Nutrient Controls on Export Production in the Southern Ocean
We use observations from novel biogeochemical profiling floats deployed by the Southern Ocean Carbon and Climate Observations and Modeling program to estimate annual net community production (ANCP; associated with carbon export) from the seasonal drawdown of mesopelagic oxygen and surface nitrate in...
Published in: | Global Biogeochemical Cycles |
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ftoceanrep:oai:oceanrep.geomar.de:47356 2023-05-15T14:00:39+02:00 Nutrient Controls on Export Production in the Southern Ocean Arteaga, Lionel Pahlow, Markus Bushinsky, Seth M. Sarmiento, Jorge L. 2020-08 text https://oceanrep.geomar.de/id/eprint/47356/ https://oceanrep.geomar.de/id/eprint/47356/1/Arteaga_et_al-2019-Global_Biogeochemical_Cycles.pdf https://doi.org/10.1029/2019gb006236 en eng AGU (American Geophysical Union) Wiley https://oceanrep.geomar.de/id/eprint/47356/1/Arteaga_et_al-2019-Global_Biogeochemical_Cycles.pdf Arteaga, L. , Pahlow, M., Bushinsky, S. M. and Sarmiento, J. L. (2020) Nutrient Controls on Export Production in the Southern Ocean. Open Access Global Biogeochemical Cycles, 33 (8). pp. 942-956. DOI 10.1029/2019gb006236 <https://doi.org/10.1029/2019gb006236>. doi:10.1029/2019gb006236 info:eu-repo/semantics/openAccess Course of study: MSc Biological Oceanography Article PeerReviewed 2020 ftoceanrep https://doi.org/10.1029/2019gb006236 2023-04-07T15:46:50Z We use observations from novel biogeochemical profiling floats deployed by the Southern Ocean Carbon and Climate Observations and Modeling program to estimate annual net community production (ANCP; associated with carbon export) from the seasonal drawdown of mesopelagic oxygen and surface nitrate in the Southern Ocean. Our estimates agree with previous observations in showing an increase in ANCP in the vicinity of the polar front (∼3 mol C m−2 y−1), compared to lower rates in the subtropical zone (≤ 1 mol C m−2 y−1) and the seasonal ice zone (<2 mol C m−2 y−1). Paradoxically, the increase in ANCP south of the subtropical front is associated with elevated surface nitrate and silicate concentrations, but decreasing surface iron. We hypothesize that iron limitation promotes silicification in diatoms, which is evidenced by the low silicate to nitrate ratio of surface waters around the Antarctic polar front. High diatom silicification increases the ballasting effect of particulate organic carbon and overall ANCP in this region. A model-based assessment of our methods shows a good agreement between ANCP estimates based on oxygen and nitrate drawdown and the modeled downward organic carbon flux at 100 m. This agreement supports the presumption that net biological consumption is the dominant process affecting the drawdown of these chemical tracers and that, given sufficient data, ANCP can be inferred from observations of oxygen and/or nitrate drawdown in the Southern Ocean. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Southern Ocean The Antarctic Global Biogeochemical Cycles 33 8 942 956 |
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Open Polar |
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OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
topic |
Course of study: MSc Biological Oceanography |
spellingShingle |
Course of study: MSc Biological Oceanography Arteaga, Lionel Pahlow, Markus Bushinsky, Seth M. Sarmiento, Jorge L. Nutrient Controls on Export Production in the Southern Ocean |
topic_facet |
Course of study: MSc Biological Oceanography |
description |
We use observations from novel biogeochemical profiling floats deployed by the Southern Ocean Carbon and Climate Observations and Modeling program to estimate annual net community production (ANCP; associated with carbon export) from the seasonal drawdown of mesopelagic oxygen and surface nitrate in the Southern Ocean. Our estimates agree with previous observations in showing an increase in ANCP in the vicinity of the polar front (∼3 mol C m−2 y−1), compared to lower rates in the subtropical zone (≤ 1 mol C m−2 y−1) and the seasonal ice zone (<2 mol C m−2 y−1). Paradoxically, the increase in ANCP south of the subtropical front is associated with elevated surface nitrate and silicate concentrations, but decreasing surface iron. We hypothesize that iron limitation promotes silicification in diatoms, which is evidenced by the low silicate to nitrate ratio of surface waters around the Antarctic polar front. High diatom silicification increases the ballasting effect of particulate organic carbon and overall ANCP in this region. A model-based assessment of our methods shows a good agreement between ANCP estimates based on oxygen and nitrate drawdown and the modeled downward organic carbon flux at 100 m. This agreement supports the presumption that net biological consumption is the dominant process affecting the drawdown of these chemical tracers and that, given sufficient data, ANCP can be inferred from observations of oxygen and/or nitrate drawdown in the Southern Ocean. |
format |
Article in Journal/Newspaper |
author |
Arteaga, Lionel Pahlow, Markus Bushinsky, Seth M. Sarmiento, Jorge L. |
author_facet |
Arteaga, Lionel Pahlow, Markus Bushinsky, Seth M. Sarmiento, Jorge L. |
author_sort |
Arteaga, Lionel |
title |
Nutrient Controls on Export Production in the Southern Ocean |
title_short |
Nutrient Controls on Export Production in the Southern Ocean |
title_full |
Nutrient Controls on Export Production in the Southern Ocean |
title_fullStr |
Nutrient Controls on Export Production in the Southern Ocean |
title_full_unstemmed |
Nutrient Controls on Export Production in the Southern Ocean |
title_sort |
nutrient controls on export production in the southern ocean |
publisher |
AGU (American Geophysical Union) |
publishDate |
2020 |
url |
https://oceanrep.geomar.de/id/eprint/47356/ https://oceanrep.geomar.de/id/eprint/47356/1/Arteaga_et_al-2019-Global_Biogeochemical_Cycles.pdf https://doi.org/10.1029/2019gb006236 |
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_relation |
https://oceanrep.geomar.de/id/eprint/47356/1/Arteaga_et_al-2019-Global_Biogeochemical_Cycles.pdf Arteaga, L. , Pahlow, M., Bushinsky, S. M. and Sarmiento, J. L. (2020) Nutrient Controls on Export Production in the Southern Ocean. Open Access Global Biogeochemical Cycles, 33 (8). pp. 942-956. DOI 10.1029/2019gb006236 <https://doi.org/10.1029/2019gb006236>. doi:10.1029/2019gb006236 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2019gb006236 |
container_title |
Global Biogeochemical Cycles |
container_volume |
33 |
container_issue |
8 |
container_start_page |
942 |
op_container_end_page |
956 |
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1766269876732690432 |