Highly branched isoprenoids for Southern Ocean sea ice reconstructions: a pilot study from the Western Antarctic Peninsula
<p>Organic geochemical and micropaleontological analyses of surface sediments collected in the southern Drake Passage and the Bransfield Strait, Western Antarctic Peninsula, enable a proxy-based reconstruction of recent sea ice conditions in this climate-sensitive area. We study the distribut...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-08-01
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| Series: | Biogeosciences |
| Online Access: | https://www.biogeosciences.net/16/2961/2019/bg-16-2961-2019.pdf |
| _version_ | 1818541397278457856 |
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| author | M.-E. Vorrath J. Müller J. Müller J. Müller O. Esper G. Mollenhauer G. Mollenhauer C. Haas E. Schefuß K. Fahl |
| author_facet | M.-E. Vorrath J. Müller J. Müller J. Müller O. Esper G. Mollenhauer G. Mollenhauer C. Haas E. Schefuß K. Fahl |
| author_sort | M.-E. Vorrath |
| collection | DOAJ |
| description | <p>Organic geochemical and micropaleontological analyses of surface
sediments collected in the southern Drake Passage and the Bransfield Strait, Western
Antarctic Peninsula, enable a proxy-based reconstruction of recent sea ice
conditions in this climate-sensitive area. We study the distribution of the
sea ice biomarker IPSO<span class="inline-formula"><sub>25</sub></span>, and biomarkers of open marine environments
such as more unsaturated highly branched isoprenoid alkenes and
phytosterols. Comparison of the sedimentary distribution of these biomarker
lipids with sea ice data obtained from satellite observations and
diatom-based sea ice estimates provide for an evaluation of the suitability
of these biomarkers to reflect recent sea surface conditions. The
distribution of IPSO<span class="inline-formula"><sub>25</sub></span> supports earlier suggestions that the source
diatom seems to be common in near-coastal environments characterized by
annually recurring sea ice cover, while the distribution of the other
biomarkers is highly variable. Offsets between sea ice estimates deduced
from the abundance of biomarkers and satellite-based sea ice data are
attributed to the different time intervals recorded within the sediments and
the instrumental records from the study area, which experienced rapid
environmental changes during the past 100 years. To distinguish areas
characterized by permanently ice-free conditions, seasonal sea ice cover and
extended sea ice cover, we apply the concept of the PIP<span class="inline-formula"><sub>25</sub></span> index from
the Arctic Ocean to our data and introduce the term PIPSO<span class="inline-formula"><sub>25</sub></span> as a
potential sea ice proxy. While the trends in PIPSO<span class="inline-formula"><sub>25</sub></span> are generally
consistent with satellite sea ice data and winter sea ice concentrations in
the study area estimated by diatom transfer functions, more studies on the
environmental significance of IPSO<span class="inline-formula"><sub>25</sub></span> as a Southern Ocean sea ice proxy
are needed before this biomarker can be applied for semi-quantitative sea
ice reconstructions.</p> |
| first_indexed | 2024-12-11T22:08:45Z |
| format | Article |
| id | doaj.art-d4595e0430884293bf81da192f854f7b |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-11T22:08:45Z |
| publishDate | 2019-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-d4595e0430884293bf81da192f854f7b2022-12-22T00:48:52ZengCopernicus PublicationsBiogeosciences1726-41701726-41892019-08-01162961298110.5194/bg-16-2961-2019Highly branched isoprenoids for Southern Ocean sea ice reconstructions: a pilot study from the Western Antarctic PeninsulaM.-E. Vorrath0J. Müller1J. Müller2J. Müller3O. Esper4G. Mollenhauer5G. Mollenhauer6C. Haas7E. Schefuß8K. Fahl9Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, GermanyAlfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, GermanyMARUM – Center for Marine Environmental Sciences, University of Bremen, Bremen, GermanyDepartment of Geosciences, University of Bremen, Bremen, GermanyAlfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, GermanyAlfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, GermanyMARUM – Center for Marine Environmental Sciences, University of Bremen, Bremen, GermanyAlfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, GermanyMARUM – Center for Marine Environmental Sciences, University of Bremen, Bremen, GermanyAlfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany<p>Organic geochemical and micropaleontological analyses of surface sediments collected in the southern Drake Passage and the Bransfield Strait, Western Antarctic Peninsula, enable a proxy-based reconstruction of recent sea ice conditions in this climate-sensitive area. We study the distribution of the sea ice biomarker IPSO<span class="inline-formula"><sub>25</sub></span>, and biomarkers of open marine environments such as more unsaturated highly branched isoprenoid alkenes and phytosterols. Comparison of the sedimentary distribution of these biomarker lipids with sea ice data obtained from satellite observations and diatom-based sea ice estimates provide for an evaluation of the suitability of these biomarkers to reflect recent sea surface conditions. The distribution of IPSO<span class="inline-formula"><sub>25</sub></span> supports earlier suggestions that the source diatom seems to be common in near-coastal environments characterized by annually recurring sea ice cover, while the distribution of the other biomarkers is highly variable. Offsets between sea ice estimates deduced from the abundance of biomarkers and satellite-based sea ice data are attributed to the different time intervals recorded within the sediments and the instrumental records from the study area, which experienced rapid environmental changes during the past 100 years. To distinguish areas characterized by permanently ice-free conditions, seasonal sea ice cover and extended sea ice cover, we apply the concept of the PIP<span class="inline-formula"><sub>25</sub></span> index from the Arctic Ocean to our data and introduce the term PIPSO<span class="inline-formula"><sub>25</sub></span> as a potential sea ice proxy. While the trends in PIPSO<span class="inline-formula"><sub>25</sub></span> are generally consistent with satellite sea ice data and winter sea ice concentrations in the study area estimated by diatom transfer functions, more studies on the environmental significance of IPSO<span class="inline-formula"><sub>25</sub></span> as a Southern Ocean sea ice proxy are needed before this biomarker can be applied for semi-quantitative sea ice reconstructions.</p>https://www.biogeosciences.net/16/2961/2019/bg-16-2961-2019.pdf |
| spellingShingle | M.-E. Vorrath J. Müller J. Müller J. Müller O. Esper G. Mollenhauer G. Mollenhauer C. Haas E. Schefuß K. Fahl Highly branched isoprenoids for Southern Ocean sea ice reconstructions: a pilot study from the Western Antarctic Peninsula Biogeosciences |
| title | Highly branched isoprenoids for Southern Ocean sea ice reconstructions: a pilot study from the Western Antarctic Peninsula |
| title_full | Highly branched isoprenoids for Southern Ocean sea ice reconstructions: a pilot study from the Western Antarctic Peninsula |
| title_fullStr | Highly branched isoprenoids for Southern Ocean sea ice reconstructions: a pilot study from the Western Antarctic Peninsula |
| title_full_unstemmed | Highly branched isoprenoids for Southern Ocean sea ice reconstructions: a pilot study from the Western Antarctic Peninsula |
| title_short | Highly branched isoprenoids for Southern Ocean sea ice reconstructions: a pilot study from the Western Antarctic Peninsula |
| title_sort | highly branched isoprenoids for southern ocean sea ice reconstructions a pilot study from the western antarctic peninsula |
| url | https://www.biogeosciences.net/16/2961/2019/bg-16-2961-2019.pdf |
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