Articles | Volume 21, issue 3
https://doi.org/10.5194/cp-21-679-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/cp-21-679-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Contrasts in the marine inorganic carbon chemistry of the Benguela Upwelling System since the Last Glacial Maximum
Department of Ocean Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, the Netherlands
Lennart J. de Nooijer
Department of Ocean Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, the Netherlands
Bas van der Wagt
Department of Ocean Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, the Netherlands
Marcel T. J. van der Meer
Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, Texel, the Netherlands
Sambuddha Misra
Centre for Earth Sciences, Indian Institute of Science, Bengaluru, India
Rick Hennekam
Department of Ocean Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, the Netherlands
Zeynep Erdem
Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, Texel, the Netherlands
Julie Lattaud
Department of Environmental Sciences, University of Basel, Basel, Switzerland
Negar Haghipour
Geological Institute, Department of Earth Sciences, ETH Zürich, Zürich, Switzerland
Laboratory of Ion Beam Physics, ETH Zürich, Zürich, Switzerland
Stefan Schouten
Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, Texel, the Netherlands
Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, the Netherlands
Gert-Jan Reichart
Department of Ocean Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, the Netherlands
Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, the Netherlands
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Clim. Past, 21, 957–971, https://doi.org/10.5194/cp-21-957-2025, https://doi.org/10.5194/cp-21-957-2025, 2025
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As human activities lower marine oxygen levels, understanding the impact on the marine nitrogen cycle is vital. The Black Sea, which became oxygen-deprived 9600 years ago, offers key insights. By studying organic compounds linked to nitrogen cycle processes, we found that, 7200 years ago, the Black Sea's nitrogen cycle significantly altered due to severe deoxygenation. This suggests that continued marine oxygen decline could similarly alter the marine nitrogen cycle, affecting vital ecosystems.
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EGUsphere, https://doi.org/10.5194/egusphere-2025-1796, https://doi.org/10.5194/egusphere-2025-1796, 2025
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EGUsphere, https://doi.org/10.5194/egusphere-2025-1870, https://doi.org/10.5194/egusphere-2025-1870, 2025
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Yannick F. Bats, Klaas G. J. Nierop, Alice Stuart-Lee, Joost Frieling, Linda van Roij, Gert-Jan Reichart, and Appy Sluijs
EGUsphere, https://doi.org/10.5194/egusphere-2025-1678, https://doi.org/10.5194/egusphere-2025-1678, 2025
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Babette A.A. Hoogakker, Catherine Davis, Yi Wang, Stephanie Kusch, Katrina Nilsson-Kerr, Dalton S. Hardisty, Allison Jacobel, Dharma Reyes Macaya, Nicolaas Glock, Sha Ni, Julio Sepúlveda, Abby Ren, Alexandra Auderset, Anya V. Hess, Katrin J. Meissner, Jorge Cardich, Robert Anderson, Christine Barras, Chandranath Basak, Harold J. Bradbury, Inda Brinkmann, Alexis Castillo, Madelyn Cook, Kassandra Costa, Constance Choquel, Paula Diz, Jonas Donnenfield, Felix J. Elling, Zeynep Erdem, Helena L. Filipsson, Sebastián Garrido, Julia Gottschalk, Anjaly Govindankutty Menon, Jeroen Groeneveld, Christian Hallmann, Ingrid Hendy, Rick Hennekam, Wanyi Lu, Jean Lynch-Stieglitz, Lélia Matos, Alfredo Martínez-García, Giulia Molina, Práxedes Muñoz, Simone Moretti, Jennifer Morford, Sophie Nuber, Svetlana Radionovskaya, Morgan Reed Raven, Christopher J. Somes, Anja S. Studer, Kazuyo Tachikawa, Raúl Tapia, Martin Tetard, Tyler Vollmer, Xingchen Wang, Shuzhuang Wu, Yan Zhang, Xin-Yuan Zheng, and Yuxin Zhou
Biogeosciences, 22, 863–957, https://doi.org/10.5194/bg-22-863-2025, https://doi.org/10.5194/bg-22-863-2025, 2025
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Atmos. Meas. Tech., 18, 319–325, https://doi.org/10.5194/amt-18-319-2025, https://doi.org/10.5194/amt-18-319-2025, 2025
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Biogeosciences, 21, 4875–4888, https://doi.org/10.5194/bg-21-4875-2024, https://doi.org/10.5194/bg-21-4875-2024, 2024
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EGUsphere, https://doi.org/10.5194/egusphere-2024-2853, https://doi.org/10.5194/egusphere-2024-2853, 2024
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Charlotte Eich, Mathijs van Manen, J. Scott P. McCain, Loay J. Jabre, Willem H. van de Poll, Jinyoung Jung, Sven B. E. H. Pont, Hung-An Tian, Indah Ardiningsih, Gert-Jan Reichart, Erin M. Bertrand, Corina P. D. Brussaard, and Rob Middag
Biogeosciences, 21, 4637–4663, https://doi.org/10.5194/bg-21-4637-2024, https://doi.org/10.5194/bg-21-4637-2024, 2024
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Guangnan Wu, Klaas G. J. Nierop, Bingjie Yang, Stefan Schouten, Gert-Jan Reichart, and Peter Kraal
EGUsphere, https://doi.org/10.5194/egusphere-2024-3192, https://doi.org/10.5194/egusphere-2024-3192, 2024
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Estuaries store and process large amounts of carbon, making them vital to the global carbon cycle. In the Port of Rotterdam, we studied the source of organic matter (OM) in sediments and how it influences OM breakdown. We found that marine OM degrades faster than land OM, and human activities like dredging can accelerate this by exposing sediments to oxygen. Our findings highlight the impact of human activities on carbon storage in estuaries, which is key for managing estuarine carbon dynamics.
Zoë Rebecca van Kemenade, Zeynep Erdem, Ellen Christine Hopmans, Jaap Smede Sinninghe Damsté, and Darci Rush
Biogeosciences, 21, 1517–1532, https://doi.org/10.5194/bg-21-1517-2024, https://doi.org/10.5194/bg-21-1517-2024, 2024
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The California Current system (CCS) hosts the eastern subtropical North Pacific oxygen minimum zone (ESTNP OMZ). This study shows anaerobic ammonium oxidizing (anammox) bacteria cause a loss of bioavailable nitrogen (N) in the ESTNP OMZ throughout the late Quaternary. Anammox occurred during both glacial and interglacial periods and was driven by the supply of organic matter and changes in ocean currents. These findings may have important consequences for biogeochemical models of the CCS.
Vera Dorothee Meyer, Jürgen Pätzold, Gesine Mollenhauer, Isla S. Castañeda, Stefan Schouten, and Enno Schefuß
Clim. Past, 20, 523–546, https://doi.org/10.5194/cp-20-523-2024, https://doi.org/10.5194/cp-20-523-2024, 2024
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The climatic factors sustaining vegetation in the Sahara during the African humid period (AHP) are still not fully understood. Using biomarkers in a marine sediment core from the eastern Mediterranean, we infer variations in Mediterranean (winter) and monsoonal (summer) rainfall in the Nile river watershed around the AHP. We find that winter and summer rain enhanced during the AHP, suggesting that Mediterranean moisture supported the monsoon in sustaining the “green Sahara”.
Miguel Bartolomé, Ana Moreno, Carlos Sancho, Isabel Cacho, Heather Stoll, Negar Haghipour, Ánchel Belmonte, Christoph Spötl, John Hellstrom, R. Lawrence Edwards, and Hai Cheng
Clim. Past, 20, 467–494, https://doi.org/10.5194/cp-20-467-2024, https://doi.org/10.5194/cp-20-467-2024, 2024
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Reconstructing past temperatures at regional scales during the Common Era is necessary to place the current warming in the context of natural climate variability. We present a climate reconstruction based on eight stalagmites from four caves in the Pyrenees, NE Spain. These stalagmites were dated precisely and analysed for their oxygen isotopes, which appear dominated by temperature changes. Solar variability and major volcanic eruptions are the two main drivers of observed climate variability.
Kirsi H. Keskitalo, Lisa Bröder, Tommaso Tesi, Paul J. Mann, Dirk J. Jong, Sergio Bulte Garcia, Anna Davydova, Sergei Davydov, Nikita Zimov, Negar Haghipour, Timothy I. Eglinton, and Jorien E. Vonk
Biogeosciences, 21, 357–379, https://doi.org/10.5194/bg-21-357-2024, https://doi.org/10.5194/bg-21-357-2024, 2024
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Permafrost thaw releases organic carbon into waterways. Decomposition of this carbon pool emits greenhouse gases into the atmosphere, enhancing climate warming. We show that Arctic river carbon and water chemistry are different between the spring ice breakup and summer and that primary production is initiated in small Arctic rivers right after ice breakup, in contrast to in large rivers. This may have implications for fluvial carbon dynamics and greenhouse gas uptake and emission balance.
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.
Katrin Hättig, Devika Varma, Stefan Schouten, and Marcel T. J. van der Meer
Clim. Past, 19, 1919–1930, https://doi.org/10.5194/cp-19-1919-2023, https://doi.org/10.5194/cp-19-1919-2023, 2023
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Water isotopes, both hydrogen and oxygen, correlate with the salinity of the sea. Here we reconstruct the surface seawater isotopic composition during the last deglaciation based on the measured hydrogen isotopic composition of alkenones, organic compounds derived from haptophyte algae, and compared it to oxygen isotopes of calcite shells produced in the bottom water. Our results suggest that surface seawater experienced more freshening during the last 20 000 years than the bottom seawater.
Laura Pacho, Lennart de Nooijer, and Gert-Jan Reichart
Biogeosciences, 20, 4043–4056, https://doi.org/10.5194/bg-20-4043-2023, https://doi.org/10.5194/bg-20-4043-2023, 2023
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We analyzed Mg / Ca and other El / Ca (Na / Ca, B / Ca, Sr / Ca and Ba / Ca) in Nodosariata. Their calcite chemistry is markedly different to that of the other calcifying orders of foraminifera. We show a relation between the species average Mg / Ca and its sensitivity to changes in temperature. Differences were reflected in both the Mg incorporation and the sensitivities of Mg / Ca to temperature.
Niels J. de Winter, Daniel Killam, Lukas Fröhlich, Lennart de Nooijer, Wim Boer, Bernd R. Schöne, Julien Thébault, and Gert-Jan Reichart
Biogeosciences, 20, 3027–3052, https://doi.org/10.5194/bg-20-3027-2023, https://doi.org/10.5194/bg-20-3027-2023, 2023
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Mollusk shells are valuable recorders of climate and environmental changes of the past down to a daily resolution. To explore this potential, we measured changes in the composition of shells of two types of bivalves recorded at the hourly scale: the king scallop Pecten maximus and giant clams (Tridacna) that engaged in photosymbiosis. We find that photosymbiosis produces more day–night fluctuation in shell chemistry but that most of the variation is not periodic, perhaps recording weather.
Oliver Kost, Saúl González-Lemos, Laura Rodríguez-Rodríguez, Jakub Sliwinski, Laura Endres, Negar Haghipour, and Heather Stoll
Hydrol. Earth Syst. Sci., 27, 2227–2255, https://doi.org/10.5194/hess-27-2227-2023, https://doi.org/10.5194/hess-27-2227-2023, 2023
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Cave monitoring studies including cave drip water are unique opportunities to sample water which has percolated through the soil and rock. The change in drip water chemistry is resolved over the course of 16 months, inferring seasonal and hydrological variations in soil and karst processes at the water–air and water–rock interface. Such data sets improve the understanding of hydrological and hydrochemical processes and ultimately advance the interpretation of geochemical stalagmite records.
Thibauld M. Béjard, Andrés S. Rigual-Hernández, José A. Flores, Javier P. Tarruella, Xavier Durrieu de Madron, Isabel Cacho, Neghar Haghipour, Aidan Hunter, and Francisco J. Sierro
Biogeosciences, 20, 1505–1528, https://doi.org/10.5194/bg-20-1505-2023, https://doi.org/10.5194/bg-20-1505-2023, 2023
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The Mediterranean Sea is undergoing a rapid and unprecedented environmental change. Planktic foraminifera calcification is affected on different timescales. On seasonal and interannual scales, calcification trends differ according to the species and are linked mainly to sea surface temperatures and carbonate system parameters, while comparison with pre/post-industrial assemblages shows that all three species have reduced their calcification between 10 % to 35 % according to the species.
Dirk Jong, Lisa Bröder, Tommaso Tesi, Kirsi H. Keskitalo, Nikita Zimov, Anna Davydova, Philip Pika, Negar Haghipour, Timothy I. Eglinton, and Jorien E. Vonk
Biogeosciences, 20, 271–294, https://doi.org/10.5194/bg-20-271-2023, https://doi.org/10.5194/bg-20-271-2023, 2023
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With this study, we want to highlight the importance of studying both land and ocean together, and water and sediment together, as these systems function as a continuum, and determine how organic carbon derived from permafrost is broken down and its effect on global warming. Although on the one hand it appears that organic carbon is removed from sediments along the pathway of transport from river to ocean, it also appears to remain relatively ‘fresh’, despite this removal and its very old age.
