Articles | Volume 20, issue 1
https://doi.org/10.5194/bg-20-229-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-20-229-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
16 Jan 2023
Research article |
| 16 Jan 2023
| 16 Jan 2023
Biomarker characterization of the North Water Polynya, Baffin Bay: implications for local sea ice and temperature proxies
David J. Harning
CORRESPONDING AUTHOR
Institute of Arctic and Alpine Research, University of Colorado,
Boulder, USA
Brooke Holman
Institute of Arctic and Alpine Research, University of Colorado,
Boulder, USA
Lineke Woelders
Institute of Arctic and Alpine Research, University of Colorado,
Boulder, USA
Anne E. Jennings
Institute of Arctic and Alpine Research, University of Colorado,
Boulder, USA
Julio Sepúlveda
Institute of Arctic and Alpine Research, University of Colorado,
Boulder, USA
Department of Geological Sciences, University of Colorado, Boulder,
USA
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David J. Harning, Anne E. Jennings, Denizcan Köseoğlu, Simon T. Belt, Áslaug Geirsdóttir, and Julio Sepúlveda
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Short summary
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Kelly A. Hogan, Martin Jakobsson, Larry Mayer, Brendan T. Reilly, Anne E. Jennings, Joseph S. Stoner, Tove Nielsen, Katrine J. Andresen, Egon Nørmark, Katrien A. Heirman, Elina Kamla, Kevin Jerram, Christian Stranne, and Alan Mix
The Cryosphere, 14, 261–286, https://doi.org/10.5194/tc-14-261-2020, https://doi.org/10.5194/tc-14-261-2020, 2020
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Glacial sediments in fjords hold a key record of environmental and ice dynamic changes during ice retreat. Here we use a comprehensive geophysical survey from the Petermann Fjord system in NW Greenland to map these sediments, identify depositional processes and calculate glacial erosion rates for the retreating palaeo-Petermann ice stream. Ice streaming is the dominant control on glacial erosion rates which vary by an order of magnitude during deglaciation and are in line with modern rates.
Áslaug Geirsdóttir, Gifford H. Miller, John T. Andrews, David J. Harning, Leif S. Anderson, Christopher Florian, Darren J. Larsen, and Thor Thordarson
Clim. Past, 15, 25–40, https://doi.org/10.5194/cp-15-25-2019, https://doi.org/10.5194/cp-15-25-2019, 2019
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Corals can record ocean properties such as temperature in their skeletons. These records are useful for where and when we have no instrumental record like in the distant past. However, coral growth must be understood to interpret these records. Here, we analyze slices of a branching deep-sea coral from Antarctica to determine how to best sample these corals for past-climate work. We recommend sampling from the innermost portion of a coral skeleton for accurate temperature reconstructions.
Zita Kelemen, David P. Gillikin, and Steven Bouillon
EGUsphere, https://doi.org/10.5194/egusphere-2024-2714, https://doi.org/10.5194/egusphere-2024-2714, 2024
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We analysed the C and O stable isotope composition (δ13C, δ18O) across the growth axis of museum-archived and recent Chambardia wissmanni shells from the Oubangui River (Congo Basin) covering sections of the past ~120 years. Recent shells showed a much wider range in δ18O values compared to historical specimens, consistent with the suggestion that dry periods in the upper Congo basin are becoming more extreme in recent times; highlighting their potential to reconstruct hydroclimatic conditions.
Alexandra Auderset, Sandi M. Smart, Yeongjun Ryu, Dario Marconi, Haojia Abby Ren, Lena Heins, Hubert Vonhof, Ralf Schiebel, Janne Repschläger, Daniel M. Sigman, Gerald H. Haug, and Alfredo Martínez-García
EGUsphere, https://doi.org/10.5194/egusphere-2024-2291, https://doi.org/10.5194/egusphere-2024-2291, 2024
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This study investigates foraminifera-bound nitrogen isotopes (FB-δ15N) as a tool to study the history of photosymbiosis in planktic foraminifera. By analysing multiple species from the South Atlantic, we found that FB-δ15N differentiates between species with dinoflagellate symbionts and those without, probably due to internal ammonium recycling in the former. Overall, this study provides strong support for FB-δ15N as a tool for exploring the evolution of symbiosis in marine ecosystems.
Allix J. Baxter, Francien Peterse, Dirk Verschuren, Aihemaiti Maitituerdi, Nicolas Waldmann, and Jaap S. Sinninghe Damsté
Biogeosciences, 21, 2877–2908, https://doi.org/10.5194/bg-21-2877-2024, https://doi.org/10.5194/bg-21-2877-2024, 2024
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This study investigates the impact of long-term lake-system evolution on the climate signal recorded by glycerol dialkyl glycerol tetraethers (GDGTs), a popular biomarker in paleoclimate research. It compares downcore changes in GDGTs in the 250 000 year sediment sequence of Lake Chala (Kenya/Tanzania) to independent data for lake mixing and water-column chemistry. These factors influence the GDGT proxies in the earliest depositional phases (before ~180 ka), confounding the climate signal.
Frances A. Procter, Sandra Piazolo, Eleanor H. John, Richard Walshaw, Paul N. Pearson, Caroline H. Lear, and Tracy Aze
Biogeosciences, 21, 1213–1233, https://doi.org/10.5194/bg-21-1213-2024, https://doi.org/10.5194/bg-21-1213-2024, 2024
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This study uses novel techniques to look at the microstructure of planktonic foraminifera (single-celled marine organisms) fossils, to further our understanding of how they form their hard exterior shells and how the microstructure and chemistry of these shells can change as a result of processes that occur after deposition on the seafloor. Understanding these processes is of critical importance for using planktonic foraminifera for robust climate and environmental reconstructions of the past.
Josie L. Mottram, Anne M. Gothmann, Maria G. Prokopenko, Austin Cordova, Veronica Rollinson, Katie Dobkowski, and Julie Granger
Biogeosciences, 21, 1071–1091, https://doi.org/10.5194/bg-21-1071-2024, https://doi.org/10.5194/bg-21-1071-2024, 2024
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Knowledge of ancient ocean N cycling can help illuminate past climate change. Using field and lab studies, this work ground-truths a promising proxy for marine N cycling, the N isotope composition of cold-water coral (CWC) skeletons. Our results estimate N turnover in CWC tissue; quantify the isotope effects between CWC tissue, diet, and skeleton; and suggest that CWCs possibly feed mainly on metazoan zooplankton, suggesting that the marine N proxy may be sensitive to the food web structure.
Axelle Gardin, Emmanuelle Pucéat, Géraldine Garcia, Jean-Renaud Boisserie, Adélaïde Euriat, Michael M. Joachimski, Alexis Nutz, Mathieu Schuster, and Olga Otero
Biogeosciences, 21, 437–454, https://doi.org/10.5194/bg-21-437-2024, https://doi.org/10.5194/bg-21-437-2024, 2024
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We introduce a novel approach using stable oxygen isotopes from crocodilian fossil teeth to unravel palaeohydrological changes in past continental contexts. Applying it to the Plio-Pleistocene Ethiopian Shungura Formation, we found a significant increase in δ18O in the last 3 million years, likely due to monsoonal shifts and reduced rainfall, and that the local diversity of waterbodies (lakes, rivers, ponds) became restricted.
Angelica Feurdean, Richard S. Vachula, Diana Hanganu, Astrid Stobbe, and Maren Gumnior
Biogeosciences, 20, 5069–5085, https://doi.org/10.5194/bg-20-5069-2023, https://doi.org/10.5194/bg-20-5069-2023, 2023
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This paper presents novel results of laboratory-produced charcoal forms from various grass, forb and shrub taxa from the Eurasian steppe to facilitate more robust interpretations of fuel sources and fire types in grassland-dominated ecosystems. Advancements in identifying fuel sources and changes in fire types make charcoal analysis relevant to studies of plant evolution and fire management.
Joost Frieling, Linda van Roij, Iris Kleij, Gert-Jan Reichart, and Appy Sluijs
Biogeosciences, 20, 4651–4668, https://doi.org/10.5194/bg-20-4651-2023, https://doi.org/10.5194/bg-20-4651-2023, 2023
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We present a first species-specific evaluation of marine core-top dinoflagellate cyst carbon isotope fractionation (εp) to assess natural pCO2 dependency on εp and explore its geological deep-time paleo-pCO2 proxy potential. We find that εp differs between genera and species and that in Operculodinium centrocarpum, εp is controlled by pCO2 and nutrients. Our results highlight the added value of δ13C analyses of individual micrometer-scale sedimentary organic carbon particles.
Julia Homann, Niklas Karbach, Stacy A. Carolin, Daniel H. James, David Hodell, Sebastian F. M. Breitenbach, Ola Kwiecien, Mark Brenner, Carlos Peraza Lope, and Thorsten Hoffmann
Biogeosciences, 20, 3249–3260, https://doi.org/10.5194/bg-20-3249-2023, https://doi.org/10.5194/bg-20-3249-2023, 2023
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Cave stalagmites contain substances that can be used to reconstruct past changes in local and regional environmental conditions. We used two classes of biomarkers (polycyclic aromatic hydrocarbons and monosaccharide anhydrides) to detect the presence of fire and to also explore changes in fire regime (e.g. fire frequency, intensity, and fuel source). We tested our new method on a stalagmite from Mayapan, a large Maya city on the Yucatán Peninsula.
Claudia Voigt, Anne Alexandre, Ilja M. Reiter, Jean-Philippe Orts, Christine Vallet-Coulomb, Clément Piel, Jean-Charles Mazur, Julie C. Aleman, Corinne Sonzogni, Helene Miche, and Jérôme Ogée
Biogeosciences, 20, 2161–2187, https://doi.org/10.5194/bg-20-2161-2023, https://doi.org/10.5194/bg-20-2161-2023, 2023
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Data on past relative humidity (RH) ARE needed to improve its representation in Earth system models. A novel isotope parameter (17O-excess) of plant silica has been developed to quantify past RH. Using comprehensive monitoring and novel methods, we show how environmental and plant physiological parameters influence the 17O-excess of plant silica and leaf water, i.e. its source water. The insights gained from this study will help to improve estimates of RH from fossil plant silica deposits.
