Contribution of seasonal sub-Antarctic surface water variability to millennial-scale changes in atmospheric CO2 over the last deglaciation and Marine Isotope Stage 3
The Southern Ocean is thought to have played a key role in past atmospheric carbon dioxide (CO2,(atm)) changes. Three main factors are understood to control the Southern Ocean's influence on CO2,(atm), via their impact on surface ocean pCO(2) and therefore regional ocean-atmosphere CO2 fluxes:...
Published in: | Earth and Planetary Science Letters |
---|---|
Main Authors: | , , |
Format: | Text |
Language: | English |
Published: |
Elsevier Science Bv
2015
|
Subjects: | |
Online Access: | https://doi.org/10.1016/j.epsl.2014.11.051 https://archimer.ifremer.fr/doc/00297/40868/39920.pdf https://archimer.ifremer.fr/doc/00297/40868/39921.pdf https://archimer.ifremer.fr/doc/00297/40868/ |
id |
fttriple:oai:gotriple.eu:10670/1.z83v19 |
---|---|
record_format |
openpolar |
spelling |
fttriple:oai:gotriple.eu:10670/1.z83v19 2023-05-15T13:56:43+02:00 Contribution of seasonal sub-Antarctic surface water variability to millennial-scale changes in atmospheric CO2 over the last deglaciation and Marine Isotope Stage 3 Gottschalk, Julia Skinner, Luke C. Waelbroeck, Claire 2015-02-01 https://doi.org/10.1016/j.epsl.2014.11.051 https://archimer.ifremer.fr/doc/00297/40868/39920.pdf https://archimer.ifremer.fr/doc/00297/40868/39921.pdf https://archimer.ifremer.fr/doc/00297/40868/ en eng Elsevier Science Bv doi:10.1016/j.epsl.2014.11.051 10670/1.z83v19 https://archimer.ifremer.fr/doc/00297/40868/39920.pdf https://archimer.ifremer.fr/doc/00297/40868/39921.pdf https://archimer.ifremer.fr/doc/00297/40868/ Archimer, archive institutionnelle de l'Ifremer Earth And Planetary Science Letters (0012-821X) (Elsevier Science Bv), 2015-02-01 , Vol. 411 , P. 87-99 geo envir Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ 2015 fttriple https://doi.org/10.1016/j.epsl.2014.11.051 2023-01-22T17:10:01Z The Southern Ocean is thought to have played a key role in past atmospheric carbon dioxide (CO2,(atm)) changes. Three main factors are understood to control the Southern Ocean's influence on CO2,(atm), via their impact on surface ocean pCO(2) and therefore regional ocean-atmosphere CO2 fluxes: 1) the efficiency of air-sea gas exchange, which may be attenuated by seasonal- or annual sea-ice coverage or the development of a shallow pycnocline; 2) the supply of CO2-rich water masses from the subsurface and the deep ocean, which is associated with turbulent mixing and surface buoyancy- and/or wind forcing; and 3) biological carbon fixation, which depends on nutrient availability and is therefore influenced by dust deposition and/or upwelling. In order to investigate the possible contributions of these processes to millennial-scale CO2,(atm) variations during the last glacial and deglacial periods, we make use of planktonic foraminifer census counts and stable oxygen- and carbon isotope measurements in the planktonic foraminifera Globigerina bulloides and Neogloboquadrina pachyderma (sinistral) from marine sediment core MD07-3076Q in the sub-Antarctic Atlantic. These data are interpreted on the basis of a comparison of core-top and modern seawater isotope data, which permits an assessment of the seasonal biases and geochemical controls on the stable isotopic compositions of G. bulloides and N. pachyderma (s.). Based on a comparison of our down-core results with similar data from the Southeast Atlantic (Cape Basin) we infer past basin-wide changes in the surface hydrography of the sub-Antarctic Atlantic. We find that millennial-scale rises in CO2,(atm) over the last 70 ka are consistently linked with evidence for increased spring upwelling, and enhanced summer air-sea exchange in the sub-Antarctic Atlantic. Parallel evidence for increased summer export production would suggest that seasonal changes in upwelling and air-sea exchange exerted a dominant influence on surface pCO(2) in the sub-Antarctic Atlantic. These ... Text Antarc* Antarctic Neogloboquadrina pachyderma Planktonic foraminifera Sea ice Southern Ocean Unknown Antarctic Southern Ocean Earth and Planetary Science Letters 411 87 99 |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
English |
topic |
geo envir |
spellingShingle |
geo envir Gottschalk, Julia Skinner, Luke C. Waelbroeck, Claire Contribution of seasonal sub-Antarctic surface water variability to millennial-scale changes in atmospheric CO2 over the last deglaciation and Marine Isotope Stage 3 |