Kasia K. Śliwińska, Helen K. Coxall, David K. Hutchinson, Diederik Liebrand, Stefan Schouten, and Agatha M. de Boer
Clim. Past, 19, 123–140, https://doi.org/10.5194/cp-19-123-2023, https://doi.org/10.5194/cp-19-123-2023, 2023
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We provide a sea surface temperature record from the Labrador Sea (ODP Site 647) based on organic geochemical proxies across the late Eocene and early Oligocene. Our study reveals heterogenic cooling of the Atlantic. The cooling of the North Atlantic is difficult to reconcile with the active Atlantic Meridional Overturning Circulation (AMOC). We discuss possible explanations like uncertainty in the data, paleogeography and atmospheric CO2 boundary conditions, model weaknesses, and AMOC activity.
Melissa Sophia Schwab, Hannah Gies, Chantal Valérie Freymond, Maarten Lupker, Negar Haghipour, and Timothy Ian Eglinton
Biogeosciences, 19, 5591–5616, https://doi.org/10.5194/bg-19-5591-2022, https://doi.org/10.5194/bg-19-5591-2022, 2022
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The majority of river studies focus on headwater or floodplain systems, while often neglecting intermediate river segments. Our study on the subalpine Sihl River bridges the gap between streams and lowlands and demonstrates that moderately steep river segments are areas of significant instream alterations, modulating the export of organic carbon over short distances.
Rick Hennekam, Katharine M. Grant, Eelco J. Rohling, Rik Tjallingii, David Heslop, Andrew P. Roberts, Lucas J. Lourens, and Gert-Jan Reichart
Clim. Past, 18, 2509–2521, https://doi.org/10.5194/cp-18-2509-2022, https://doi.org/10.5194/cp-18-2509-2022, 2022
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The ratio of titanium to aluminum (Ti/Al) is an established way to reconstruct North African climate in eastern Mediterranean Sea sediments. We demonstrate here how to obtain reliable Ti/Al data using an efficient scanning method that allows rapid acquisition of long climate records at low expense. Using this method, we reconstruct a 3-million-year North African climate record. African environmental variability was paced predominantly by low-latitude insolation from 3–1.2 million years ago.
Frédérique M. S. A. Kirkels, Hugo J. de Boer, Paulina Concha Hernández, Chris R. T. Martes, Marcel T. J. van der Meer, Sayak Basu, Muhammed O. Usman, and Francien Peterse
Biogeosciences, 19, 4107–4127, https://doi.org/10.5194/bg-19-4107-2022, https://doi.org/10.5194/bg-19-4107-2022, 2022
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The distinct carbon isotopic values of C3 and C4 plants are widely used to reconstruct past hydroclimate, where more C3 plants reflect wetter and C4 plants drier conditions. Here we examine the impact of regional hydroclimatic conditions on plant isotopic values in the Godavari River basin, India. We find that it is crucial to identify regional plant isotopic values and consider drought stress, which introduces a bias in C3 / C4 plant estimates and associated hydroclimate reconstructions.
Carolien M. H. van der Weijst, Koen J. van der Laan, Francien Peterse, Gert-Jan Reichart, Francesca Sangiorgi, Stefan Schouten, Tjerk J. T. Veenstra, and Appy Sluijs
Clim. Past, 18, 1947–1962, https://doi.org/10.5194/cp-18-1947-2022, https://doi.org/10.5194/cp-18-1947-2022, 2022
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The TEX86 proxy is often used by paleoceanographers to reconstruct past sea-surface temperatures. However, the origin of the TEX86 signal in marine sediments has been debated since the proxy was first proposed. In our paper, we show that TEX86 carries a mixed sea-surface and subsurface temperature signal and should be calibrated accordingly. Using our 15-million-year record, we subsequently show how a TEX86 subsurface temperature record can be used to inform us on past sea-surface temperatures.
Carolien M. H. van der Weijst, Josse Winkelhorst, Wesley de Nooijer, Anna von der Heydt, Gert-Jan Reichart, Francesca Sangiorgi, and Appy Sluijs
Clim. Past, 18, 961–973, https://doi.org/10.5194/cp-18-961-2022, https://doi.org/10.5194/cp-18-961-2022, 2022
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A hypothesized link between Pliocene (5.3–2.5 million years ago) global climate and tropical thermocline depth is currently only backed up by data from the Pacific Ocean. In our paper, we present temperature, salinity, and thermocline records from the tropical Atlantic Ocean. Surprisingly, the Pliocene thermocline evolution was remarkably different in the Atlantic and Pacific. We need to reevaluate the mechanisms that drive thermocline depth, and how these are tied to global climate change.
Gabriella M. Weiss, Julie Lattaud, Marcel T. J. van der Meer, and Timothy I. Eglinton
Clim. Past, 18, 233–248, https://doi.org/10.5194/cp-18-233-2022, https://doi.org/10.5194/cp-18-233-2022, 2022
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Here we study the elemental signatures of plant wax compounds as well as molecules from algae and bacteria to understand how water sources changed over the last 11 000 years in the northeastern part of Europe surrounding the Baltic Sea. Our results show diversity in plant and aquatic microorganisms following the melting of the large ice sheet that covered northern Europe as the regional climate continued to warm. A shift in water source from ice melt to rain also occurred around the same time.
Maxence Guillermic, Sambuddha Misra, Robert Eagle, and Aradhna Tripati
Clim. Past, 18, 183–207, https://doi.org/10.5194/cp-18-183-2022, https://doi.org/10.5194/cp-18-183-2022, 2022
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Here we reconstruct atmospheric CO2 values across major climate transitions over the past 16 million years (Myr) from two sites in the West Pacific Warm Pool using a pH proxy on surface-dwelling foraminifera. We are able to reproduce pCO2 data from ice cores; therefore we apply the same framework to older samples to create a long-term pH and pCO2 reconstruction. We give quantitative constraints on pH and pCO2 changes over the main climate transitions of the last 16 Myr.
Blanca Ausín, Negar Haghipour, Elena Bruni, and Timothy Eglinton
Biogeosciences, 19, 613–627, https://doi.org/10.5194/bg-19-613-2022, https://doi.org/10.5194/bg-19-613-2022, 2022
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The preservation and distribution of alkenones – organic molecules produced by marine algae – in marine sediments allows us to reconstruct past variations in sea surface temperature, primary productivity and CO2. Here, we explore the impact of remobilization and lateral transport of sedimentary alkenones on their fate in marine sediments. We demonstrate the pervasive influence of these processes on alkenone-derived environmental signals, compromising the reliability of related paleorecords.
Matthew P. Humphreys, Erik H. Meesters, Henk de Haas, Szabina Karancz, Louise Delaigue, Karel Bakker, Gerard Duineveld, Siham de Goeyse, Andreas F. Haas, Furu Mienis, Sharyn Ossebaar, and Fleur C. van Duyl
Biogeosciences, 19, 347–358, https://doi.org/10.5194/bg-19-347-2022, https://doi.org/10.5194/bg-19-347-2022, 2022
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A series of submarine sinkholes were recently discovered on Luymes Bank, part of Saba Bank, a carbonate platform in the Caribbean Netherlands. Here, we investigate the waters inside these sinkholes for the first time. One of the sinkholes contained a body of dense, low-oxygen and low-pH water, which we call the
acid lake. We use measurements of seawater chemistry to work out what processes were responsible for forming the acid lake and discuss the consequences for the carbonate platform.
Alice E. Webb, Didier M. de Bakker, Karline Soetaert, Tamara da Costa, Steven M. A. C. van Heuven, Fleur C. van Duyl, Gert-Jan Reichart, and Lennart J. de Nooijer
Biogeosciences, 18, 6501–6516, https://doi.org/10.5194/bg-18-6501-2021, https://doi.org/10.5194/bg-18-6501-2021, 2021
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The biogeochemical behaviour of shallow reef communities is quantified to better understand the impact of habitat degradation and species composition shifts on reef functioning. The reef communities investigated barely support reef functions that are usually ascribed to conventional coral reefs, and the overall biogeochemical behaviour is found to be similar regardless of substrate type. This suggests a decrease in functional diversity which may therefore limit services provided by this reef.
Franziska A. Lechleitner, Christopher C. Day, Oliver Kost, Micah Wilhelm, Negar Haghipour, Gideon M. Henderson, and Heather M. Stoll
Clim. Past, 17, 1903–1918, https://doi.org/10.5194/cp-17-1903-2021, https://doi.org/10.5194/cp-17-1903-2021, 2021
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Soil respiration is a critical but poorly constrained component of the global carbon cycle. We analyse the effect of changing soil respiration rates on the stable carbon isotope ratio of speleothems from northern Spain covering the last deglaciation. Using geochemical analysis and forward modelling we quantify the processes affecting speleothem stable carbon isotope ratios and extract a signature of increasing soil respiration synchronous with deglacial warming.
Indah Ardiningsih, Kyyas Seyitmuhammedov, Sylvia G. Sander, Claudine H. Stirling, Gert-Jan Reichart, Kevin R. Arrigo, Loes J. A. Gerringa, and Rob Middag
Biogeosciences, 18, 4587–4601, https://doi.org/10.5194/bg-18-4587-2021, https://doi.org/10.5194/bg-18-4587-2021, 2021
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Organic Fe speciation is investigated along a natural gradient of the western Antarctic Peninsula from an ice-covered shelf to the open ocean. The two major fronts in the region affect the distribution of ligands. The excess ligands not bound to dissolved Fe (DFe) comprised up to 80 % of the total ligand concentrations, implying the potential to solubilize additional Fe input. The ligands on the shelf can increase the DFe residence time and fuel local primary production upon ice melt.
Elena T. Bruni, Richard F. Ott, Vincenzo Picotti, Negar Haghipour, Karl W. Wegmann, and Sean F. Gallen
Earth Surf. Dynam., 9, 771–793, https://doi.org/10.5194/esurf-9-771-2021, https://doi.org/10.5194/esurf-9-771-2021, 2021
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The Klados River catchment contains seemingly overlarge, well-preserved alluvial terraces and fans. Unlike previous studies, we argue that the deposits formed in the Holocene based on their position relative to a paleoshoreline uplifted in 365 CE and seven radiocarbon dates. We also find that constant sediment supply from high-lying landslide deposits disconnected the valley from regional tectonics and climate controls, which resulted in fan and terrace formation guided by stochastic events.
Charlotte L. Spencer-Jones, Erin L. McClymont, Nicole J. Bale, Ellen C. Hopmans, Stefan Schouten, Juliane Müller, E. Povl Abrahamsen, Claire Allen, Torsten Bickert, Claus-Dieter Hillenbrand, Elaine Mawbey, Victoria Peck, Aleksandra Svalova, and James A. Smith
Biogeosciences, 18, 3485–3504, https://doi.org/10.5194/bg-18-3485-2021, https://doi.org/10.5194/bg-18-3485-2021, 2021
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Long-term ocean temperature records are needed to fully understand the impact of West Antarctic Ice Sheet collapse. Glycerol dialkyl glycerol tetraethers (GDGTs) are powerful tools for reconstructing ocean temperature but can be difficult to apply to the Southern Ocean. Our results show active GDGT synthesis in relatively warm depths of the ocean. This research improves the application of GDGT palaeoceanographic proxies in the Southern Ocean.
Jannik Martens, Evgeny Romankevich, Igor Semiletov, Birgit Wild, Bart van Dongen, Jorien Vonk, Tommaso Tesi, Natalia Shakhova, Oleg V. Dudarev, Denis Kosmach, Alexander Vetrov, Leopold Lobkovsky, Nikolay Belyaev, Robie W. Macdonald, Anna J. Pieńkowski, Timothy I. Eglinton, Negar Haghipour, Salve Dahle, Michael L. Carroll, Emmelie K. L. Åström, Jacqueline M. Grebmeier, Lee W. Cooper, Göran Possnert, and Örjan Gustafsson
Earth Syst. Sci. Data, 13, 2561–2572, https://doi.org/10.5194/essd-13-2561-2021, https://doi.org/10.5194/essd-13-2561-2021, 2021
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The paper describes the establishment, structure and current status of the first Circum-Arctic Sediment CArbon DatabasE (CASCADE), which is a scientific effort to harmonize and curate all published and unpublished data of carbon, nitrogen, carbon isotopes, and terrigenous biomarkers in sediments of the Arctic Ocean in one database. CASCADE will enable a variety of studies of the Arctic carbon cycle and thus contribute to a better understanding of how climate change affects the Arctic.
Cécile L. Blanchet, Rik Tjallingii, Anja M. Schleicher, Stefan Schouten, Martin Frank, and Achim Brauer
Clim. Past, 17, 1025–1050, https://doi.org/10.5194/cp-17-1025-2021, https://doi.org/10.5194/cp-17-1025-2021, 2021
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The Mediterranean Sea turned repeatedly into an oxygen-deprived basin during the geological past, as evidenced by distinct sediment layers called sapropels. We use here records of the last sapropel S1 retrieved in front of the Nile River to explore the relationships between riverine input and seawater oxygenation. We decipher the seasonal cycle of fluvial input and seawater chemistry as well as the decisive influence of primary productivity on deoxygenation at millennial timescales.