Jessica G. M. Crumpton-Banks, Thomas Tanner, Ivan Hernández Almeida, James W. B. Rae, and Heather Stoll
Biogeosciences, 19, 5633–5644, https://doi.org/10.5194/bg-19-5633-2022, https://doi.org/10.5194/bg-19-5633-2022, 2022
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Past ocean carbon is reconstructed using proxies, but it is unknown whether preparing ocean sediment for one proxy might damage the data given by another. We have tested whether the extraction of an organic proxy archive from sediment samples impacts the geochemistry of tiny shells also within the sediment. We find no difference in shell geochemistry between samples which come from treated and untreated sediment. This will help us to maximize scientific return from valuable sediment samples.
Pablo Forjanes, María Simonet Roda, Martina Greiner, Erika Griesshaber, Nelson A. Lagos, Sabino Veintemillas-Verdaguer, José Manuel Astilleros, Lurdes Fernández-Díaz, and Wolfgang W. Schmahl
Biogeosciences, 19, 3791–3823, https://doi.org/10.5194/bg-19-3791-2022, https://doi.org/10.5194/bg-19-3791-2022, 2022
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Aragonitic skeletons are employed to decipher past climate dynamics and environmental change. Unfortunately, the information that these skeletons keep can be destroyed during diagenesis. In this work, we study the first changes undergone by aragonitic skeletons upon hydrothermal alteration. We observe that major changes occur from the very beginning of the alteration, even without mineralogical changes. These results have major implications for the use of these archives to understand the past.
Inga Labuhn, Franziska Tell, Ulrich von Grafenstein, Dan Hammarlund, Henning Kuhnert, and Bénédicte Minster
Biogeosciences, 19, 2759–2777, https://doi.org/10.5194/bg-19-2759-2022, https://doi.org/10.5194/bg-19-2759-2022, 2022
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This study presents the isotopic composition of recent biogenic carbonates from several lacustrine species which calcify during different times of the year. The authors demonstrate that when biological offsets are corrected, the dominant cause of differences between species is the seasonal variation in temperature-dependent fractionation of oxygen isotopes. Consequently, such carbonates from lake sediments can provide proxy records of seasonal water temperature changes in the past.
Gerard J. M. Versteegh, Karin A. F. Zonneveld, Jens Hefter, Oscar E. Romero, Gerhard Fischer, and Gesine Mollenhauer
Biogeosciences, 19, 1587–1610, https://doi.org/10.5194/bg-19-1587-2022, https://doi.org/10.5194/bg-19-1587-2022, 2022
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A 5-year record of long-chain mid-chain diol export flux and composition is presented with a 1- to 3-week resolution sediment trap CBeu (in the NW African upwelling). All environmental parameters as well as the diol composition are dominated by the seasonal cycle, albeit with different phase relations for temperature and upwelling. Most diol-based proxies are dominated by upwelling. The long-chain diol index reflects temperatures of the oligotrophic summer sea surface.
Johannes Hepp, Christoph Mayr, Kazimierz Rozanski, Imke Kathrin Schäfer, Mario Tuthorn, Bruno Glaser, Dieter Juchelka, Willibald Stichler, Roland Zech, and Michael Zech
Biogeosciences, 18, 5363–5380, https://doi.org/10.5194/bg-18-5363-2021, https://doi.org/10.5194/bg-18-5363-2021, 2021
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Deriving more quantitative climate information like relative air humidity is one of the key challenges in paleostudies. Often only qualitative reconstructions can be done when single-biomarker-isotope data are derived from a climate archive. However, the coupling of hemicellulose-derived sugar with leaf-wax-derived n-alkane isotope results has the potential to overcome this limitation and allow a quantitative relative air humidity reconstruction.
Angelica Feurdean
Biogeosciences, 18, 3805–3821, https://doi.org/10.5194/bg-18-3805-2021, https://doi.org/10.5194/bg-18-3805-2021, 2021
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This study characterized the diversity of laboratory-produced charcoal morphological features of various fuel types from Siberia at different temperatures. The results obtained improve the attribution of charcoal particles to fuel types and fire characteristics. This work also provides recommendations for the application of this information to refine the past wildfire history.
Martin Tetard, Laetitia Licari, Ekaterina Ovsepyan, Kazuyo Tachikawa, and Luc Beaufort
Biogeosciences, 18, 2827–2841, https://doi.org/10.5194/bg-18-2827-2021, https://doi.org/10.5194/bg-18-2827-2021, 2021
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Oxygen minimum zones are oceanic regions almost devoid of dissolved oxygen and are currently expanding due to global warming. Investigation of their past behaviour will allow better understanding of these areas and better prediction of their future evolution. A new method to estimate past [O2] was developed based on morphometric measurements of benthic foraminifera. This method and two other approaches based on foraminifera assemblages and porosity were calibrated using 45 core tops worldwide.
Maximiliano Rodríguez and Christelle Not
Biogeosciences, 18, 1987–2001, https://doi.org/10.5194/bg-18-1987-2021, https://doi.org/10.5194/bg-18-1987-2021, 2021
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Mg/Ca in calcium carbonate shells of marine organisms such as foraminifera and ostracods has been used as a proxy to reconstruct water temperature. Here we provide new Mg/Ca–temperature calibrations for two shallow marine species of ostracods. We show that the water temperature in spring produces the best calibrations, which suggests the potential use of ostracod shells to reconstruct this parameter at a seasonal scale.
Hongrui Zhang, Chuanlian Liu, Luz María Mejía, and Heather Stoll
Biogeosciences, 18, 1909–1916, https://doi.org/10.5194/bg-18-1909-2021, https://doi.org/10.5194/bg-18-1909-2021, 2021
Delphine Dissard, Gert Jan Reichart, Christophe Menkes, Morgan Mangeas, Stephan Frickenhaus, and Jelle Bijma
Biogeosciences, 18, 423–439, https://doi.org/10.5194/bg-18-423-2021, https://doi.org/10.5194/bg-18-423-2021, 2021
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Results from a data set acquired from living foraminifera T. sacculifer collected from surface waters are presented, allowing us to establish a new Mg/Ca–Sr/Ca–temperature equation improving temperature reconstructions. When combining equations, δ18Ow can be reconstructed with a precision of ± 0.5 ‰, while successive reconstructions involving Mg/Ca and δ18Oc preclude salinity reconstruction with a precision better than ± 1.69. A new direct linear fit to reconstruct salinity could be established.
Feng Wang, Dominique Arseneault, Étienne Boucher, Shulong Yu, Steeven Ouellet, Gwenaëlle Chaillou, Ann Delwaide, and Lily Wang
Biogeosciences, 17, 4559–4570, https://doi.org/10.5194/bg-17-4559-2020, https://doi.org/10.5194/bg-17-4559-2020, 2020
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Wood stain is challenging the use of the blue intensity technique for dendroclimatic reconstructions. Using stained subfossil trees from eastern Canadian lakes, we compared chemical destaining approaches with the
delta bluemathematical correction of blue intensity data. Although no chemical treatment was completely efficient, the delta blue method is unaffected by the staining problem and thus is promising for climate reconstructions based on lake subfossil material.
Dulcinea V. Groff, David G. Williams, and Jacquelyn L. Gill
Biogeosciences, 17, 4545–4557, https://doi.org/10.5194/bg-17-4545-2020, https://doi.org/10.5194/bg-17-4545-2020, 2020
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Tussock grasses that grow along coastlines of the Falkland Islands are slow to decay and build up thick peat layers over thousands of years. Grass fragments found in ancient peat can be used to reconstruct past climate because grasses can preserve a record of growing conditions in their leaves. We found that modern living tussock grasses in the Falkland Islands reliably record temperature and humidity in their leaves, and the peat they form can be used to understand past climate change.
Maxence Guillermic, Sambuddha Misra, Robert Eagle, Alexandra Villa, Fengming Chang, and Aradhna Tripati
Biogeosciences, 17, 3487–3510, https://doi.org/10.5194/bg-17-3487-2020, https://doi.org/10.5194/bg-17-3487-2020, 2020
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Boron isotope ratios (δ11B) of foraminifera are a promising proxy for seawater pH and can be used to constrain pCO2. In this study, we derived calibrations for new foraminiferal taxa which extend the application of the boron isotope proxy. We discuss the origin of different δ11B signatures in species and also discuss the potential of using multispecies δ11B analyses to constrain vertical pH and pCO2 gradients in ancient water columns to shed light on biogeochemical carbon cycling in the past.
Zeynep Erdem, Joachim Schönfeld, Anthony E. Rathburn, Maria-Elena Pérez, Jorge Cardich, and Nicolaas Glock
Biogeosciences, 17, 3165–3182, https://doi.org/10.5194/bg-17-3165-2020, https://doi.org/10.5194/bg-17-3165-2020, 2020
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Recent observations from today’s oceans revealed that oxygen concentrations are decreasing, and oxygen minimum zones are expanding together with current climate change. With the aim of understanding past climatic events and their relationship with oxygen content, we looked at the fossils, called benthic foraminifera, preserved in the sediment archives from the Peruvian margin and quantified the bottom-water oxygen content for the last 22 000 years.
