Atmospheric deposition of nutrients and excess N formation in the North Atlantic
Anthropogenic emissions of nitrogen (N) to the atmosphere have been strongly increasing during the last century, leading to greater atmospheric N deposition to the oceans. The North Atlantic subtropical gyre (NASTG) is particularly impacted. Here, upwind sources of anthropogenic N from North America...
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Copernicus Publications
2010
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00029202 2023-05-15T17:31:31+02:00 Atmospheric deposition of nutrients and excess N formation in the North Atlantic Zamora, L. M. Landolfi, A. Oschlies, A. Hansell, D. A. Dietze, H. Dentener, F. 2010-02 electronic https://doi.org/10.5194/bg-7-777-2010 https://noa.gwlb.de/receive/cop_mods_00029202 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00029157/bg-7-777-2010.pdf https://bg.copernicus.org/articles/7/777/2010/bg-7-777-2010.pdf eng eng Copernicus Publications Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-7-777-2010 https://noa.gwlb.de/receive/cop_mods_00029202 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00029157/bg-7-777-2010.pdf https://bg.copernicus.org/articles/7/777/2010/bg-7-777-2010.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2010 ftnonlinearchiv https://doi.org/10.5194/bg-7-777-2010 2022-02-08T22:47:49Z Anthropogenic emissions of nitrogen (N) to the atmosphere have been strongly increasing during the last century, leading to greater atmospheric N deposition to the oceans. The North Atlantic subtropical gyre (NASTG) is particularly impacted. Here, upwind sources of anthropogenic N from North American and European sources have raised atmospheric N deposition to rates comparable with N2 fixation in the gyre. However, the biogeochemical fate of the deposited N is unclear because there is no detectable accumulation in the surface waters. Most likely, deposited N accumulates in the main thermocline instead, where there is a globally unique pool of N in excess of the canonical Redfield ratio of 16N:1 phosphorus (P). To investigate this depth zone as a sink for atmospheric N, we used a biogeochemical ocean transport model and year 2000 nutrient deposition data. We examined the maximum effects of three mechanisms that may transport excess N from the ocean surface to the main thermocline: physical transport, preferential P remineralization of sinking particles, and nutrient uptake and export by phytoplankton at higher than Redfield N:P ratios. Our results indicate that atmospheric deposition may contribute 13–19% of the annual excess N input to the main thermocline. Modeled nutrient distributions in the NASTG were comparable to observations only when non-Redfield dynamics were invoked. Preferential P remineralization could not produce realistic results on its own; if it is an important contributor to ocean biogeochemistry, it must co-occur with N2 fixation. The results suggest that: 1) the main thermocline is an important sink for anthropogenic N deposition, 2) non-Redfield surface dynamics determine the biogeochemical fate of atmospherically deposited nutrients, and 3) atmospheric N accumulation in the main thermocline has long term impacts on surface ocean biology. Article in Journal/Newspaper North Atlantic Niedersächsisches Online-Archiv NOA Biogeosciences 7 2 777 793 |
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Open Polar |
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Niedersächsisches Online-Archiv NOA |
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ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Zamora, L. M. Landolfi, A. Oschlies, A. Hansell, D. A. Dietze, H. Dentener, F. Atmospheric deposition of nutrients and excess N formation in the North Atlantic |
topic_facet |
article Verlagsveröffentlichung |
description |
Anthropogenic emissions of nitrogen (N) to the atmosphere have been strongly increasing during the last century, leading to greater atmospheric N deposition to the oceans. The North Atlantic subtropical gyre (NASTG) is particularly impacted. Here, upwind sources of anthropogenic N from North American and European sources have raised atmospheric N deposition to rates comparable with N2 fixation in the gyre. However, the biogeochemical fate of the deposited N is unclear because there is no detectable accumulation in the surface waters. Most likely, deposited N accumulates in the main thermocline instead, where there is a globally unique pool of N in excess of the canonical Redfield ratio of 16N:1 phosphorus (P). To investigate this depth zone as a sink for atmospheric N, we used a biogeochemical ocean transport model and year 2000 nutrient deposition data. We examined the maximum effects of three mechanisms that may transport excess N from the ocean surface to the main thermocline: physical transport, preferential P remineralization of sinking particles, and nutrient uptake and export by phytoplankton at higher than Redfield N:P ratios. Our results indicate that atmospheric deposition may contribute 13–19% of the annual excess N input to the main thermocline. Modeled nutrient distributions in the NASTG were comparable to observations only when non-Redfield dynamics were invoked. Preferential P remineralization could not produce realistic results on its own; if it is an important contributor to ocean biogeochemistry, it must co-occur with N2 fixation. The results suggest that: 1) the main thermocline is an important sink for anthropogenic N deposition, 2) non-Redfield surface dynamics determine the biogeochemical fate of atmospherically deposited nutrients, and 3) atmospheric N accumulation in the main thermocline has long term impacts on surface ocean biology. |
format |
Article in Journal/Newspaper |
author |
Zamora, L. M. Landolfi, A. Oschlies, A. Hansell, D. A. Dietze, H. Dentener, F. |
author_facet |
Zamora, L. M. Landolfi, A. Oschlies, A. Hansell, D. A. Dietze, H. Dentener, F. |
author_sort |
Zamora, L. M. |
title |
Atmospheric deposition of nutrients and excess N formation in the North Atlantic |
title_short |
Atmospheric deposition of nutrients and excess N formation in the North Atlantic |
title_full |
Atmospheric deposition of nutrients and excess N formation in the North Atlantic |
title_fullStr |
Atmospheric deposition of nutrients and excess N formation in the North Atlantic |
title_full_unstemmed |
Atmospheric deposition of nutrients and excess N formation in the North Atlantic |
title_sort |
atmospheric deposition of nutrients and excess n formation in the north atlantic |
publisher |
Copernicus Publications |
publishDate |
2010 |
url |
https://doi.org/10.5194/bg-7-777-2010 https://noa.gwlb.de/receive/cop_mods_00029202 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00029157/bg-7-777-2010.pdf https://bg.copernicus.org/articles/7/777/2010/bg-7-777-2010.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-7-777-2010 https://noa.gwlb.de/receive/cop_mods_00029202 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00029157/bg-7-777-2010.pdf https://bg.copernicus.org/articles/7/777/2010/bg-7-777-2010.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/bg-7-777-2010 |
container_title |
Biogeosciences |
container_volume |
7 |
container_issue |
2 |
container_start_page |
777 |
op_container_end_page |
793 |
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1766129157474877440 |