Ove H. Meisel, Joshua F. Dean, Jorien E. Vonk, Lukas Wacker, Gert-Jan Reichart, and Han Dolman
Biogeosciences, 18, 2241–2258, https://doi.org/10.5194/bg-18-2241-2021, https://doi.org/10.5194/bg-18-2241-2021, 2021
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Arctic permafrost lakes form thaw bulbs of unfrozen soil (taliks) beneath them where carbon degradation and greenhouse gas production are increased. We analyzed the stable carbon isotopes of Alaskan talik sediments and their porewater dissolved organic carbon and found that the top layers of these taliks are likely more actively degraded than the deeper layers. This in turn implies that these top layers are likely also more potent greenhouse gas producers than the underlying deeper layers.
Nadine T. Smit, Laura Villanueva, Darci Rush, Fausto Grassa, Caitlyn R. Witkowski, Mira Holzheimer, Adriaan J. Minnaard, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 18, 1463–1479, https://doi.org/10.5194/bg-18-1463-2021, https://doi.org/10.5194/bg-18-1463-2021, 2021
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Soils from an everlasting fire (gas seep) in Sicily, Italy, reveal high relative abundances of novel uncultivated mycobacteria and unique 13C-depleted mycocerosic acids (multi-methyl branched fatty acids) close to the main gas seep. Our results imply that mycocerosic acids in combination with their depleted δ13C values offer a new biomarker tool to study the role of soil mycobacteria as hydrocarbon consumers in the modern and past global carbon cycle.
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.
Siham de Goeyse, Alice E. Webb, Gert-Jan Reichart, and Lennart J. de Nooijer
Biogeosciences, 18, 393–401, https://doi.org/10.5194/bg-18-393-2021, https://doi.org/10.5194/bg-18-393-2021, 2021
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Foraminifera are calcifying organisms that play a role in the marine inorganic-carbon cycle and are widely used to reconstruct paleoclimates. However, the fundamental process by which they calcify remains essentially unknown. Here we use inhibitors to show that an enzyme is speeding up the conversion between bicarbonate and CO2. This helps the foraminifera acquire sufficient carbon for calcification and might aid their tolerance to elevated CO2 level.
Hannah Gies, Frank Hagedorn, Maarten Lupker, Daniel Montluçon, Negar Haghipour, Tessa Sophia van der Voort, and Timothy Ian Eglinton
Biogeosciences, 18, 189–205, https://doi.org/10.5194/bg-18-189-2021, https://doi.org/10.5194/bg-18-189-2021, 2021
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Understanding controls on the persistence of organic matter in soils is essential to constrain its role in the carbon cycle. Emerging concepts suggest that the soil carbon pool is predominantly comprised of stabilized microbial residues. To test this hypothesis we isolated microbial membrane lipids from two Swiss soil profiles and measured their radiocarbon age. We find that the ages of these compounds are in the range of millenia and thus provide evidence for stabilized microbial mass in soils.
Linda K. Dämmer, Lennart de Nooijer, Erik van Sebille, Jan G. Haak, and Gert-Jan Reichart
Clim. Past, 16, 2401–2414, https://doi.org/10.5194/cp-16-2401-2020, https://doi.org/10.5194/cp-16-2401-2020, 2020
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The compositions of foraminifera shells often vary with environmental parameters such as temperature or salinity; thus, they can be used as proxies for these environmental variables. Often a single proxy is influenced by more than one parameter. Here, we show that while salinity impacts shell Na / Ca, temperature has no effect. We also show that the combination of different proxies (Mg / Ca and δ18O) to reconstruct salinity does not seem to work as previously thought.
Appy Sluijs, Joost Frieling, Gordon N. Inglis, Klaas G. J. Nierop, Francien Peterse, Francesca Sangiorgi, and Stefan Schouten
Clim. Past, 16, 2381–2400, https://doi.org/10.5194/cp-16-2381-2020, https://doi.org/10.5194/cp-16-2381-2020, 2020
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We revisit 15-year-old reconstructions of sea surface temperatures in the Arctic Ocean for the late Paleocene and early Eocene epochs (∼ 57–53 million years ago) based on the distribution of fossil membrane lipids of archaea preserved in Arctic Ocean sediments. We find that improvements in the methods over the past 15 years do not lead to different results. However, data quality is now higher and potential biases better characterized. Results confirm remarkable Arctic warmth during this time.
Anne Roepert, Lubos Polerecky, Esmee Geerken, Gert-Jan Reichart, and Jack J. Middelburg
Biogeosciences, 17, 4727–4743, https://doi.org/10.5194/bg-17-4727-2020, https://doi.org/10.5194/bg-17-4727-2020, 2020
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We investigated, for the first time, the spatial distribution of chlorine and fluorine in the shell walls of four benthic foraminifera species: Ammonia tepida, Amphistegina lessonii, Archaias angulatus, and Sorites marginalis. Cross sections of specimens were imaged using nanoSIMS. The distribution of Cl and F was co-located with organics in the rotaliids and rather homogeneously distributed in miliolids. We suggest that the incorporation is governed by the biomineralization pathway.
Marlow Julius Cramwinckel, Lineke Woelders, Emiel P. Huurdeman, Francien Peterse, Stephen J. Gallagher, Jörg Pross, Catherine E. Burgess, Gert-Jan Reichart, Appy Sluijs, and Peter K. Bijl
Clim. Past, 16, 1667–1689, https://doi.org/10.5194/cp-16-1667-2020, https://doi.org/10.5194/cp-16-1667-2020, 2020
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Phases of past transient warming can be used as a test bed to study the environmental response to climate change independent of tectonic change. Using fossil plankton and organic molecules, here we reconstruct surface ocean temperature and circulation in and around the Tasman Gateway during a warming phase 40 million years ago termed the Middle Eocene Climatic Optimum. We find that plankton assemblages track ocean circulation patterns, with superimposed variability being related to temperature.
Cited articles
Alldredge, A. L. and Silver, M. W.: Characteristics, dynamics and significance of marine snow, Prog. Oceanogr., 20, 41–82, https://doi.org/10.1016/0079-6611(88)90053-5, 1988.
Allen, K. A., Hönisch, B., Eggins, S. M., Haynes, L. L., Rosenthal, Y., and Yu, J.: Trace element proxies for surface ocean conditions: A synthesis of culture calibrations with planktic foraminifera, Geochim. Cosmochim. Ac., 193, 197–221, https://doi.org/10.1016/j.gca.2016.08.015, 2016.
Alley, R. B.: The Younger Dryas cold interval as viewed from central Greenland, Quaternary Sci. Rev., 19, 213–226, https://doi.org/10.1016/S0277-3791(99)00062-1, 2000.
Andersen, N., Müller, P. J., Kirst, G., and Schneider, R. R.: Alkenone δ13C as a Proxy for Past PCO2 in Surface Waters: Results from the Late Quaternary Angola Current, in: Use of Proxies in Paleoceanography: Examples from the South Atlantic, edited by: Fischer, G. and Wefer, G., Springer Berlin Heidelberg, Berlin, Heidelberg, 469–488, https://doi.org/10.1007/978-3-642-58646-0_19, 1999.
Armstrong, R. A., Lee, C., Hedges, J. I., Honjo, S., and Wakeham, S. G.: A new, mechanistic model for organic carbon fluxes in the ocean based on the quantitative association of POC with ballast minerals, Deep-Sea Res. Pt. II, 49, 219-236, https://doi.org/10.1016/S0967-0645(01)00101-1, 2001.
Badger, M. P. S.: Alkenone isotopes show evidence of active carbon concentrating mechanisms in coccolithophores as aqueous carbon dioxide concentrations fall below 7 µmol L−1, Biogeosciences, 18, 1149–1160, https://doi.org/10.5194/bg-18-1149-2021, 2021.
Bae, S. W., Lee, K. E., and Kim, K.: Use of carbon isotopic composition of alkenone as a CO2 proxy in the East Sea/Japan Sea, Cont. Shelf Res., 107, 24–32, https://doi.org/10.1016/j.csr.2015.07.010, 2015.
Barber, D. C., Dyke, A., Hillaire-Marcel, C., Jennings, A. E., Andrews, J. T., Kerwin, M. W., Bilodeau, G., McNeely, R., Southon, J., Morehead, M. D., and Gagnon, J. M.: Forcing of the cold event of 8,200 years ago by catastrophic drainage of Laurentide lakes, Nature, 400, 344–348, https://doi.org/10.1038/22504, 1999.
Barker, S., Greaves, M., and Elderfield, H.: A study of cleaning procedures used for foraminiferal Mg Ca paleothermometry, Geochem. Geophy. Geosy., 4, 8407, https://doi.org/10.1029/2003GC000559, 2003.
Bemis, B. E., Spero, H. J., Lea, D. W., and Bijma, J.: Temperature influence on the carbon isotopic composition of Globigerina bulloides and Orbulina universa (planktonic foraminifera), Mar. Micropaleontol., 38, 213–228, https://doi.org/10.1016/S0377-8398(00)00006-2, 2000.
Bice, K. L., Birgel, D., Meyers, P. A., Dahl, K. A., Hinrichs, K.-U., and Norris, R. D.: A multiple proxy and model study of Cretaceous upper ocean temperatures and atmospheric CO2 concentrations, Paleoceanography, 21, PA2002, https://doi.org/10.1029/2005PA001203, 2006.
Bidigare, R. R., Fluegge, A., Freeman, K. H., Hanson, K. L., Hayes, J. M., Hollander, D., Jasper, J. P., King, L. L., Laws, E. A., and Milder, J.: Consistent fractionation of 13C in nature and in the laboratory: Growth-rate effects in some haptophyte algae, Global Biogeochem. Cy., 11, 279–292, https://doi.org/10.1029/96GB03939, 1997.
Bijl, P. K., Houben, A. J. P., Schouten, S., Bohaty, S. M., Sluijs, A., Reichart, G.-J., Sinninghe Damsté, J. S., and Brinkhuis, H.: Transient Middle Eocene atmospheric CO2 and temperature variations, Science, 330, 819–821, https://doi.org/10.1126/science.1193654, 2010.
Bijma, J., Spero, H., and Lea, D.: Reassessing foraminiferal stable isotope geochemistry: Impact of the oceanic carbonate system (experimental results), in: Use of proxies in paleoceanography, edited by: Fischer, G. and Wefer, G., Springer, Berlin, Heidelberg, 489–512, https://doi.org/10.1007/978-3-642-58646-0_20, 1999.
Bird, C., Darling, K. F., Russell, A. D., Davis, C. V., Fehrenbacher, J., Free, A., Wyman, M., and Ngwenya, B. T.: Cyanobacterial endobionts within a major marine planktonic calcifier (Globigerina bulloides, Foraminifera) revealed by 16S rRNA metabarcoding, Biogeosciences, 14, 901–920, https://doi.org/10.5194/bg-14-901-2017, 2017.
Blaauw, M. and Christen, J. A.: Flexible paleoclimate age-depth models using an autoregressive gamma process, Bayesian Anal., 6, 457–474, https://doi.org/10.1214/11-BA618, 2011.
Blunier, T. and Brook, E. J.: Timing of Millennial-Scale Climate Change in Antarctica and Greenland During the Last Glacial Period, Science, 291, 109–112, https://doi.org/10.1126/science.291.5501.109, 2001.
Blunier, T., Schwander, J., Stauffer, B., Stocker, T., Dällenbach, A., Indermühle, A., Tschumi, J., Chappellaz, J., Raynaud, D., and Barnola, J. M.: Timing of the Antarctic cold reversal and the atmospheric CO2 increase with respect to the Younger Dryas Event, Geophys. Res. Lett., 24, 2683–2686, https://doi.org/10.1029/97GL02658, 1997.
Boer, W., Nordstad, S., Weber, M., Mertz-Kraus, R., Hönisch, B., Bijma, J., Raitzsch, M., Wilhelms-Dick, D., Foster, G. L., and Goring-Harford, H.: New calcium carbonate nano-particulate pressed powder pellet (NFHS-2-NP) for LA-ICP-OES, LA-(MC)-ICP-MS and μ XRF, Geostand. Geoanal. Res., 46, 411–432, https://doi.org/10.1111/ggr.12425, 2022.
Bolton, C. T. and Stoll, H. M.: Late Miocene threshold response of marine algae to carbon dioxide limitation, Nature, 500, 558–562, https://doi.org/10.1038/nature12448, 2013.
Bond, G., Broecker, W., Johnsen, S., McManus, J., Labeyrie, L., Jouzel, J., and Bonani, G.: Correlations between climate records from North Atlantic sediments and Greenland ice, Nature, 365, 143–147, https://doi.org/10.1038/365143a0, 1993.
Brady, R. X., Lovenduski, N. S., Alexander, M. A., Jacox, M., and Gruber, N.: On the role of climate modes in modulating the air–sea CO2 fluxes in eastern boundary upwelling systems, Biogeosciences, 16, 329–346, https://doi.org/10.5194/bg-16-329-2019, 2019.
Broecker, W. S.: Paleocean circulation during the last deglaciation: a bipolar seesaw?, Paleoceanography, 13, 119–121, https://doi.org/10.1029/97PA03707, 1998.
Cacho, I., Grimalt, J. O., Pelejero, C., Canals, M., Sierro, F. J., Flores, J. A., and Shackleton, N.: Dansgaard-Oeschger and Heinrich event imprints in Alboran Sea paleotemperatures, Paleoceanography, 14, 698–705, https://doi.org/10.1029/1999PA900044, 1999.