Hannah K. Donald, Gavin L. Foster, Nico Fröhberg, George E. A. Swann, Alex J. Poulton, C. Mark Moore, and Matthew P. Humphreys
Biogeosciences, 17, 2825–2837, https://doi.org/10.5194/bg-17-2825-2020, https://doi.org/10.5194/bg-17-2825-2020, 2020
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The boron isotope pH proxy is increasingly being used to reconstruct ocean pH in the past. Here we detail a novel analytical methodology for measuring the boron isotopic composition (δ11B) of diatom opal and apply this to the study of the diatom Thalassiosira weissflogii grown in culture over a range of pH. To our knowledge this is the first study of its kind and provides unique insights into the way in which diatoms incorporate boron and their potential as archives of palaeoclimate records.
Eleonora Fossile, Maria Pia Nardelli, Arbia Jouini, Bruno Lansard, Antonio Pusceddu, Davide Moccia, Elisabeth Michel, Olivier Péron, Hélène Howa, and Meryem Mojtahid
Biogeosciences, 17, 1933–1953, https://doi.org/10.5194/bg-17-1933-2020, https://doi.org/10.5194/bg-17-1933-2020, 2020
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This study focuses on benthic foraminiferal distribution in an Arctic fjord characterised by continuous sea ice production during winter and the consequent cascading of salty and corrosive waters (brine) to the seabed. The inner fjord is dominated by calcareous species (C). In the central deep basins, where brines are persistent, calcareous foraminifera are dissolved and agglutinated (A) dominate. The high A/C ratio is suggested as a proxy for brine persistence and sea ice production.
Johannes Hepp, Imke Kathrin Schäfer, Verena Lanny, Jörg Franke, Marcel Bliedtner, Kazimierz Rozanski, Bruno Glaser, Michael Zech, Timothy Ian Eglinton, and Roland Zech
Biogeosciences, 17, 741–756, https://doi.org/10.5194/bg-17-741-2020, https://doi.org/10.5194/bg-17-741-2020, 2020
Julian Struck, Marcel Bliedtner, Paul Strobel, Jens Schumacher, Enkhtuya Bazarradnaa, and Roland Zech
Biogeosciences, 17, 567–580, https://doi.org/10.5194/bg-17-567-2020, https://doi.org/10.5194/bg-17-567-2020, 2020
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We present leaf wax n-alkanes and their compound-specific (CS) δ13C isotopes from semi-arid and/or arid Mongolia to test their potential for paleoenvironmental reconstructions. Plants and topsoils were analysed and checked for climatic control. Chain-length variations are distinct between grasses and Caragana, which are not biased by climate. However CS δ13C is strongly correlated to climate, so n-alkanes and their CS δ13C show great potential for paleoenvironmental reconstruction in Mongolia.
Elena Lo Giudice Cappelli, Jessica Louise Clarke, Craig Smeaton, Keith Davidson, and William Edward Newns Austin
Biogeosciences, 16, 4183–4199, https://doi.org/10.5194/bg-16-4183-2019, https://doi.org/10.5194/bg-16-4183-2019, 2019
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Fjords are known sinks of organic carbon (OC); however, little is known about the long-term fate of the OC stored in these sediments. The reason for this knowledge gap is the post-depositional degradation of OC. This study uses benthic foraminifera (microorganisms with calcite shells) to discriminate between post-depositional OC degradation and actual OC burial and accumulation in fjordic sediments, as foraminifera would only preserve the latter information in their assemblage composition.
Sara K. E. Goulden, Naohiko Ohkouchi, Katherine H. Freeman, Yoshito Chikaraishi, Nanako O. Ogawa, Hisami Suga, Oliver Chadwick, and Benjamin Z. Houlton
Biogeosciences, 16, 3869–3882, https://doi.org/10.5194/bg-16-3869-2019, https://doi.org/10.5194/bg-16-3869-2019, 2019
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We investigate whether soil organic compounds preserve information about nitrogen availability to plants. We isolate chlorophyll degradation products in leaves, litter, and soil and explore possible species and climate effects on preservation and interpretation. We find that compound-specific nitrogen isotope measurements in soil have potential as a new tool to reconstruct changes in nitrogen cycling on a landscape over time, avoiding issues that have limited other proxies.
Nicolai Schleinkofer, Jacek Raddatz, André Freiwald, David Evans, Lydia Beuck, Andres Rüggeberg, and Volker Liebetrau
Biogeosciences, 16, 3565–3582, https://doi.org/10.5194/bg-16-3565-2019, https://doi.org/10.5194/bg-16-3565-2019, 2019
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In this study we tried to correlate Na / Ca ratios from cold-water corals with environmental parameters such as salinity, temperature and pH. We do not observe a correlation between Na / Ca ratios and seawater salinity, but we do observe a strong correlation with temperature. Na / Ca data from warm-water corals (Porites spp.) and bivalves (Mytilus edulis) support this correlation, indicating that similar controls on the incorporation of sodium exist in these aragonitic organisms.
Mattia Greco, Lukas Jonkers, Kerstin Kretschmer, Jelle Bijma, and Michal Kucera
Biogeosciences, 16, 3425–3437, https://doi.org/10.5194/bg-16-3425-2019, https://doi.org/10.5194/bg-16-3425-2019, 2019
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To be able to interpret the paleoecological signal contained in N. pachyderma's shells, its habitat depth must be known. Our investigation on 104 density profiles of this species from the Arctic and North Atlantic shows that specimens reside closer to the surface when sea-ice and/or surface chlorophyll concentrations are high. This is in contrast with previous investigations that pointed at the position of the deep chlorophyll maximum as the main driver of N. pachyderma vertical distribution.
Anna Mikis, Katharine R. Hendry, Jennifer Pike, Daniela N. Schmidt, Kirsty M. Edgar, Victoria Peck, Frank J. C. Peeters, Melanie J. Leng, Michael P. Meredith, Chloe L. C. Jones, Sharon Stammerjohn, and Hugh Ducklow
Biogeosciences, 16, 3267–3282, https://doi.org/10.5194/bg-16-3267-2019, https://doi.org/10.5194/bg-16-3267-2019, 2019
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Antarctic marine calcifying organisms are threatened by regional climate change and ocean acidification. Future projections of regional carbonate production are challenging due to the lack of historical data combined with complex climate variability. We present a 6-year record of flux, morphology and geochemistry of an Antarctic planktonic foraminifera, which shows that their growth is most sensitive to sea ice dynamics and is linked with the El Niño–Southern Oscillation.
Eunmi Park, Jens Hefter, Gerhard Fischer, Morten Hvitfeldt Iversen, Simon Ramondenc, Eva-Maria Nöthig, and Gesine Mollenhauer
Biogeosciences, 16, 2247–2268, https://doi.org/10.5194/bg-16-2247-2019, https://doi.org/10.5194/bg-16-2247-2019, 2019
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We analyzed GDGT-based proxy temperatures in the polar oceans. In the eastern Fram Strait (79° N), the nutrient distribution may determine the depth habit of Thaumarchaeota and thus the proxy temperature. In the Antarctic Polar Front (50° S), the contribution of Euryarchaeota or the nonlinear correlation between the proxy values and temperatures may cause the warm biases of the proxy temperatures relative to SSTs.
Marijke W. de Bar, Jenny E. Ullgren, Robert C. Thunnell, Stuart G. Wakeham, Geert-Jan A. Brummer, Jan-Berend W. Stuut, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 16, 1705–1727, https://doi.org/10.5194/bg-16-1705-2019, https://doi.org/10.5194/bg-16-1705-2019, 2019
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We analyzed sediment traps from the Cariaco Basin, the tropical Atlantic and the Mozambique Channel to evaluate seasonal imprints in the concentrations and fluxes of long-chain diols (LDIs), in addition to the long-chain diol index proxy (sea surface temperature proxy) and the diol index (upwelling indicator). Despite significant degradation, LDI-derived temperatures were very similar for the sediment traps and seafloor sediments, and corresponded to annual mean sea surface temperatures.
Jens Zinke, Juan P. D'Olivo, Christoph J. Gey, Malcolm T. McCulloch, J. Henrich Bruggemann, Janice M. Lough, and Mireille M. M. Guillaume
Biogeosciences, 16, 695–712, https://doi.org/10.5194/bg-16-695-2019, https://doi.org/10.5194/bg-16-695-2019, 2019
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Here we report seasonally resolved sea surface temperature (SST) reconstructions for the southern Mozambique Channel in the SW Indian Ocean, a region located along the thermohaline ocean surface circulation route, based on multi-trace-element temperature proxy records preserved in two Porites sp. coral cores for the past 42 years. Particularly, we show the suitability of both separate and combined Sr / Ca and Li / Mg proxies for improved multielement SST reconstructions.
Hilde Pracht, Brett Metcalfe, and Frank J. C. Peeters
Biogeosciences, 16, 643–661, https://doi.org/10.5194/bg-16-643-2019, https://doi.org/10.5194/bg-16-643-2019, 2019
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In palaeoceanography the shells of single-celled foraminifera are routinely used as proxies to reconstruct the temperature, salinity and circulation of the ocean in the past. Traditionally a number of specimens were pooled for a single stable isotope measurement; however, technical advances now mean that a single shell or chamber of a shell can be measured individually. Three different hypotheses regarding foraminiferal biology and ecology were tested using this approach.
Anna Jentzen, Dirk Nürnberg, Ed C. Hathorne, and Joachim Schönfeld
Biogeosciences, 15, 7077–7095, https://doi.org/10.5194/bg-15-7077-2018, https://doi.org/10.5194/bg-15-7077-2018, 2018
Shauna Ní Fhlaithearta, Christophe Fontanier, Frans Jorissen, Aurélia Mouret, Adriana Dueñas-Bohórquez, Pierre Anschutz, Mattias B. Fricker, Detlef Günther, Gert J. de Lange, and Gert-Jan Reichart
Biogeosciences, 15, 6315–6328, https://doi.org/10.5194/bg-15-6315-2018, https://doi.org/10.5194/bg-15-6315-2018, 2018
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This study looks at how foraminifera interact with their geochemical environment in the seabed. We focus on the incorporation of the trace metal manganese (Mn), with the aim of developing a tool to reconstruct past pore water profiles. Manganese concentrations in foraminifera are investigated relative to their ecological preferences and geochemical environment. This study demonstrates that Mn in foraminiferal tests is a promising tool to reconstruct oxygen conditions in the seabed.
