Articles | Volume 10, issue 1
https://doi.org/10.5194/cp-10-251-2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/cp-10-251-2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Salinity changes in the Agulhas leakage area recorded by stable hydrogen isotopes of C37 alkenones during Termination I and II
S. Kasper
NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, P.O. Box 59, 1790 AB Den Burg (Texel), the Netherlands
M. T. J. van der Meer
NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, P.O. Box 59, 1790 AB Den Burg (Texel), the Netherlands
A. Mets
NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, P.O. Box 59, 1790 AB Den Burg (Texel), the Netherlands
R. Zahn
Institució Catalana de Recerca i Estudis Avançats, ICREA, Barcelona, Spain
Universitat Autònoma de Barcelona, Institut de Ciència i Tecnologia Ambientals (ICTA) and Departament de Física, 08193 Bellaterra, Spain
J. S. Sinninghe Damsté
NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, P.O. Box 59, 1790 AB Den Burg (Texel), the Netherlands
S. Schouten
NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, P.O. Box 59, 1790 AB Den Burg (Texel), the Netherlands
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Szabina Karancz, Lennart J. de Nooijer, Bas van der Wagt, Marcel T. J. van der Meer, Sambuddha Misra, Rick Hennekam, Zeynep Erdem, Julie Lattaud, Negar Haghipour, Stefan Schouten, and Gert-Jan Reichart
EGUsphere, https://doi.org/10.5194/egusphere-2024-1915, https://doi.org/10.5194/egusphere-2024-1915, 2024
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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 intermediate and surface waters reveal 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.
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.
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.
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.
Caitlyn R. Witkowski, Sylvain Agostini, Ben P. Harvey, Marcel T. J. van der Meer, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 16, 4451–4461, https://doi.org/10.5194/bg-16-4451-2019, https://doi.org/10.5194/bg-16-4451-2019, 2019
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Carbon dioxide concentrations (pCO2) in the atmosphere play an integral role in Earth system dynamics, especially climate. Past climates help us understand future ones, but reconstructing pCO2 over the geologic record remains a challenge. This research demonstrates new approaches for exploring past pCO2 via the carbon isotope fractionation in general algal lipids, which we test over a high CO2 gradient from a naturally occurring CO2 seep.
Darci Rush, Helen M. Talbot, Marcel T. J. van der Meer, Ellen C. Hopmans, Ben Douglas, and Jaap S. Sinninghe Damsté
Biogeosciences, 16, 2467–2479, https://doi.org/10.5194/bg-16-2467-2019, https://doi.org/10.5194/bg-16-2467-2019, 2019
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Sapropels are layers of sediment that regularly occur in the Mediterranean. They indicate periods when the Mediterranean Sea water contained no oxygen, a gas vital for most large organisms. This research investigated a key process in the nitrogen cycle (anaerobic ammonium oxidation, anammox), which removes nitrogen – an important nutrient to algae – from the water, during sapropel events. Using lipids to trace this process, we found that anammox was active during the no-oxygen times.
Gabriella M. Weiss, David Chivall, Sebastian Kasper, Hideto Nakamura, Fiz da Costa, Philippe Soudant, Jaap S. Sinninghe Damsté, Stefan Schouten, and Marcel T. J. van der Meer
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-147, https://doi.org/10.5194/bg-2019-147, 2019
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In this study, we used four different haptophyte species and six different organic compounds to investigate the relationship between organic matter synthesis and salinity. We showed that creation in different parts of the cell (chloroplast versus cytosol) determined which compounds retain a correlation between their hydrogen isotopes and salinity. This is important for using hydrogen isotopes to reconstruct salinity in the geologic record.
Julie Lattaud, Frédérique Kirkels, Francien Peterse, Chantal V. Freymond, Timothy I. Eglinton, Jens Hefter, Gesine Mollenhauer, Sergio Balzano, Laura Villanueva, Marcel T. J. van der Meer, Ellen C. Hopmans, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 15, 4147–4161, https://doi.org/10.5194/bg-15-4147-2018, https://doi.org/10.5194/bg-15-4147-2018, 2018
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Long-chain diols (LCDs) are biomarkers that occur widespread in marine environments and also in lakes and rivers. In this study, we looked at the distribution of LCDs in three river systems (Godavari, Danube, and Rhine) in relation to season, precipitation, and temperature. We found out that the LCDs are likely being produced in calm areas of the river systems and that marine LCDs have a different distribution than riverine LCDs.