Calvo, E., Pelejero, C., De Deckker, P., and Logan, G. A.: Antarctic deglacial pattern in a 30 kyr record of sea surface temperature offshore South Australia, Geophys. Res. Lett., 34, L13707, https://doi.org/10.1029/2007GL029937, 2007.
Carr, M.-E.: Estimation of potential productivity in Eastern Boundary Currents using remote sensing, Deep-Sea Res. Pt. II, 49, 59-80, https://doi.org/10.1016/S0967-0645(01)00094-7, 2001.
Chanakya, I. V. S. and Misra, S.: Accurate and precise determination of the boron isotope ratio by QQQ-ICP-MS: application to natural waters and carbonates, J. Anal. Atom. Spectrom., 37, 1327–1339, https://doi.org/10.1039/D2JA00051B, 2022.
Charles, C. D. and Morley, J. J.: The paleoceanographic significance of the radiolarian didymocyrtis tetrathalamus in Eastern Cape basin sediments, Palaeogeogr. Palaeocl., 66, 113–126, https://doi.org/10.1016/0031-0182(88)90084-3, 1988.
Chavez, F. P. and Messié, M.: A comparison of eastern boundary upwelling ecosystems, Prog. Oceanogr., 83, 80–96, https://doi.org/10.1016/j.pocean.2009.07.032, 2009.
Clark, P. U., Dyke, A. S., Shakun, J. D., Carlson, A. E., Clark, J., Wohlfarth, B., Mitrovica, J. X., Hostetler, S. W., and McCabe, A. M.: The Last Glacial Maximum, Science, 325, 710–714, https://doi.org/10.1126/science.1172873, 2009.
Cockcroft, M. J., Wilkinson, M. J., and Tyson, P. D.: The application of a present-day climatic model to the late quaternary in southern Africa, Clim. Change, 10, 161–181, https://doi.org/10.1007/BF00140253, 1987.
Conte, M., Volkman, J., and Eglinton, G.: Lipid biomarkers of the Haptophyta, in: The haptophyte algae, edited by: Green, J. C. and Leadbeater, B. S. C., Clarendon Press: Oxford, https://doi.org/10.1093/oso/9780198577720.003.0019, 1994.
Conte, M. H., Sicre, M.-A., Rühlemann, C., Weber, J. C., Schulte, S., Schulz-Bull, D., and Blanz, T.: Global temperature calibration of the alkenone unsaturation index (UK′37) in surface waters and comparison with surface sediments, Geochem. Geophy. Geosy., 7, Q02005, https://doi.org/10.1029/2005GC001054, 2006.
Curry, W. B. and Oppo, D. W.: Glacial water mass geometry and the distribution of δ13C of ΣCO2 in the western Atlantic Ocean, Paleoceanography, 20, PA1017, https://doi.org/10.1029/2004PA001021, 2005.
Damsté, J. S. S., Kuypers, M. M. M., Pancost, R. D., and Schouten, S.: The carbon isotopic response of algae, (cyano)bacteria, archaea and higher plants to the late Cenomanian perturbation of the global carbon cycle: Insights from biomarkers in black shales from the Cape Verde Basin (DSDP Site 367), Org. Geochem., 39, 1703–1718, https://doi.org/10.1016/j.orggeochem.2008.01.012, 2008.
Davis, C. V., Fehrenbacher, J. S., Benitez-Nelson, C., and Thunell, R. C.: Trace element heterogeneity across individual planktic foraminifera from the modern Cariaco Basin, J. Foramin. Res., 50, 204–218, https://doi.org/10.2113/gsjfr.50.2.204, 2020.
De La Rocha, C. L. and Passow, U.: Factors influencing the sinking of POC and the efficiency of the biological carbon pump, Deep-Sea Res. Pt. II, 54, 639–658, https://doi.org/10.1016/j.dsr2.2007.01.004, 2007.
de la Vega, E., Chalk, T. B., Hain, M. P., Wilding, M. R., Casey, D., Gledhill, R., Luo, C., Wilson, P. A., and Foster, G. L.: Orbital CO2 reconstruction using boron isotopes during the late Pleistocene, an assessment of accuracy, Clim. Past, 19, 2493–2510, https://doi.org/10.5194/cp-19-2493-2023, 2023.
de Nooijer, L. J., Spero, H., Erez, J., Bijma, J., and Reichart, G.-J.: Biomineralization in perforate foraminifera, Earth-Sci. Rev., 135, 48–58, https://doi.org/10.1016/j.earscirev.2014.03.013, 2014.
de Villiers, S., Greaves, M., and Elderfield, H.: An intensity ratio calibration method for the accurate determination of Mg Ca and Sr/Ca of marine carbonates by ICP-AES, Geochem. Geophy. Geosy., 3, 1001, https://doi.org/10.1029/2001GC000169, 2002.
Degens, E. T., Guillard, R. R. L., Sackett, W. M., and Hellebust, J. A.: Metabolic fractionation of carbon isotopes in marine plankton—I. Temperature and respiration experiments, Deep-Sea Res., 15, 1–9, https://doi.org/10.1016/0011-7471(68)90024-7, 1968.
Dekens, P. S., Lea, D. W., Pak, D. K., and Spero, H. J.: Core top calibration of Mg Ca in tropical foraminifera: Refining paleotemperature estimation, Geochem. Geophy. Geosy., 3, 1–29, https://doi.org/10.1029/2001GC000200, 2002.
Denton, G. H., Anderson, R. F., Toggweiler, J. R., Edwards, R. L., Schaefer, J. M., and Putnam, A. E.: The Last Glacial Termination, Science, 328, 1652–1656, https://doi.org/10.1126/science.1184119, 2010.
Des Combes, H. J. and Abelmann, A.: A 350-ky radiolarian record off Lüderitz, Namibia–evidence for changes in the upwelling regime, Mar. Micropaleontol., 62, 194–210, https://doi.org/10.1016/j.marmicro.2006.08.004, 2007.
DeVries, T. and Weber, T.: The export and fate of organic matter in the ocean: New constraints from combining satellite and oceanographic tracer observations, Global Biogeochem. Cy., 31, 535–555, https://doi.org/10.1002/2016GB005551, 2017.
Dewar, G., Reimer, P. J., Sealy, J., and Woodborne, S.: Late-Holocene marine radiocarbon reservoir correction (ΔR) for the west coast of South Africa, Holocene, 22, 1481–1489, https://doi.org/10.1177/0959683612449755, 2012.
Dickson, A. G.: Thermodynamics of the dissociation of boric acid in synthetic seawater from 273.15 to 318.15 K, Deep-Sea Res. Pt. I, 37, 755–766, https://doi.org/10.1016/0198-0149(90)90004-F, 1990.
Diester-Haass, L., Meyers, P. A., and Rothe, P.: The Benguela Current and associated upwelling on the southwest African Margin: a synthesis of the Neogene-Quaternary sedimentary record at DSDP sites 362 and 532, Geological Society, London, Special Publications, 64, 331–342, https://doi.org/10.1144/GSL.SP.1992.064.01.22, 1992.
Ducklow, H. W., Steinberg, D. K., and Buesseler, K. O.: Upper ocean carbon export and the biological pump, Oceanography, 14, 50–58, 2001.
Dueñas-Bohórquez, A., da Rocha, R. E., Kuroyanagi, A., Bijma, J., and Reichart, G.-J.: Effect of salinity and seawater calcite saturation state on Mg and Sr incorporation in cultured planktonic foraminifera, Mar. Micropaleontol., 73, 178–189, https://doi.org/10.1016/j.marmicro.2009.09.002, 2009.
Emeis, K., Eggert, A., Flohr, A., Lahajnar, N., Nausch, G., Neumann, A., Rixen, T., Schmidt, M., Van der Plas, A., and Wasmund, N.: Biogeochemical processes and turnover rates in the Northern Benguela Upwelling System, J. Mar. Syst., 188, 63–80, https://doi.org/10.1016/j.jmarsys.2017.10.001, 2018.
Erez, J.: The source of ions for biomineralization in foraminifera and their implications for paleoceanographic proxies, Rev. Mineral. Geochem., 54, 115–149, https://doi.org/10.2113/0540115, 2003.
Fahrni, S. M., Wacker, L., Synal, H. A., and Szidat, S.: Improving a gas ion source for 14C AMS, Nucl. Instrum. Meth. B, 294, 320–327, https://doi.org/10.1016/j.nimb.2012.03.037, 2013.
Flores, J.-A., Gersonde, R., and Sierro, F. J.: Pleistocene fluctuations in the Agulhas Current Retroflection based on the calcareous plankton record, Mar. Micropaleontol., 37, 1–22, https://doi.org/10.1016/S0377-8398(99)00012-2, 1999.
Foster, G. L. and Rae, J. W.: Reconstructing ocean pH with boron isotopes in foraminifera, Annu. Rev. Earth Planet. Sci., 44, 207–237, https://doi.org/10.1146/annurev-earth-060115-012226, 2016.
Foster, G. L., Pogge von Strandmann, P. A. E., and Rae, J. W. B.: Boron and magnesium isotopic composition of seawater, Geochem. Geophy. Geosy., 11, Q08015, https://doi.org/10.1029/2010GC003201, 2010.
Fowler, S. W. and Knauer, G. A.: Role of large particles in the transport of elements and organic compounds through the oceanic water column, Prog. Oceanogr., 16, 147–194, https://doi.org/10.1016/0079-6611(86)90032-7, 1986.
Francois, R., Honjo, S., Krishfield, R., and Manganini, S.: Factors controlling the flux of organic carbon to the bathypelagic zone of the ocean, Global Biogeochem. Cy., 16, 34-31–34-20, https://doi.org/10.1029/2001GB001722, 2002.
Franzese, A. M., Hemming, S. R., Goldstein, S. L., and Anderson, R. F.: Reduced Agulhas Leakage during the Last Glacial Maximum inferred from an integrated provenance and flux study, Earth. Planet. Sc. Lett., 250, 72–88, https://doi.org/10.1016/j.epsl.2006.07.002, 2006.
Gaillardet, J., Lemarchand, D., Göpel, C., and Manhès, G.: Evaporation and sublimation of boric acid: Application for boron purification from organic rich solutions, Geostandard. Newslett., 25, 67–75, https://doi.org/10.1111/j.1751-908X.2001.tb00788.x, 2001.
Gordon, A. L.: Interocean exchange of thermocline water, J. Geophys. Res.-Oceans, 91, 5037–5046, https://doi.org/10.1029/JC091iC04p05037, 1986.
Goudet, M. M., Orr, D. J., Melkonian, M., Müller, K. H., Meyer, M. T., Carmo-Silva, E., and Griffiths, H.: Rubisco and carbon-concentrating mechanism co-evolution across chlorophyte and streptophyte green algae, New Phytol., 227, 810–823, https://doi.org/10.1111/nph.16577, 2020.
Gray, W. R. and Evans, D.: Nonthermal influences on Mg Ca in planktonic foraminifera: A review of culture studies and application to the last glacial maximum, Paleoceanogr. Paleoclimatol., 34, 306–315, https://doi.org/10.1029/2018PA003517, 2019.
Gray, W. R., Weldeab, S., Lea, D. W., Rosenthal, Y., Gruber, N., Donner, B., and Fischer, G.: The effects of temperature, salinity, and the carbonate system on Mg Ca in Globigerinoides ruber (white): A global sediment trap calibration, Earth. Planet. Sc. Lett., 482, 607–620, https://doi.org/10.1016/j.epsl.2017.11.026, 2018.
Gregor, L. and Monteiro, P. M.: Is the southern Benguela a significant regional sink of CO2?, S. Afr. J. Sci., 109, 1–5, https://doi.org/10.1590/sajs.2013/20120094, 2013.
Gruber, N., Gloor, M., Mikaloff Fletcher, S. E., Doney, S. C., Dutkiewicz, S., Follows, M. J., Gerber, M., Jacobson, A. R., Joos, F., and Lindsay, K.: Oceanic sources, sinks, and transport of atmospheric CO2, Global Biogeochem. Cy., 23, GB1005, https://doi.org/10.1029/2008GB003349, 2009.
Gu, S., Liu, Z., Zhang, J., Rempfer, J., Joos, F., and Oppo, D. W.: Coherent response of Antarctic Intermediate Water and Atlantic Meridional Overturning Circulation during the last deglaciation: Reconciling contrasting neodymium isotope reconstructions from the tropical Atlantic, Paleoceanography, 32, 1036–1053, https://doi.org/10.1002/2017PA003092, 2017.
Hain, M. P., Sigman, D., and Haug, G.: The biological pump in the past, Reference Module in Earth Systems and Environmental Sciences, Treatise on Geochemistry (Second Edition), Oceans and Marine Geochemistry, 8, 485–517, https://doi.org/10.1016/B978-0-08-095975-7.00618-5, 2014.
Hales, B., Takahashi, T., and Bandstra, L.: Atmospheric CO2 uptake by a coastal upwelling system, Global Biogeochem. Cy., 19, GB1009, https://doi.org/10.1029/2004GB002295, 2005.
