Articles | Volume 17, issue 2
https://doi.org/10.5194/cp-17-805-2021
© Author(s) 2021. 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-17-805-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
08 Apr 2021
Research article |
| 08 Apr 2021
| 08 Apr 2021
A global climatology of the ocean surface during the Last Glacial Maximum mapped on a regular grid (GLOMAP)
MARUM – Center for Marine Environmental Sciences and Department of Geosciences, University of Bremen, Bremen, Germany
Stefan Mulitza
MARUM – Center for Marine Environmental Sciences and Department of Geosciences, University of Bremen, Bremen, Germany
Rüdiger Stein
MARUM – Center for Marine Environmental Sciences and Department of Geosciences, University of Bremen, Bremen, Germany
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), Bremerhaven, Germany
Martin Werner
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), Bremerhaven, Germany
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Jiajia Wang, Hongxi Pang, Shuangye Wu, Spruce W. Schoenemann, Ryu Uemura, Alexey Ekaykin, Martin Werner, Alexandre Cauquoin, Sentia Goursaud Oger, Summer Rupper, and Shugui Hou
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This paper presents a compilation of high-resolution (11 cm) water isotopic records, including published and new measurements, for the last 800 000 years from the EPICA Dome C ice core, Antarctica. Using this new combined water isotopes (δ18O and δD) dataset, we study the variability and possible influence of diffusion at the multi-decadal to multi-centennial scale. We observe a stronger variability at the onset of the interglacial interval corresponding to a warm period.
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Kaveh Purkiani, Matthias Haeckel, Sabine Haalboom, Katja Schmidt, Peter Urban, Iason-Zois Gazis, Henko de Stigter, André Paul, Maren Walter, and Annemiek Vink
Ocean Sci., 18, 1163–1181, https://doi.org/10.5194/os-18-1163-2022, https://doi.org/10.5194/os-18-1163-2022, 2022
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Based on altimetry data and in situ hydrographic observations, the impacts of an anticyclone mesoscale eddy (large rotating body of water) on the seawater characteristics were investigated during a research campaign. The particular eddy presents significant anomalies on the seawater properties at 1500 m. The potential role of eddies in the seafloor and its consequential effect on the altered dispersion of mining-related sediment plumes are important to assess future mining operations.
Janica C. Bühler, Josefine Axelsson, Franziska A. Lechleitner, Jens Fohlmeister, Allegra N. LeGrande, Madhavan Midhun, Jesper Sjolte, Martin Werner, Kei Yoshimura, and Kira Rehfeld
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We collected and standardized the output of five isotope-enabled simulations for the last millennium and assess differences and similarities to records from a global speleothem database. Modeled isotope variations mostly arise from temperature differences. While lower-resolution speleothems do not capture extreme changes to the extent of models, they show higher variability on multi-decadal timescales. As no model excels in all comparisons, we advise a multi-model approach where possible.
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
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Clim. Past, 18, 1047–1070, https://doi.org/10.5194/cp-18-1047-2022, https://doi.org/10.5194/cp-18-1047-2022, 2022
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Since the orbital parameters of the past are different from today, applying the modern calendar to the past climate can lead to an artificial bias in seasonal cycles. With the use of multiple model outputs, we found that such a bias is non-ignorable and should be corrected to ensure an accurate comparison between modeled results and observational records, as well as between simulated past and modern climates, especially for the Last Interglacial.
Stephan Krätschmer, Michèlle van der Does, Frank Lamy, Gerrit Lohmann, Christoph Völker, and Martin Werner
Clim. Past, 18, 67–87, https://doi.org/10.5194/cp-18-67-2022, https://doi.org/10.5194/cp-18-67-2022, 2022
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We use an atmospheric model coupled to an aerosol model to investigate the global mineral dust cycle with a focus on the Southern Hemisphere for warmer and colder climate states and compare our results to observational data. Our findings suggest that Australia is the predominant source of dust deposited over Antarctica during the last glacial maximum. In addition, we find that the southward transport of dust from all sources to Antarctica happens at lower altitudes in colder climates.
Fabienne Dahinden, Franziska Aemisegger, Heini Wernli, Matthias Schneider, Christopher J. Diekmann, Benjamin Ertl, Peter Knippertz, Martin Werner, and Stephan Pfahl
Atmos. Chem. Phys., 21, 16319–16347, https://doi.org/10.5194/acp-21-16319-2021, https://doi.org/10.5194/acp-21-16319-2021, 2021
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We use high-resolution numerical isotope modelling and Lagrangian backward trajectories to identify moisture transport pathways and governing physical and dynamical processes that affect the free-tropospheric humidity and isotopic variability over the eastern subtropical North Atlantic. Furthermore, we conduct a thorough isotope modelling validation with aircraft and remote-sensing observations of water vapour isotopes.