Gabriella M. Weiss, Eva Y. Pfannerstill, Stefan Schouten, Jaap S. Sinninghe Damsté, and Marcel T. J. van der Meer
Biogeosciences, 14, 5693–5704, https://doi.org/10.5194/bg-14-5693-2017, https://doi.org/10.5194/bg-14-5693-2017, 2017
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Algal-derived compounds allow us to make assumptions about environmental conditions in the past. In order to better understand how organisms record environmental conditions, we grew microscopic marine algae at different light intensities, salinities, and alkalinities in a temperature-controlled environment. We determined how these environmental parameters affected specific algal-derived compounds, especially their relative deuterium content, which seems to be mainly affected by salinity.
Sandra Mariam Heinzelmann, Nicole Jane Bale, Laura Villanueva, Danielle Sinke-Schoen, Catharina Johanna Maria Philippart, Jaap Smede Sinninghe Damsté, Stefan Schouten, and Marcel Teunis Jan van der Meer
Biogeosciences, 13, 5527–5539, https://doi.org/10.5194/bg-13-5527-2016, https://doi.org/10.5194/bg-13-5527-2016, 2016
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In order to understand microbial communities in the environment it is necessary to assess their metabolic potential. The hydrogen isotopic composition of fatty acids has been shown to be promising tool to study the general metabolism of microorganisms in pure culture. Here we showed that it is possible to study seasonal changes in the general metabolism of the whole community by studying the hydrogen isotopic composition of fatty acids.
Douwe S. Maat, Nicole J. Bale, Ellen C. Hopmans, Jaap S. Sinninghe Damsté, Stefan Schouten, and Corina P. D. Brussaard
Biogeosciences, 13, 1667–1676, https://doi.org/10.5194/bg-13-1667-2016, https://doi.org/10.5194/bg-13-1667-2016, 2016
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This study shows that the phytoplankter Micromonas pusilla alters its lipid composition when the macronutrient phosphate is in low supply. This reduction in phospholipids is directly dependent on the strength of the limitation. Furthermore we show that, when M. pusilla is infected by viruses, lipid remodeling is lower. The study was carried out to investigate how phytoplankton and its viruses are affected by environmental factors and how this affects food web dynamics.
R. L. Sobrinho, M. C. Bernardes, G. Abril, J.-H. Kim, C. I Zell, J.-M. Mortillaro, T. Meziane, P. Moreira-Turcq, and J. S. Sinninghe Damsté
Biogeosciences, 13, 467–482, https://doi.org/10.5194/bg-13-467-2016, https://doi.org/10.5194/bg-13-467-2016, 2016
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The principal objective of the present work is to quantify the fractions of the principal sources of sedimentary organic matter (SOM) in floodplain lakes of the central Amazon basin. The results indicate that the main source of SOM is not the riverine particulate material, as postulated by the literature, but the macrophytes and the forests.
M. Rodrigo-Gámiz, S. W. Rampen, H. de Haas, M. Baas, S. Schouten, and J. S. Sinninghe Damsté
Biogeosciences, 12, 6573–6590, https://doi.org/10.5194/bg-12-6573-2015, https://doi.org/10.5194/bg-12-6573-2015, 2015
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This research reports a test of the applicability of three organic-derived temperature proxies (UK'37, TEX86 and LDI) at high latitudes around Iceland. A range of samples including suspended particular material (SPM), trapped descending particles and surface sediments were collected to test the different proxies in the water column and the sediment.The combination of three independent SST organic proxies provided important information about seasonality and differences in habitat depth.
M. Sollai, E. C. Hopmans, S. Schouten, R. G. Keil, and J. S. Sinninghe Damsté
Biogeosciences, 12, 4725–4737, https://doi.org/10.5194/bg-12-4725-2015, https://doi.org/10.5194/bg-12-4725-2015, 2015
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The distribution of Thaumarchaeota and anammox bacteria in the water column of the eastern tropical North Pacific (ETNP) oxygen-deficient zone (ODZ) was investigated by collecting suspended particulate matter (SPM) and analyzing it for the content of specific intact polar lipids (IPLs) produced by the two microbial groups. We found a clear niche segregation in the distribution of the two groups in the coastal waters of the ETNP but a partial overlap of their niches in the open-water setting.