Hart, T. J. and Currie, R. I.: The benguela current, Discov. Rep., 31, 123–297, 1960.
Hayes, J. M.: Factors controlling 13C contents of sedimentary organic compounds: Principles and evidence, Mar. Geol., 113, 111–125, https://doi.org/10.1016/0025-3227(93)90153-M, 1993.
Heaton, T. J., Köhler, P., Butzin, M., Bard, E., Reimer, R. W., Austin, W. E. N., Bronk Ramsey, C., Grootes, P. M., Hughen, K. A., Kromer, B., Reimer, P. J., Adkins, J., Burke, A., Cook, M. S., Olsen, J., and Skinner, L. C.: Marine20 – The Marine Radiocarbon Age Calibration Curve (0–55,000 cal BP), Radiocarbon, 62, 779–820, https://doi.org/10.1017/RDC.2020.68, 2020.
Hemleben, C., Spindler, M., and Anderson, O. R.: Modern planktonic foraminifera, Springer-Verlag, New York, https://doi.org/10.1007/978-1-4612-3544-6, 1989.
Hemming, N. and Hanson, G.: Boron isotopic composition and concentration in modern marine carbonates, Geochim. Cosmochim. Ac., 56, 537–543, https://doi.org/10.1016/0016-7037(92)90151-8, 1992.
Henehan, M. J., Rae, J. W. B., Foster, G. L., Erez, J., Prentice, K. C., Kucera, M., Bostock, H. C., Martínez-Botí, M. A., Milton, J. A., Wilson, P. A., Marshall, B. J., and Elliott, T.: Calibration of the boron isotope proxy in the planktonic foraminifera Globigerinoides ruber for use in palaeo-CO2 reconstruction, Earth. Planet. Sc. Lett., 364, 111–122, https://doi.org/10.1016/j.epsl.2012.12.029, 2013.
Henehan, M. J., Foster, G. L., Bostock, H. C., Greenop, R., Marshall, B. J., and Wilson, P. A.: A new boron isotope-pH calibration for Orbulina universa , with implications for understanding and accounting for “vital effects”, Earth. Planet. Sc. Lett., 454, 282–292, https://doi.org/10.1016/j.epsl.2016.09.024, 2016.
Henson, S. A., Sanders, R., Madsen, E., Morris, P. J., Le Moigne, F., and Quartly, G. D.: A reduced estimate of the strength of the ocean's biological carbon pump, Geophys. Res. Lett., 38, L04606, https://doi.org/10.1029/2011GL046735, 2011.
Heureux, A. M. C., Young, J. N., Whitney, S. M., Eason-Hubbard, M. R., Lee, R. B. Y., Sharwood, R. E., and Rickaby, R. E. M.: The role of Rubisco kinetics and pyrenoid morphology in shaping the CCM of haptophyte microalgae, J. Exp. Bot., 68, 3959–3969, https://doi.org/10.1093/jxb/erx179, 2017.
Hill, A. E.: Eastern Ocean Boundaries, Sea, VII, 29–67, 1998.
Hilting, A. K., Kump, L. R., and Bralower, T. J.: Variations in the oceanic vertical carbon isotope gradient and their implications for the Paleocene-Eocene biological pump, Paleoceanography, 23, PA3222, https://doi.org/10.1029/2007PA001458, 2008.
Hodell, D. A., Nicholl, J. A., Bontognali, T. R. R., Danino, S., Dorador, J., Dowdeswell, J. A., Einsle, J., Kuhlmann, H., Martrat, B., Mleneck-Vautravers, M. J., Rodríguez-Tovar, F. J., and Röhl, U.: Anatomy of Heinrich Layer 1 and its role in the last deglaciation, Paleoceanography, 32, 284–303, https://doi.org/10.1002/2016PA003028, 2017.
Hönisch, B. and Hemming, N. G.: Ground-truthing the boron isotope-paleo-pH proxy in planktonic foraminifera shells: Partial dissolution and shell size effects, Paleoceanography, 19, PA4010, https://doi.org/10.1029/2004PA001026, 2004.
Hönisch, B., Allen, K. A., Russell, A. D., Eggins, S. M., Bijma, J., Spero, H. J., Lea, D. W., and Yu, J.: Planktic foraminifers as recorders of seawater Ba/Ca, Mar. Micropaleontol., 79, 52–57, https://doi.org/10.1016/j.marmicro.2011.01.003, 2011.
Hover, V. C., Walter, L. M., and Peacor, D. R.: Early marine diagenesis of biogenic aragonite and Mg-calcite: new constraints from high-resolution STEM and AEM analyses of modern platform carbonates, Chem. Geol., 175, 221–248, https://doi.org/10.1016/S0009-2541(00)00326-0, 2001.
Howe, J. N. W., Piotrowski, A. M., Oppo, D. W., Huang, K.-F., Mulitza, S., Chiessi, C. M., and Blusztajn, J.: Antarctic intermediate water circulation in the South Atlantic over the past 25,000 years, Paleoceanography, 31, 1302–1314, https://doi.org/10.1002/2016PA002975, 2016.
Hughes, P. D., Gibbard, P. L., and Ehlers, J.: Timing of glaciation during the last glacial cycle: evaluating the concept of a global “Last Glacial Maximum” (LGM), Earth-Sci. Rev., 125, 171–198, https://doi.org/10.1016/j.earscirev.2013.07.003, 2013.
Humphreys, M. P., Lewis, E. R., Sharp, J. D., and Pierrot, D.: PyCO2SYS v1.8: marine carbonate system calculations in Python, Geosci. Model Dev., 15, 15–43, https://doi.org/10.5194/gmd-15-15-2022, 2022.
Jasper, J. P. and Hayes, J. M.: A carbon isotope record of CO2 levels during the late Quaternary, Nature, 347, 462–464, https://doi.org/10.1038/347462a0, 1990.
Jasper, J. P., Hayes, J., Mix, A. C., and Prahl, F. G.: Photosynthetic fractionation of 13C and concentrations of dissolved CO2 in the central equatorial Pacific during the last 255,000 years, Paleoceanography, 9, 781–798, https://doi.org/10.1029/94PA02116, 1994.
Jonkers, L., van Heuven, S., Zahn, R., and Peeters, F. J. C.: Seasonal patterns of shell flux, δ18O and δ13C of small and large N.pachyderma (s) and G.bulloides in the subpolar North Atlantic, Paleoceanography, 28, 164–174, https://doi.org/10.1002/palo.20018, 2013.
Jouzel, J., Masson-Delmotte, V., Cattani, O., Dreyfus, G., Falourd, S., Hoffmann, G., Minster, B., Nouet, J., Barnola, J. M., Chappellaz, J., Fischer, H., Gallet, J. C., Johnsen, S., Leuenberger, M., Loulergue, L., Luethi, D., Oerter, H., Parrenin, F., Raisbeck, G., Raynaud, D., Schilt, A., Schwander, J., Selmo, E., Souchez, R., Spahni, R., Stauffer, B., Steffensen, J. P., Stenni, B., Stocker, T. F., Tison, J. L., Werner, M., and Wolff, E. W.: Orbital and Millennial Antarctic Climate Variability over the Past 800,000 Years, Science, 317, 793–796, https://doi.org/10.1126/science.1141038, 2007.
Kahn, M.: Non-equilibrium oxygen and carbon isotopic fractionation in tests of living planktonic-foraminifera, Oceanol. Acta, 2, 195–208, 1979.
Kahn, M. I. and Williams, D. F.: Oxygen and carbon isotopic composition of living planktonic foraminifera from the northeast Pacific Ocean, Palaeogeogr. Palaeocl., 33, 47–69, https://doi.org/10.1016/0031-0182(81)90032-8, 1981.
Kämpf, J. and Chapman, P.: Upwelling systems of the world, Springer Cham, https://doi.org/10.1007/978-3-319-42524-5, 2016.
Kaplan, M. R., Schaefer, J. M., Denton, G. H., Barrell, D. J. A., Chinn, T. J. H., Putnam, A. E., Andersen, B. G., Finkel, R. C., Schwartz, R., and Doughty, A. M.: Glacier retreat in New Zealand during the Younger Dryas stadial, Nature, 467, 194–197, https://doi.org/10.1038/nature09313, 2010.
Karancz, S., de Nooijer, L. J., van der Wagt, B., van der Meer, M. T. J., Misra, S., Hennekam, R., Erdem, Z., Lattaud, J., Haghipour, N., Schouten, S., and Reichart, G.-J.: Dataset belonging to “Contrasts in the marine inorganic carbon chemistry of the Benguela Upwelling System since the Last Glacial Maximum” (V5), NIOZ [data set], https://doi.org/10.25850/nioz/7b.b.lh, 2024.
Key, R. M., Olsen, A., van Heuven, S., Lauvset, S. K., Velo, A., Lin, X., Schirnick, C., Kozyr, A., Tanhua, T., Hoppema, M., Jutterström, S., Steinfeldt, R., Jeansson, E., Ishii, M., Perez, F. F., and Suzuki, T.: Global Ocean Data Analysis Project, Version 2 (GLODAPv2), ORNL/CDIAC-162, NDP-093, Carbon Dioxide Inf. Anal. Cent. Oak Ridge Natl. Lab. Oak Ridge, TN, https://doi.org/10.3334/CDIAC/OTG.NDP093_GLODAPv2, 2015.
Kirst, G. J., Schneider, R. R., Müller, P. J., von Storch, I., and Wefer, G.: Late Quaternary temperature variability in the Benguela Current System derived from alkenones, Quaternary Res., 52, 92–103, https://doi.org/10.1006/qres.1999.2040, 1999.
Klaas, C. and Archer, D. E.: Association of sinking organic matter with various types of mineral ballast in the deep sea: Implications for the rain ratio, Global Biogeochem. Cy., 16, 63-61–63-14, https://doi.org/10.1029/2001GB001765, 2002.
Klochko, K., Kaufman, A. J., Yao, W., Byrne, R. H., and Tossell, J. A.: Experimental measurement of boron isotope fractionation in seawater, Earth Planet. Sc. Lett., 248, 276–285, https://doi.org/10.1016/j.epsl.2006.05.034, 2006.
Knorr, G. and Lohmann, G.: Southern Ocean origin for the resumption of Atlantic thermohaline circulation during deglaciation, Nature, 424, 532–536, https://doi.org/10.1038/nature01855, 2003.
Kohfeld, K. E., Quéré, C. L., Harrison, S. P., and Anderson, R. F.: Role of marine biology in glacial-interglacial CO2 cycles, Science, 308, 74–78, https://doi.org/10.1126/science.1105375, 2005.
Kozdon, R., Kelly, D. C., Kitajima, K., Strickland, A., Fournelle, J. H., and Valley, J. W.: In situ δ18O and Mg Ca analyses of diagenetic and planktic foraminiferal calcite preserved in a deep-sea record of the Paleocene-Eocene thermal maximum, Paleoceanography, 28, 517–528, https://doi.org/10.1002/palo.20048, 2013.
Kroopnick, P.: The distribution of 13C in the Atlantic Ocean, Earth. Planet. Sc. Lett., 49, 469–484, https://doi.org/10.1016/0012-821X(80)90088-6, 1980.
Kroopnick, P. M.: The distribution of 13C of ΣCO2 in the world oceans, Deep-Sea Res. Pt. I., 32, 57-84, https://doi.org/10.1016/0198-0149(85)90017-2, 1985.
Kwon, E. Y., Primeau, F., and Sarmiento, J. L.: The impact of remineralization depth on the air–sea carbon balance, Nat. Geosci., 2, 630–635, https://doi.org/10.1038/ngeo612, 2009.
Lacerra, M., Lund, D. C., Gebbie, G., Oppo, D. W., Yu, J., Schmittner, A., and Umling, N. E.: Less remineralized carbon in the intermediate-depth South Atlantic during Heinrich Stadial 1, Paleoceanogr. Paleoclimatol., 34, 1218–1233, https://doi.org/10.1029/2018PA003537, 2019.
Lamy, F., Kaiser, J., Arz, H. W., Hebbeln, D., Ninnemann, U., Timm, O., Timmermann, A., and Toggweiler, J. R.: Modulation of the bipolar seesaw in the Southeast Pacific during Termination 1, Earth. Planet. Sc. Lett., 259, 400–413, https://doi.org/10.1016/j.epsl.2007.04.040, 2007.
Laruelle, G. G., Lauerwald, R., Pfeil, B., and Regnier, P.: Regionalized global budget of the CO2 exchange at the air-water interface in continental shelf seas, Global Biogeochem. Cy., 28, 1199–1214, https://doi.org/10.1002/2014GB004832, 2014.
Lauvset, S. K., Lange, N., Tanhua, T., Bittig, H. C., Olsen, A., Kozyr, A., Álvarez, M., Azetsu-Scott, K., Brown, P. J., Carter, B. R., Cotrim da Cunha, L., Hoppema, M., Humphreys, M. P., Ishii, M., Jeansson, E., Murata, A., Müller, J. D., Pérez, F. F., Schirnick, C., Steinfeldt, R., Suzuki, T., Ulfsbo, A., Velo, A., Woosley, R. J., and Key, R. M.: The annual update GLODAPv2.2023: the global interior ocean biogeochemical data product, Earth Syst. Sci. Data, 16, 2047–2072, https://doi.org/10.5194/essd-16-2047-2024, 2024.
