Quantitative reconstruction of sea-surface conditions over the last 150 yr in the Beaufort Sea based on dinoflagellate cyst assemblages: the role of large-scale atmospheric circulation patterns
International audience Dinoflagellate cyst (dinocyst) assemblages have been widely used over the Arctic Ocean to reconstruct sea-surface parameters on a quantitative basis. Such reconstructions provide insights into the role of anthropogenic vs natural forcings in the actual climatic trend. Here, we...
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Language: | English |
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HAL CCSD
2012
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Online Access: | https://hal.science/hal-04113955 https://doi.org/10.5194/bg-9-5391-201210.5194/bgd-9-7257-2012 |
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ftmuseumnhn:oai:HAL:hal-04113955v1 |
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openpolar |
institution |
Open Polar |
collection |
Muséum National d'Histoire Naturelle (MNHM): HAL |
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ftmuseumnhn |
language |
English |
topic |
Earth Science [SDU]Sciences of the Universe [physics] |
spellingShingle |
Earth Science [SDU]Sciences of the Universe [physics] Durantou, L. Rochon, A. Ledu, D. Massé, G. Schmidt, S. Babin, M. Quantitative reconstruction of sea-surface conditions over the last 150 yr in the Beaufort Sea based on dinoflagellate cyst assemblages: the role of large-scale atmospheric circulation patterns |
topic_facet |
Earth Science [SDU]Sciences of the Universe [physics] |
description |
International audience Dinoflagellate cyst (dinocyst) assemblages have been widely used over the Arctic Ocean to reconstruct sea-surface parameters on a quantitative basis. Such reconstructions provide insights into the role of anthropogenic vs natural forcings in the actual climatic trend. Here, we present the palynological analysis of a dated 36 cm-long core collected from the Mackenzie Trough in the Canadian Beaufort Sea. Dinocyst assemblages were used to quantitatively reconstruct the evolution of sea-surface conditions (temperature, salinity, sea ice) and freshwater palynomorphs fluxes were used as local paleo-river discharge indicators over the last ~ 150 yr. Dinocyst assemblages are dominated by autotrophic taxa (68 to 96%). Cyst of Pentapharsodinium dalei is the dominant species throughout most of the core, except at the top where the assemblages are dominated by Operculodinium centrocarpum. Quantitative reconstructions of sea-surface parameters display a series of relatively warm, lower sea ice and saline episodes in surface waters, alternately with relatively cool and low salinity episodes. Variations of dinocyst fluxes and reconstructed sea-surface conditions may be closely linked to large scale atmospheric circulation patterns such as the Pacific Decadal Oscillation (PDO) and to a lesser degree, the Arctic Oscillation (AO). Positive phases of the PDO correspond to increases of dinocyst fluxes, warmer and saltier surface waters, which we associate with upwelling events of warm and relatively saline water from Pacific origin. Freshwater palynomorph fluxes increased in three phases from AD 1857 until reaching maximum values in AD 1991, suggesting that the Mackenzie River discharge followed the same trend when its discharge peaked between AD 1989 and AD 1992. The PDO mode seems to dominate the climatic variations at multi-annual to decadal timescales in the western Canadian Arctic and Beaufort Sea areas. |
author2 |
Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Durantou, L. Rochon, A. Ledu, D. Massé, G. Schmidt, S. Babin, M. |
author_facet |
Durantou, L. Rochon, A. Ledu, D. Massé, G. Schmidt, S. Babin, M. |
author_sort |
Durantou, L. |
title |
Quantitative reconstruction of sea-surface conditions over the last 150 yr in the Beaufort Sea based on dinoflagellate cyst assemblages: the role of large-scale atmospheric circulation patterns |
title_short |
Quantitative reconstruction of sea-surface conditions over the last 150 yr in the Beaufort Sea based on dinoflagellate cyst assemblages: the role of large-scale atmospheric circulation patterns |
title_full |
Quantitative reconstruction of sea-surface conditions over the last 150 yr in the Beaufort Sea based on dinoflagellate cyst assemblages: the role of large-scale atmospheric circulation patterns |
title_fullStr |
Quantitative reconstruction of sea-surface conditions over the last 150 yr in the Beaufort Sea based on dinoflagellate cyst assemblages: the role of large-scale atmospheric circulation patterns |