Siobhan Williams, Walter Adey, Jochen Halfar, Andreas Kronz, Patrick Gagnon, David Bélanger, and Merinda Nash
Biogeosciences, 15, 5745–5759, https://doi.org/10.5194/bg-15-5745-2018, https://doi.org/10.5194/bg-15-5745-2018, 2018
Robert Frei, Cora Paulukat, Sylvie Bruggmann, and Robert M. Klaebe
Biogeosciences, 15, 4905–4922, https://doi.org/10.5194/bg-15-4905-2018, https://doi.org/10.5194/bg-15-4905-2018, 2018
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The reconstruction of paleo-redox conditions of seawater has the potential to link to climatic changes on land and therefore to contribute to our understanding of past climate change. The redox-sensitive chromium isotope system is applied to marine calcifiers in order to characterize isotope offsets that result from vital processes during calcification processes and which can be eventually used in fossil equivalents to reconstruct past seawater compositions.
Thomas M. DeCarlo, Michael Holcomb, and Malcolm T. McCulloch
Biogeosciences, 15, 2819–2834, https://doi.org/10.5194/bg-15-2819-2018, https://doi.org/10.5194/bg-15-2819-2018, 2018
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Understanding the mechanisms of coral calcification is limited by the isolation of the calcifying environment. The boron systematics (B / Ca and δ11B) of aragonite have recently been developed as a proxy for the carbonate chemistry of the calcifying fluid, but a variety of approaches have been utilized. We assess the available experimental B / Ca partitioning data and present a computer code for deriving calcifying fluid carbonate chemistry from the boron systematics of coral skeletons.
Manuel Bringué, Robert C. Thunell, Vera Pospelova, James L. Pinckney, Oscar E. Romero, and Eric J. Tappa
Biogeosciences, 15, 2325–2348, https://doi.org/10.5194/bg-15-2325-2018, https://doi.org/10.5194/bg-15-2325-2018, 2018
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We document 2.5 yr of dinoflagellate cyst production in the Cariaco Basin using a sediment trap record. Each species' production pattern is interpreted in the context of the physico-chemical (e.g., temperature, nutrients) and biological (other planktonic groups) environment. Most species respond positively to upwelling, but seem to be negatively impacted by an El Niño event with a 1-year lag. This work helps understanding dinoflagellate ecology and interpreting fossil assemblages in sediments.
Gabriella M. Weiss, Eva Y. Pfannerstill, Stefan Schouten, Jaap S. Sinninghe Damsté, and Marcel T. J. van der Meer
Biogeosciences, 14, 5693–5704, https://doi.org/10.5194/bg-14-5693-2017, https://doi.org/10.5194/bg-14-5693-2017, 2017
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Algal-derived compounds allow us to make assumptions about environmental conditions in the past. In order to better understand how organisms record environmental conditions, we grew microscopic marine algae at different light intensities, salinities, and alkalinities in a temperature-controlled environment. We determined how these environmental parameters affected specific algal-derived compounds, especially their relative deuterium content, which seems to be mainly affected by salinity.
S. Nemiah Ladd, Nathalie Dubois, and Carsten J. Schubert
Biogeosciences, 14, 3979–3994, https://doi.org/10.5194/bg-14-3979-2017, https://doi.org/10.5194/bg-14-3979-2017, 2017
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Hydrogen isotopes of lipids provide valuable information about microbial activity, climate, and environmental stress. We show that heavy hydrogen in fatty acids declines from spring to summer in a nutrient-rich and a nutrient-poor lake and that the effect is nearly 3 times as big in the former. This effect is likely a combination of increased biomass from algae, warmer temperatures, and higher algal growth rates.
Karoliina A. Koho, Lennart J. de Nooijer, Christophe Fontanier, Takashi Toyofuku, Kazumasa Oguri, Hiroshi Kitazato, and Gert-Jan Reichart
Biogeosciences, 14, 3067–3082, https://doi.org/10.5194/bg-14-3067-2017, https://doi.org/10.5194/bg-14-3067-2017, 2017
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Here we report Mn / Ca ratios in living benthic foraminifera from the NE Japan margin. The results show that the Mn incorporation directly reflects the environment where the foraminifera calcify. Foraminifera that live deeper in sediment, under greater redox stress, generally incorporate more Mn into their carbonate skeletons. As such, foraminifera living close to the Mn reduction zone in sediment appear promising tools for paleoceanographic reconstructions of sedimentary redox conditions.
Cited articles
Amiraux, R., Smik, L., Köseoğlu, D., Rontani, J.-F., Galindo, V.,
Grondin, P.-L., Babin, M., and Belt, S. T.: Temporal evolution of IP25
and other highly branched isoprenoid lipids in sea ice and the underlying
water column during an Arctic melting season, Elementa-Sci. Anthrop., 7,
1–23, https://doi.org/10.1525/elementa.377, 2019.
Amiraux, R., Archambault, P., Moriceau, B., Lemire, M., Babin, M., Memery,
L., Massé, G., and Tremblay, J.-E.: Efficiency of the
sympagic-benthic coupling revealed by n-3 fatty acids, IP25 and other
highly branched isoprenoid analyses of two filter-feeding Arctic benthic
molluscs: Mya truncate and Serripes groenlandicus, Org. Geochem., 151, 104160,
https://doi.org/10.1016/j.orggeochem.2020.104160, 2021.
Arrigo, K. R. and van Dijken, G. L.: Annual cycles of sea ice and
phytoplankton in Cape Bathurst polynya, southeastern Beaufort Sea, Can.
Arctic, Geophys. Res. Lett., 31, L08304,
https://doi.org/10.1029/2003GL018978, 2004.
Azetsu-Scott, K., Clarke, A., Falkner, K., Hamilton, J., Jones, P. E., Lee,
C., Petrie, B., Prinsenberg, S., Starr, M., and Yeats, P.: Calcium carbonate
saturation states in the waters of the Canadian Arctic Archipelago and the
Labrador Sea, J. Geophys. Res., 115, 1–18,
https://doi.org/10.1029/2009JC005917, 2010.
Bale, N. J., Palatinszky, M., Rijpstra, W. I. C., Herbold, C. W., Wagner,
M., and Sinninghe Damsté, J. S.: Membrane lipid composition of the
moderately thermophilic ammonia-oxidizing archaeon “Candidatus Nitrosotenuis
uzonensis” at different growth temperatures, Appl. Environ. Microbiol., 85,
e01332, https://doi.org/10.1128/AEM.01332-19, 2019.
Barber, D., Mardsen, R., Minnett, P., Ingram, G., and Fortier, L.: Physical
processes within the North Water (NOW) polynya, Atmos. Ocean, 39,
163–166, https://doi.org/10.1080/07055900.2001.9649673, 2001.
Barnhart, K. R., Miller, C. R., Overeem, I., and Kay, J. E.: Mapping the
future expansion of Arctic open water, Nat. Clim. Change, 6, 280–285,
https://doi.org/10.1038/nclimate2848, 2015.
Belt, S. T.: Source-specific biomarkers as proxies for Arctic and Antarctic
sea ice, Org. Geochem., 125, 277–298,
https://doi.org/10.1016/j.orggeochem.2018.10.002, 2018.
Belt, S. T., Allard, W. G., Massé, G., Robert, J.-M., and Rowland, S.
J.: Highly branched isoprenoids (HBIs): Identification of the most common
and abundant sedimentary isomers, Geochim. Cosmochim. Ac., 64, 3839–3851,
https://doi.org/10.1016/S0016-7037(00)00464-6, 2000.
Belt, S. T., Massé, G., Rowland, S. J., Poulin, M., Michel, C., and
LeBlanc, B.: A novel chemical fossil of palaeo sea ice: IP25, Org.
Geochem., 38, 16–27, https://doi.org/10.1016/j.orggeochem.2006.09.013,
2007.
Belt, S. T., Massé, G., Vare, L. L., Rowland, S. J., Poulin, M., Sicre,
M.-A., Sampei, M., and Fortier, L.: Distinctive 13C isotopic signature
distinguishes a novel sea ice biomarker in Arctic sediments and sediment
traps, Mar. Chem., 112, 158–167,
https://doi.org/10.1016/j.marchem.2008.09.002, 2008.
Belt, S. T., Brown, T. A., Navarro Rodriguez, A., Cabedo-Sanz, P., Tonkin,
A., and Ingle, R.: A reproducible method for the extraction, identification
and quantification of the Arctic sea ice proxy IP25 from marine
sediments, Anal. Method., 4, 705–713, https://doi.org/10.1039/C2Ay05728J,
2012.
Belt, S. T., Brown, T. A., Ringrose, A. E., Cabedo-Sanz, P., Mundy, C. J.,
Gosselin, M., and Poulin, M.: Quantitative measurement of the sea ice diatom
biomarker IP25 and sterols in Arctic sea ice and underlying sediments:
further considerations for palaeo sea ice reconstruction, Org. Geochem., 62,
33–45, https://doi.org/10.1016/j.orggeochem.2013.07.002, 2013.
Belt, S. T., Brown, T. A., Ampel, L., Cabedo-Sanz, P., Fahl, K., Kocis, J.
J., Masse, G., Navarro-Rodriguez, A., Ruan, J., and Xu, Y.: An
inter-laboratory investigation of the Arctic sea ice biomarker proxy IP25 in
marine sediments: key outcomes and recommendations, Clim. Past, 10,
155–166, https://doi.org/10.5194/cp-10-155-2014, 2014.