Laws, E. A., Popp, B. N., Bidigare, R. R., Kennicutt, M. C., and Macko, S. A.: Dependence of phytoplankton carbon isotopic composition on growth rate and [CO2]aq: Theoretical considerations and experimental results, Geochim. Cosmochim. Ac., 59, 1131–1138, https://doi.org/10.1016/0016-7037(95)00030-4, 1995.
Laws, E. A., Falkowski, P. G., Smith Jr., W. O., Ducklow, H., and McCarthy, J. J.: Temperature effects on export production in the open ocean, Global Biogeochem. Cy., 14, 1231–1246, https://doi.org/10.1029/1999GB001229, 2000.
Lea, D. and Boyle, E.: Barium content of benthic foraminifera controlled by bottom-water composition, Nature, 338, 751–753, https://doi.org/10.1038/338751a0, 1989.
Lea, D. W. and Boyle, E. A.: A 210,000-year record of barium variability in the deep northwest Atlantic Ocean, Nature, 347, 269–272, https://doi.org/10.1038/347269a0, 1990a.
Lea, D. W. and Boyle, E. A.: Foraminiferal reconstruction of barium distributions in water masses of the glacial oceans, Paleoceanography, 5, 719–742, https://doi.org/10.1029/PA005i005p00719, 1990b.
Lea, D. W. and Boyle, E. A.: Barium in planktonic foraminifera, Geochim. Cosmochim. Ac., 55, 3321–3331, https://doi.org/10.1016/0016-7037(91)90491-M, 1991.
Lea, D. W. and Spero, H. J.: Assessing the reliability of paleochemical tracers: Barium uptake in the shells of planktonic foraminifera, Paleoceanography, 9, 445–452, https://doi.org/10.1029/94PA00151, 1994.
Leduc, G., Schneider, R., Kim, J. H., and Lohmann, G.: Holocene and Eemian sea surface temperature trends as revealed by alkenone and Mg Ca paleothermometry, Quaternary Sci. Rev., 29, 989–1004, https://doi.org/10.1016/j.quascirev.2010.01.004, 2010.
Lessa, D., Morard, R., Jonkers, L., Venancio, I. M., Reuter, R., Baumeister, A., Albuquerque, A. L., and Kucera, M.: Distribution of planktonic foraminifera in the subtropical South Atlantic: depth hierarchy of controlling factors, Biogeosciences, 17, 4313–4342, https://doi.org/10.5194/bg-17-4313-2020, 2020.
Li, L., Liu, Z., Zhu, C., He, C., and Otto-Bliesner, B.: Shallowing Glacial Antarctic Intermediate Water by changes in sea ice and hydrological cycle, Geophys. Res. Lett., 48, e2021GL094317, https://doi.org/10.1029/2021GL094317, 2021.
Little, M., Schneider, R., Kroon, D., Price, B., Bickert, T., and Wefer, G.: Rapid palaeoceanographic changes in the Benguela Upwelling System for the last 160,000 years as indicated by abundances of planktonic foraminifera, Palaeogeogr. Palaeocl., 130, 135–161, https://doi.org/10.1016/S0031-0182(96)00136-8, 1997.
Lloyd, N. S., Sadekov, A. Y., and Misra, S.: Application of 1013 ohm Faraday cup current amplifiers for boron isotopic analyses by solution mode and laser ablation multicollector inductively coupled plasma mass spectrometry, Rapid Commun. Mass Spectrom., 32, 9–18, https://doi.org/10.1002/rcm.8009, 2018.
Longhurst, A. R. and Glen Harrison, W.: The biological pump: Profiles of plankton production and consumption in the upper ocean, Prog. Oceanogr., 22, 47–123, https://doi.org/10.1016/0079-6611(89)90010-4, 1989.
Lutjeharms, J. and Meeuwis, J.: The extent and variability of South-East Atlantic upwelling, S. Afr. J. Marine Sci., 5, 51–62, https://doi.org/10.2989/025776187784522621, 1987.
Lutjeharms, J. and Valentine, H.: Water types and volumetric considerations of the South-East Atlantic upwelling regime, S. Afr. J. Marine Sci., 5, 63–71, https://doi.org/10.2989/025776187784522487, 1987.
Lutjeharms, J. R. E. and Stockton, P. L.: Kinematics of the upwelling front off southern Africa, S. Afr. J. Marine Sci., 5, 35–49, https://doi.org/10.2989/025776187784522612, 1987.
Lynch-Stieglitz, J., Stocker, T. F., Broecker, W. S., and Fairbanks, R. G.: The influence of air-sea exchange on the isotopic composition of oceanic carbon: Observations and modeling, Global Biogeochem. Cy., 9, 653–665, https://doi.org/10.1029/95GB02574, 1995.
Martin, J. H.: Glacial-interglacial CO2 change: The iron hypothesis, Paleoceanography, 5, 1–13, https://doi.org/10.1029/PA005i001p00001, 1990.
Martin, P. A. and Lea, D. W.: Comparison of water mass changes in the deep tropical Atlantic derived from Cd/Ca and carbon isotope records: Implications for changing Ba composition of Deep Atlantic Water Masses, Paleoceanography, 13, 572–585, https://doi.org/10.1029/98PA02670, 1998.
Martinez-Boti, M. A., Marino, G., Foster, G. L., Ziveri, P., Henehan, M. J., Rae, J. W., Mortyn, P. G., and Vance, D.: Boron isotope evidence for oceanic carbon dioxide leakage during the last deglaciation, Nature, 518, 219–222, https://doi.org/10.1038/nature14155, 2015.
Martínez-García, A., Sigman, D. M., Ren, H., Anderson, R. F., Straub, M., Hodell, D. A., Jaccard, S. L., Eglinton, T. I., and Haug, G. H.: Iron fertilization of the Subantarctic Ocean during the Last Ice Age, Science, 343, 1347–1350, https://doi.org/10.1126/science.1246848, 2014.
Mashiotta, T. A., Lea, D. W., and Spero, H. J.: Glacial–interglacial changes in Subantarctic sea surface temperature and δ18O-water using foraminiferal Mg, Earth Planet. Sc. Lett., 170, 417–432, https://doi.org/10.1016/S0012-821X(99)00116-8, 1999.
Matero, I. S. O., Gregoire, L. J., Ivanovic, R. F., Tindall, J. C., and Haywood, A. M.: The 8.2 ka cooling event caused by Laurentide ice saddle collapse, Earth Planet. Sc. Lett., 473, 205–214, https://doi.org/10.1016/j.epsl.2017.06.011, 2017.
McKay, C. L., Filipsson, H. L., Romero, O. E., Stuut, J. B. W., and Björck, S.: The interplay between the surface and bottom water environment within the Benguela Upwelling System over the last 70 ka, Paleoceanography, 31, 266–285, https://doi.org/10.1002/2015PA002792, 2016.
McManus, J. F., Bond, G. C., Broecker, W. S., Johnsen, S., Labeyrie, L., and Higgins, S.: High-resolution climate records from the North Atlantic during the last interglacial, Nature, 371, 326–329, https://doi.org/10.1038/371326a0, 1994.
McManus, J. F., Francois, R., Gherardi, J. M., Keigwin, L. D., and Brown-Leger, S.: Collapse and rapid resumption of Atlantic meridional circulation linked to deglacial climate changes, Nature, 428, 834–837, https://doi.org/10.1038/nature02494, 2004.
Mekik, F., François, R., and Soon, M.: A novel approach to dissolution correction of Mg Ca–based paleothermometry in the tropical Pacific, Paleoceanography, 22, PA3217, https://doi.org/10.1029/2007PA001504, 2007.
Metcalfe, B., Feldmeijer, W., de Vringer-Picon, M., Brummer, G.-J. A., Peeters, F. J. C., and Ganssen, G. M.: Late Pleistocene glacial–interglacial shell-size–isotope variability in planktonic foraminifera as a function of local hydrography, Biogeosciences, 12, 4781–4807, https://doi.org/10.5194/bg-12-4781-2015, 2015.
Mezger, E., De Nooijer, L., Boer, W., Brummer, G., and Reichart, G.: Salinity controls on Na incorporation in Red Sea planktonic foraminifera, Paleoceanography, 31, 1562–1582, https://doi.org/10.1002/2016PA003052, 2016.
Misra, S., Owen, R., Kerr, J., Greaves, M., and Elderfield, H.: Determination of δ11B by HR-ICP-MS from mass limited samples: Application to natural carbonates and water samples, Geochim. Cosmochim. Ac., 140, 531–552, https://doi.org/10.1016/j.gca.2014.05.047, 2014.
Mollenhauer, G., Schneider, R. R., Müller, P. J., Spieß, V., and Wefer, G.: Glacial/interglacial variablity in the Benguela upwelling system: Spatial distribution and budgets of organic carbon accumulation, Global Biogeochem. Cy., 16, 81-81–81-15, https://doi.org/10.1029/2001GB001488, 2002.
Mollenhauer, G., Eglinton, T. I., Ohkouchi, N., Schneider, R. R., Müller, P. J., Grootes, P. M., and Rullkötter, J.: Asynchronous alkenone and foraminifera records from the Benguela Upwelling System, Geochim. Cosmochim. Ac., 67, 2157–2171, https://doi.org/10.1016/s0016-7037(03)00168-6, 2003.
Mook, W. G., Bommerson, J. C., and Staverman, W. H.: Carbon isotope fractionation between dissolved bicarbonate and gaseous carbon dioxide, Earth Planet. Sc. Lett., 22, 169–176, https://doi.org/10.1016/0012-821X(74)90078-8, 1974.
Muller-Karger, F. E., Varela, R., Thunell, R., Luerssen, R., Hu, C., and Walsh, J. J.: The importance of continental margins in the global carbon cycle, Geophys. Res. Lett., 32, L01602, https://doi.org/10.1029/2004GL021346, 2005.
Muratli, J. M., Chase, Z., Mix, A. C., and McManus, J.: Increased glacial-age ventilation of the Chilean margin by Antarctic Intermediate Water, Nat. Geosci., 3, 23–26, https://doi.org/10.1038/ngeo715, 2010.
Ni, S., Quintana Krupinski, N. B., Groeneveld, J., Persson, P., Somogyi, A., Brinkmann, I., Knudsen, K. L., Seidenkrantz, M. S., and Filipsson, H. L.: Early diagenesis of foraminiferal calcite under anoxic conditions: A case study from the Landsort Deep, Baltic Sea (IODP Site M0063), Chem. Geol., 558, 119871, https://doi.org/10.1016/j.chemgeo.2020.119871, 2020.
North Greenland Ice Core Project members: High-resolution record of Northern Hemisphere climate extending into the last interglacial period, Nature, 431, 147–151, https://doi.org/10.1038/nature02805, 2004.
Oberhänsli, H.: Upwelling signals at the northeastern Walvis Ridge during the past 500,000 years, Paleoceanography, 6, 53–71, https://doi.org/10.1029/90PA02106, 1991.
Okai, T., Suzuki, A., Terashima, S., Inoue, M., Nohara, M., Kawahata, H., and Imai, N.: Collaborative analysis of GSJ/AIST geochemical reference materials JCp-1 (Coral) and JCt-1 (Giant Clam), Geochem, 38, 281–286, 2004.
Olsen, A., Key, R. M., van Heuven, S., Lauvset, S. K., Velo, A., Lin, X., Schirnick, C., Kozyr, A., Tanhua, T., Hoppema, M., Jutterström, S., Steinfeldt, R., Jeansson, E., Ishii, M., Pérez, F. F., and Suzuki, T.: The Global Ocean Data Analysis Project version 2 (GLODAPv2) – an internally consistent data product for the world ocean, Earth Syst. Sci. Data, 8, 297–323, https://doi.org/10.5194/essd-8-297-2016, 2016.
Oppo, D. W. and Fairbanks, R. G.: Carbon isotope composition of tropical surface water during the past 22,000 years, Paleoceanography, 4, 333–351, https://doi.org/10.1029/PA004i004p00333, 1989.
Oppo, D. W. and Rosenthal, Y.: Cd/Ca changes in a Deep Cape Basin Core over the past 730,000 years: Response of circumpolar deepwater variability to northern hemisphere ice sheet melting?, Paleoceanography, 9, 661–675, https://doi.org/10.1029/93PA02199, 1994.
Osborne, E. B., Thunell, R. C., Marshall, B. J., Holm, J. A., Tappa, E. J., Benitez-Nelson, C., Cai, W.-J., and Chen, B.: Calcification of the planktonic foraminifera Globigerina bulloides and carbonate ion concentration: Results from the Santa Barbara Basin, Paleoceanography, 31, 1083–1102, https://doi.org/10.1002/2016PA002933, 2016.
Pagani, M.: Biomarker-based inferences of past climate: The alkenone pCO2 Proxy, in: Treatise on Geochemistry, Elsevier, Oxford, 361–378, https://doi.org/10.1016/b978-0-08-095975-7.01027-5, 2014.
Pagani, M., Arthur, M. A., and Freeman, K. H.: Miocene evolution of atmospheric carbon dioxide, Paleoceanography, 14, 273–292, https://doi.org/10.1029/1999PA900006, 1999.
