Subtropical Contribution to Sub-Antarctic Mode Waters
Sub-Antarctic Mode Waters (SAMW) form to the north of the Antarctic Circumpolar Current (ACC) through deep winter mixing. SAMW connect the atmosphere with the oceanic pycnocline, transferring heat and carbon into the ocean interior and supplying nutrients to the northern ocean basins. The processes...
Published in: | Geophysical Research Letters |
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American Geophysical Union (AGU)
2022
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ftunivliverpool:oai:livrepository.liverpool.ac.uk:3164044 2023-05-15T13:52:10+02:00 Subtropical Contribution to Sub-Antarctic Mode Waters Castro, Bieito Fernandez Mazloff, Matthew Williams, Richard G Garabato, Alberto C Naveira 2022 text http://livrepository.liverpool.ac.uk/3164044/ https://doi.org/10.1029/2021gl097560 http://livrepository.liverpool.ac.uk/3164044/1/grl_2022_bfc.pdf en eng American Geophysical Union (AGU) http://livrepository.liverpool.ac.uk/3164044/1/grl_2022_bfc.pdf Castro, Bieito Fernandez, Mazloff, Matthew, Williams, Richard G orcid:0000-0002-3180-7558 and Garabato, Alberto C Naveira (2022) Subtropical Contribution to Sub-Antarctic Mode Waters. GEOPHYSICAL RESEARCH LETTERS, 49 (11). Article NonPeerReviewed 2022 ftunivliverpool https://doi.org/10.1029/2021gl097560 2023-01-20T00:18:51Z Sub-Antarctic Mode Waters (SAMW) form to the north of the Antarctic Circumpolar Current (ACC) through deep winter mixing. SAMW connect the atmosphere with the oceanic pycnocline, transferring heat and carbon into the ocean interior and supplying nutrients to the northern ocean basins. The processes controlling SAMW ventilation and properties remain poorly understood. Here, we investigate the significance and origin of a ubiquitous feature of SAMW formation regions: The seasonal build-up of a subsurface salinity maximum. With biogeochemical Argo floats, we show that this feature influences SAMW mixed-layer dynamics, and that its formation is associated with a decline in preformed nutrients comparable to biological drawdown in surface waters (∼0.15 mol m−2 y−1). Our analysis reveals that these features are driven by advection of warm, salty, nutrient-poor waters of subtropical origin along the ACC. This influx represents a leading-order term in the SAMW physical and biogeochemical budgets, and can impact large-scale nutrient distributions. Article in Journal/Newspaper Antarc* Antarctic The University of Liverpool Repository Antarctic The Antarctic Geophysical Research Letters 49 11 |
institution |
Open Polar |
collection |
The University of Liverpool Repository |
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ftunivliverpool |
language |
English |
description |
Sub-Antarctic Mode Waters (SAMW) form to the north of the Antarctic Circumpolar Current (ACC) through deep winter mixing. SAMW connect the atmosphere with the oceanic pycnocline, transferring heat and carbon into the ocean interior and supplying nutrients to the northern ocean basins. The processes controlling SAMW ventilation and properties remain poorly understood. Here, we investigate the significance and origin of a ubiquitous feature of SAMW formation regions: The seasonal build-up of a subsurface salinity maximum. With biogeochemical Argo floats, we show that this feature influences SAMW mixed-layer dynamics, and that its formation is associated with a decline in preformed nutrients comparable to biological drawdown in surface waters (∼0.15 mol m−2 y−1). Our analysis reveals that these features are driven by advection of warm, salty, nutrient-poor waters of subtropical origin along the ACC. This influx represents a leading-order term in the SAMW physical and biogeochemical budgets, and can impact large-scale nutrient distributions. |
format |
Article in Journal/Newspaper |
author |
Castro, Bieito Fernandez Mazloff, Matthew Williams, Richard G Garabato, Alberto C Naveira |
spellingShingle |
Castro, Bieito Fernandez Mazloff, Matthew Williams, Richard G Garabato, Alberto C Naveira Subtropical Contribution to Sub-Antarctic Mode Waters |
author_facet |
Castro, Bieito Fernandez Mazloff, Matthew Williams, Richard G Garabato, Alberto C Naveira |
author_sort |
Castro, Bieito Fernandez |
title |
Subtropical Contribution to Sub-Antarctic Mode Waters |
title_short |
Subtropical Contribution to Sub-Antarctic Mode Waters |
title_full |
Subtropical Contribution to Sub-Antarctic Mode Waters |
title_fullStr |
Subtropical Contribution to Sub-Antarctic Mode Waters |
title_full_unstemmed |
Subtropical Contribution to Sub-Antarctic Mode Waters |
title_sort |
subtropical contribution to sub-antarctic mode waters |
publisher |
American Geophysical Union (AGU) |
publishDate |
2022 |
url |
http://livrepository.liverpool.ac.uk/3164044/ https://doi.org/10.1029/2021gl097560 http://livrepository.liverpool.ac.uk/3164044/1/grl_2022_bfc.pdf |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
http://livrepository.liverpool.ac.uk/3164044/1/grl_2022_bfc.pdf Castro, Bieito Fernandez, Mazloff, Matthew, Williams, Richard G orcid:0000-0002-3180-7558 and Garabato, Alberto C Naveira (2022) Subtropical Contribution to Sub-Antarctic Mode Waters. GEOPHYSICAL RESEARCH LETTERS, 49 (11). |
op_doi |
https://doi.org/10.1029/2021gl097560 |
container_title |
Geophysical Research Letters |
container_volume |
49 |
container_issue |
11 |
_version_ |
1766256428786384896 |