Belt, S. T., Cabedo-Sanz, P., Smik, L., Rodriguez-Navarro, A., Berben, S. M.
P., Knies, J., and Husum, K.: Identification of paleo Arctic winter sea ice
limits and the marginal ice zone: Optimised biomarker-based reconstructions
of late Quaternary Arctic sea ice, Earth Planet. Sc. Lett., 431, 127–139,
https://doi.org/10.1016/j.epsl.2015.09.020, 2015.
Belt, S. T., Brown, T. A., Smik, L., Tatarek, A., Wiktor, J., Stowasser, G.,
Assmy, P., Allen, C. S., and Husum, K.: Identification of C25 highly
branched isoprenoid (HBI) alkenes in diatoms of the genus Rhizosolenia in polar and
sub-polar marine phytoplankton, Org. Geochem., 110, 65–72,
https://doi.org/10.1016/j.orggeochem.2017.05.007, 2017.
Belt, S. T., Brown, T. A., Smik, L., Assmy, P., and Mundy, C. J.: Sterol
identification in floating Arctic sea ice algal aggregates and the Antarctic
sea ice diatom Berkeleya adeliensis, Org. Geochem., 118, 1–3,
https://doi.org/10.1016/j.orggeochem.2018.01.008, 2018.
Belt, S. T., Smik, L., Köseoğlu, D., Knies, J., and Husum, K.: A
novel biomarker-based proxy for the spring phytoplankton bloom in Arctic and
sub-arctic settings – HBI T25, Earth Planet. Sc. Lett., 523,
115703, https://doi.org/10.1016/j.epsl.2019.06.038, 2019.
Besseling, M. A., Hopmans, E. C., Bale, N. J., Schouten, S., Sinninghe
Damsté, J. S., and Villanueva, L.: The absence of intact polar
lipid-derived GDGTs in marine waters dominated by Marine Group II:
Implications for lipid biosynthesis in Archaea, Sci. Rep., 10, 294,
https://doi.org/10.1038/s41598-019-57035-0, 1-10.
Bi, H., Zhang, Z., Wang, Y., Xu, X., Liang, Y., Huang, J., Liu, Y., and Fu, M.: Baffin Bay sea ice inflow and outflow: 1978–1979 to 2016–2017, The Cryosphere, 13, 1025–1042, https://doi.org/10.5194/tc-13-1025-2019, 2019.
Boon, J. J., Rijpstra, W. I. C., De Lange, F., De Leeuw, J. W., Yoshioka,
M., and Shimizu, Y.: Black Sea sterol – a molecular fossil for
dinoflagellate blooms, Nature, 277, 125–127,
https://doi.org/10.1038/277125a0, 1976.
Boudinot, F. G., Dildar, N., Leckie, R. M., Parker, A., Jones, M. M.,
Sageman, B. B., Bralower, T. J., and Sepúlveda, J.: Neritic ecosystem
response to Oceanic Anoxic Event 2 in the Cretaceous Western Interior
Seaway, USA, Palaeogr. Palaeocl., 546, 109673,
https://doi.org/10.1016/j.palaeo.2020.109673, 2020.
Brown, T. A., Belt, S. T., Philippe, B., Mundy, C. J., Massé, G.,
Poulin, M., and Gosselin, M.: Temporal and vertical variations of lipid
biomarkers during a bottom ice diatom bloom in the Canadian Beaufort Sea:
further evidence for the use of the IP25 biomarker as a proxy for
spring Arctic sea ice, Polar Biol., 34, 1857–1868,
https://doi.org/10.1007/s00300-010-0942-5, 2011.
Brown, T. A., Belt, S. T., Tatarek, A., and Mundy, C. J.: Source
identification of the Arctic sea ice proxy IP25, Nat. Comm., 5, 1–7,
https://doi.org/10.1038/ncomms5197, 2014.
Cabedo-Sanz, P., Belt, S. T., Knies, J., and Husum, K.: Identification of
contrasting seasonal sea ice conditions during the Younger Dryas, Quaternary Sci.
Rev., 79, 74–86, https://doi.org/10.1016/j.quascirev.2012.10.028, 2013.
Cavalieri, D. J., Parkinson, C. L., Gloersen, P., and Zwally, H. J.: Sea Ice
Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS Passive Microwave
Data, Version 1, Boulder, Colorado USA, NASA National Snow
and Ice Data Center Distributed Active Archive Center [datat set],
https://doi.org/10.5067/8GQ8LZQVL0VL, 1996.
Church, M. J., Wai, B., Karl, D. M., and DeLong, E. F.: Abundances of
crenarchaeal amoA genes and transcripts in the Pacific Ocean, Environ.
Microbiol., 12, 679–688, https://doi.org/10.1111/j.1462-2920.2009.02108.x,
2010.
Detlef, H., Reilly, B., Jennings, A., Mørk Jensen, M., O'Regan, M., Glasius, M., Olsen, J., Jakobsson, M., and Pearce, C.: Holocene sea-ice dynamics in Petermann Fjord in relation to ice tongue stability and Nares Strait ice arch formation, The Cryosphere, 15, 4357–4380, https://doi.org/10.5194/tc-15-4357-2021, 2021.
Elling, F. J., Könneke, M., Lipp, J. S., Becker, K. W., Gagen, E. J.,
and Hinrichs, K.-U.: Effects of growth phase on the membrane lipid
composition of the thaumarchaeon Nitrosopumilus maritimus and their
implications for archaeal lipid distributions in the marine environment,
Geochim. Cosmochim. Ac., 141, 579–597,
https://doi.org/10.1016/j.gca.2014.07.005, 2014.
Elling, F. J., Könneke, M., Mußmann, M., Greve, A., and Hinrichs,
K.-U.: Influence of temperature, pH, and salinity on membrane lipid
composition and TEX86 of marine planktonic thaumarchaeal isolates,
Geochim. Cosmochim. Ac., 171, 238–255,
https://doi.org/10.1016/j.gca.2015.09.004, 2015.
Elling, F. J., Könneke, M., Nicol, G. W., Stieglmeier, M., Bayer, B.,
Spieck, E., de la Torre, J. R., Becker, K. W., Thomm, M., Prosser, J. I.,
Herndl, G. J., Schleper, C., and Hinrichs, K.-U.: Chemotaxonomic
characterisation of the thaumarchaeal lipidome, Environ. Microbiol., 19,
681–700, https://doi.org/10.1111/1462-2920.13759, 2017.
Fietz, S., Huguet, C., Rueda, G., Hambach, B., and Rosell-Melé, A.:
Hydroxylated isoprenoidal GDGTs in the Nordic Seas, Mar. Chem., 152, 1–10,
https://doi.org/10.1016/j.marchem.2013.02.007, 2013.
Fietz, S., Ho, S. L., and Huguet, C.: Archaeal membrane lipid-based
paleothermometry for application in polar oceans, Oceanography, 33, 104–114,
https://doi.org/10.5670/oceanog.2020.207, 2020.
Francis, C. A., Roberts, K. J., Beman, J. M., Santoro, A. E., and Oakley, B.
B.: Ubiquity and diversity of ammonia-oxidizing archaea in water columns and
sediments of the ocean, P. Natl. Acad. Sci. USA, 102, 14683–14688,
https://doi.org/10.1073/pnas.0506625102, 2005.
Garcia, H. E., Weathers, K., Paver, C. R., Smolyar, I., Boyer, T. P.,
Locarnini, R. A., Zweng, M. M., Mishonov, A. V., Baranova, O. K., Seidov,
D., and Reagan, J. R.: World Ocean Atlas 2018, Vol. 3, Dissolved Oxygen, Apparent Oxygen Utilization, and Oxygen Saturation, A. Mishonov Technical Edn., NOAA Atlas NESDIS 83, NOAA National Centers for Environmental Information [data set], 38
pp., 2018a.
Garcia, H. E., Weathers, K., Paver, C. R., Smolyar, I., Boyer, T. P.,
Locarnini, R. A., Zweng, M. M., Mishonov, A. V., Baranova, O. K., Seidov,
D., and Reagan, J. R.: World Ocean Atlas 2018, Vol. 4, Dissolved Inorganic Nutrients (phosphate, nitrate and nitrate + nitrite, silicate), A. Mishonov Technical Edn., NOAA Atlas NESDIS 84,
35 pp., NOAA Atlas NESDIS 83, NOAA National Centers for Environmental Information [data set], 2018b.
Georgiadis, E., Giraudeau, J., Jennings, A., Limoges, A., Jackson, R.,
Ribeiro, S., and Massé, G.: Local and regional controls on Holocene sea
ice dynamics and oceanography in Nares Strait, Northwest Greenland, Mar.
Geol., 442, 106115, https://doi.org/10.1016/j.margeo.2020.106115, 2020.
Gould, W. A., Raynolds, M., and Walker, D. A.: Vegetation, plant biomass,
and net primary productivity patterns in the Canadian Arctic, J. Geophys.
Res.-Atmos., 108, 1–14, https://doi.org/10.1029/2001JD000948, 2003.
Grønnow, B. and Sørensen, M.: Palaeo-Eskimo migrations into
Greenland: The Canadian Connection, in: Dynamics of Northern Societies,
Proceedings of the SILA/NABO Conference on Arctic and North Atlantic
Archaeology, edited by: Arneborg, J. and Grønnow, B., Copenhagen, National Museum, Studies in Archaeology and History, 59–74,
2006.
Harning, D. J., Andrews, J. T., Belt, S. T., Cabedo-Sanz, P.,
Geirsdóttir, Á, Dildar, N., Miller, G. H., and Sepúlveda, J.:
Sea ice control on winter subsurface temperatures of the North Iceland Shelf
during the Little Ice Age: A TEX86 calibration case study,
Paleoceanogr. Paleocl., 34, 1006–1021,
https://doi.org/10.1029/2018PA003523, 2019.