J. Steinhardt, C. Cléroux, L. J. de Nooijer, G.-J. Brummer, R. Zahn, G. Ganssen, and G.-J. Reichart
Biogeosciences, 12, 2411–2429, https://doi.org/10.5194/bg-12-2411-2015, https://doi.org/10.5194/bg-12-2411-2015, 2015
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In this paper we present, for the first time, results from single-chamber Mg/Ca analyses combined with single-shell δ18O and δ13C for four planktonic foraminiferal species from a sediment trap in the Mozambique Channel. Eddy-induced hydrographic variability is reflected in test carbonate chemistry of these different species. A species-specific depth-resolved mass balance model confirms distinctive migration and calcification patterns for each species as a function of hydrography.
C. Bottini, E. Erba, D. Tiraboschi, H. C. Jenkyns, S. Schouten, and J. S. Sinninghe Damsté
Clim. Past, 11, 383–402, https://doi.org/10.5194/cp-11-383-2015, https://doi.org/10.5194/cp-11-383-2015, 2015
C. Zell, J.-H. Kim, M. Balsinha, D. Dorhout, C. Fernandes, M. Baas, and J. S. Sinninghe Damsté
Biogeosciences, 11, 5637–5655, https://doi.org/10.5194/bg-11-5637-2014, https://doi.org/10.5194/bg-11-5637-2014, 2014
L. K. Buckles, J. W. H. Weijers, X.-M. Tran, S. Waldron, and J. S. Sinninghe Damsté
Biogeosciences, 11, 5539–5563, https://doi.org/10.5194/bg-11-5539-2014, https://doi.org/10.5194/bg-11-5539-2014, 2014
C. López-Rodríguez, A. Stadnitskaia, G. J. De Lange, F. Martínez-Ruíz, M. Comas, and J. S. Sinninghe Damsté
Biogeosciences, 11, 3187–3204, https://doi.org/10.5194/bg-11-3187-2014, https://doi.org/10.5194/bg-11-3187-2014, 2014
S. K. Lengger, Y. A. Lipsewers, H. de Haas, J. S. Sinninghe Damsté, and S. Schouten
Biogeosciences, 11, 201–216, https://doi.org/10.5194/bg-11-201-2014, https://doi.org/10.5194/bg-11-201-2014, 2014
D. S. Maat, N. J. Bale, E. C. Hopmans, A.-C. Baudoux, J. S. Sinninghe Damsté, S. Schouten, and C. P. D. Brussaard
Biogeosciences, 11, 185–194, https://doi.org/10.5194/bg-11-185-2014, https://doi.org/10.5194/bg-11-185-2014, 2014
N. J. Bale, L. Villanueva, E. C. Hopmans, S. Schouten, and J. S. Sinninghe Damsté
Biogeosciences, 10, 7195–7206, https://doi.org/10.5194/bg-10-7195-2013, https://doi.org/10.5194/bg-10-7195-2013, 2013
J. Etourneau, L. G. Collins, V. Willmott, J.-H. Kim, L. Barbara, A. Leventer, S. Schouten, J. S. Sinninghe Damsté, A. Bianchini, V. Klein, X. Crosta, and G. Massé
Clim. Past, 9, 1431–1446, https://doi.org/10.5194/cp-9-1431-2013, https://doi.org/10.5194/cp-9-1431-2013, 2013
B. Veuger, A. Pitcher, S. Schouten, J. S. Sinninghe Damsté, and J. J. Middelburg
Biogeosciences, 10, 1775–1785, https://doi.org/10.5194/bg-10-1775-2013, https://doi.org/10.5194/bg-10-1775-2013, 2013
Related subject area
Subject: Proxy Use-Development-Validation | Archive: Marine Archives | Timescale: Pleistocene
Testing the reliability of global surface temperature reconstructions of the last glacial cycle
Monsoon-driven changes in aeolian and fluvial sediment input to the central Red Sea recorded throughout the last 200 000 years
Orbital CO2 reconstruction using boron isotopes during the late Pleistocene, an assessment of accuracy
Bayesian age models and stacks: combining age inferences from radiocarbon and benthic δ18O stratigraphic alignment
A 600 kyr reconstruction of deep Arctic seawater δ18O from benthic foraminiferal δ18O and ostracode Mg ∕ Ca paleothermometry
Antarctic sea ice over the past 130 000 years – Part 1: a review of what proxy records tell us
Reorganization of Atlantic Waters at sub-polar latitudes linked to deep-water overflow in both glacial and interglacial climate states
Parallel between the isotopic composition of coccolith calcite and carbon levels across Termination II: developing a new paleo-CO2 probe
A global climatology of the ocean surface during the Last Glacial Maximum mapped on a regular grid (GLOMAP)
Contrasting late-glacial paleoceanographic evolution between the upper and lower continental slope of the western South Atlantic
Modal shift in North Atlantic seasonality during the last deglaciation
Technical note: PaleoDataView – a software toolbox for the collection, homogenization and visualization of marine proxy data
Sensitivity to species selection indicates the effect of nuisance variables on marine microfossil transfer functions
