Systematic changes in circumpolar dust transport to the Subantarctic Pacific Ocean over the last two glacial cycles
The input of the soluble micronutrients iron (Fe) and/or manganese (Mn) by mineral dust stimulates net primary productivity in the Fe/Mn-deficient Southern Ocean. This mechanism is thought to increase carbon export, thus reducing atmospheric CO(2) during the Pleistocene glacial cycles. Yet, relative...
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ftpubmed:oai:pubmedcentral.nih.gov:9704702 2023-05-15T18:25:09+02:00 Systematic changes in circumpolar dust transport to the Subantarctic Pacific Ocean over the last two glacial cycles Struve, Torben Longman, Jack Zander, Martin Lamy, Frank Winckler, Gisela Pahnke, Katharina 2022-11-21 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9704702/ http://www.ncbi.nlm.nih.gov/pubmed/36399546 https://doi.org/10.1073/pnas.2206085119 en eng National Academy of Sciences http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9704702/ http://www.ncbi.nlm.nih.gov/pubmed/36399546 http://dx.doi.org/10.1073/pnas.2206085119 Copyright © 2022 the Author(s). Published by PNAS. https://creativecommons.org/licenses/by/4.0/This open access article is distributed under Creative Commons Attribution License 4.0 (CC BY) (https://creativecommons.org/licenses/by/4.0/) . CC-BY Proc Natl Acad Sci U S A Physical Sciences Text 2022 ftpubmed https://doi.org/10.1073/pnas.2206085119 2022-12-04T02:02:50Z The input of the soluble micronutrients iron (Fe) and/or manganese (Mn) by mineral dust stimulates net primary productivity in the Fe/Mn-deficient Southern Ocean. This mechanism is thought to increase carbon export, thus reducing atmospheric CO(2) during the Pleistocene glacial cycles. Yet, relatively little is known about changes in the sources and transport pathways of Southern Hemisphere dust over glacial cycles. Here, we use the geochemical fingerprint of the dust fraction in marine sediments and multiisotope mixture modeling to identify changes in dust transport to the South Pacific Subantarctic Zone (SAZ). Our data show that dust from South America dominated the South Pacific SAZ during most of the last 260,000 a with maximum contributions of up to ∼70% in the early part of the glacial cycles. The enhanced dust-Fe fluxes of the latter parts of the glacial cycles show increased contributions from Australia and New Zealand, but South American dust remains the dominant component. The systematic changes in dust provenance correspond with grain size variations, consistent with the circumpolar transport of dust by the westerly winds. Maximum contributions of dust from more proximal sources in Australia and New Zealand (up to ∼63%) paired with a finer dust grain size indicate reduced westerly wind speeds over the South Pacific SAZ during deglacial and peak interglacial intervals. These quantitative dust provenance changes provide source-specific dust-Fe fluxes in the South Pacific SAZ and show how their systematic changes in magnitude and timing influence the Southern Ocean dust-Fe feedback on glacial-interglacial to millennial time scales. Text Southern Ocean PubMed Central (PMC) New Zealand Pacific Southern Ocean Proceedings of the National Academy of Sciences 119 47 |
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PubMed Central (PMC) |
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ftpubmed |
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English |
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Physical Sciences |
spellingShingle |
Physical Sciences Struve, Torben Longman, Jack Zander, Martin Lamy, Frank Winckler, Gisela Pahnke, Katharina Systematic changes in circumpolar dust transport to the Subantarctic Pacific Ocean over the last two glacial cycles |
topic_facet |
Physical Sciences |
description |
The input of the soluble micronutrients iron (Fe) and/or manganese (Mn) by mineral dust stimulates net primary productivity in the Fe/Mn-deficient Southern Ocean. This mechanism is thought to increase carbon export, thus reducing atmospheric CO(2) during the Pleistocene glacial cycles. Yet, relatively little is known about changes in the sources and transport pathways of Southern Hemisphere dust over glacial cycles. Here, we use the geochemical fingerprint of the dust fraction in marine sediments and multiisotope mixture modeling to identify changes in dust transport to the South Pacific Subantarctic Zone (SAZ). Our data show that dust from South America dominated the South Pacific SAZ during most of the last 260,000 a with maximum contributions of up to ∼70% in the early part of the glacial cycles. The enhanced dust-Fe fluxes of the latter parts of the glacial cycles show increased contributions from Australia and New Zealand, but South American dust remains the dominant component. The systematic changes in dust provenance correspond with grain size variations, consistent with the circumpolar transport of dust by the westerly winds. Maximum contributions of dust from more proximal sources in Australia and New Zealand (up to ∼63%) paired with a finer dust grain size indicate reduced westerly wind speeds over the South Pacific SAZ during deglacial and peak interglacial intervals. These quantitative dust provenance changes provide source-specific dust-Fe fluxes in the South Pacific SAZ and show how their systematic changes in magnitude and timing influence the Southern Ocean dust-Fe feedback on glacial-interglacial to millennial time scales. |
format |
Text |
author |
Struve, Torben Longman, Jack Zander, Martin Lamy, Frank Winckler, Gisela Pahnke, Katharina |
author_facet |
Struve, Torben Longman, Jack Zander, Martin Lamy, Frank Winckler, Gisela Pahnke, Katharina |
author_sort |
Struve, Torben |
title |
Systematic changes in circumpolar dust transport to the Subantarctic Pacific Ocean over the last two glacial cycles |
title_short |
Systematic changes in circumpolar dust transport to the Subantarctic Pacific Ocean over the last two glacial cycles |
title_full |
Systematic changes in circumpolar dust transport to the Subantarctic Pacific Ocean over the last two glacial cycles |
title_fullStr |
Systematic changes in circumpolar dust transport to the Subantarctic Pacific Ocean over the last two glacial cycles |
title_full_unstemmed |
Systematic changes in circumpolar dust transport to the Subantarctic Pacific Ocean over the last two glacial cycles |
title_sort |
systematic changes in circumpolar dust transport to the subantarctic pacific ocean over the last two glacial cycles |
publisher |
National Academy of Sciences |
publishDate |
2022 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9704702/ http://www.ncbi.nlm.nih.gov/pubmed/36399546 https://doi.org/10.1073/pnas.2206085119 |
geographic |
New Zealand Pacific Southern Ocean |
geographic_facet |
New Zealand Pacific Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Proc Natl Acad Sci U S A |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9704702/ http://www.ncbi.nlm.nih.gov/pubmed/36399546 http://dx.doi.org/10.1073/pnas.2206085119 |
op_rights |
Copyright © 2022 the Author(s). Published by PNAS. https://creativecommons.org/licenses/by/4.0/This open access article is distributed under Creative Commons Attribution License 4.0 (CC BY) (https://creativecommons.org/licenses/by/4.0/) . |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1073/pnas.2206085119 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
119 |
container_issue |
47 |
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