Archaeal Intact Polar Lipids in Polar Waters: A Comparison Between the Amundsen and Scotia Seas
The West Antarctic Ice Sheet (WAIS) is one of the largest potential sources of future sea-level rise, with glaciers draining the WAIS thinning at an accelerating rate over the past 40 years. Due to complexities in calibrating palaeoceanographic proxies for the Southern Ocean, it remains difficult to...
Published in: | Biogeosciences |
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Copernicus Publications
2021
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Online Access: | http://dro.dur.ac.uk/33195/ http://dro.dur.ac.uk/33195/1/33195.pdf https://doi.org/10.5194/bg-18-3485-2021 |
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ftunivdurham:oai:dro.dur.ac.uk.OAI2:33195 2023-05-15T13:23:52+02:00 Archaeal Intact Polar Lipids in Polar Waters: A Comparison Between the Amundsen and Scotia Seas Spencer-Jones, Charlotte L. McClymont, Erin L. Bale, N.J. Hopmans, E.C. Schouten, S. Muller, J. Abrahamsen, E.P. Allen, C. Bickert, T. Hillenbrand, C.D. Mawbey, E. Peck, V. Svalova, A. Smith, J.A. 2021 application/pdf http://dro.dur.ac.uk/33195/ http://dro.dur.ac.uk/33195/1/33195.pdf https://doi.org/10.5194/bg-18-3485-2021 unknown Copernicus Publications dro:33195 issn:1726-4170 issn: 1726-4189 doi:10.5194/bg-18-3485-2021 http://dro.dur.ac.uk/33195/ https://doi.org/10.5194/bg-18-3485-2021 http://dro.dur.ac.uk/33195/1/33195.pdf © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. CC-BY Biogeosciences, 2021, Vol.18(11), pp.3485-3504 [Peer Reviewed Journal] Article PeerReviewed 2021 ftunivdurham https://doi.org/10.5194/bg-18-3485-2021 2021-06-17T22:23:15Z The West Antarctic Ice Sheet (WAIS) is one of the largest potential sources of future sea-level rise, with glaciers draining the WAIS thinning at an accelerating rate over the past 40 years. Due to complexities in calibrating palaeoceanographic proxies for the Southern Ocean, it remains difficult to assess whether similar changes have occurred earlier during the Holocene or whether there is underlying centennial- to millennial-scale forcing in oceanic variability. Archaeal lipid-based proxies, specifically glycerol dialkyl glycerol tetraether (GDGT; e.g. TEX86 and TEXL86), are powerful tools for reconstructing ocean temperature, but these proxies have been shown previously to be difficult to apply to the Southern Ocean. A greater understanding of the parameters that control Southern Ocean GDGT distributions would improve the application of these biomarker proxies and thus help provide a longer-term perspective on ocean forcing of Antarctic ice sheet changes. In this study, we characterised intact polar lipid (IPL)-GDGTs, representing (recently) living archaeal populations in suspended particulate matter (SPM) from the Amundsen Sea and the Scotia Sea. SPM samples from the Amundsen Sea were collected from up to four water column depths representing the surface waters through to Circumpolar Deep Water (CDW), whereas the Scotia Sea samples were collected along a transect encompassing the sub-Antarctic front through to the southern boundary of the Antarctic Circumpolar Current. IPL-GDGTs with low cyclic diversity were detected throughout the water column with high relative abundances of hydroxylated IPL-GDGTs identified in both the Amundsen and Scotia seas. Results from the Scotia Sea show shifts in IPL-GDGT signatures across well-defined fronts of the Southern Ocean. Indicating that the physicochemical parameters of these water masses determine changes in IPL-GDGT distributions. The Amundsen Sea results identified GDGTs with hexose-phosphohexose head groups in the CDW, suggesting active GDGT synthesis at these depths. These results suggest that GDGTs synthesised at CDW depths may be a significant source of GDGTs exported to the sedimentary record and that temperature reconstructions based on TEX86 or TEXL86 proxies may be significantly influenced by the warmer waters of the CDW. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Ice Sheet Scotia Sea Southern Ocean Durham University: Durham Research Online Amundsen Sea Antarctic Scotia Sea Southern Ocean The Antarctic West Antarctic Ice Sheet Biogeosciences 18 11 3485 3504 |
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Open Polar |
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Durham University: Durham Research Online |
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ftunivdurham |
language |
unknown |
description |
