Late Holocene surface water changes in the eastern Nordic Seas : the message from carbonate and organic-walled phytoplankton microfossils
Five marine sediment cores distributed along the Norwegian, western Barents Sea, and Svalbard continental margins have been investigated in order to reconstruct late Holocene changes in the poleward flow of the Norwegian Atlantic Current (NwAC) and West Spitsbergen Current (WSC) and the nature of th...
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Other Authors: | , , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
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HAL CCSD
2013
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Online Access: | https://theses.hal.science/tel-00959281 https://theses.hal.science/tel-00959281/document https://theses.hal.science/tel-00959281/file/DYLMER_CHRISTIAN_2013.pdf |
id |
ftecolephe:oai:HAL:tel-00959281v1 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
EPHE (Ecole pratique des hautes études, Paris): HAL |
op_collection_id |
ftecolephe |
language |
English |
topic |
Eastern Nordic Seas Late Holocene Atlantic water flow Surface waters Coccoliths Dinocysts Mers Nordiques Holocène terminal Flux d’eaux atlantiques Eaux de surface Coccolithes Dinokystes [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology |
spellingShingle |
Eastern Nordic Seas Late Holocene Atlantic water flow Surface waters Coccoliths Dinocysts Mers Nordiques Holocène terminal Flux d’eaux atlantiques Eaux de surface Coccolithes Dinokystes [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology Dylmer, Christian Late Holocene surface water changes in the eastern Nordic Seas : the message from carbonate and organic-walled phytoplankton microfossils |
topic_facet |
Eastern Nordic Seas Late Holocene Atlantic water flow Surface waters Coccoliths Dinocysts Mers Nordiques Holocène terminal Flux d’eaux atlantiques Eaux de surface Coccolithes Dinokystes [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology |
description |
Five marine sediment cores distributed along the Norwegian, western Barents Sea, and Svalbard continental margins have been investigated in order to reconstruct late Holocene changes in the poleward flow of the Norwegian Atlantic Current (NwAC) and West Spitsbergen Current (WSC) and the nature of the upper surface water masses within the eastern Nordic Seas. This research project is based on the use of dinocyst and coccolith assemblages for qualitative and quantitative reconstructions of surface water conditions from high resolution sediment cores, and involve upstream investigations on proxy reliabilities. The investigated area (66 to 77°N) was affected by an overall increase in the strength of the AW flow from 3000 cal. yrs BP to the Present. The long-term modulation of westerlies strength and location which are essentially driven by the dominant mode of the North Atlantic Oscillation (NAO), is thought to explain the observed dynamics of the AW flow. The same mechanism also reconciles the recorded opposite zonal shifts in the location of the Arctic Front between the area off western Norway and the western Barents Sea-eastern Fram Strait region. Submillenial changes in AW flow are organised according to known pre-Anthropocene warm (RWP, MCA and the Modern period: strong poleward flow) and cold (LIA, DA: weak poleward flow) climatic spells. A sudden short pulse of resumed high WSC flow interrupted the LIA in the eastern Nordic Seas from 330 to 410 cal. yrs BP. Our results are indicative of a major impact of AW flow dynamics on the Arctic sea ice distribution during the last millenium, when changes in reconstructed sea-ice extent are negatively correlated with the strength of the WSC flow off western Barents Sea and western Svalbard. The extensive decrease in sea ice extent during the last century is synchronous with an exceptional increase in AW flow. The previously reconstructed high amplitude warming of surface waters in eastern Fram Strait at the turn of the 19th century was therefore primarily induced by an ... |
author2 |
Environnements et Paléoenvironnements OCéaniques (EPOC) Observatoire aquitain des sciences de l'univers (OASU) Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) Université Sciences et Technologies - Bordeaux I Jacques Giraudeau |
format |
Doctoral or Postdoctoral Thesis |
author |
Dylmer, Christian |
author_facet |
Dylmer, Christian |
author_sort |
Dylmer, Christian |
title |
Late Holocene surface water changes in the eastern Nordic Seas : the message from carbonate and organic-walled phytoplankton microfossils |
title_short |
Late Holocene surface water changes in the eastern Nordic Seas : the message from carbonate and organic-walled phytoplankton microfossils |
title_full |
Late Holocene surface water changes in the eastern Nordic Seas : the message from carbonate and organic-walled phytoplankton microfossils |
title_fullStr |
Late Holocene surface water changes in the eastern Nordic Seas : the message from carbonate and organic-walled phytoplankton microfossils |