title_full_unstemmed |
Quantitative reconstruction of sea-surface conditions over the last 150 yr in the Beaufort Sea based on dinoflagellate cyst assemblages: the role of large-scale atmospheric circulation patterns |
title_sort |
quantitative reconstruction of sea-surface conditions over the last 150 yr in the beaufort sea based on dinoflagellate cyst assemblages: the role of large-scale atmospheric circulation patterns |
publisher |
HAL CCSD |
publishDate |
2012 |
url |
https://hal.science/hal-04113955 https://doi.org/10.5194/bg-9-5391-201210.5194/bgd-9-7257-2012 |
long_lat |
ENVELOPE(-138.025,-138.025,69.528,69.528) |
geographic |
Arctic Arctic Ocean Mackenzie River Pacific MacKenzie Trough |
geographic_facet |
Arctic Arctic Ocean Mackenzie River Pacific MacKenzie Trough |
genre |
Arctic Arctic Ocean Beaufort Sea Mackenzie river Sea ice |
genre_facet |
Arctic Arctic Ocean Beaufort Sea Mackenzie river Sea ice |
op_source |
Biogeosciences https://hal.science/hal-04113955 Biogeosciences, 2012, 9, pp.5391-5406. ⟨10.5194/bg-9-5391-201210.5194/bgd-9-7257-2012⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-9-5391-201210.5194/bgd-9-7257-2012 hal-04113955 https://hal.science/hal-04113955 BIBCODE: 2012BGeo.9.5391D doi:10.5194/bg-9-5391-201210.5194/bgd-9-7257-2012 |
op_doi |
https://doi.org/10.5194/bg-9-5391-201210.5194/bgd-9-7257-2012 |
_version_ |
1769004016421830656 |
spelling |
ftmuseumnhn:oai:HAL:hal-04113955v1 2023-06-18T03:39:14+02:00 Quantitative reconstruction of sea-surface conditions over the last 150 yr in the Beaufort Sea based on dinoflagellate cyst assemblages: the role of large-scale atmospheric circulation patterns Durantou, L. Rochon, A. Ledu, D. Massé, G. Schmidt, S. Babin, M. Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) 2012 https://hal.science/hal-04113955 https://doi.org/10.5194/bg-9-5391-201210.5194/bgd-9-7257-2012 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-9-5391-201210.5194/bgd-9-7257-2012 hal-04113955 https://hal.science/hal-04113955 BIBCODE: 2012BGeo.9.5391D doi:10.5194/bg-9-5391-201210.5194/bgd-9-7257-2012 Biogeosciences https://hal.science/hal-04113955 Biogeosciences, 2012, 9, pp.5391-5406. ⟨10.5194/bg-9-5391-201210.5194/bgd-9-7257-2012⟩ Earth Science [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2012 ftmuseumnhn https://doi.org/10.5194/bg-9-5391-201210.5194/bgd-9-7257-2012 2023-06-07T16:19:44Z International audience Dinoflagellate cyst (dinocyst) assemblages have been widely used over the Arctic Ocean to reconstruct sea-surface parameters on a quantitative basis. Such reconstructions provide insights into the role of anthropogenic vs natural forcings in the actual climatic trend. Here, we present the palynological analysis of a dated 36 cm-long core collected from the Mackenzie Trough in the Canadian Beaufort Sea. Dinocyst assemblages were used to quantitatively reconstruct the evolution of sea-surface conditions (temperature, salinity, sea ice) and freshwater palynomorphs fluxes were used as local paleo-river discharge indicators over the last ~ 150 yr. Dinocyst assemblages are dominated by autotrophic taxa (68 to 96%). Cyst of Pentapharsodinium dalei is the dominant species throughout most of the core, except at the top where the assemblages are dominated by Operculodinium centrocarpum. Quantitative reconstructions of sea-surface parameters display a series of relatively warm, lower sea ice and saline episodes in surface waters, alternately with relatively cool and low salinity episodes. Variations of dinocyst fluxes and reconstructed sea-surface conditions may be closely linked to large scale atmospheric circulation patterns such as the Pacific Decadal Oscillation (PDO) and to a lesser degree, the Arctic Oscillation (AO). Positive phases of the PDO correspond to increases of dinocyst fluxes, warmer and saltier surface waters, which we associate with upwelling events of warm and relatively saline water from Pacific origin. Freshwater palynomorph fluxes increased in three phases from AD 1857 until reaching maximum values in AD 1991, suggesting that the Mackenzie River discharge followed the same trend when its discharge peaked between AD 1989 and AD 1992. The PDO mode seems to dominate the climatic variations at multi-annual to decadal timescales in the western Canadian Arctic and Beaufort Sea areas. Article in Journal/Newspaper Arctic Arctic Ocean Beaufort Sea Mackenzie river Sea ice Muséum National d'Histoire Naturelle (MNHM): HAL Arctic Arctic Ocean Mackenzie River Pacific MacKenzie Trough ENVELOPE(-138.025,-138.025,69.528,69.528) |