The West Antarctic Ice Sheet (WAIS) is one of the largest potential sources of future sea-level rise, with glaciers draining the WAIS thinning at an accelerating rate over the past 40 years. Due to complexities in calibrating palaeoceanographic proxies for the Southern Ocean, it remains difficult to assess whether similar changes have occurred earlier during the Holocene or whether there is underlying centennial- to millennial-scale forcing in oceanic variability. Archaeal lipid-based proxies, specifically glycerol dialkyl glycerol tetraether (GDGT; e.g. TEX86 and TEXL86), are powerful tools for reconstructing ocean temperature, but these proxies have been shown previously to be difficult to apply to the Southern Ocean. A greater understanding of the parameters that control Southern Ocean GDGT distributions would improve the application of these biomarker proxies and thus help provide a longer-term perspective on ocean forcing of Antarctic ice sheet changes. In this study, we characterised intact polar lipid (IPL)-GDGTs, representing (recently) living archaeal populations in suspended particulate matter (SPM) from the Amundsen Sea and the Scotia Sea. SPM samples from the Amundsen Sea were collected from up to four water column depths representing the surface waters through to Circumpolar Deep Water (CDW), whereas the Scotia Sea samples were collected along a transect encompassing the sub-Antarctic front through to the southern boundary of the Antarctic Circumpolar Current. IPL-GDGTs with low cyclic diversity were detected throughout the water column with high relative abundances of hydroxylated IPL-GDGTs identified in both the Amundsen and Scotia seas. Results from the Scotia Sea show shifts in IPL-GDGT signatures across well-defined fronts of the Southern Ocean. Indicating that the physicochemical parameters of these water masses determine changes in IPL-GDGT distributions. The Amundsen Sea results identified GDGTs with hexose-phosphohexose head groups in the CDW, suggesting active GDGT synthesis at these depths. These results suggest that GDGTs synthesised at CDW depths may be a significant source of GDGTs exported to the sedimentary record and that temperature reconstructions based on TEX86 or TEXL86 proxies may be significantly influenced by the warmer waters of the CDW. |
format |
Article in Journal/Newspaper |
author |
Spencer-Jones, Charlotte L. McClymont, Erin L. Bale, N.J. Hopmans, E.C. Schouten, S. Muller, J. Abrahamsen, E.P. Allen, C. Bickert, T. Hillenbrand, C.D. Mawbey, E. Peck, V. Svalova, A. Smith, J.A. |
spellingShingle |
Spencer-Jones, Charlotte L. McClymont, Erin L. Bale, N.J. Hopmans, E.C. Schouten, S. Muller, J. Abrahamsen, E.P. Allen, C. Bickert, T. Hillenbrand, C.D. Mawbey, E. Peck, V. Svalova, A. Smith, J.A. Archaeal Intact Polar Lipids in Polar Waters: A Comparison Between the Amundsen and Scotia Seas |
author_facet |
Spencer-Jones, Charlotte L. McClymont, Erin L. Bale, N.J. Hopmans, E.C. Schouten, S. Muller, J. Abrahamsen, E.P. Allen, C. Bickert, T. Hillenbrand, C.D. Mawbey, E. Peck, V. Svalova, A. Smith, J.A. |
author_sort |
Spencer-Jones, Charlotte L. |
title |
Archaeal Intact Polar Lipids in Polar Waters: A Comparison Between the Amundsen and Scotia Seas |
title_short |
Archaeal Intact Polar Lipids in Polar Waters: A Comparison Between the Amundsen and Scotia Seas |
title_full |
Archaeal Intact Polar Lipids in Polar Waters: A Comparison Between the Amundsen and Scotia Seas |
title_fullStr |
Archaeal Intact Polar Lipids in Polar Waters: A Comparison Between the Amundsen and Scotia Seas |
title_full_unstemmed |
Archaeal Intact Polar Lipids in Polar Waters: A Comparison Between the Amundsen and Scotia Seas |
title_sort |
archaeal intact polar lipids in polar waters: a comparison between the amundsen and scotia seas |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
http://dro.dur.ac.uk/33195/ http://dro.dur.ac.uk/33195/1/33195.pdf https://doi.org/10.5194/bg-18-3485-2021 |
geographic |
Amundsen Sea Antarctic Scotia Sea Southern Ocean The Antarctic West Antarctic Ice Sheet |
geographic_facet |
Amundsen Sea Antarctic Scotia Sea Southern Ocean The Antarctic West Antarctic Ice Sheet |
genre |
Amundsen Sea Antarc* Antarctic Ice Sheet Scotia Sea Southern Ocean |
genre_facet |
Amundsen Sea Antarc* Antarctic Ice Sheet Scotia Sea Southern Ocean |
op_source |
Biogeosciences, 2021, Vol.18(11), pp.3485-3504 [Peer Reviewed Journal] |
op_relation |
dro:33195 issn:1726-4170 issn: 1726-4189 doi:10.5194/bg-18-3485-2021 http://dro.dur.ac.uk/33195/ https://doi.org/10.5194/bg-18-3485-2021 http://dro.dur.ac.uk/33195/1/33195.pdf |
op_rights |
© Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/bg-18-3485-2021 |
container_title |
Biogeosciences |
container_volume |
18 |
container_issue |
11 |
container_start_page |
3485 |
op_container_end_page |
3504 |
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1766375964446556160 |