Rapid climate change in the glacial North Atlantic : new insights from geochemical records of temperature, CO₂, redox and circulation
Rapid climate change events of the last glacial period are a prime example of the climate system’s ability to flip quickly between different states. These are associated with abrupt shifts in temperature, productivity and CO₂ and are commonly linked with major changes in circulation and sea-ice cove...
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Online Access: | http://hdl.handle.net/10023/23880 https://doi.org/10.17630/sta/128 |
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ftstandrewserep:oai:research-repository.st-andrews.ac.uk:10023/23880 2023-07-02T03:32:36+02:00 Rapid climate change in the glacial North Atlantic : new insights from geochemical records of temperature, CO₂, redox and circulation Littley, Eloise Frances Margaret Rae, James W. B. Burke, Andrea Natural Environment Research Council (NERC) 194 p. 2021-09-01T11:04:10Z http://hdl.handle.net/10023/23880 https://doi.org/10.17630/sta/128 en eng University of St Andrews The University of St Andrews Rapid climate change in the glacial North Atlantic: New insights from geochemical records of temperature, CO₂, redox and circulation (thesis data) Littley, E.F.M, University of St Andrews. DOI: https://doi.org/10.17630/4b7dae1d-57ec-44b6-900d-87a8316349cf https://doi.org/10.17630/4b7dae1d-57ec-44b6-900d-87a8316349cf http://hdl.handle.net/10023/23880 https://doi.org/10.17630/sta/128 NE/L002590/1 Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ 2026-08-11 Thesis restricted in accordance with University regulations. Print and electronic copy restricted until 11th August 2026 North Atlantic AMOC Heinrich stadial CO₂ Palaeoclimate Palaeoceanography Boron isotopes Rapid climate change Sea ice Redox Thesis Doctoral PhD Doctor of Philosophy 2021 ftstandrewserep https://doi.org/10.17630/sta/12810.17630/4b7dae1d-57ec-44b6-900d-87a8316349cf 2023-06-13T18:26:58Z Rapid climate change events of the last glacial period are a prime example of the climate system’s ability to flip quickly between different states. These are associated with abrupt shifts in temperature, productivity and CO₂ and are commonly linked with major changes in circulation and sea-ice coverage in the high latitude North Atlantic Ocean. However, despite what is an increasingly well-established paradigm, major questions remain about the links between circulation, temperature, ice-sheet stability and CO₂ storage. This thesis presents a collection of new, high resolution records from Northeast Atlantic core ODP 980, which develop our understanding of the region’s role in rapid climate change. Analysis of two robust paleo-temperature proxies (percentage abundance and Mg/Ca of Neogloboquadrina pachyderma) reveals the first marine evidence that Heinrich stadials were intervals of extreme seasonality, characterised by very cold winters and increasingly warm summers. These rising temperatures which are attributed to weak Atlantic Meridional Overturning circulation (AMOC), climbing atmospheric CO₂ and the insulating effect of sea ice, support theories for ice-sheet destabilisation in an otherwise cold climate. High resolution boron isotope data also resolve major perturbations of CO₂ in the surface ocean at climate transitions. These show that the North Atlantic CO₂ sink, which persists during stadial periods, weakened dramatically at interstadial onset, likely maintaining elevated atmospheric CO₂ and uncovering a new role for the region in rapid climate change. Recent studies using authigenic coatings on foraminifera, have employed redox sensitive elements to reconstruct deep water oxygen concentrations. However, data from different oceanic settings, combined with a geochemical model, highlight the sensitivity of element enrichment to changes in surface productivity. The influence of sediment composition is also examined with regards to authigenic Nd/Mn ratios, which show exciting promise as a new indicator of ... Doctoral or Postdoctoral Thesis Ice Sheet Neogloboquadrina pachyderma North Atlantic Northeast Atlantic Sea ice University of St Andrews: Digital Research Repository |
institution |
Open Polar |
collection |
University of St Andrews: Digital Research Repository |
op_collection_id |
ftstandrewserep |
language |
English |
topic |
North Atlantic AMOC Heinrich stadial CO₂ Palaeoclimate Palaeoceanography Boron isotopes Rapid climate change Sea ice Redox |
spellingShingle |
