio‐temporal variations effectively modify the ocean circulation and related carbon cycle, which affects climate evolution throughout geological time. Using early‐Eocene bathymetry and enhanced atmospheric CO2 concentration, the IPSL‐CM5A2 climate model has simulated a well‐ventilated Southern Ocean associated with a strong anticlockwise MOC. To trace the fates of these paleo Antarctic Bottom Water (paleo‐AABW), we conducted Lagrangian analyses using these IPSL‐CM5A2 model results and tracking virtual particles released at the lower limb of the MOC, defined as an initial section at 60°S below 1900m depth. Diagnostic analysis of these particles trajectories reveals that most paleo‐AABW circulates back to the Southern Ocean through either the initial section (43%) or the section above (31%); the remaining (>25%) crossing the base of the mixed layer mostly in tropical regions (up to half). The majority of water parcels ending in the mixed layer experience negative density transformations, intensified in the upper 500m and mostly occurring in tropical upwelling regions, with a spatial pattern consistent with the wind‐driven Ekman pumping, largely determined by the Eocene wind stress and continental geometry. In the same way as present‐day North Atlantic Deep Water upwells in the Southern Ocean, our results suggest that the strong tropical and equatorial upwelling during the Eocene provides an efficient pathway from the abyss to the surface, but at much higher temperature, with potential implications for the oceanic carbon cycle. |
format |
Article in Journal/Newspaper |
author |
Zhang, Yurui Grima, Nicolas Huck, Thierry |
author_facet |
Zhang, Yurui Grima, Nicolas Huck, Thierry |
author_sort |
Zhang, Yurui |
title |
Fates of paleo Antarctic Bottom Water during the early Eocene ― based on a Lagrangian analysis of IPSL‐CM5A2 climate model simulations |
title_short |
Fates of paleo Antarctic Bottom Water during the early Eocene ― based on a Lagrangian analysis of IPSL‐CM5A2 climate model simulations |
title_full |
Fates of paleo Antarctic Bottom Water during the early Eocene ― based on a Lagrangian analysis of IPSL‐CM5A2 climate model simulations |
title_fullStr |
Fates of paleo Antarctic Bottom Water during the early Eocene ― based on a Lagrangian analysis of IPSL‐CM5A2 climate model simulations |
title_full_unstemmed |
Fates of paleo Antarctic Bottom Water during the early Eocene ― based on a Lagrangian analysis of IPSL‐CM5A2 climate model simulations |
title_sort |
fates of paleo antarctic bottom water during the early eocene ― based on a lagrangian analysis of ipsl‐cm5a2 climate model simulations |
publisher |
American Geophysical Union (AGU) |
publishDate |
2021 |
url |
https://archimer.ifremer.fr/doc/00663/77556/79448.pdf https://archimer.ifremer.fr/doc/00663/77556/79449.docx https://doi.org/10.1029/2019PA003845 https://archimer.ifremer.fr/doc/00663/77556/ |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic North Atlantic Deep Water North Atlantic Southern Ocean |
genre_facet |
Antarc* Antarctic North Atlantic Deep Water North Atlantic Southern Ocean |
op_source |
Paleoceanography And Paleoclimatology (2572-4517) (American Geophysical Union (AGU)), 2021-01 , Vol. 36 , N. 1 , P. e2019PA003845 (24p.) |
op_relation |
https://archimer.ifremer.fr/doc/00663/77556/79448.pdf https://archimer.ifremer.fr/doc/00663/77556/79449.docx doi:10.1029/2019PA003845 https://archimer.ifremer.fr/doc/00663/77556/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1029/2019PA003845 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
36 |
container_issue |
1 |
_version_ |
1766247522820423680 |