Antarctic Circumpolar Current Transport Through Drake Passage: What Can We Learn From Comparing High-resolution Model Results To Observations?
Uncertainty exists in the time-mean total transport of the Antarctic Circumpolar Current (ACC), the world's strongest ocean current. The two most recent observational programs in Drake Passage, DRAKE and cDrake, yielded transports of 141 and 173.3 Sv, respectively. In this paper, we use a reali...
Published in: | Journal of Geophysical Research: Oceans |
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Language: | English |
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2020
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Online Access: | https://doi.org/10.1029/2020JC016365 |
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ftfloridasu:oai:diginole.lib.fsu.edu:fsu_773815 2024-06-09T07:39:25+00:00 Antarctic Circumpolar Current Transport Through Drake Passage: What Can We Learn From Comparing High-resolution Model Results To Observations? Xu, Xiaobiao (author) Chassignet, Eric P. (author) Firing, Yvonne L. (author) Donohue, Kathleen (author) 2020-07 computer online resource 1 online resource application/pdf https://doi.org/10.1029/2020JC016365 English eng Journal of Geophysical Research-Oceans--2169-9275 fsu:773815 iid: FSU_libsubv1_wos_000560011100002 doi:10.1029/2020JC016365 Text journal article 2020 ftfloridasu https://doi.org/10.1029/2020JC016365 2024-05-10T08:08:13Z Uncertainty exists in the time-mean total transport of the Antarctic Circumpolar Current (ACC), the world's strongest ocean current. The two most recent observational programs in Drake Passage, DRAKE and cDrake, yielded transports of 141 and 173.3 Sv, respectively. In this paper, we use a realistic 1/12 degrees global ocean simulation to interpret these observational estimates and reconcile their differences. We first show that the modeled ACC transport in the upper 1,000 m is in excellent agreement with repeat shipboard acoustic Doppler current profiler (SADCP) transects and that the exponentially decaying transport profile in the model is consistent with the profile derived from repeat hydrographic data. By further comparing the model results to the cDrake and DRAKE observations, we argue that the modeled 157.3 Sv transport, that is, approximately the average of the cDrake and DRAKE estimates, is actually representative of the time-mean ACC transport through the Drake Passage. The cDrake experiment overestimated the barotropic contribution in part because the array undersampled the deep recirculation southwest of the Shackleton Fracture Zone, whereas the surface geostrophic currents used in the DRAKE estimate yielded a weaker near-surface transport than implied by the SADCP data. We also find that the modeled baroclinic and barotropic transports are not correlated; thus, monitoring either baroclinic or barotropic transport alone may be insufficient to assess the temporal variability of the total ACC transport. variability, time-series, pressure, acc , closure, Drake Passage , exchange, fronts, high-resolution model , in-situ, overturning circulation, scotland, volume transport , volume transport The publisher's version of record is availible at https://doi.org/10.1029/2020JC016365 Article in Journal/Newspaper Antarc* Antarctic Drake Passage Florida State University: DigiNole Commons Antarctic Drake Passage Shackleton Shackleton Fracture Zone ENVELOPE(-60.000,-60.000,-60.000,-60.000) The Antarctic Journal of Geophysical Research: Oceans 125 7 |
institution |
Open Polar |
collection |
Florida State University: DigiNole Commons |
op_collection_id |
ftfloridasu |
language |
English |
description |
Uncertainty exists in the time-mean total transport of the Antarctic Circumpolar Current (ACC), the world's strongest ocean current. The two most recent observational programs in Drake Passage, DRAKE and cDrake, yielded transports of 141 and 173.3 Sv, respectively. In this paper, we use a realistic 1/12 degrees global ocean simulation to interpret these observational estimates and reconcile their differences. We first show that the modeled ACC transport in the upper 1,000 m is in excellent agreement with repeat shipboard acoustic Doppler current profiler (SADCP) transects and that the exponentially decaying transport profile in the model is consistent with the profile derived from repeat hydrographic data. By further comparing the model results to the cDrake and DRAKE observations, we argue that the modeled 157.3 Sv transport, that is, approximately the average of the cDrake and DRAKE estimates, is actually representative of the time-mean ACC transport through the Drake Passage. The cDrake experiment overestimated the barotropic contribution in part because the array undersampled the deep recirculation southwest of the Shackleton Fracture Zone, whereas the surface geostrophic currents used in the DRAKE estimate yielded a weaker near-surface transport than implied by the SADCP data. We also find that the modeled baroclinic and barotropic transports are not correlated; thus, monitoring either baroclinic or barotropic transport alone may be insufficient to assess the temporal variability of the total ACC transport. variability, time-series, pressure, acc , closure, Drake Passage , exchange, fronts, high-resolution model , in-situ, overturning circulation, scotland, volume transport , volume transport The publisher's version of record is availible at https://doi.org/10.1029/2020JC016365 |
author2 |
Xu, Xiaobiao (author) Chassignet, Eric P. (author) Firing, Yvonne L. (author) Donohue, Kathleen (author) |
format |
Article in Journal/Newspaper |
title |
Antarctic Circumpolar Current Transport Through Drake Passage: What Can We Learn From Comparing High-resolution Model Results To Observations? |
spellingShingle |
Antarctic Circumpolar Current Transport Through Drake Passage: What Can We Learn From Comparing High-resolution Model Results To Observations? |
title_short |
Antarctic Circumpolar Current Transport Through Drake Passage: What Can We Learn From Comparing High-resolution Model Results To Observations? |
title_full |
Antarctic Circumpolar Current Transport Through Drake Passage: What Can We Learn From Comparing High-resolution Model Results To Observations? |
title_fullStr |
Antarctic Circumpolar Current Transport Through Drake Passage: What Can We Learn From Comparing High-resolution Model Results To Observations? |
title_full_unstemmed |
Antarctic Circumpolar Current Transport Through Drake Passage: What Can We Learn From Comparing High-resolution Model Results To Observations? |
title_sort |
antarctic circumpolar current transport through drake passage: what can we learn from comparing high-resolution model results to observations? |
publishDate |
2020 |
url |
https://doi.org/10.1029/2020JC016365 |
long_lat |
ENVELOPE(-60.000,-60.000,-60.000,-60.000) |
geographic |
Antarctic Drake Passage Shackleton Shackleton Fracture Zone The Antarctic |
geographic_facet |
Antarctic Drake Passage Shackleton Shackleton Fracture Zone The Antarctic |
genre |
Antarc* Antarctic Drake Passage |
genre_facet |
Antarc* Antarctic Drake Passage |
op_relation |
Journal of Geophysical Research-Oceans--2169-9275 fsu:773815 iid: FSU_libsubv1_wos_000560011100002 doi:10.1029/2020JC016365 |
op_doi |
https://doi.org/10.1029/2020JC016365 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
125 |
container_issue |
7 |
_version_ |
1801379332036231168 |