Pagani, M., Freeman, K. H., Ohkouchi, N., and Caldeira, K.: Comparison of water column [CO2aq] with sedimentary alkenone-based estimates: A test of the alkenone-CO2 proxy, Paleoceanography, 17, 21-21–21-12, https://doi.org/10.1029/2002pa000756, 2002.
Pagani, M., Zachos, J. C., Freeman, K. H., Tipple, B., and Bohaty, S.: Marked decline in atmospheric carbon dioxide concentrations during the Paleogene, Science, 309, 600–603, https://doi.org/10.1126/science.1110063, 2005.
Pagani, M., Liu, Z., LaRiviere, J., and Ravelo, A. C.: High Earth-system climate sensitivity determined from Pliocene carbon dioxide concentrations, Nat. Geosci., 3, 27–30, https://doi.org/10.1038/ngeo724, 2010.
Pagani, M., Huber, M., Liu, Z., Bohaty, S. M., Henderiks, J., Sijp, W., Krishnan, S., and DeConto, R. M.: The role of carbon dioxide during the onset of Antarctic Glaciation, Science, 334, 1261–1264, https://doi.org/10.1126/science.1203909, 2011.
Pahnke, K., Goldstein, S. L., and Hemming, S. R.: Abrupt changes in Antarctic Intermediate Water circulation over the past 25,000 years, Nat. Geosci., 1, 870–874, https://doi.org/10.1038/ngeo360, 2008.
Palmer, M. and Pearson, P. N.: A 23,000-year record of surface water pH and PCO2 in the western equatorial Pacific Ocean, Science, 300, 480–482, https://doi.org/10.1126/science.1080796, 2003.
Palmer, M. R., Brummer, G. J., Cooper, M. J., Elderfield, H., Greaves, M. J., Reichart, G. J., Schouten, S., and Yu, J. M.: Multi-proxy reconstruction of surface water pCO2 in the northern Arabian Sea since 29 ka, Earth Planet. Sc. Lett., 295, 49–57, https://doi.org/10.1016/j.epsl.2010.03.023, 2010.
Panieri, G., Lepland, A., Whitehouse, M. J., Wirth, R., Raanes, M. P., James, R. H., Graves, C. A., Crémière, A., and Schneider, A.: Diagenetic Mg-calcite overgrowths on foraminiferal tests in the vicinity of methane seeps, Earth Planet. Sc. Lett., 458, 203–212, https://doi.org/10.1016/j.epsl.2016.10.024, 2017.
Panmei, C., Divakar Naidu, P., and Mohtadi, M.: Bay of Bengal exhibits warming trend during the Younger Dryas: Implications of AMOC, Geochem. Geophy. Geosy., 18, 4317–4325, https://doi.org/10.1002/2017GC007075, 2017.
Parekh, P., Dutkiewicz, S., Follows, M. J., and Ito, T.: Atmospheric carbon dioxide in a less dusty world, Geophys. Res. Lett., 33, L03610, https://doi.org/10.1029/2005GL025098, 2006.
Partridge, T. C., Scott, L., and Hamilton, J. E.: Synthetic reconstructions of southern African environments during the Last Glacial Maximum (21–18 kyr) and the Holocene Altithermal (8–6 kyr), Quatern. Int., 57–58, 207–214, https://doi.org/10.1016/S1040-6182(98)00061-5, 1999.
Pedro, J. B., Bostock, H. C., Bitz, C. M., He, F., Vandergoes, M. J., Steig, E. J., Chase, B. M., Krause, C. E., Rasmussen, S. O., Markle, B. R., and Cortese, G.: The spatial extent and dynamics of the Antarctic Cold Reversal, Nat. Geosci., 9, 51–55, https://doi.org/10.1038/ngeo2580, 2016.
Peeters, F. J., Acheson, R., Brummer, G.-J. A., De Ruijter, W. P., Schneider, R. R., Ganssen, G. M., Ufkes, E., and Kroon, D.: Vigorous exchange between the Indian and Atlantic oceans at the end of the past five glacial periods, Nature, 430, 661–665, https://doi.org/10.1038/nature02785, 2004.
Peterson, R. G. and Stramma, L.: Upper-level circulation in the South Atlantic Ocean, Prog. Oceanogr., 26, 1–73, https://doi.org/10.1016/0079-6611(91)90006-8, 1991.
Pether, J.: Molluscan evidence for enhanced deglacial advection of Agulhas water in the Benguela current, off southwestern Africa, Palaeogeogr. Palaeocl., 111, 99–117, https://doi.org/10.1016/0031-0182(94)90350-6, 1994.
Petit, J. R., Jouzel, J., Raynaud, D., Barkov, N. I., Barnola, J. M., Basile, I., Bender, M., Chappellaz, J., Davis, M., Delaygue, G., Delmotte, M., Kotlyakov, V. M., Legrand, M., Lipenkov, V. Y., Lorius, C., Pépin, L., Ritz, C., Saltzman, E., and Stievenard, M.: Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica, Nature, 399, 429–436, https://doi.org/10.1038/20859, 1999.
Popp, B. N., Laws, E. A., Bidigare, R. R., Dore, J. E., Hanson, K. L., and Wakeham, S. G.: Effect of phytoplankton cell geometry on carbon isotopic fractionation, Geochim. Cosmochim. Ac., 62, 69–77, https://doi.org/10.1016/S0016-7037(97)00333-5, 1998.
Pöppelmeier, F., Jeltsch-Thömmes, A., Lippold, J., Joos, F., and Stocker, T. F.: Multi-proxy constraints on Atlantic circulation dynamics since the last ice age, Nat. Geosci., 16, 349–356, https://doi.org/10.1038/s41561-023-01140-3, 2023.
Prahl, F. G. and Wakeham, S. G.: Calibration of unsaturation patterns in long-chain ketone compositions for palaeotemperature assessment, Nature, 330, 367–369, https://doi.org/10.1038/330367a0, 1987.
Rae, J. W. B., Zhang, Y. G., Liu, X., Foster, G. L., Stoll, H. M., and Whiteford, R. D. M.: Atmospheric CO2 over the Past 66 Million Years from Marine Archives, Annu. Rev. Earth Pl. Sc., 49, 609–641, https://doi.org/10.1146/annurev-earth-082420-063026, 2021.
Rahmstorf, S.: Ocean circulation and climate during the past 120,000 years, Nature, 419, 207–214, https://doi.org/10.1038/nature01090, 2002.
Raitzsch, M., Bijma, J., Benthien, A., Richter, K.-U., Steinhoefel, G., and Kučera, M.: Boron isotope-based seasonal paleo-pH reconstruction for the Southeast Atlantic – A multispecies approach using habitat preference of planktonic foraminifera, Earth Planet. Sc. Lett., 487, 138–150, https://doi.org/10.1016/j.epsl.2018.02.002, 2018.
Rau, A. J., Rogers, J., Lutjeharms, J. R. E., Giraudeau, J., Lee-Thorp, J. A., Chen, M. T., and Waelbroeck, C.: A 450-kyr record of hydrological conditions on the western Agulhas Bank Slope, south of Africa, Mar. Geol., 180, 183–201, https://doi.org/10.1016/S0025-3227(01)00213-4, 2002.
Rau, G. H., Riebesell, U., and Wolf-Gladrow, D.: A model of photosynthetic 13C fractionation by marine phytoplankton based on diffusive molecular CO2 uptake, Mar. Ecol. Prog. Ser., 133, 275–285, https://doi.org/10.3354/meps133275, 1996.
Rebotim, A., Voelker, A. H. L., Jonkers, L., Waniek, J. J., Meggers, H., Schiebel, R., Fraile, I., Schulz, M., and Kucera, M.: Factors controlling the depth habitat of planktonic foraminifera in the subtropical eastern North Atlantic, Biogeosciences, 14, 827–859, https://doi.org/10.5194/bg-14-827-2017, 2017.
Redfield, A. C.: The biological control of chemical factors in the environment, Am. Sci., 46, 205–221, https://www.jstor.org/stable/27827150 (last access: 19 March 2025), 1958.
Regenberg, M., Nürnberg, D., Steph, S., Groeneveld, J., Garbe-Schönberg, D., Tiedemann, R., and Dullo, W. C.: Assessing the effect of dissolution on planktonic foraminiferal Mg Ca ratios: Evidence from Caribbean core tops, Geochem. Geophy. Geosy., 7, Q07P15, https://doi.org/10.1029/2005GC001019, 2006.
Reinfelder, J. R.: Carbon concentrating mechanisms in eukaryotic marine phytoplankton, Ann. Rev. Mar. Sci., 3, 291–315, https://doi.org/10.1146/annurev-marine-120709-142720, 2011.
Riebesell, U., Revill, A. T., Holdsworth, D. G., and Volkman, J. K.: The effects of varying CO2 concentration on lipid composition and carbon isotope fractionation in Emiliania huxleyi, Geochim. Cosmochim. Ac., 64, 4179–4192, https://doi.org/10.1016/S0016-7037(00)00474-9, 2000.
Romanek, C. S., Grossman, E. L., and Morse, J. W.: Carbon isotopic fractionation in synthetic aragonite and calcite: Effects of temperature and precipitation rate, Geochim. Cosmochim. Ac., 56, 419–430, https://doi.org/10.1016/0016-7037(92)90142-6, 1992.
Romero, O., Mollenhauer, G., Schneider, R., and Wefer, G.: Oscillations of the siliceous imprint in the central Benguela Upwelling System from MIS 3 through to the early Holocene: The influence of the Southern Ocean, J. Quaternary Sci., 18, 733–743, https://doi.org/10.1002/jqs.789, 2003.
Ronge, T. A., Steph, S., Tiedemann, R., Prange, M., Merkel, U., Nürnberg, D., and Kuhn, G.: Pushing the boundaries: Glacial/interglacial variability of intermediate and deep waters in the southwest Pacific over the last 350,000 years, Paleoceanography, 30, 23–38, https://doi.org/10.1002/2014PA002727, 2015.
Roobaert, A., Laruelle, G. G., Landschützer, P., Gruber, N., Chou, L., and Regnier, P.: The spatiotemporal dynamics of the sources and sinks of CO2 in the global coastal ocean, Global Biogeochem. Cy., 33, 1693–1714, https://doi.org/10.1029/2019GB006239, 2019.
Rühlemann, C., Mulitza, S., Müller, P. J., Wefer, G., and Zahn, R.: Warming of the tropical Atlantic Ocean and slowdown of thermohaline circulation during the last deglaciation, Nature, 402, 511–514, https://doi.org/10.1038/990069, 1999.
Salt, L. A., van Heuven, S. M. A. C., Claus, M. E., Jones, E. M., and de Baar, H. J. W.: Rapid acidification of mode and intermediate waters in the southwestern Atlantic Ocean, Biogeosciences, 12, 1387–1401, https://doi.org/10.5194/bg-12-1387-2015, 2015.
Santana-Casiano, J. M., González-Dávila, M., and Ucha, I. R.: Carbon dioxide fluxes in the Benguela upwelling system during winter and spring: A comparison between 2005 and 2006, Deep-Sea Res. Pt. II, 56, 533–541, https://doi.org/10.1016/j.dsr2.2008.12.010, 2009.
Sarnthein, M., Winn, K., Jung, S. J. A., Duplessy, J.-C., Labeyrie, L., Erlenkeuser, H., and Ganssen, G.: Changes in East Atlantic Deepwater Circulation over the last 30,000 years: Eight time slice reconstructions, Paleoceanography, 9, 209–267, https://doi.org/10.1029/93PA03301, 1994.
Schlitzer, R.: eWOCE-Electronic Atlas of WOCE Data, WOCE Global Data, Version 2.0 CD-ROM, WOCE Intern. Project Office, WOCE Report No. 171/00, Southampton, UK, https://doi.org/10013/epic.14768, 2000.
Schmittner, A., Gruber, N., Mix, A. C., Key, R. M., Tagliabue, A., and Westberry, T. K.: Biology and air–sea gas exchange controls on the distribution of carbon isotope ratios (δ13C) in the ocean, Biogeosciences, 10, 5793–5816, https://doi.org/10.5194/bg-10-5793-2013, 2013.
Schouten, S., Klein Breteler, W. C. M., Blokker, P., Schogt, N., Rijpstra, W. I. C., Grice, K., Baas, M., and Sinninghe Damsté, J. S.: Biosynthetic effects on the stable carbon isotopic compositions of algal lipids: implications for deciphering the carbon isotopic biomarker record, Geochim. Cosmochim. Ac., 62, 1397–1406, https://doi.org/10.1016/S0016-7037(98)00076-3, 1998.
Scussolini, P. and Peeters, F. J.: A record of the last 460 thousand years of upper ocean stratification from the central Walvis Ridge, South Atlantic, Paleoceanography, 28, 426–439, https://doi.org/10.1002/palo.20041, 2013.
Seki, O., Foster, G. L., Schmidt, D. N., Mackensen, A., Kawamura, K., and Pancost, R. D.: Alkenone and boron-based Pliocene pCO2 records, Earth Planet. Sc. Lett., 292, 201–211, https://doi.org/10.1016/j.epsl.2010.01.037, 2010.
