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Late Pleistocene evolution of nutrient cycling in the subarctic Pacific and Southern Ocean inferred from diatom-bound nitrogen isotopes

Applicant Studer Anja
Number 145695
Funding scheme Fellowships for prospective researchers
Research institution Department of Geosciences Princeton University
Institution of higher education Institution abroad - IACH
Main discipline Geochemistry
Start/End 01.06.2013 - 31.05.2014
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Keywords (4)

polar ocean nutrient cycling; pleistocene climate evolution; diatom-bound nitrogen isotopes; SPLITT fractionation technique

Lay Summary (German)

Lead
In den polaren Ozeangebieten geben sedimentäre Stickstoffisotopen Auskunft über den Nährstoffkreislauf im Oberflächenozean. Das Ausmass der Nährstoffzehrung im Nordpazifik und Südozean bestimmt die Effizienz der biologischen Pumpe, d.h. die Eigenschaft der biologischen Primärproduktion, Kohlendioxid der Atmosphäre zu entziehen und im tiefen Ozean zu speichern. Die Kenntnis der Nährstoffzehrung der Vergangenheit hilft abzuschätzen, inwiefern diese Regionen das atmosphärische CO2 reguliert haben.
Lay summary

Inhalt und Ziel des Forschungsprojekts

Das Ziel dieses Projekts ist, die Nährstoffzehrung im Nordpazifik und im Südozean über die letzten Eis- und Warmzeiten zu rekonstruieren, um den Einfluss dieser polaren Ozeangebiete auf die CO2-Schwankungen der Atmosphäre abzuschätzen. Dazu werden Stickstoffisotopen gebunden in Kieselalgen (d15Ndb) in verschiedenen Sedimentkernen aus dem südlichen Indischen und Pazifischen Ozean und dem subarktischen Nordpazifik gemessen. Indem eine neue Technik zur hydrodynamischen Separation der Kieselalgen in die bestehende Methodik integriert wird, werden präzisere und artenspezifische d15Ndb Messungen ermöglicht.

Wissenschaftlicher und gesellschaftlicher Kontext

Die Resultate dieser Arbeit werden dazu beitragen, das Verständnis der Rolle der polaren Ozeanregionen in der Regulierung des atmosphärischen CO2 voranzubringen. Gerade im Hinblick auf die anthropogene Klimaerwärmung werden die Erkenntnisse aus der Vergangenheit helfen die Reaktion des Systems Erde in der Zukunft besser vorherzusagen.  


Direct link to Lay Summary Last update: 05.03.2013

Responsible applicant and co-applicants

Publications

Publication
Increased nutrient supply to the Southern Ocean during the Holocene and its implications for the pre-industrial atmospheric CO2rise
Studer A.S., Sigman D.M., Martínez-García A., Thöle L.M., Michel E., Jaccard S.L., Lippold J.A., Mazaud A., Wang X.T., Robinson L.F., Adkins J.F., Haug G.H. (2018), Increased nutrient supply to the Southern Ocean during the Holocene and its implications for the pre-industrial atmospheric CO2rise, in Nature Geoscience, 11(10), 756-160.
Antarctic Zone nutrient conditions during the last two glacial cycles
Studer Anja S., Sigman Daniel M., Martinez-Garcia Alfredo, Benz Verena, Winckler Gisela, Kuhn Gerhard, Esper Oliver, Lamy Frank, Jaccard Samuel L., Wacker Lukas, Oleynik Sergey, Gersonde Rainer, Haug Gerald H., Studer Anja S., Sigman Daniel M., Martinez-Garcia Alfredo, Benz Verena, Winckler Gisela, Kuhn Gerhard, Esper Oliver, Lamy Frank, Jaccard Samuel L., Wacker Lukas, Oleynik Sergey, Gersonde Rainer, Haug Gerald H. (2015), Antarctic Zone nutrient conditions during the last two glacial cycles, in Paleoceanography, PA002745.
Glacial-to-interglacial changes in nitrate supply and consumption in the subarctic North Pacific from microfossil-bound N isotopes at two trophic levels
Ren Haojia, Studer Anja S., Serno Sascha, Sigman Daniel M., Winckler Gisela, Anderson Robert F., Oleynik Sergey, Gersonde Rainer, Haug Gerald H., Ren Haojia, Studer Anja S., Serno Sascha, Sigman Daniel M., Winckler Gisela, Anderson Robert F., Oleynik Sergey, Gersonde Rainer, Haug Gerald H. (2015), Glacial-to-interglacial changes in nitrate supply and consumption in the subarctic North Pacific from microfossil-bound N isotopes at two trophic levels, in Paleoceanography, (9), 1217-1232.

Collaboration

Group / person Country
Types of collaboration
Academia Sinica Taiwan (Asia)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Columbia University United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Alfred Wegener Institut Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
ETH Zurich Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Laboratoire des Sciences du Climat et de l'Environnement France (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Associated projects

Number Title Start Funding scheme
200766 Ground-truthing the diatom-bound nitrogen isotope proxy: Experimental and field studies in the marine and lacustrine environments (NISOPROX) 01.08.2021 Project funding

Abstract

One of the most important, yet unresolved questions in paleoclimate research are the ultimate causes for glacial/interglacial variations in atmospheric carbon dioxide (CO2) concentrations. Studying its causes and mechanisms can provide key insights into the future responses of the climate system and the oceans to anthropogenic CO2 forcing. Investigating past changes in nutrient cycling in the polar oceans is one important aspect, as it reveals the capacity for change in the ocean’s “biological pump”, the tendency of open ocean biological export production to sequester CO2 in the ocean’s voluminous interior. A key goal of the paleoclimate community is to generate data on whether and by what mechanisms the polar oceans, the Southern Ocean in particular and to a lesser extent also the subarctic North Pacific, were the dominant driver of the glacial/interglacial variations in atmospheric CO2, through the combined interactions of physical ocean circulation, ocean chemistry, and marine biological productivity. My PhD work has revealed the remarkable potential of the nitrogen isotopes preserved within diatom (siliceous algae) fossils to provide insight of the polar ocean’s past nutrient conditions with a degree of detail not previously envisaged. The goal for my postdoctoral work is to more fully realize this potential by adapting a hydrodynamic sorting technology to separate diatoms from marine sediments for high sensitivity nitrogen isotopic analysis. This project leverages my PhD experience to extend my technical expertise in novel sedimentological and geochemical methods while advancing a key question in climate science.
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