Harning, D. J., Jennings, A. E., Köseoğlu, D., Belt, S. T.,
Geirsdóttir, Á., and Sepúlveda, J.: Response of biological
productivity to North Atlantic marine front migration during the Holocene,
Clim. Past, 17, 379–396, https://doi.org/10.5194/cp-17-379-2021, 2021.
Hastrup, K., Mosbech, A., and Grønnow, B.: Introducing the North Water:
Histories of exploration, ice dynamics, living resources, and human
settlement in the Thule Region, Ambio, 47, 162–174,
https://doi.org/10.1007/s13280-018-1030-2, 2018.
Herfort, L., Schouten, S., Boon, J. P., and Sinninghe Damsté, J. S.:
Application of TEX86 temperature proxy to the southern North Sea, Org.
Geochem., 37, 1715–1726, https://doi.org/10.1016/j.orggeochem.2006.07.021,
2006.
Hopmans, E. C., Schouten, S., and Sinninghe Damsté, J. S.: The effect of
improved chromatography on GDGT-based palaeoproxies, Org. Geochem., 93, 1–6,
https://doi.org/10.1016/j.orggeochem.2015.12.006, 2016.
Huang, W. Y. and Meinschein, W. G.: Sterols as source indicators of organic
materials in sediments, Geochem. Cosmochim. Ac., 40, 323–330,
https://doi.org/10.1016/0016-7037(76)90210-6, 1976.
Huguet, C., Hopmans, E. C., Febo-Ayala, W., Thompson, D. H., Sinninghe
Damsté, J. S., and Schouten, S.: An improved method to determine the
absolute abundance of glycerol dibiphytanyl glycerol tetraether lipids, Org.
Geochem., 37, 1036–1041, https://doi.org/10.1016/j.orggeochem.2006.05.008,
2006.
Huguet, C., Fietz, S., and Rosell-Melé, A.: Global distribution patterns
of hydroxy glycerol dialkyl glycerol tetraethers, Org. Geochem., 57, 107–118,
https://doi.org/10.1016/j.orggeochem.2013.01.010, 2013.
Huguet, C., Fietz, S., Rosell-Melé, A., Daura, X., and Costenaro, L.:
Molecular dynamics simulation study of the effect of glycerol dialkyl
glycerol tetraether hydroxylation on membrane thermostability, Biochim.
Biophys. Ac., 1859, 966–974,
https://doi.org/10.1016/j.bbamem.2017.02.009, 2017.
Hurley, S. J., Elling, F. J., Könneke, M., Buchwald, C., Wankel, S. D.,
Santoro, A. E., Lipp, J. S., Hinrichs, K.-U., and Pearson, A.: Influence of
ammonia oxidation rate on thaumarchaeal lipid composition and the TEX86
temperature proxy, P. Natl. Acad. Sci. USA, 113, 7762–7767,
https://doi.org/10.1073/pnas.1518534113, 2016.
Hurley, S. J., Lipp, J. S., Close, H. G., Hinrichs, K.-U., and Pearson, A.:
Distribution and export of isoprenoid tetraether lipids in suspended
particulate matter from the water column of the Western Atlantic Ocean, Org.
Geochem., 116, 90–102, https://doi.org/10.1016/j.orggeochem.2017.11.010,
2018.
Ingram, R. G., Bacle, J., Barber, D. G., Gratton, Y., and Melling, H.: An
overview of physical processes in the North Water, Deep-Sea Res. Pt. II, 49,
4893–4906, https://doi.org/10.1016/S0967-0645(02)00169-8, 2002.
Jackson, R., Kvorning, A. B., Limoges, A., Georgiadis, E., Olsen, S. M.,
Tallberg, P., Andersen, T. J., Mikkelsen, N., Giraudeau, J., Massé, G.,
Wacker, L., and Ribeiro, S.: Holocene polynya dynamics and their interaction
with oceanic heat transport in northernmost Baffin Bay, Sci. Rep., 11, 1–17,
https://doi.org/10.1038/s41598-021-88517-9, 2021.
Jia, G., Wang, X., Guo, W., and Dong, L.: Seasonal distribution of archaeal
lipids in surface water and its constraint on their sources and the TEX86
temperature proxy in sediments of the South China Sea, J. Geophys.
Res.-Biogeo., 122, 592–606, https://doi.org/10.1002/2016JG003732, 2017.
Jones, E. P., Swift, J. H. Anderson, L. G., Lipizer, M., Civitarese, G.,
Falkner, K. K., Kattner, G., and McLaughlin, F.: Tracing Pacific water in
the North Atlantic Ocean, J. Geophys. Res., 108, 3116,
https://doi.org/10.1029/2001JC001141, 2003.
Kang, S., Shin, K. H., and Kim, J. H.: Occurrence and distribution of
hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers (OH-GDGTs) in
the Han River system, South Korea, Acta Geochim., 36, 367–369,
https://doi.org/10.1007/s11631-017-0165-3, 2017.
Karner, M. B., DeLong, E. F., and Karl, D. M.: Archaeal dominance in the
mesopelagic zone of the Pacific Ocean, Nature, 409, 507–510,
https://doi.org/10.1038/35054051, 2001.
Kim, J.-H., van der Meer, J., Schouten, S., Helmke, P., Willmott, V.,
Sangiorgi, F., Koç, N., Hopmans, E. C., and Sinninghe Damsté, J. S.:
New indices and calibrations derived from the distribution of crenarchaeal
isoprenoid tetraether lipids: Implications for past sea surface temperature
reconstructions, Geochim. Cosmochim. Ac., 74, 4639–4654,
https://doi.org/10.1016/j.gca.2010.05.027, 2010.
Kim, J.-H., Crosta, X., Willmott, V., Renssen, H., Bonnin, J., Helmke, P.,
Schouten, S., and Sinninghe Damsté, J. S.: Holocene subsurface
temperature variability in the eastern Antarctic continental margin,
Geophys. Res. Lett., 39, 3–8, https://doi.org/10.1029/2012GL051157, 2012.
Kim, J.-H., Schouten, S., Rodrigo-Gámiz, M., Rampen, S., Marino, G.,
Huguet, C., Helmke, P., Buscail, R., Hopmans, E. C., Pross, J., Sangiorgi,
F., Middelburg, J. B. M., and Sinninghe Damsté, J. S.: Influence of
deep-water derived isoprenoid tetraether lipids on the TEX
Kim, J.-H., Villanueva, L., Zell, C., and Sinninghe Damsté, J. S.:
Biological source and provenance of deep-water derived isoprenoid tetraether
lipids along the Portuguese continental margin, Geochim. Cosmochim. Ac.,
172, 177–204, https://doi.org/10.1016/j.gca.2015.09.010, 2016.
Klein, B., LeBlanc, B., Mei, Z.-P., Beret, R., Michaud, J., Mundy, C. J.,
von Quillfeldt, C. H., EÌve Garneau, M., Roy, S., Gratton, Y., Cochran, J.
K., Beìlanger, S., Larouche, P., Pakulski, J. D., Rivkin, R. B., and
Legendre, L.: Phytoplankton biomass, production and potential export in the
North Water, Deep-Sea Res. Pt. II, 49, 4983–5002,
https://doi.org/10.1016/S0967-0645(02)00174-1, 2002.
Knies, J., Köseoğlu, D., Rise, L., Baeten, N., Bellec, V. K.,
Bøe, R., Klug, M., Panieri, G., Jernas, P. E., and Belt, S. T.: Nordic
Seas polynyas and their role in preconditioning marine productivity during
the Last Glacial Maximum, Nat. Comm., 9, 3959,
https://doi.org/10.1038/s41467-018-06252-8, 2018.
Koch, C. W., Cooper, L. W., Lalande, C., Brown, T. A., Frey, K. E., and
Grebmeler, J. M.: Seasonal and latitudinal variations in sea ice algae
deposition in the Northern Bering and Chukchi Seas determined by algal
biomarkers, PLoS ONE, 15, e0231178,
https://doi.org/10.1371/journal.pone.0231178, 2020.
Kolling, H. M., Stein, R., Fahl, K., Sadatzki, H., de Vernal, A., and Xiao,
X.: Biomarker distributions in (sub)-Arctic surface sediments and their
potential for sea-ice reconstructions, Geochem. Geophy. Geosy., 21,
e2019GC008629, https://doi.org/10.1029/2019GC008629, 2020.
Könneke, M., Bernhard, A. E., de la Torre, J. R., Walker, C. B.,
Waterbury, J. B., and Stahl, D. A.: Isolation of an autotrophic
ammonia-oxidizing marine archaeon, Nature, 437, 543–546,
https://doi.org/10.1038/nature03911, 2005.
Köseoğlu, D., Belt, S. T., Smik, L., Yao, H., Panieri, G., and
Knies, J.: Complementary biomarker-based methods for characterizing Arctic
sea ice conditions: A case study comparison between multivariate analysis
and the PIP25 index, Geochim. Cosmochim. Ac., 222, 406–420,
https://doi.org/10.1016/j.gca.2017.11.001, 2018.
Köseoğlu, D., Belt., S. T., and Knies, J.: Abrupt shifts of
productivity and sea ice regimes at the western Barents Sea slope from the
Last Glacial Maximum to the Bølling-Allerød interstadial, Quaternary Sci.
Rev., 222, 105903, https://doi.org/10.1016/j.quascirev.2019.105903, 2019.
Kuhlbrodt, T., Griesel, A., Montoya, M., Levermann, A., Hofmann, M., and
Rahmstorf, S.: On the driving processes of the Atlantic meridional
overturning circulation, Rev. Geophys., 45, RG2001,
https://doi.org/10.1029/2004RG000166, 2007.