Insensitivity of alkenone carbon isotopes to atmospheric CO2 at low to moderate CO2 levels
Extreme lowering of deglacial seawater radiocarbon recorded by both epifaunal and infaunal benthic foraminifera in a wood-dated sediment core
A Late Quaternary climate record based on long-chain diol proxies from the Chilean margin
Moving beyond the age–depth model paradigm in deep-sea palaeoclimate archives: dual radiocarbon and stable isotope analysis on single foraminifera
Quantifying the effect of seasonal and vertical habitat tracking on planktonic foraminifera proxies
Water and carbon stable isotope records from natural archives: a new database and interactive online platform for data browsing, visualizing and downloading
Palaeo-sea-level and palaeo-ice-sheet databases: problems, strategies, and perspectives
Multiproxy reconstruction for Kuroshio responses to northern hemispheric oceanic climate and the Asian Monsoon since Marine Isotope Stage 5.1 (∼88 ka)
Hydrographic changes in the Agulhas Recirculation Region during the late Quaternary
Mismatch between the depth habitat of planktonic foraminifera and the calibration depth of SST transfer functions may bias reconstructions
Jean-Philippe Baudouin, Nils Weitzel, Maximilian May, Lukas Jonkers, Andrew M. Dolman, and Kira Rehfeld
EGUsphere, https://doi.org/10.5194/egusphere-2024-1387, https://doi.org/10.5194/egusphere-2024-1387, 2024
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We explore past global temperatures, critical for climate change comprehension. We devise a method to test temperature reconstruction using climate simulations. Uncertainties, mainly from past temperature measurement methods and age determination, impact reconstructions over time. While more data enhances accuracy for long-term trends, high quality data are more important for short-term precision. Our study lays the groundwork for better reconstructions and suggests avenues for improvement.
Werner Ehrmann, Paul A. Wilson, Helge W. Arz, Hartmut Schulz, and Gerhard Schmiedl
Clim. Past, 20, 37–52, https://doi.org/10.5194/cp-20-37-2024, https://doi.org/10.5194/cp-20-37-2024, 2024
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Climatic and associated hydrological changes controlled the aeolian versus fluvial transport processes and the composition of the sediments in the central Red Sea through the last ca. 200 kyr. We identify source areas of the mineral dust and pulses of fluvial discharge based on high-resolution grain size, clay mineral, and geochemical data, together with Nd and Sr isotope data. We provide a detailed reconstruction of changes in aridity/humidity.
Elwyn de la Vega, Thomas B. Chalk, Mathis P. Hain, Megan R. Wilding, Daniel Casey, Robin Gledhill, Chongguang Luo, Paul A. Wilson, and Gavin L. Foster
Clim. Past, 19, 2493–2510, https://doi.org/10.5194/cp-19-2493-2023, https://doi.org/10.5194/cp-19-2493-2023, 2023
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We evaluate how faithfully the boron isotope composition of foraminifera records atmospheric CO2 by comparing it to the high-fidelity CO2 record from the Antarctic ice cores. We evaluate potential factors and find that partial dissolution of foraminifera shells, assumptions of seawater chemistry, and the biology of foraminifera all have a negligible effect on reconstructed CO2. This gives confidence in the use of boron isotopes beyond the interval when ice core CO2 is available.
Taehee Lee, Devin Rand, Lorraine E. Lisiecki, Geoffrey Gebbie, and Charles Lawrence
Clim. Past, 19, 1993–2012, https://doi.org/10.5194/cp-19-1993-2023, https://doi.org/10.5194/cp-19-1993-2023, 2023
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Understanding of past climate change depends, in part, on how accurately we can estimate the ages of events recorded in geologic archives. Here we present a new software package, called BIGMACS, to improve age estimates for paleoclimate data from ocean sediment cores. BIGMACS creates multiproxy age estimates that reduce age uncertainty by probabilistically combining information from direct age estimates, such as radiocarbon dates, and the alignment of regional paleoclimate time series.
