Fueling export production: nutrient return pathways from the deep ocean and their dependence on the Meridional Overturning Circulation
In the Southern Ocean, mixing and upwelling in the presence of heat and freshwater surface fluxes transform subpycnocline water to lighter densities as part of the upward branch of the Meridional Overturning Circulation (MOC). One hypothesized impact of this transformation is the restoration of nutr...
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Online Access: | https://doi.org/10.5194/bg-7-3549-2010 https://doaj.org/article/ea03d4b3b83c4c5ca4898a06e5cf034c |
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ftdoajarticles:oai:doaj.org/article:ea03d4b3b83c4c5ca4898a06e5cf034c 2023-05-15T14:01:46+02:00 Fueling export production: nutrient return pathways from the deep ocean and their dependence on the Meridional Overturning Circulation J. B. Palter J. L. Sarmiento A. Gnanadesikan J. Simeon R. D. Slater 2010-11-01T00:00:00Z https://doi.org/10.5194/bg-7-3549-2010 https://doaj.org/article/ea03d4b3b83c4c5ca4898a06e5cf034c EN eng Copernicus Publications http://www.biogeosciences.net/7/3549/2010/bg-7-3549-2010.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-7-3549-2010 1726-4170 1726-4189 https://doaj.org/article/ea03d4b3b83c4c5ca4898a06e5cf034c Biogeosciences, Vol 7, Iss 11, Pp 3549-3568 (2010) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2010 ftdoajarticles https://doi.org/10.5194/bg-7-3549-2010 2023-01-08T01:29:05Z In the Southern Ocean, mixing and upwelling in the presence of heat and freshwater surface fluxes transform subpycnocline water to lighter densities as part of the upward branch of the Meridional Overturning Circulation (MOC). One hypothesized impact of this transformation is the restoration of nutrients to the global pycnocline, without which biological productivity at low latitudes would be significantly reduced. Here we use a novel set of modeling experiments to explore the causes and consequences of the Southern Ocean nutrient return pathway. Specifically, we quantify the contribution to global productivity of nutrients that rise from the ocean interior in the Southern Ocean, the northern high latitudes, and by mixing across the low latitude pycnocline. In addition, we evaluate how the strength of the Southern Ocean winds and the parameterizations of subgridscale processes change the dominant nutrient return pathways in the ocean. Our results suggest that nutrients upwelled from the deep ocean in the Antarctic Circumpolar Current and subducted in Subantartic Mode Water support between 33 and 75% of global export production between 30° S and 30° N. The high end of this range results from an ocean model in which the MOC is driven primarily by wind-induced Southern Ocean upwelling, a configuration favored due to its fidelity to tracer data, while the low end results from an MOC driven by high diapycnal diffusivity in the pycnocline. In all models, nutrients exported in the SAMW layer are utilized and converted rapidly (in less than 40 years) to remineralized nutrients, explaining previous modeling results that showed little influence of the drawdown of SAMW surface nutrients on atmospheric carbon concentrations. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean Directory of Open Access Journals: DOAJ Articles Antarctic Southern Ocean The Antarctic Biogeosciences 7 11 3549 3568 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 J. B. Palter J. L. Sarmiento A. Gnanadesikan J. Simeon R. D. Slater Fueling export production: nutrient return pathways from the deep ocean and their dependence on the Meridional Overturning Circulation |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
In the Southern Ocean, mixing and upwelling in the presence of heat and freshwater surface fluxes transform subpycnocline water to lighter densities as part of the upward branch of the Meridional Overturning Circulation (MOC). One hypothesized impact of this transformation is the restoration of nutrients to the global pycnocline, without which biological productivity at low latitudes would be significantly reduced. Here we use a novel set of modeling experiments to explore the causes and consequences of the Southern Ocean nutrient return pathway. Specifically, we quantify the contribution to global productivity of nutrients that rise from the ocean interior in the Southern Ocean, the northern high latitudes, and by mixing across the low latitude pycnocline. In addition, we evaluate how the strength of the Southern Ocean winds and the parameterizations of subgridscale processes change the dominant nutrient return pathways in the ocean. Our results suggest that nutrients upwelled from the deep ocean in the Antarctic Circumpolar Current and subducted in Subantartic Mode Water support between 33 and 75% of global export production between 30° S and 30° N. The high end of this range results from an ocean model in which the MOC is driven primarily by wind-induced Southern Ocean upwelling, a configuration favored due to its fidelity to tracer data, while the low end results from an MOC driven by high diapycnal diffusivity in the pycnocline. In all models, nutrients exported in the SAMW layer are utilized and converted rapidly (in less than 40 years) to remineralized nutrients, explaining previous modeling results that showed little influence of the drawdown of SAMW surface nutrients on atmospheric carbon concentrations. |
format |
Article in Journal/Newspaper |
author |
J. B. Palter J. L. Sarmiento A. Gnanadesikan J. Simeon R. D. Slater |
author_facet |
J. B. Palter J. L. Sarmiento A. Gnanadesikan J. Simeon R. D. Slater |
author_sort |
J. B. Palter |
title |
Fueling export production: nutrient return pathways from the deep ocean and their dependence on the Meridional Overturning Circulation |
title_short |
Fueling export production: nutrient return pathways from the deep ocean and their dependence on the Meridional Overturning Circulation |
title_full |
Fueling export production: nutrient return pathways from the deep ocean and their dependence on the Meridional Overturning Circulation |
title_fullStr |
Fueling export production: nutrient return pathways from the deep ocean and their dependence on the Meridional Overturning Circulation |
title_full_unstemmed |
Fueling export production: nutrient return pathways from the deep ocean and their dependence on the Meridional Overturning Circulation |
title_sort |
fueling export production: nutrient return pathways from the deep ocean and their dependence on the meridional overturning circulation |
publisher |
Copernicus Publications |
publishDate |
2010 |
url |
https://doi.org/10.5194/bg-7-3549-2010 https://doaj.org/article/ea03d4b3b83c4c5ca4898a06e5cf034c |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
Biogeosciences, Vol 7, Iss 11, Pp 3549-3568 (2010) |
op_relation |
http://www.biogeosciences.net/7/3549/2010/bg-7-3549-2010.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-7-3549-2010 1726-4170 1726-4189 https://doaj.org/article/ea03d4b3b83c4c5ca4898a06e5cf034c |
op_doi |
https://doi.org/10.5194/bg-7-3549-2010 |
container_title |
Biogeosciences |
container_volume |
7 |
container_issue |
11 |
container_start_page |
3549 |
op_container_end_page |
3568 |
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1766271797537275904 |