Antarctic Zone nutrient conditions during the last two glacial cycles
In a sediment core from the Pacific sector of the Antarctic Zone (AZ) of the Southern Ocean, we report diatom-bound N isotope (δ15Ndb) records for total recoverable diatoms and two distinct diatom assemblages (pennate and centric rich). These data indicate tight coupling between the degree of nitrat...
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American Geophysical Union
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ftdatacite:10.7892/boris.70683 2023-05-15T13:54:54+02:00 Antarctic Zone nutrient conditions during the last two glacial cycles Jaccard, Samuel Esper, Oliver Gersonde, Rainer Martinez-Garcia, Alfredo Oleynik, Sergey Winckler, Gisela Studer, Anja Kuhn, Gerhard Lamy, Frank Wacker, Lukas Haug, Gerald Sigman, Daniel Benz, Verena 2015 application/pdf https://dx.doi.org/10.7892/boris.70683 http://boris.unibe.ch/70683/ en eng American Geophysical Union info:eu-repo/semantics/openAccess 550 Earth sciences & geology Text article-journal ScholarlyArticle 2015 ftdatacite https://doi.org/10.7892/boris.70683 2021-11-05T12:55:41Z In a sediment core from the Pacific sector of the Antarctic Zone (AZ) of the Southern Ocean, we report diatom-bound N isotope (δ15Ndb) records for total recoverable diatoms and two distinct diatom assemblages (pennate and centric rich). These data indicate tight coupling between the degree of nitrate consumption and Antarctic climate across the last two glacial cycles, with δ15Ndb (and thus the degree of nitrate consumption) increasing at each major Antarctic cooling event. Coupled with evidence from opal- and barium-based proxies for reduced export production during ice ages, the δ15Ndb increases point to ice age reductions in the supply of deep ocean-sourced nitrate to the AZ surface. The two diatom assemblages and species abundance data indicate that the δ15Ndb changes are not the result of changing species composition. The pennate and centric assemblage δ15Ndb records indicate similar changes but with a significant decline in their difference during peak ice ages. A tentative seasonality-based interpretation of the centric-to-pennate δ15Ndb difference suggests that late summer surface waters became nitrate free during the peak glacials. Text Antarc* Antarctic Southern Ocean DataCite Metadata Store (German National Library of Science and Technology) Antarctic Southern Ocean The Antarctic Pacific |
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Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
topic |
550 Earth sciences & geology |
spellingShingle |
550 Earth sciences & geology Jaccard, Samuel Esper, Oliver Gersonde, Rainer Martinez-Garcia, Alfredo Oleynik, Sergey Winckler, Gisela Studer, Anja Kuhn, Gerhard Lamy, Frank Wacker, Lukas Haug, Gerald Sigman, Daniel Benz, Verena Antarctic Zone nutrient conditions during the last two glacial cycles |
topic_facet |
550 Earth sciences & geology |
description |
In a sediment core from the Pacific sector of the Antarctic Zone (AZ) of the Southern Ocean, we report diatom-bound N isotope (δ15Ndb) records for total recoverable diatoms and two distinct diatom assemblages (pennate and centric rich). These data indicate tight coupling between the degree of nitrate consumption and Antarctic climate across the last two glacial cycles, with δ15Ndb (and thus the degree of nitrate consumption) increasing at each major Antarctic cooling event. Coupled with evidence from opal- and barium-based proxies for reduced export production during ice ages, the δ15Ndb increases point to ice age reductions in the supply of deep ocean-sourced nitrate to the AZ surface. The two diatom assemblages and species abundance data indicate that the δ15Ndb changes are not the result of changing species composition. The pennate and centric assemblage δ15Ndb records indicate similar changes but with a significant decline in their difference during peak ice ages. A tentative seasonality-based interpretation of the centric-to-pennate δ15Ndb difference suggests that late summer surface waters became nitrate free during the peak glacials. |
format |
Text |
author |
Jaccard, Samuel Esper, Oliver Gersonde, Rainer Martinez-Garcia, Alfredo Oleynik, Sergey Winckler, Gisela Studer, Anja Kuhn, Gerhard Lamy, Frank Wacker, Lukas Haug, Gerald Sigman, Daniel Benz, Verena |
author_facet |
Jaccard, Samuel Esper, Oliver Gersonde, Rainer Martinez-Garcia, Alfredo Oleynik, Sergey Winckler, Gisela Studer, Anja Kuhn, Gerhard Lamy, Frank Wacker, Lukas Haug, Gerald Sigman, Daniel Benz, Verena |
author_sort |
Jaccard, Samuel |
title |
Antarctic Zone nutrient conditions during the last two glacial cycles |
title_short |
Antarctic Zone nutrient conditions during the last two glacial cycles |
title_full |
Antarctic Zone nutrient conditions during the last two glacial cycles |
title_fullStr |
Antarctic Zone nutrient conditions during the last two glacial cycles |
title_full_unstemmed |
Antarctic Zone nutrient conditions during the last two glacial cycles |
title_sort |
antarctic zone nutrient conditions during the last two glacial cycles |
publisher |
American Geophysical Union |
publishDate |
2015 |
url |
https://dx.doi.org/10.7892/boris.70683 http://boris.unibe.ch/70683/ |
geographic |
Antarctic Southern Ocean The Antarctic Pacific |
geographic_facet |
Antarctic Southern Ocean The Antarctic Pacific |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.7892/boris.70683 |
_version_ |
1766261106993528832 |