CONSTRAINING VARIABILITY OF THE INDONESIAN THROUGHFLOW AND THE ANTARCTIC CIRCUMPOLAR CURRENT ACROSS THE PLIO-PLEISTOCENE: AN ORGANIC GEOCHEMICAL APPROACH
Accurate reconstructions of ocean circulation over geologic time provide climate models with critical information used for configuration and validation. These reconstructions rely largely on paleoceanographic datasets, however certain regions remain unexplored and create uncertainty in model predict...
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ftunivmassamh:oai:scholarworks.umass.edu:dissertations_2-3877 2024-04-28T07:56:32+00:00 CONSTRAINING VARIABILITY OF THE INDONESIAN THROUGHFLOW AND THE ANTARCTIC CIRCUMPOLAR CURRENT ACROSS THE PLIO-PLEISTOCENE: AN ORGANIC GEOCHEMICAL APPROACH Smith, Rebecca A. 2023-02-01T08:00:00Z application/pdf https://scholarworks.umass.edu/dissertations_2/2779 https://doi.org/10.7275/33234881 https://scholarworks.umass.edu/context/dissertations_2/article/3877/viewcontent/auto_convert.pdf unknown ScholarWorks@UMass Amherst https://scholarworks.umass.edu/dissertations_2/2779 doi:10.7275/33234881 https://scholarworks.umass.edu/context/dissertations_2/article/3877/viewcontent/auto_convert.pdf http://creativecommons.org/licenses/by/4.0/ Doctoral Dissertations paleoclimate Southern Ocean Indonesian throughflow biogeochemistry organic geochemistry lipid alkenone GDGT alkane Geochemistry text 2023 ftunivmassamh https://doi.org/10.7275/33234881 2024-04-03T14:54:47Z Accurate reconstructions of ocean circulation over geologic time provide climate models with critical information used for configuration and validation. These reconstructions rely largely on paleoceanographic datasets, however certain regions remain unexplored and create uncertainty in model predictions. This study focuses on constraining the behavior of two specific ocean currents in the Southern Hemisphere in the Plio-Pleistocene (3.5 to 1.5 Ma), namely the Indonesian Throughflow (ITF) and the Antarctic Circumpolar Current (ACC). The ITF travels through the Indonesian Gateway and transports warm equatorial Pacific waters into the Indian Ocean, ultimately driving the strength and intensity of the southward flowing Leeuwin Current along the western coast of Australia. It therefore influences the amount of warm water reaching high-latitude current systems such as the ACC. Despite its importance to both low and high latitude climate, significant debate still exists on the timing of Plio- Pleistocene oceanographic changes around the ITF. Furthermore, outstanding questions remain on the influence of the ITF on nearby Australian continental paleoclimate. The other focus of this study, the ACC, is the strongest and fastest moving current on the planet that mixes and redistributes water between all major ocean basins. Furthermore, the ACC is the primary connection between Antarctica and the rest of the globe. While fundamentally important to atmosphere-ocean-cryosphere dynamics in the Southern Hemisphere, the ACC remains poorly constrained through geologic time due to an overall lack of long, continuous sedimentary records under its influence. Here we use a suite of different organic geochemical biomarker proxies preserved in marine sediments to reconstruct the behavior of the ITF and the ACC over geologic time. We also examine the relationship between both currents and Australian continental paleoclimate. Finally, we thoroughly investigate the applicability and limitations of different biomarker proxies in ... Text Antarc* Antarctic Antarctica Southern Ocean University of Massachusetts: ScholarWorks@UMass Amherst |
institution |
Open Polar |
collection |
University of Massachusetts: ScholarWorks@UMass Amherst |
op_collection_id |
ftunivmassamh |
language |
unknown |
topic |
paleoclimate Southern Ocean Indonesian throughflow biogeochemistry organic geochemistry lipid alkenone GDGT alkane Geochemistry |
spellingShingle |
paleoclimate Southern Ocean Indonesian throughflow biogeochemistry organic geochemistry lipid alkenone GDGT alkane Geochemistry Smith, Rebecca A. CONSTRAINING VARIABILITY OF THE INDONESIAN THROUGHFLOW AND THE ANTARCTIC CIRCUMPOLAR CURRENT ACROSS THE PLIO-PLEISTOCENE: AN ORGANIC GEOCHEMICAL APPROACH |
