Impact of river discharge, upwelling and vertical mixing on the nutrient loading and productivity of the Canadian Beaufort Shelf
International audience The concentrations and elemental stoichiometry of particulate and dissolved pools of carbon (C), nitrogen (N), phosphorus (P) and silicon (Si) on the Canadian Beaufort Shelf during summer 2009 (MALINA program) were assessed and compared with those of surface waters provided by...
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Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2014
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Online Access: | https://hal.science/hal-04114610 https://doi.org/10.5194/bg-11-4853-201410.5194/bgd-10-16675-2013 |
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ftccsdartic:oai:HAL:hal-04114610v1 |
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openpolar |
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Open Polar |
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Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
Earth Science [SDU]Sciences of the Universe [physics] |
spellingShingle |
Earth Science [SDU]Sciences of the Universe [physics] Tremblay, J. -É. Raimbault, P. Garcia, N. Lansard, B. Babin, M. Gagnon, J. Impact of river discharge, upwelling and vertical mixing on the nutrient loading and productivity of the Canadian Beaufort Shelf |
topic_facet |
Earth Science [SDU]Sciences of the Universe [physics] |
description |
International audience The concentrations and elemental stoichiometry of particulate and dissolved pools of carbon (C), nitrogen (N), phosphorus (P) and silicon (Si) on the Canadian Beaufort Shelf during summer 2009 (MALINA program) were assessed and compared with those of surface waters provided by the Mackenzie river as well as by winter mixing and upwelling of upper halocline waters at the shelf break. Neritic surface waters showed a clear enrichment in dissolved and particulate organic carbon (DOC and POC, respectively), nitrate, total particulate nitrogen (TPN) and dissolved organic nitrogen (DON) originating from the river. Silicate as well as bulk DON and DOC declined in a near-conservative manner away from the delta's outlet, whereas nitrate dropped non-conservatively to very low background concentrations inside the brackish zone. By contrast, the excess of soluble reactive P (SRP) present in oceanic waters declined in a non-conservative manner toward the river outlet, where concentrations were very low and consistent with P shortage in the Mackenzie River. These opposite gradients imply that the admixture of Pacific-derived, SRP-rich water is necessary to allow phytoplankton to use river-derived nitrate and to a lesser extent DON. A coarse budget based on concurrent estimates of primary production shows that river N deliveries support a modest fraction of primary production when considering the entire shelf, due to the ability of phytoplankton to thrive in the subsurface chlorophyll maximum beneath the thin, nitrate-depleted river plume. Away from shallow coastal bays, local elevations in the concentration of primary production and dissolved organic constituents were consistent with upwelling at the shelf break. By contrast with shallow winter mixing, nutrient deliveries by North American rivers and upwelling relax surface communities from N limitation and permit a more extant utilization of the excess SRP entering through the Bering Strait. In this context, increased nitrogen supply by rivers and ... |
author2 |
Institut méditerranéen d'océanologie (MIO) Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS) Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) Laboratoire d'océanographie de Villefranche (LOV) Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV) Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Tremblay, J. -É. Raimbault, P. Garcia, N. Lansard, B. Babin, M. Gagnon, J. |
author_facet |
Tremblay, J. -É. Raimbault, P. Garcia, N. Lansard, B. Babin, M. Gagnon, J. |
author_sort |
Tremblay, J. -É. |
title |
Impact of river discharge, upwelling and vertical mixing on the nutrient loading and productivity of the Canadian Beaufort Shelf |
title_short |
Impact of river discharge, upwelling and vertical mixing on the nutrient loading and productivity of the Canadian Beaufort Shelf |
title_full |
Impact of river discharge, upwelling and vertical mixing on the nutrient loading and productivity of the Canadian Beaufort Shelf |
title_fullStr |
Impact of river discharge, upwelling and vertical mixing on the nutrient loading and productivity of the Canadian Beaufort Shelf |
title_full_unstemmed |