title_full_unstemmed |
Late Holocene surface water changes in the eastern Nordic Seas : the message from carbonate and organic-walled phytoplankton microfossils |
title_sort |
late holocene surface water changes in the eastern nordic seas : the message from carbonate and organic-walled phytoplankton microfossils |
publisher |
HAL CCSD |
publishDate |
2013 |
url |
https://theses.hal.science/tel-00959281 https://theses.hal.science/tel-00959281/document https://theses.hal.science/tel-00959281/file/DYLMER_CHRISTIAN_2013.pdf |
genre |
Arctic Barents Sea Fram Strait Nordic Seas North Atlantic North Atlantic oscillation Phytoplankton Sea ice Svalbard Spitsbergen |
genre_facet |
Arctic Barents Sea Fram Strait Nordic Seas North Atlantic North Atlantic oscillation Phytoplankton Sea ice Svalbard Spitsbergen |
op_source |
https://theses.hal.science/tel-00959281 Paleontology. Université Sciences et Technologies - Bordeaux I, 2013. English. ⟨NNT : 2013BOR15205⟩ |
op_relation |
NNT: 2013BOR15205 tel-00959281 https://theses.hal.science/tel-00959281 https://theses.hal.science/tel-00959281/document https://theses.hal.science/tel-00959281/file/DYLMER_CHRISTIAN_2013.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1799475258951991296 |
spelling |
ftecolephe:oai:HAL:tel-00959281v1 2024-05-19T07:36:12+00:00 Late Holocene surface water changes in the eastern Nordic Seas : the message from carbonate and organic-walled phytoplankton microfossils Paléohydrologie de surface des mers nordiques à l’Holocène terminal (derniers 3000 ans) : le message du phytoplancton à squelette calcaire et organique Dylmer, Christian Environnements et Paléoenvironnements OCéaniques (EPOC) Observatoire aquitain des sciences de l'univers (OASU) Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) Université Sciences et Technologies - Bordeaux I Jacques Giraudeau 2013-12-17 https://theses.hal.science/tel-00959281 https://theses.hal.science/tel-00959281/document https://theses.hal.science/tel-00959281/file/DYLMER_CHRISTIAN_2013.pdf en eng HAL CCSD NNT: 2013BOR15205 tel-00959281 https://theses.hal.science/tel-00959281 https://theses.hal.science/tel-00959281/document https://theses.hal.science/tel-00959281/file/DYLMER_CHRISTIAN_2013.pdf info:eu-repo/semantics/OpenAccess https://theses.hal.science/tel-00959281 Paleontology. Université Sciences et Technologies - Bordeaux I, 2013. English. ⟨NNT : 2013BOR15205⟩ Eastern Nordic Seas Late Holocene Atlantic water flow Surface waters Coccoliths Dinocysts Mers Nordiques Holocène terminal Flux d’eaux atlantiques Eaux de surface Coccolithes Dinokystes [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology info:eu-repo/semantics/doctoralThesis Theses 2013 ftecolephe 2024-04-25T00:45:27Z Five marine sediment cores distributed along the Norwegian, western Barents Sea, and Svalbard continental margins have been investigated in order to reconstruct late Holocene changes in the poleward flow of the Norwegian Atlantic Current (NwAC) and West Spitsbergen Current (WSC) and the nature of the upper surface water masses within the eastern Nordic Seas. This research project is based on the use of dinocyst and coccolith assemblages for qualitative and quantitative reconstructions of surface water conditions from high resolution sediment cores, and involve upstream investigations on proxy reliabilities. The investigated area (66 to 77°N) was affected by an overall increase in the strength of the AW flow from 3000 cal. yrs BP to the Present. The long-term modulation of westerlies strength and location which are essentially driven by the dominant mode of the North Atlantic Oscillation (NAO), is thought to explain the observed dynamics of the AW flow. The same mechanism also reconciles the recorded opposite zonal shifts in the location of the Arctic Front between the area off western Norway and the western Barents Sea-eastern Fram Strait region. Submillenial changes in AW flow are organised according to known pre-Anthropocene warm (RWP, MCA and the Modern period: strong poleward flow) and cold (LIA, DA: weak poleward flow) climatic spells. A sudden short pulse of resumed high WSC flow interrupted the LIA in the eastern Nordic Seas from 330 to 410 cal. yrs BP. Our results are indicative of a major impact of AW flow dynamics on the Arctic sea ice distribution during the last millenium, when changes in reconstructed sea-ice extent are negatively correlated with the strength of the WSC flow off western Barents Sea and western Svalbard. The extensive decrease in sea ice extent during the last century is synchronous with an exceptional increase in AW flow. The previously reconstructed high amplitude warming of surface waters in eastern Fram Strait at the turn of the 19th century was therefore primarily induced by an ... Doctoral or Postdoctoral Thesis Arctic Barents Sea Fram Strait Nordic Seas North Atlantic North Atlantic oscillation Phytoplankton Sea ice Svalbard Spitsbergen EPHE (Ecole pratique des hautes études, Paris): HAL |