North Atlantic AMOC Heinrich stadial CO₂ Palaeoclimate Palaeoceanography Boron isotopes Rapid climate change Sea ice Redox Littley, Eloise Frances Margaret Rapid climate change in the glacial North Atlantic : new insights from geochemical records of temperature, CO₂, redox and circulation |
topic_facet |
North Atlantic AMOC Heinrich stadial CO₂ Palaeoclimate Palaeoceanography Boron isotopes Rapid climate change Sea ice Redox |
description |
Rapid climate change events of the last glacial period are a prime example of the climate system’s ability to flip quickly between different states. These are associated with abrupt shifts in temperature, productivity and CO₂ and are commonly linked with major changes in circulation and sea-ice coverage in the high latitude North Atlantic Ocean. However, despite what is an increasingly well-established paradigm, major questions remain about the links between circulation, temperature, ice-sheet stability and CO₂ storage. This thesis presents a collection of new, high resolution records from Northeast Atlantic core ODP 980, which develop our understanding of the region’s role in rapid climate change. Analysis of two robust paleo-temperature proxies (percentage abundance and Mg/Ca of Neogloboquadrina pachyderma) reveals the first marine evidence that Heinrich stadials were intervals of extreme seasonality, characterised by very cold winters and increasingly warm summers. These rising temperatures which are attributed to weak Atlantic Meridional Overturning circulation (AMOC), climbing atmospheric CO₂ and the insulating effect of sea ice, support theories for ice-sheet destabilisation in an otherwise cold climate. High resolution boron isotope data also resolve major perturbations of CO₂ in the surface ocean at climate transitions. These show that the North Atlantic CO₂ sink, which persists during stadial periods, weakened dramatically at interstadial onset, likely maintaining elevated atmospheric CO₂ and uncovering a new role for the region in rapid climate change. Recent studies using authigenic coatings on foraminifera, have employed redox sensitive elements to reconstruct deep water oxygen concentrations. However, data from different oceanic settings, combined with a geochemical model, highlight the sensitivity of element enrichment to changes in surface productivity. The influence of sediment composition is also examined with regards to authigenic Nd/Mn ratios, which show exciting promise as a new indicator of ... |
author2 |
Rae, James W. B. Burke, Andrea Natural Environment Research Council (NERC) |
format |
Doctoral or Postdoctoral Thesis |
author |
Littley, Eloise Frances Margaret |
author_facet |
Littley, Eloise Frances Margaret |
author_sort |
Littley, Eloise Frances Margaret |
title |
Rapid climate change in the glacial North Atlantic : new insights from geochemical records of temperature, CO₂, redox and circulation |
title_short |
Rapid climate change in the glacial North Atlantic : new insights from geochemical records of temperature, CO₂, redox and circulation |
title_full |
Rapid climate change in the glacial North Atlantic : new insights from geochemical records of temperature, CO₂, redox and circulation |
title_fullStr |
Rapid climate change in the glacial North Atlantic : new insights from geochemical records of temperature, CO₂, redox and circulation |
title_full_unstemmed |
Rapid climate change in the glacial North Atlantic : new insights from geochemical records of temperature, CO₂, redox and circulation |
title_sort |
rapid climate change in the glacial north atlantic : new insights from geochemical records of temperature, co₂, redox and circulation |
publisher |
University of St Andrews |
publishDate |
2021 |
url |
http://hdl.handle.net/10023/23880 https://doi.org/10.17630/sta/128 |
op_coverage |
194 p. |
genre |
Ice Sheet Neogloboquadrina pachyderma North Atlantic Northeast Atlantic Sea ice |
genre_facet |
Ice Sheet Neogloboquadrina pachyderma North Atlantic Northeast Atlantic Sea ice |
op_relation |
Rapid climate change in the glacial North Atlantic: New insights from geochemical records of temperature, CO₂, redox and circulation (thesis data) Littley, E.F.M, University of St Andrews. DOI: https://doi.org/10.17630/4b7dae1d-57ec-44b6-900d-87a8316349cf https://doi.org/10.17630/4b7dae1d-57ec-44b6-900d-87a8316349cf http://hdl.handle.net/10023/23880 https://doi.org/10.17630/sta/128 NE/L002590/1 |
op_rights |
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ 2026-08-11 Thesis restricted in accordance with University regulations. Print and electronic copy restricted until 11th August 2026 |
op_doi |
https://doi.org/10.17630/sta/12810.17630/4b7dae1d-57ec-44b6-900d-87a8316349cf |
_version_ |
1770272218594410496 |