topic_facet |
geo envir |
description |
The Southern Ocean is thought to have played a key role in past atmospheric carbon dioxide (CO2,(atm)) changes. Three main factors are understood to control the Southern Ocean's influence on CO2,(atm), via their impact on surface ocean pCO(2) and therefore regional ocean-atmosphere CO2 fluxes: 1) the efficiency of air-sea gas exchange, which may be attenuated by seasonal- or annual sea-ice coverage or the development of a shallow pycnocline; 2) the supply of CO2-rich water masses from the subsurface and the deep ocean, which is associated with turbulent mixing and surface buoyancy- and/or wind forcing; and 3) biological carbon fixation, which depends on nutrient availability and is therefore influenced by dust deposition and/or upwelling. In order to investigate the possible contributions of these processes to millennial-scale CO2,(atm) variations during the last glacial and deglacial periods, we make use of planktonic foraminifer census counts and stable oxygen- and carbon isotope measurements in the planktonic foraminifera Globigerina bulloides and Neogloboquadrina pachyderma (sinistral) from marine sediment core MD07-3076Q in the sub-Antarctic Atlantic. These data are interpreted on the basis of a comparison of core-top and modern seawater isotope data, which permits an assessment of the seasonal biases and geochemical controls on the stable isotopic compositions of G. bulloides and N. pachyderma (s.). Based on a comparison of our down-core results with similar data from the Southeast Atlantic (Cape Basin) we infer past basin-wide changes in the surface hydrography of the sub-Antarctic Atlantic. We find that millennial-scale rises in CO2,(atm) over the last 70 ka are consistently linked with evidence for increased spring upwelling, and enhanced summer air-sea exchange in the sub-Antarctic Atlantic. Parallel evidence for increased summer export production would suggest that seasonal changes in upwelling and air-sea exchange exerted a dominant influence on surface pCO(2) in the sub-Antarctic Atlantic. These ... |
format |
Text |
author |
Gottschalk, Julia Skinner, Luke C. Waelbroeck, Claire |
author_facet |
Gottschalk, Julia Skinner, Luke C. Waelbroeck, Claire |
author_sort |
Gottschalk, Julia |
title |
Contribution of seasonal sub-Antarctic surface water variability to millennial-scale changes in atmospheric CO2 over the last deglaciation and Marine Isotope Stage 3 |
title_short |
Contribution of seasonal sub-Antarctic surface water variability to millennial-scale changes in atmospheric CO2 over the last deglaciation and Marine Isotope Stage 3 |
title_full |
Contribution of seasonal sub-Antarctic surface water variability to millennial-scale changes in atmospheric CO2 over the last deglaciation and Marine Isotope Stage 3 |
title_fullStr |
Contribution of seasonal sub-Antarctic surface water variability to millennial-scale changes in atmospheric CO2 over the last deglaciation and Marine Isotope Stage 3 |
title_full_unstemmed |
Contribution of seasonal sub-Antarctic surface water variability to millennial-scale changes in atmospheric CO2 over the last deglaciation and Marine Isotope Stage 3 |
title_sort |
contribution of seasonal sub-antarctic surface water variability to millennial-scale changes in atmospheric co2 over the last deglaciation and marine isotope stage 3 |
publisher |
Elsevier Science Bv |
publishDate |
2015 |
url |
https://doi.org/10.1016/j.epsl.2014.11.051 https://archimer.ifremer.fr/doc/00297/40868/39920.pdf https://archimer.ifremer.fr/doc/00297/40868/39921.pdf https://archimer.ifremer.fr/doc/00297/40868/ |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Neogloboquadrina pachyderma Planktonic foraminifera Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Neogloboquadrina pachyderma Planktonic foraminifera Sea ice Southern Ocean |
op_source |
Archimer, archive institutionnelle de l'Ifremer Earth And Planetary Science Letters (0012-821X) (Elsevier Science Bv), 2015-02-01 , Vol. 411 , P. 87-99 |
op_relation |
doi:10.1016/j.epsl.2014.11.051 10670/1.z83v19 https://archimer.ifremer.fr/doc/00297/40868/39920.pdf https://archimer.ifremer.fr/doc/00297/40868/39921.pdf https://archimer.ifremer.fr/doc/00297/40868/ |
op_doi |
https://doi.org/10.1016/j.epsl.2014.11.051 |
container_title |
Earth and Planetary Science Letters |
container_volume |
411 |
container_start_page |
87 |
op_container_end_page |
99 |
_version_ |
1766264296942075904 |