Kuypers, M. M. M., Marchant, H. K., and Kartal, B.: The microbial
nitrogen-cycling network, Nat. Rev. Microbiol., 16, 263–276,
https://doi.org/10.1038/nrmicro.2018.9, 2018.
Lewis, L., Ponton, D., Legendre, L., and Leblanc, B.: Springtime sensible
heat, nutrients and phytoplankton in the Northwater Polynya, Can.
Arctic. Cont. Shelf Res., 16, 1775–1792,
https://doi.org/10.1016/0278-4343(96)00015-5, 1996.
International Hydrographic Organization (IHO): Limits of Oceans and Seas, International Hydrographic Organization, Special Publication No. 23, 3rd Edn., IMP, Monégasque – Monte Carlo, 45 pp., https://doi.org/10.1594/PANGAEA.777975, 1953.
Limoges, A., Massé, G., Weckström, K., Poulin, M., Ellegaard, M.,
Heikkilä, M., Geilfus, N.-X., Sejr, M. K., Rysgaard, S., and Ribeiro,
S.: Spring succession and vertical export of diatoms and IP25 in a
seasonally ice-covered high arctic fjord, Front. Earth Sci., 6,
1–15, https://doi.org/10.3389/feart.2018.00226, 2018.
Liu, X.-L., Lipp, J. S., Simpson, J. H., Lin, Y.-S., Summons, R. E., and
Hinrichs, K.-U.: Mono- and dihydroxyl dibiphytanyl glycerol tetraethers in
marine sediments: Identification of both core and intact polar lipid forms,
Geochim. Cosmochim. Ac., 89, 102–115,
https://doi.org/10.1016/j.gca.2012.04.053, 2012.
Locarnini, R. A., Mishonov, A. V., Baranova, O. K., Boyer, T. P., Zweng, M.
M., Garcia, H. E., Reagan, J. R., Seidov, D., Weathers, K., Paver, C. R.,
and Smolyar, I.: World Ocean Atlas 2018, Vol. 1, Temperature, A. Mishonov Technical Edn., NOAA Atlas NESDIS 81, 52 pp., NOAA National Centers for Environmental Information [data set],
2018.
Lü, X., Liu, X.-L., Elling F. J., Yang, H., Xie, S., Song, J., Li, X.,
Yuan, H., Li, N., and Hinrichs, K. U.: Hydroxylated isoprenoid GDGTs in
Chinese coastal seas and their potential as a paleo-temperature proxy for
mid-to-low latitude marginal seas, Org. Geochem., 89/90, 31–43,
https://doi.org/10.1016/j.orggeochem.2015.10.004, 2015.
Lü, X., Chen, J., Han, T., Yang, H., Wu, W., Ding, W., and Hinrichs, K.
U.: Origin of hydroxyl GDGTs and regular isoprenoid GDGTs in suspended
particulate matter of Yangtze River Estuary, Org. Geochem., 128, 78–85,
https://doi.org/10.1016/j.orggeochem.2018.12.010, 2019.
Melling, H., Gratton, Y., and Ingram, G.: Ocean circulation within the North
Water polynya of Baffin Bay, Atmos. Ocean, 39, 301–325,
https://doi.org/10.1080/07055900.2001.9649683, 2001.
Meredith, M., Sommerkorn, M., Cassotta, S., Derksen, C., Ekaykin, A.,
Hollowed, A., Kofinas, G., Mackintosh, A., Melbourne-Thomas, J., Muelbert,
M. M. C., Ottersen, G., Pritchard, H., and Schuur, E. A. G.: Polar Regions,
in: IPCC Special Report on the Ocean and Cryosphere in a Changing Climate, edited by:
Pörtner, H.-O., Roberts, D. C., Masson-Delmotte, V., Zhai, P., Tignor,
M., Poloczanska, E., Mintenbeck, K., Alegría, A., Nicolai, M., Okem,
A., Petzold, J., Rama, B., and Weyer, N. M., Cambridge University Press, Cambridge, UK and New York, NY, USA, https://doi.org/10.1017/9781009157964.005, 2019.
Meyers, P. A.: Preservation of elemental and isotopic source identification
of sedimentary organic matter, Chem. Geol., 114, 289–302,
https://doi.org/10.1016/0009-2541(94)90059-0, 1994.
Moore, G. W. K., Howell, S. E. L., Brady, M., Xu, X., and McNeil, K.:
Anomalous collapses of Nares Strait ice arches leads to enhanced export of
Arctic sea ice, Nat. Comm., 12, 1–8,
https://doi.org/10.1038/s41467-020-20314-w, 2021.
Müller, J., Wagner, A., Fahl, K., Stein, R., Prange, M., and Lohmann,
G.: Towards quantitative sea ice reconstructions in the northern North
Atlantic: A combined biomarker and numerical modelling approach, Earth
Planet. Sc. Lett., 306, 137–148,
https://doi.org/10.1016/j.epsl.2011.04.011, 2011.
Münchow, A., Falkner, K. K., and Melling, H.: Spatial
continuity of measured seawater and tracer fluxes through Nares Strait, a
dynamically wide channel bordering the Canadian Archipelago, J. Marine Res.,
65, 759–788, https://doi.org/10.1357/002224007784219048, 2006.
Münchow, A., Kelly, K. Falkner, K. K., and Melling, H.:
Baffin Island and West Greenland Current Systems in northern Baffin Bay,
Prog. Oceanogr., 132, 305–337, https://doi.org/10.1016/j.pocean.2014.04.001,
2015.
Navarro-Rodriguez, A., Belt, S. T., Knies, J., and Brown, T. A.: Mapping
recent sea ice conditions in the Barents Sea using the proxy biomarker IP25:
implications for palaeo sea ice reconstructions, Quaternary Sci. Rev., 79, 26–39,
https://doi.org/10.1016/j.quascirev.2012.11.025, 2013.
Nichols, P. D., Palmisano, A. C., Rayner, M. S., Smith, G. A., and White, D.
C.: Occurrence of novel C30 sterols in Antarctic sea-ice diatom communities
during a spring bloom, Org. Geochem., 15, 503–508,
https://doi.org/10.1016/0146-6380(90)90096-I, 1990.
Onarheim, I. H., Eldevik, T., Smedsrud, L. H., and Stroeve, J. C.: Seasonal
and regional manifestation of Arctic sea ice loss, J. Clim., 31, 4917–4932,
https://doi.org/10.1175/JCLI-D-17-0427.1, 2018.
Park, E., Hefter, J., Fischer, G., Iversen, M. H., Ramondenc, S.,
Nöthig, E.-M., and Mollenhauer, G.: Seasonality of archaeal lipid flux
and GDGT-based thermometry in sinking particles of high-latitude oceans:
Fram Strait (79∘ N) and Antarctic Polar Front (50∘ S),
Biogeosciences, 16, 2247–2268, https://doi.org/10.5194/bg-16-2247-2019,
2019.
Pearson, A. and Ingalls, A. E.: Assessing the use of archaeal lipids in
marine environmental proxies, Annu. Rev. Earth Pl. Sc., 41, 359–384,
https://doi.org/10.1146/annurev-earth-050212-123947, 2013.
Pitcher, A., Hopmans, E. C., Mosier, A. C., Park, S.-J., Rhee, S.-K.,
Francis, C. A., Schouten, S., and Sinninghe Damsté, J. S.: Core and
intact polar glycerol dibiphytanyl glycerol tetraether lipids of
ammonia-oxidizing archaea enriched from marine and estuarine sediments,
Appl. Environ. Microbiol., 77, 3468–3477, https://doi.org/10.1128/AEM.02758-10,
2011.
Qin, W., Carlson, L. T., Armbrust, E. V., Devol, A. H., Moffett, J. W.,
Stahl, D. A., and Ingalls, A. E.: Confounding effects of oxygen and
temperature on the TEX86 signature of marine Thaumarchaeota, P. Natl.
Acad. Sci. USA, 112, 10979–10984, https://doi.org/10.1073/pnas.1501568112,
2015.
Raghavan, M., DeGiorgio, M., Albrechtsen, A., Moltke, I., Skoglund, P.,
Korneliussen, T. S., Grønnow, B., Appelt, M., Gulløv, H. C., Friesen,
T. M., Fitzhugh, W., Malmström, H., Rasmussen, S., Olsen, J., Melchior,
L., Fuller, B. T., Fahrni, S. M., Stafford, T. Jr., Grimes, V., Renouf, M.
A. P., Cybulski, J., Lynnerup, N., Lahr, M. M., Britton, K., Knecht, R.,
Arneborg, J., Metspalu, M., Cornejo, O. E., Malaspinas, A.-S., Wang, Y.,
Rasmussen, M., Raghavan, V., Hansen, T. V. O., Khusnutdinova, E., Pierre,
T., Dneprovsky, K., Andreasen, C., Lange, H., Hayes, M. G., Coltrain, J.,
Spitsyn, V. A., Götherström, A., Orlando, L., Kivisild, T., Villems,
R., Crawford, M. H., Nielsen, F. C., Dissing, J., Heinemeier, J., Meldgaard,
M., Bustamante, C., O'Rourke, D. H., Jakobsson, M., Gilbert, M. T. P.,
Nielsen, R., and Willerslev, E.: The genetic prehistory of the New World
Arctic, Science, 345, 1255832, https://doi.org/10.1126/science.1255832, 2014.
Rampen, S. W., Abbas, B. A., Schouten, S., and Sinninghe Damste, J. S.: A
comprehensive study of sterols in marine diatoms (Bacillariophyta):
implications for their use as tracers for diatom productivity, Limnol.
Oceanogr., 55, 91–105, https://doi.org/10.4319/lo.2010.55.1.0091, 2010.