Impact of river discharge, upwelling and vertical mixing on the nutrient loading and productivity of the Canadian Beaufort Shelf |
title_sort |
impact of river discharge, upwelling and vertical mixing on the nutrient loading and productivity of the canadian beaufort shelf |
publisher |
HAL CCSD |
publishDate |
2014 |
url |
https://hal.science/hal-04114610 https://doi.org/10.5194/bg-11-4853-201410.5194/bgd-10-16675-2013 |
long_lat |
ENVELOPE(-142.500,-142.500,70.000,70.000) |
geographic |
Bering Strait Mackenzie River Pacific Beaufort Shelf |
geographic_facet |
Bering Strait Mackenzie River Pacific Beaufort Shelf |
genre |
Bering Strait Mackenzie river |
genre_facet |
Bering Strait Mackenzie river |
op_source |
Biogeosciences https://hal.science/hal-04114610 Biogeosciences, 2014, 11, pp.4853-4868. ⟨10.5194/bg-11-4853-201410.5194/bgd-10-16675-2013⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-11-4853-201410.5194/bgd-10-16675-2013 hal-04114610 https://hal.science/hal-04114610 BIBCODE: 2014BGeo.11.4853T doi:10.5194/bg-11-4853-201410.5194/bgd-10-16675-2013 |
op_doi |
https://doi.org/10.5194/bg-11-4853-201410.5194/bgd-10-16675-2013 |
_version_ |
1769004837647679488 |
spelling |
ftccsdartic:oai:HAL:hal-04114610v1 2023-06-18T03:40:02+02:00 Impact of river discharge, upwelling and vertical mixing on the nutrient loading and productivity of the Canadian Beaufort Shelf Tremblay, J. -É. Raimbault, P. Garcia, N. Lansard, B. Babin, M. Gagnon, J. Institut méditerranéen d'océanologie (MIO) Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS) Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) Laboratoire d'océanographie de Villefranche (LOV) Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV) Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) 2014 https://hal.science/hal-04114610 https://doi.org/10.5194/bg-11-4853-201410.5194/bgd-10-16675-2013 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-11-4853-201410.5194/bgd-10-16675-2013 hal-04114610 https://hal.science/hal-04114610 BIBCODE: 2014BGeo.11.4853T doi:10.5194/bg-11-4853-201410.5194/bgd-10-16675-2013 Biogeosciences https://hal.science/hal-04114610 Biogeosciences, 2014, 11, pp.4853-4868. ⟨10.5194/bg-11-4853-201410.5194/bgd-10-16675-2013⟩ Earth Science [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2014 ftccsdartic https://doi.org/10.5194/bg-11-4853-201410.5194/bgd-10-16675-2013 2023-06-03T23:49:54Z International audience The concentrations and elemental stoichiometry of particulate and dissolved pools of carbon (C), nitrogen (N), phosphorus (P) and silicon (Si) on the Canadian Beaufort Shelf during summer 2009 (MALINA program) were assessed and compared with those of surface waters provided by the Mackenzie river as well as by winter mixing and upwelling of upper halocline waters at the shelf break. Neritic surface waters showed a clear enrichment in dissolved and particulate organic carbon (DOC and POC, respectively), nitrate, total particulate nitrogen (TPN) and dissolved organic nitrogen (DON) originating from the river. Silicate as well as bulk DON and DOC declined in a near-conservative manner away from the delta's outlet, whereas nitrate dropped non-conservatively to very low background concentrations inside the brackish zone. By contrast, the excess of soluble reactive P (SRP) present in oceanic waters declined in a non-conservative manner toward the river outlet, where concentrations were very low and consistent with P shortage in the Mackenzie River. These opposite gradients imply that the admixture of Pacific-derived, SRP-rich water is necessary to allow phytoplankton to use river-derived nitrate and to a lesser extent DON. A coarse budget based on concurrent estimates of primary production shows that river N deliveries support a modest fraction of primary production when considering the entire shelf, due to the ability of phytoplankton to thrive in the subsurface chlorophyll maximum beneath the thin, nitrate-depleted river plume. Away from shallow coastal bays, local elevations in the concentration of primary production and dissolved organic constituents were consistent with upwelling at the shelf break. By contrast with shallow winter mixing, nutrient deliveries by North American rivers and upwelling relax surface communities from N limitation and permit a more extant utilization of the excess SRP entering through the Bering Strait. In this context, increased nitrogen supply by rivers and ... Article in Journal/Newspaper Bering Strait Mackenzie river Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Bering Strait Mackenzie River Pacific Beaufort Shelf ENVELOPE(-142.500,-142.500,70.000,70.000) |