topic_facet |
paleoclimate Southern Ocean Indonesian throughflow biogeochemistry organic geochemistry lipid alkenone GDGT alkane Geochemistry |
description |
Accurate reconstructions of ocean circulation over geologic time provide climate models with critical information used for configuration and validation. These reconstructions rely largely on paleoceanographic datasets, however certain regions remain unexplored and create uncertainty in model predictions. This study focuses on constraining the behavior of two specific ocean currents in the Southern Hemisphere in the Plio-Pleistocene (3.5 to 1.5 Ma), namely the Indonesian Throughflow (ITF) and the Antarctic Circumpolar Current (ACC). The ITF travels through the Indonesian Gateway and transports warm equatorial Pacific waters into the Indian Ocean, ultimately driving the strength and intensity of the southward flowing Leeuwin Current along the western coast of Australia. It therefore influences the amount of warm water reaching high-latitude current systems such as the ACC. Despite its importance to both low and high latitude climate, significant debate still exists on the timing of Plio- Pleistocene oceanographic changes around the ITF. Furthermore, outstanding questions remain on the influence of the ITF on nearby Australian continental paleoclimate. The other focus of this study, the ACC, is the strongest and fastest moving current on the planet that mixes and redistributes water between all major ocean basins. Furthermore, the ACC is the primary connection between Antarctica and the rest of the globe. While fundamentally important to atmosphere-ocean-cryosphere dynamics in the Southern Hemisphere, the ACC remains poorly constrained through geologic time due to an overall lack of long, continuous sedimentary records under its influence. Here we use a suite of different organic geochemical biomarker proxies preserved in marine sediments to reconstruct the behavior of the ITF and the ACC over geologic time. We also examine the relationship between both currents and Australian continental paleoclimate. Finally, we thoroughly investigate the applicability and limitations of different biomarker proxies in ... |
format |
Text |
author |
Smith, Rebecca A. |
author_facet |
Smith, Rebecca A. |
author_sort |
Smith, Rebecca A. |
title |
CONSTRAINING VARIABILITY OF THE INDONESIAN THROUGHFLOW AND THE ANTARCTIC CIRCUMPOLAR CURRENT ACROSS THE PLIO-PLEISTOCENE: AN ORGANIC GEOCHEMICAL APPROACH |
title_short |
CONSTRAINING VARIABILITY OF THE INDONESIAN THROUGHFLOW AND THE ANTARCTIC CIRCUMPOLAR CURRENT ACROSS THE PLIO-PLEISTOCENE: AN ORGANIC GEOCHEMICAL APPROACH |
title_full |
CONSTRAINING VARIABILITY OF THE INDONESIAN THROUGHFLOW AND THE ANTARCTIC CIRCUMPOLAR CURRENT ACROSS THE PLIO-PLEISTOCENE: AN ORGANIC GEOCHEMICAL APPROACH |
title_fullStr |
CONSTRAINING VARIABILITY OF THE INDONESIAN THROUGHFLOW AND THE ANTARCTIC CIRCUMPOLAR CURRENT ACROSS THE PLIO-PLEISTOCENE: AN ORGANIC GEOCHEMICAL APPROACH |
title_full_unstemmed |
CONSTRAINING VARIABILITY OF THE INDONESIAN THROUGHFLOW AND THE ANTARCTIC CIRCUMPOLAR CURRENT ACROSS THE PLIO-PLEISTOCENE: AN ORGANIC GEOCHEMICAL APPROACH |
title_sort |
constraining variability of the indonesian throughflow and the antarctic circumpolar current across the plio-pleistocene: an organic geochemical approach |
publisher |
ScholarWorks@UMass Amherst |
publishDate |
2023 |
url |
https://scholarworks.umass.edu/dissertations_2/2779 https://doi.org/10.7275/33234881 https://scholarworks.umass.edu/context/dissertations_2/article/3877/viewcontent/auto_convert.pdf |
genre |
Antarc* Antarctic Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Southern Ocean |
op_source |
Doctoral Dissertations |
op_relation |
https://scholarworks.umass.edu/dissertations_2/2779 doi:10.7275/33234881 https://scholarworks.umass.edu/context/dissertations_2/article/3877/viewcontent/auto_convert.pdf |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.7275/33234881 |
_version_ |
1797583650638790656 |