Sexton, P. F., Wilson, P. A., and Pearson, P. N.: Microstructural and geochemical perspectives on planktic foraminiferal preservation: “Glassy” versus “Frosty”, Geochem. Geophy. Geosy., 7, Q12P19, https://doi.org/10.1029/2006gc001291, 2006.
Shannon, L. and Nelson, G.: The Benguela: large scale features and processes and system variability, in: The south atlantic, Springer, Berlin, Heidelberg, 163–210, https://doi.org/10.1007/978-3-642-80353-6_9, 1996.
Shannon, L. V. and O'Toole, M.: Sustainability of the Benguela: ex Africa semper aliquid novi, in: Large Marine Ecosystems of the World: Trends in Exploitation, Protection and Research, edited by: Hempel, G. and Sherman, K., Elsevier B.V., Amsterdam, 227–253, 978-0444510273, 2003.
Shi, N., Dupont, L. M., Beug, H.-J., and Schneider, R.: Vegetation and climate changes during the last 21 000 years in S.W. Africa based on a marine pollen record, Veg. Hist. Archaeobot., 7, 127–140, https://doi.org/10.1007/BF01374001, 1998.
Shillington, F.: The Benguela upwelling system off southwestern Africa, Sea, 11, 583–604, 1998.
Spero, H. J.: Do planktic foraminifera accurately record shifts in the carbon isotopic composition of seawater ΣCO2?, Mar. Micropaleontol., 19, 275–285, https://doi.org/10.1016/0377-8398(92)90033-G, 1992.
Spero, H. J. and Lea, D. W.: Intraspecific stable isotope variability in the planktic foraminifera Globigerinoides sacculifer: Results from laboratory experiments, Mar. Micropaleontol., 22, 221–234, https://doi.org/10.1016/0377-8398(93)90045-Y, 1993.
Spero, H. J. and Lea, D. W.: Experimental determination of stable isotope variability in Globigerina bulloides: implications for paleoceanographic reconstructions, Mar. Micropaleontol., 28, 231–246, https://doi.org/10.1016/0377-8398(96)00003-5, 1996.
Spero, H. J., Bijma, J., Lea, D. W., and Bemis, B. E.: Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes, Nature, 390, 497–500, https://doi.org/10.1038/37333, 1997.
Stainbank, S., Spezzaferri, S., De Boever, E., Bouvier, A.-S., Chilcott, C., De Leau, E. S., Foubert, A., Kunkelova, T., Pichevin, L., Raddatz, J., Rüggeberg, A., Wright, J. D., Yu, S. M., Zhang, M., and Kroon, D.: Assessing the impact of diagenesis on foraminiferal geochemistry from a low latitude, shallow-water drift deposit, Earth Planet. Sc. Lett., 545, 116390, https://doi.org/10.1016/j.epsl.2020.116390, 2020.
Stephens, B. B. and Keeling, R. F.: The influence of Antarctic sea ice on glacial–interglacial CO2 variations, Nature, 404, 171–174, https://doi.org/10.1038/35004556, 2000.
Stocker, T. F.: The Seesaw Effect, Science, 282, 61–62, https://doi.org/10.1126/science.282.5386.61, 1998.
Stoll, H. M., Guitian, J., Hernandez-Almeida, I., Mejia, L. M., Phelps, S., Polissar, P., Rosenthal, Y., Zhang, H., and Ziveri, P.: Upregulation of phytoplankton carbon concentrating mechanisms during low CO2 glacial periods and implications for the phytoplankton pCO2 proxy, Quaternary Sci. Rev., 208, 1–20, https://doi.org/10.1016/j.quascirev.2019.01.012, 2019.
Stramma, L. and England, M.: On the water masses and mean circulation of the South Atlantic Ocean, J. Geophys. Res.-Oceans, 104, 20863–20883, https://doi.org/10.1029/1999JC900139, 1999.
Stuut, J.-B. W., Prins, M. A., Schneider, R. R., Weltje, G. J., Jansen, J. H. F., and Postma, G.: A 300-kyr record of aridity and wind strength in southwestern Africa: inferences from grain-size distributions of sediments on Walvis Ridge, SE Atlantic, Mar. Geol., 180, 221–233, https://doi.org/10.1016/S0025-3227(01)00215-8, 2002.
Suggate, R. P. and Almond, P. C.: The Last Glacial Maximum (LGM) in western South Island, New Zealand: implications for the global LGM and MIS 2, Quaternary Sci. Rev., 24, 1923–1940, https://doi.org/10.1016/j.quascirev.2004.11.007, 2005.
Synal, H.-A., Stocker, M., and Suter, M.: MICADAS: A new compact radiocarbon AMS system, Nucl. Instrum. Meth. B, 259, 7–13, https://doi.org/10.1016/j.nimb.2007.01.138, 2007.
Tapia, R., Ho, S. L., Wang, H.-Y., Groeneveld, J., and Mohtadi, M.: Contrasting vertical distributions of recent planktic foraminifera off Indonesia during the southeast monsoon: implications for paleoceanographic reconstructions, Biogeosciences, 19, 3185–3208, https://doi.org/10.5194/bg-19-3185-2022, 2022.
Thomas, E. and Shackleton, N. J.: The Paleocene-Eocene benthic foraminiferal extinction and stable isotope anomalies, Geological Society, London, Special Publications, 101, 401–441, https://doi.org/10.1144/GSL.SP.1996.101.01.20, 1996.
Tian, H.-A., van Manen, M., Bunnell, Z. B., Jung, J., Lee, S. H., Kim, T.-W., Reichart, G.-J., Conway, T. M., and Middag, R.: Biogeochemistry of iron in coastal Antarctica: isotopic insights for external sources and biological uptake in the Amundsen Sea polynyas, Geochim. Cosmochim. Ac., 363, 51–67, https://doi.org/10.1016/j.gca.2023.10.029, 2023.
Turi, G., Lachkar, Z., and Gruber, N.: Spatiotemporal variability and drivers of pCO2 and air–sea CO2 fluxes in the California Current System: an eddy-resolving modeling study, Biogeosciences, 11, 671–690, https://doi.org/10.5194/bg-11-671-2014, 2014.
Turner, J. T.: Zooplankton fecal pellets, marine snow, phytodetritus and the ocean's biological pump, Prog. Oceanogr., 130, 205–248, https://doi.org/10.1016/j.pocean.2014.08.005, 2015.
Umling, N. E., Oppo, D. W., Chen, P., Yu, J., Liu, Z., Yan, M., Gebbie, G., Lund, D. C., Pietro, K. R., Jin, Z. D., Huang, K. F., Costa, K. B., and Toledo, F. A. L.: Atlantic circulation and ice sheet influences on upper South Atlantic temperatures during the Last Deglaciation, Paleoceanogr. Paleocl., 34, 990–1005, https://doi.org/10.1029/2019PA003558, 2019.
Vandergoes, M. J., Dieffenbacher-Krall, A. C., Newnham, R. M., Denton, G. H., and Blaauw, M.: Cooling and changing seasonality in the Southern Alps, New Zealand during the Antarctic Cold Reversal, Quaternary Sci. Rev., 27, 589–601, https://doi.org/10.1016/j.quascirev.2007.11.015, 2008.
Van Dijk, I., de Nooijer, L. J., Wolthers, M., and Reichart, G.-J.: Impacts of pH and [CO ] on the incorporation of Zn in foraminiferal calcite, Geochim. Cosmochim. Ac., 197, 263–277, https://doi.org/10.1016/j.gca.2016.10.031, 2017.
van Dongen, B. E., Schouten, S., and Damsté, J. S. S.: Carbon isotope variability in monosaccharides and lipids of aquatic algae and terrestrial plants, Mar. Ecol. Prog. Ser., 232, 83–92, https://doi.org/10.3354/meps232083, 2002.
Volk, T. and Hoffert, M. I.: Ocean carbon pumps: Analysis of relative strengths and efficiencies in ocean-driven atmospheric CO2 changes, in: The carbon cycle and atmospheric CO2: Natural variations archean to present, Geoph. Monog. Series, 32, 99–110, https://doi.org/10.1029/GM032p0099, 1985.
Wacker, L., Fahrni, S. M., Hajdas, I., Molnar, M., Synal, H. A., Szidat, S., and Zhang, Y. L.: A versatile gas interface for routine radiocarbon analysis with a gas ion source, Nucl. Instrum. Meth. B, 294, 315–319, https://doi.org/10.1016/j.nimb.2012.02.009, 2013.
Wacker, L., Güttler, D., Goll, J., Hurni, J. P., Synal, H. A., and Walti, N.: Radiocarbon dating to a single year by means of rapid atmospheric 14C changes, Radiocarbon, 56, 573–579, https://doi.org/10.2458/56.17634, 2014.
Waelbroeck, C., Labeyrie, L., Michel, E., Duplessy, J. C., McManus, J. F., Lambeck, K., Balbon, E., and Labracherie, M.: Sea-level and deep water temperature changes derived from benthic foraminifera isotopic records, Quaternary Sci. Rev., 21, 295–305, https://doi.org/10.1016/S0277-3791(01)00101-9, 2002.
Wang, B.-S., You, C.-F., Huang, K.-F., Wu, S.-F., Aggarwal, S. K., Chung, C.-H., and Lin, P.-Y.: Direct separation of boron from Na- and Ca-rich matrices by sublimation for stable isotope measurement by MC-ICP-MS, Talanta, 82, 1378–1384, https://doi.org/10.1016/j.talanta.2010.07.010, 2010.
Wang, Y. V., Leduc, G., Regenberg, M., Andersen, N., Larsen, T., Blanz, T., and Schneider, R. R.: Northern and southern hemisphere controls on seasonal sea surface temperatures in the Indian Ocean during the last deglaciation, Paleoceanography, 28, 619–632, https://doi.org/10.1002/palo.20053, 2013.
Wefer, G. A., Berger, W. H., Bickert, T., Donner, B., Fischer, G., von Mücke, S. K., Meinecke, G., Müller, P., Mulitza, S., and Niebler, H.-S.: Late Quaternary surface circulation of the South Atlantic: The stable isotope record and implications for heat transport and productivity, in: The South Atlantic, Springer, Berlin, Heidelberg, 461–502, https://doi.org/10.1007/978-3-642-80353-6_25, 1996.
Weltje, G. J. and Tjallingii, R.: Calibration of XRF core scanners for quantitative geochemical logging of sediment cores: Theory and application, Earth Planet. Sc. Lett., 274, 423–438, https://doi.org/10.1016/j.epsl.2008.07.054, 2008.
Wilkes, E. B. and Pearson, A.: A general model for carbon isotopes in red-lineage phytoplankton: Interplay between unidirectional processes and fractionation by RubisCO, Geochim. Cosmochim. Ac., 265, 163–181, https://doi.org/10.1016/j.gca.2019.08.043, 2019.
Witkowski, C. R., Weijers, J. W., Blais, B., Schouten, S., and Damsté, J. S. S.: Molecular fossils from phytoplankton reveal secular PCO2 trend over the Phanerozoic, Sci. Adv., 4, eaat4556, https://doi.org/10.1126/sciadv.aat4556, 2018.
Witkowski, C. R., van der Meer, M. T., Blais, B., Damsté, J. S. S., and Schouten, S.: Algal biomarkers as a proxy for pCO2: Constraints from late quaternary sapropels in the eastern Mediterranean, Org. Geochem., 150, 104123, https://doi.org/10.1016/j.orggeochem.2020.104123, 2020.
Zeebe, R. E. and Wolf-Gladrow, D.: CO2 in seawater: Equilibrium, kinetics, isotopes, Elsevier Oceanography Series, 65, Elsevier, Amsterdam, 978-0444509468, 2001.
Zeebe, R. E., Bijma, J., and Wolf-Gladrow, D. A.: A diffusion-reaction model of carbon isotope fractionation in foraminifera, Mar. Chem., 64, 199–227, https://doi.org/10.1016/S0304-4203(98)00075-9, 1999.
Zhang, Y. G., Pagani, M., Liu, Z., Bohaty, S. M., and DeConto, R.: A 40-million-year history of atmospheric CO2, Philos. T. Roy. Soc. A, 371, 20130096, https://doi.org/10.1098/rsta.2013.0096, 2013.
Zhang, Y. G., Pearson, A., Benthien, A., Dong, L., Huybers, P., Liu, X., and Pagani, M.: Refining the alkenone-pCO2 method I: Lessons from the Quaternary glacial cycles, Geochim. Cosmochim. Ac., 260, 177–191, https://doi.org/10.1016/j.gca.2019.06.032, 2019.
Zhang, Y. G., Henderiks, J., and Liu, X.: Refining the alkenone-pCO2 method II: Towards resolving the physiological parameter “b”, Geochim. Cosmochim. Ac., 281, 118–134, https://doi.org/10.1016/j.gca.2020.05.002, 2020.
Short summary
Changes in upwelling intensity of the Benguela upwelling region during the last glacial motivated us to investigate the local CO2 history during the last glacial-to-interglacial transition. Using various geochemical tracers on archives from both subsurface and surface waters reveals enhanced storage of carbon at depth during the Last Glacial Maximum. An efficient biological pump likely prevented outgassing of CO2 from intermediate depth to the atmosphere.
Changes in upwelling intensity of the Benguela upwelling region during the last glacial...