Articles | Volume 10, issue 2
https://doi.org/10.5194/cp-10-745-2014
© 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-10-745-2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
15 Apr 2014
Research article |
| 15 Apr 2014
Hydrographic changes in the Agulhas Recirculation Region during the late Quaternary
D. K. Naik
Micropaleontology Laboratory, National Institute of Oceanography, Goa, India
R. Saraswat
Micropaleontology Laboratory, National Institute of Oceanography, Goa, India
N. Khare
Ministry of Earth Sciences, New Delhi, India
A. C. Pandey
Allahabad University, Allahabad, India
presently at: Bundelkhand University, Jhansi, India
R. Nigam
Micropaleontology Laboratory, National Institute of Oceanography, Goa, India
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Rajeev Saraswat, Thejasino Suokhrie, Dinesh K. Naik, Dharmendra P. Singh, Syed M. Saalim, Mohd Salman, Gavendra Kumar, Sudhira R. Bhadra, Mahyar Mohtadi, Sujata R. Kurtarkar, and Abhayanand S. Maurya
Earth Syst. Sci. Data, 15, 171–187, https://doi.org/10.5194/essd-15-171-2023, https://doi.org/10.5194/essd-15-171-2023, 2023
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Much effort is made to project monsoon changes by reconstructing the past. The stable oxygen isotopic ratio of marine calcareous organisms is frequently used to reconstruct past monsoons. Here, we use the published and new stable oxygen isotopic data to demonstrate a diagenetic effect and a strong salinity influence on the oxygen isotopic ratio of foraminifera in the northern Indian Ocean. We also provide updated calibration equations to deduce monsoons from the oxygen isotopic ratio.
Stefan Mulitza, Torsten Bickert, Helen C. Bostock, Cristiano M. Chiessi, Barbara Donner, Aline Govin, Naomi Harada, Enqing Huang, Heather Johnstone, Henning Kuhnert, Michael Langner, Frank Lamy, Lester Lembke-Jene, Lorraine Lisiecki, Jean Lynch-Stieglitz, Lars Max, Mahyar Mohtadi, Gesine Mollenhauer, Juan Muglia, Dirk Nürnberg, André Paul, Carsten Rühlemann, Janne Repschläger, Rajeev Saraswat, Andreas Schmittner, Elisabeth L. Sikes, Robert F. Spielhagen, and Ralf Tiedemann
Earth Syst. Sci. Data, 14, 2553–2611, https://doi.org/10.5194/essd-14-2553-2022, https://doi.org/10.5194/essd-14-2553-2022, 2022
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Stable isotope ratios of foraminiferal shells from deep-sea sediments preserve key information on the variability of ocean circulation and ice volume. We present the first global atlas of harmonized raw downcore oxygen and carbon isotope ratios of various planktonic and benthic foraminiferal species. The atlas is a foundation for the analyses of the history of Earth system components, for finding future coring sites, and for teaching marine stratigraphy and paleoceanography.
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Subject: Proxy Use-Development-Validation | Archive: Marine Archives | Timescale: Pleistocene
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
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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
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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)
Salinity changes in the Agulhas leakage area recorded by stable hydrogen isotopes of C37 alkenones during Termination I and II
Mismatch between the depth habitat of planktonic foraminifera and the calibration depth of SST transfer functions may bias reconstructions
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
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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
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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
S. Kasper, M. T. J. van der Meer, A. Mets, R. Zahn, J. S. Sinninghe Damsté, and S. Schouten
Clim. Past, 10, 251–260, https://doi.org/10.5194/cp-10-251-2014, https://doi.org/10.5194/cp-10-251-2014, 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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