Jesse R. Farmer, Katherine J. Keller, Robert K. Poirier, Gary S. Dwyer, Morgan F. Schaller, Helen K. Coxall, Matt O'Regan, and Thomas M. Cronin
Clim. Past, 19, 555–578, https://doi.org/10.5194/cp-19-555-2023, https://doi.org/10.5194/cp-19-555-2023, 2023
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Oxygen isotopes are used to date marine sediments via similar large-scale ocean patterns over glacial cycles. However, the Arctic Ocean exhibits a different isotope pattern, creating uncertainty in the timing of past Arctic climate change. We find that the Arctic Ocean experienced large local oxygen isotope changes over glacial cycles. We attribute this to a breakdown of stratification during ice ages that allowed for a unique low isotope value to characterize the ice age Arctic Ocean.
Xavier Crosta, Karen E. Kohfeld, Helen C. Bostock, Matthew Chadwick, Alice Du Vivier, Oliver Esper, Johan Etourneau, Jacob Jones, Amy Leventer, Juliane Müller, Rachael H. Rhodes, Claire S. Allen, Pooja Ghadi, Nele Lamping, Carina B. Lange, Kelly-Anne Lawler, David Lund, Alice Marzocchi, Katrin J. Meissner, Laurie Menviel, Abhilash Nair, Molly Patterson, Jennifer Pike, Joseph G. Prebble, Christina Riesselman, Henrik Sadatzki, Louise C. Sime, Sunil K. Shukla, Lena Thöle, Maria-Elena Vorrath, Wenshen Xiao, and Jiao Yang
Clim. Past, 18, 1729–1756, https://doi.org/10.5194/cp-18-1729-2022, https://doi.org/10.5194/cp-18-1729-2022, 2022
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Despite its importance in the global climate, our knowledge of Antarctic sea-ice changes throughout the last glacial–interglacial cycle is extremely limited. As part of the Cycles of Sea Ice Dynamics in the Earth system (C-SIDE) Working Group, we review marine- and ice-core-based sea-ice proxies to provide insights into their applicability and limitations. By compiling published records, we provide information on Antarctic sea-ice dynamics over the past 130 000 years.
Dakota E. Holmes, Tali L. Babila, Ulysses Ninnemann, Gordon Bromley, Shane Tyrrell, Greig A. Paterson, Michelle J. Curran, and Audrey Morley
Clim. Past, 18, 989–1009, https://doi.org/10.5194/cp-18-989-2022, https://doi.org/10.5194/cp-18-989-2022, 2022
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Our proxy-based observations of the glacial inception following MIS 11 advance our mechanistic understanding of (and elucidates antecedent conditions that can lead to) high-magnitude climate instability during low- and intermediate-ice boundary conditions. We find that irrespective of the magnitude of climate variability or boundary conditions, the reorganization between Polar Water and Atlantic Water at subpolar latitudes appears to influence deep-water flow in the Nordic Seas.
Camille Godbillot, Fabrice Minoletti, Franck Bassinot, and Michaël Hermoso
Clim. Past, 18, 449–464, https://doi.org/10.5194/cp-18-449-2022, https://doi.org/10.5194/cp-18-449-2022, 2022
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We test a new method to reconstruct past atmospheric CO2 levels based on the geochemistry of pelagic algal biominerals (coccoliths), which recent culture and numerical experiments have related to ambient CO2 concentrations. By comparing the isotopic composition of fossil coccoliths to the inferred surface ocean CO2 level at the time they calcified, we outline a transfer function and argue that coccolith vital effects can be used to reconstruct geological pCO2 beyond the ice core record.
André Paul, Stefan Mulitza, Rüdiger Stein, and Martin Werner
Clim. Past, 17, 805–824, https://doi.org/10.5194/cp-17-805-2021, https://doi.org/10.5194/cp-17-805-2021, 2021
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Maps and fields of near-sea-surface temperature differences between the past and present can be used to visualize and quantify climate changes and perform simulations with climate models. We used a statistical method to map sparse and scattered data for the Last Glacial Maximum time period (23 000 to 19 000 years before present) to a regular grid. The estimated global and tropical cooling would imply an equilibrium climate sensitivity in the lower to middle part of the currently accepted range.
