Organic nutrients and excess nitrogen in the North Atlantic subtropical gyre
International audience To enable an accurate estimate of total excess nitrogen (N) in the North Atlantic a new tracer, TNxs, is defined which includes the contribution of organic nutrients to the assessment of N:P stoichiometric anomalies. We estimate the spatial distribution of TNxs within the Nort...
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ftinsu:oai:HAL:hal-00297972v1 2023-11-12T04:21:48+01:00 Organic nutrients and excess nitrogen in the North Atlantic subtropical gyre Landolfi, A. Oschlies, A. Sanders, R. Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR) National Oceanography Centre Southampton (NOC) University of Southampton 2008-02-14 https://hal.science/hal-00297972 https://hal.science/hal-00297972/document https://hal.science/hal-00297972/file/bgd-5-685-2008.pdf en eng HAL CCSD European Geosciences Union hal-00297972 https://hal.science/hal-00297972 https://hal.science/hal-00297972/document https://hal.science/hal-00297972/file/bgd-5-685-2008.pdf info:eu-repo/semantics/OpenAccess ISSN: 1810-6277 EISSN: 1810-6285 Biogeosciences Discussions https://hal.science/hal-00297972 Biogeosciences Discussions, 2008, 5 (1), pp.685-724 [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2008 ftinsu 2023-10-25T16:28:21Z International audience To enable an accurate estimate of total excess nitrogen (N) in the North Atlantic a new tracer, TNxs, is defined which includes the contribution of organic nutrients to the assessment of N:P stoichiometric anomalies. We estimate the spatial distribution of TNxs within the North Atlantic using data from a trans-Atlantic section across 24.5° N conducted in 2004. We then employ three different approaches to infer rates of total excess nitrogen accumulation using pCFC-12 derived ventilation ages (a TNxs vertical integration, a one end-member and a two-end member mixing model). Despite some variability among the different methods the dissolved organic nutrient fraction always contributes to about half of the TNxs accumulation, which is in the order of 9.38±4.18×10 11 mol N y ?1 . Here we suggest that neglecting organic nutrients in stoichiometric balances of the marine N and P inventories can lead to systematic errors when estimating a nitrogen excess or deficit relative to the Redfield ratio in the oceans. For the North Atlantic the inclusion of the organic fraction leads to an upward revision of the N supply by N 2 fixation to 10.2±6.9×10 11 mol N y ?1 . This enhanced estimate of nitrogen fixation reconciles the geochemical estimates of N 2 fixation derived from excess nitrate and the direct estimates from N 2 fixation measurements. Article in Journal/Newspaper North Atlantic Institut national des sciences de l'Univers: HAL-INSU |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Landolfi, A. Oschlies, A. Sanders, R. Organic nutrients and excess nitrogen in the North Atlantic subtropical gyre |
topic_facet |
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience To enable an accurate estimate of total excess nitrogen (N) in the North Atlantic a new tracer, TNxs, is defined which includes the contribution of organic nutrients to the assessment of N:P stoichiometric anomalies. We estimate the spatial distribution of TNxs within the North Atlantic using data from a trans-Atlantic section across 24.5° N conducted in 2004. We then employ three different approaches to infer rates of total excess nitrogen accumulation using pCFC-12 derived ventilation ages (a TNxs vertical integration, a one end-member and a two-end member mixing model). Despite some variability among the different methods the dissolved organic nutrient fraction always contributes to about half of the TNxs accumulation, which is in the order of 9.38±4.18×10 11 mol N y ?1 . Here we suggest that neglecting organic nutrients in stoichiometric balances of the marine N and P inventories can lead to systematic errors when estimating a nitrogen excess or deficit relative to the Redfield ratio in the oceans. For the North Atlantic the inclusion of the organic fraction leads to an upward revision of the N supply by N 2 fixation to 10.2±6.9×10 11 mol N y ?1 . This enhanced estimate of nitrogen fixation reconciles the geochemical estimates of N 2 fixation derived from excess nitrate and the direct estimates from N 2 fixation measurements. |
author2 |
Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR) National Oceanography Centre Southampton (NOC) University of Southampton |
format |
Article in Journal/Newspaper |
author |
Landolfi, A. Oschlies, A. Sanders, R. |
author_facet |
Landolfi, A. Oschlies, A. Sanders, R. |
author_sort |
Landolfi, A. |
title |
Organic nutrients and excess nitrogen in the North Atlantic subtropical gyre |
title_short |
Organic nutrients and excess nitrogen in the North Atlantic subtropical gyre |
title_full |
Organic nutrients and excess nitrogen in the North Atlantic subtropical gyre |
title_fullStr |
Organic nutrients and excess nitrogen in the North Atlantic subtropical gyre |
title_full_unstemmed |
Organic nutrients and excess nitrogen in the North Atlantic subtropical gyre |
title_sort |
organic nutrients and excess nitrogen in the north atlantic subtropical gyre |
publisher |
HAL CCSD |
publishDate |
2008 |
url |
https://hal.science/hal-00297972 https://hal.science/hal-00297972/document https://hal.science/hal-00297972/file/bgd-5-685-2008.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
ISSN: 1810-6277 EISSN: 1810-6285 Biogeosciences Discussions https://hal.science/hal-00297972 Biogeosciences Discussions, 2008, 5 (1), pp.685-724 |
op_relation |
hal-00297972 https://hal.science/hal-00297972 https://hal.science/hal-00297972/document https://hal.science/hal-00297972/file/bgd-5-685-2008.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782337057434107904 |