Ribeiro, S., Limoges, A., Massé, G., Johansen, K. L., Colgan, W.,
Weckström, K., Jackson, R., Georgiadis, E., Mikkelsen, N., Kuijpers, A.,
Olsen, J., Olsen, S. M., Nissen, M., Andersen, T. J., Strunk, A., Wetterich,
S., Syväranta, J., Henderson, A. C. G., Mackay, H., Taipale, S.,
Jeppesen, E., Larsen, N. K., Crosta, X., Giraudeau, J., Wengrat, S., Nuttal,
N., Grønnow, B., Mosbech, A., and Davidson, T. A.: Vulnerability of the
North Water ecosystem to climate change, Nat. Comm., 12, 1–12,
https://doi.org/10.1038/s41467-021-24742-0, 2021.
Rodrigo-Gámiz, M., Rampen, S. W., de Haas, H., Baas, M., Schouten, S., and Sinninghe Damsté, J. S.: Constraints on the applicability of the organic temperature proxies U
Rowland, S. J., Allard, W. G., Belt, S. T., Massé, G., Robert, J.-M.,
Blackburn, S., Frampton, D., Revill, A. T., and Volkman, J. K.: Factors
influencing the distributions of polyunsaturated terpenoids in the diatom,
Rhizosolenia setigera, Phytochemistry, 58, 717–728,
https://doi.org/10.1016/S0031-9422(01)00318-1, 2001.
Rueda, G., Rosell-Melé, A., Escala, M., Gyllencreutz, R., and Backman,
J.: Comparison of instrumental and GDGT-based estimates of sea surface and
air temperatures from the Skagerrak, Org. Geochem., 40, 287–291,
https://doi.org/10.1016/j.orggeochem.2008.10.012, 2009.
Ryan, P. A. and Münchow, A.: Sea ice draft observations in Nares Strait
from 2003 to 2012, J. Geophys. Res.-Ocean., 122, 3057–3080,
https://doi.org/10.1002/2016JC011966, 2017.
Schlitzer, R.: Ocean Data View, http://odv.awi.de (last access: 1 June 2021), 2020.
Schouten, S., Hopmans, E. C., Schefuss, E., and Sinninghe Damsté, J. S.:
Distributional variations in marine crenarchaeotal membrane lipids: a new
tool for reconstructing ancient sea water temperatures?, Earth Pl. Sc.
Lett., 204, 265–274, https://doi.org/10.1016/S0012-821X(02)00979-2, 2002.
Schouten, S., Hopmans, E. C., and Sinninghe Damsté, J. S.: The organic
geochemistry of glycerol dialkyl glycerol tetraether lipids: A review, Org.
Geochem., 54, 19–61, https://doi.org/10.1016/j.orggeochem.2012.09.006, 2013.
Sinninghe Damsté, J. S., Warden, L. A., Berg, C., Jürgens, K., and
Moros, M.: Evaluation of the distributions of hydroxylated glycerol
dibiphytanyl glycerol tetraethers (GDGTs) in Holocene Baltic Sea sediments
for reconstruction of sea surface temperature: the effect of changing
salinity, Clim. Past, 18, 2271–2288,
https://doi.org/10.5194/cp-18-2271-2022, 2022.
Smik, L. and Belt, S. T.: Distributions of the Arctic sea ice biomarker
proxy IP25 and two phytoplanktonic biomarkers in surface sediments from
West Svalbard, Org. Geochem., 105, 39–41,
https://doi.org/10.1016/j.orggeochem.2017.01.005, 2017.
Smik, L., Cabedo-Sanz, P., and Belt, S. T.: Semi-quantitative estimates of
paleo Arctic sea ice concentration based on source-specific highly branched
isoprenoid alkenes: A further development of the PIP25 index, Org. Geochem.,
92, 63–69, https://doi.org/10.1016/j.orggeochem.2015.12.007, 2016.
Smith, J. A., Hillenbrand, C. D., Pudsey, C. J., Allen, C. S., and Graham,
A. G. C.: The presence of polynyas in the Weddell Sea during the Last
Glacial Period with implications for the reconstruction of sea-ice limits
and ice sheet history, Earth Pl. Sc. Lett., 296, 287–298,
https://doi.org/10.1016/j.epsl.2010.05.008, 2010.
Stirling, I.: The biological importance of polynyas in the Canadian Arctic,
Arctic, 33, 303–315, https://doi.org/10.14430/arctic2563, 1980.
Stoynova, V., Shanahan, T. M., Hughen, K. A., and de Vernal, A.: Insights
into Circum-Arctic sea ice variability from molecular geochemistry, Quaternary
Sci. Rev., 79, 63–73, https://doi.org/10.1016/j.quascirev.2012.10.006, 2013.
Syring, N., Stein, R., Fahl, K., Vahlenkamp, M., Zehnich, M., Spielhagen, R.
F., and Niessen, F.: Holocene changes in sea-ice cover and polynya formation
along the eastern North Greenland shelf: New insights from biomarker
records, Quaternary Sci. Rev., 231, 106173,
https://doi.org/10.1016/j.quascirev.2020.106173, 2020.
Tang, C. C. L., Ross, C. K., Yao, T., Petrie, B., DeTracey, B. M., and
Dunlap, E.: The circulation, water masses and sea-ice of Baffin Bay, Prog.
Oceanogr., 63, 183–228, https://doi.org/10.1016/j.pocean.2004.09.005, 2004.
Tierney, J. E. and Tingley, M. P.: A Bayesian, spatially-varying
calibration model for the TEX86 proxy, Geochim. Cosmochim. Ac., 127,
83–106, https://doi.org/10.1016/j.gca.2013.11.026, 2014.
Tierney, E. and Tingley, M. P.: BAYSPLINE: A new calibration for the alkenone paleothermometer, Paleoceanogr. Paleocl., 33, 281–301, https://doi.org/10.1002/2017PA003201, 2018.
Tremblay, J.-E., Gratton, Y., Fauchot, J., and Price, N. M.: Climatic and
oceanic forcing of new, net, and diatom production in the North Water,
Deep-Sea Res. Pt. II, 49, 4927–4946,
https://doi.org/10.1016/S0967-0645(02)00171-6, 2002.
Villanueva, L., Schouten, S., and Sinninghe Damsté, J. S.:
Depth-related distribution of a key gene of the tetraether lipid
biosynthetic pathway in marine Thaumarchaeota, Environ. Microbiol., 17,
3527–3539, https://doi.org/10.1111/1462-2920.12508, 2015.
Vincent, R. F.: A study of the North Water Polynya ice arch using four
decades of satellite data, Sci. Rep., 9, 1–12,
https://doi.org/10.1038/s41598-019-56780-6, 2019.
Volkman, J. K.: A review of sterol markers for marine and terrigenous
organic matter, Org. Geochem., 9, 83–99,
https://doi.org/10.1016/0146-6380(86)90089-6, 1986.
Volkman, J. K., Barrett, S. M., Dunstan, G. A., and Jeffrey, S. W.:
Geochemical significance of the occurrence of dinosterol and other 4-methyl
sterols in a marine diatom, Org. Geochem., 20, 7–15,
https://doi.org/10.1016/0146-6380(93)90076-N, 1993.
Wei, B., Jia, G., Hefter, J., Kang, M., Park, E., and Mollenhauer, G.:
Comparison of the U
Wuchter, C., Schouten, S., Coolen, M. J. L., and Sinninghe Damsté, J.
S.: Temperature-dependent variation in the distribution of tetraether
membrane lipids of marine Crenarchaeota: Implications for TEX86
paleothermometry, Paleoceanography, 19, PA4028,
https://doi.org/10.1029/2004PA001041, 2004.
Wuchter, C., Schouten, S., Wakeham, S. G., and Sinninghe Damsté, J. S.:
Temporal and spatial variation in tetraether membrane lipids of marine
Crenarchaeota in particulate organic matter: Implications for TEX86
paleothermometry, Paleoceanography, 20, PA3013,
https://doi.org/10.1029/2004PA001110, 2005.
Xiao, X., Fahl, K., Müller, J., and Stein, R.: Sea-ice
distribution in the modern Arctic Ocean: Biomarker records from trans-Arctic
Ocean surface sediments, Geochim. Cosmochim. Ac., 155, 16–29,
https://doi.org/10.1016/j.gca.2015.01.029, 2015.
Zhang, Y. G., Pagani, M., and Wang, Z.: Ring index: A new strategy to evaluate
the integrity of TEX86 paleothermometry, Paleoceanography, 32, 220–232,
https://doi.org/10.1002/2015PA002848, 2016.
Zhu, C., Wakeham, S. G., Elling, F. J., Basse, A., Mollenhauer, G.,
Versteegh, G. J. M., Könneke, M., and Hinrichs, K. U.: Stratification of
archaeal membrane lipids in the ocean and implications for adaptation and
chemotaxonomy of planktonic archaea, Environ. Microbiol., 18, 4324–4336,
https://doi.org/10.1111/1462-2920.13289, 2016.
Zweng, M. M., Reagan, J. R., Seidov, D., Boyer, T. P., Locarnini, R. A.,
Garcia, H. E., Mishonov, A. V., Baranova, O. K., Weathers, K., Paver, C. R.,
and Smolyar, I.: World Ocean Atlas 2018, Vol. 2, Salinity, A. Mishonov Technical Edn., NOAA Atlas NESDIS 82, 50 pp., NOAA National Centers for Environmental Information [data set],
2018.
Short summary
In order to better reconstruct the geologic history of the North Water Polynya, we provide modern validations and calibrations of lipid biomarker proxies in Baffin Bay. We find that sterols, rather than HBIs, most accurately capture the current extent of the North Water Polynya and will be a valuable tool to reconstruct its past presence or absence. Our local temperature calibrations for GDGTs and OH-GDGTs reduce the uncertainty present in global temperature calibrations.
In order to better reconstruct the geologic history of the North Water Polynya, we provide...
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