Leticia G. Luz, Thiago P. Santos, Timothy I. Eglinton, Daniel Montluçon, Blanca Ausin, Negar Haghipour, Silvia M. Sousa, Renata H. Nagai, and Renato S. Carreira
Clim. Past, 16, 1245–1261, https://doi.org/10.5194/cp-16-1245-2020, https://doi.org/10.5194/cp-16-1245-2020, 2020
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Two sediment cores retrieved from the SE Brazilian continental margin were studied using multiple organic (alkenones) and inorganic (oxygen isotopes in carbonate shells and water) proxies to reconstruct the sea surface temperature (SST) over the last 50 000 years. The findings indicate the formation of strong thermal gradients in the region during the last climate transition, a feature that may become more frequent in the future scenario of global water circulation changes.
Geert-Jan A. Brummer, Brett Metcalfe, Wouter Feldmeijer, Maarten A. Prins, Jasmijn van 't Hoff, and Gerald M. Ganssen
Clim. Past, 16, 265–282, https://doi.org/10.5194/cp-16-265-2020, https://doi.org/10.5194/cp-16-265-2020, 2020
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Here, mid-ocean seasonality is resolved through time, using differences in the oxygen isotope composition between individual shells of the commonly used (sub)polar planktonic foraminifera species in ocean-climate reconstruction, N. pachyderma and G. bulloides. Single-specimen isotope measurements during the deglacial period revealed a surprising bimodality, the cause of which was investigated.
Michael Langner and Stefan Mulitza
Clim. Past, 15, 2067–2072, https://doi.org/10.5194/cp-15-2067-2019, https://doi.org/10.5194/cp-15-2067-2019, 2019
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Collections of paleoclimate data provide valuable information on the functioning of the Earth system but are often difficult to manage due to the inconsistency of data formats and reconstruction methods. We present a software toolbox that combines a simple document-based database with functionality for the visualization and management of marine proxy data. The program allows the efficient homogenization of larger paleoceanographic data sets into quality-controlled and transparent data products.
Lukas Jonkers and Michal Kučera
Clim. Past, 15, 881–891, https://doi.org/10.5194/cp-15-881-2019, https://doi.org/10.5194/cp-15-881-2019, 2019
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Fossil plankton assemblages have been widely used to reconstruct SST. In such approaches, full taxonomic resolution is often used. We assess whether this is required for reliable reconstructions as some species may not respond to SST. We find that only a few species are needed for low reconstruction errors but that species selection has a pronounced effect on reconstructions. We suggest that the sensitivity of a reconstruction to species pruning can be used as a measure of its robustness.
Marcus P. S. Badger, Thomas B. Chalk, Gavin L. Foster, Paul R. Bown, Samantha J. Gibbs, Philip F. Sexton, Daniela N. Schmidt, Heiko Pälike, Andreas Mackensen, and Richard D. Pancost
Clim. Past, 15, 539–554, https://doi.org/10.5194/cp-15-539-2019, https://doi.org/10.5194/cp-15-539-2019, 2019
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Understanding how atmospheric CO2 has affected the climate of the past is an important way of furthering our understanding of how CO2 may affect our climate in the future. There are several ways of determining CO2 in the past; in this paper, we ground-truth one method (based on preserved organic matter from alga) against the record of CO2 preserved as bubbles in ice cores over a glacial–interglacial cycle. We find that there is a discrepancy between the two.
Patrick A. Rafter, Juan-Carlos Herguera, and John R. Southon
Clim. Past, 14, 1977–1989, https://doi.org/10.5194/cp-14-1977-2018, https://doi.org/10.5194/cp-14-1977-2018, 2018
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Carbon’s radioactive isotope (radiocarbon) is a useful tool for oceanographers investigating carbon cycling in the modern ocean and ice age oceans (using foraminifera microfossils). Here we used sediment cores with excellent age constraints and abundant foraminifera microfossils to examine interspecies radiocarbon differences. All species demonstrate the same extreme radiocarbon depletion, and we argue that these observations represent important changes in seawater carbon chemistry.
Marijke W. de Bar, Dave J. Stolwijk, Jerry F. McManus, Jaap S. Sinninghe Damsté, and Stefan Schouten
Clim. Past, 14, 1783–1803, https://doi.org/10.5194/cp-14-1783-2018, https://doi.org/10.5194/cp-14-1783-2018, 2018
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We present a past sea surface temperature and paleoproductivity record over the last 150 000 years for ODP Site 1234 (Chilean margin). We tested the applicability of long-chain diol proxies for the reconstrucion of SST (LDI), past upwelling conditions (diol index), and nutrient concentrations (NDI). The LDI likely reflects past temperature changes, but the diol index and NDI are perhaps more indicative of Proboscia diatom productivity rather than upwelling and/or nutrient conditions.
Bryan C. Lougheed, Brett Metcalfe, Ulysses S. Ninnemann, and Lukas Wacker
Clim. Past, 14, 515–526, https://doi.org/10.5194/cp-14-515-2018, https://doi.org/10.5194/cp-14-515-2018, 2018
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Palaeoclimate reconstructions from deep-sea sediment archives provide valuable insight into past rapid climate change, but only a small proportion of the ocean is suitable for such reconstructions using the existing state of the art, i.e. the age–depth approach. We use dual radiocarbon (14C) and stable isotope analysis on single foraminifera to bypass the long-standing age–depth approach, thus facilitating past ocean chemistry reconstructions from vast, previously untapped ocean areas.
Lukas Jonkers and Michal Kučera
Clim. Past, 13, 573–586, https://doi.org/10.5194/cp-13-573-2017, https://doi.org/10.5194/cp-13-573-2017, 2017
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Planktonic foraminifera – the most important proxy carriers in palaeoceanography – adjust their seasonal and vertical habitat. They are thought to do so in a way that minimises the change in their environment, implying that proxy records based on these organisms may not capture the full amplitude of past climate change. Here we demonstrate that they indeed track a particular thermal habitat and suggest that this could lead to a 40 % underestimation of reconstructed temperature change.
Timothé Bolliet, Patrick Brockmann, Valérie Masson-Delmotte, Franck Bassinot, Valérie Daux, Dominique Genty, Amaelle Landais, Marlène Lavrieux, Elisabeth Michel, Pablo Ortega, Camille Risi, Didier M. Roche, Françoise Vimeux, and Claire Waelbroeck
Clim. Past, 12, 1693–1719, https://doi.org/10.5194/cp-12-1693-2016, https://doi.org/10.5194/cp-12-1693-2016, 2016
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This paper presents a new database of past climate proxies which aims to facilitate the distribution of data by using a user-friendly interface. Available data from the last 40 years are often fragmented, with lots of different formats, and online libraries are sometimes nonintuitive. We thus built a new dynamic web portal for data browsing, visualizing, and batch downloading of hundreds of datasets presenting a homogeneous format.
André Düsterhus, Alessio Rovere, Anders E. Carlson, Benjamin P. Horton, Volker Klemann, Lev Tarasov, Natasha L. M. Barlow, Tom Bradwell, Jorie Clark, Andrea Dutton, W. Roland Gehrels, Fiona D. Hibbert, Marc P. Hijma, Nicole Khan, Robert E. Kopp, Dorit Sivan, and Torbjörn E. Törnqvist
Clim. Past, 12, 911–921, https://doi.org/10.5194/cp-12-911-2016, https://doi.org/10.5194/cp-12-911-2016, 2016
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This review/position paper addresses problems in creating new interdisciplinary databases for palaeo-climatological sea-level and ice-sheet data and gives an overview on new advances to tackle them. The focus therein is to define and explain strategies and highlight their importance to allow further progress in these fields. It also offers important insights into the general problem of designing competitive databases which are also applicable to other communities within the palaeo-environment.
X. Shi, Y. Wu, J. Zou, Y. Liu, S. Ge, M. Zhao, J. Liu, A. Zhu, X. Meng, Z. Yao, and Y. Han
Clim. Past, 10, 1735–1750, https://doi.org/10.5194/cp-10-1735-2014, https://doi.org/10.5194/cp-10-1735-2014, 2014
D. K. Naik, R. Saraswat, N. Khare, A. C. Pandey, and R. Nigam
Clim. Past, 10, 745–758, https://doi.org/10.5194/cp-10-745-2014, https://doi.org/10.5194/cp-10-745-2014, 2014
R. J. Telford, C. Li, and M. Kucera
Clim. Past, 9, 859–870, https://doi.org/10.5194/cp-9-859-2013, https://doi.org/10.5194/cp-9-859-2013, 2013
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