Saeid Bagheri Dastgerdi, Melanie Behrens, Jean-Louis Bonne, Maria Hörhold, Gerrit Lohmann, Elisabeth Schlosser, and Martin Werner
The Cryosphere, 15, 4745–4767, https://doi.org/10.5194/tc-15-4745-2021, https://doi.org/10.5194/tc-15-4745-2021, 2021
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In this study, for the first time, water vapour isotope measurements in Antarctica for all seasons of a year are performed. Local temperature is identified as the main driver of δ18O and δD variability. A similar slope of the temperature–δ18O relationship in vapour and surface snow points to the water vapour isotope content as a potential key driver. This dataset can be used as a new dataset to evaluate the capability of isotope-enhanced climate models.
Marcus Breil, Emanuel Christner, Alexandre Cauquoin, Martin Werner, Melanie Karremann, and Gerd Schädler
Clim. Past, 17, 1685–1699, https://doi.org/10.5194/cp-17-1685-2021, https://doi.org/10.5194/cp-17-1685-2021, 2021
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For the first time an isotope-enabled regional climate simulation for Greenland is performed for the mid-Holocene. Simulation results are compared with observed isotope ratios in ice cores. Compared to global climate simulations, a regional downscaling improves the agreement with measured isotope concentrations. Thus, an isotope-enabled regional climate simulation constitutes a useful supplement to reconstruct regional paleo-climate conditions during the mid-Holocene in Greenland.
Thomas Münch, Martin Werner, and Thomas Laepple
Clim. Past, 17, 1587–1605, https://doi.org/10.5194/cp-17-1587-2021, https://doi.org/10.5194/cp-17-1587-2021, 2021
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We analyse Holocene climate model simulation data to find the locations of Antarctic ice cores which are best suited to reconstruct local- to regional-scale temperatures. We find that the spatial decorrelation scales of the temperature variations and of the noise from precipitation intermittency set an effective sampling length scale. Following this, a single core should be located at the
target site for the temperature reconstruction, and a second one optimally lies more than 500 km away.
Sarah E. Parker, Sandy P. Harrison, Laia Comas-Bru, Nikita Kaushal, Allegra N. LeGrande, and Martin Werner
Clim. Past, 17, 1119–1138, https://doi.org/10.5194/cp-17-1119-2021, https://doi.org/10.5194/cp-17-1119-2021, 2021
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Regional trends in the oxygen isotope (δ18O) composition of stalagmites reflect several climate processes. We compare stalagmite δ18O records from monsoon regions and model simulations to identify the causes of δ18O variability over the last 12 000 years, and between glacial and interglacial states. Precipitation changes explain the glacial–interglacial δ18O changes in all monsoon regions; Holocene trends are due to a combination of precipitation, atmospheric circulation and temperature changes.
Masa Kageyama, Sandy P. Harrison, Marie-L. Kapsch, Marcus Lofverstrom, Juan M. Lora, Uwe Mikolajewicz, Sam Sherriff-Tadano, Tristan Vadsaria, Ayako Abe-Ouchi, Nathaelle Bouttes, Deepak Chandan, Lauren J. Gregoire, Ruza F. Ivanovic, Kenji Izumi, Allegra N. LeGrande, Fanny Lhardy, Gerrit Lohmann, Polina A. Morozova, Rumi Ohgaito, André Paul, W. Richard Peltier, Christopher J. Poulsen, Aurélien Quiquet, Didier M. Roche, Xiaoxu Shi, Jessica E. Tierney, Paul J. Valdes, Evgeny Volodin, and Jiang Zhu
Clim. Past, 17, 1065–1089, https://doi.org/10.5194/cp-17-1065-2021, https://doi.org/10.5194/cp-17-1065-2021, 2021
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The Last Glacial Maximum (LGM; ~21 000 years ago) is a major focus for evaluating how well climate models simulate climate changes as large as those expected in the future. Here, we compare the latest climate model (CMIP6-PMIP4) to the previous one (CMIP5-PMIP3) and to reconstructions. Large-scale climate features (e.g. land–sea contrast, polar amplification) are well captured by all models, while regional changes (e.g. winter extratropical cooling, precipitations) are still poorly represented.
Iris Thurnherr, Katharina Hartmuth, Lukas Jansing, Josué Gehring, Maxi Boettcher, Irina Gorodetskaya, Martin Werner, Heini Wernli, and Franziska Aemisegger
Weather Clim. Dynam., 2, 331–357, https://doi.org/10.5194/wcd-2-331-2021, https://doi.org/10.5194/wcd-2-331-2021, 2021
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Extratropical cyclones are important for the transport of moisture from low to high latitudes. In this study, we investigate how the isotopic composition of water vapour is affected by horizontal temperature advection associated with extratropical cyclones using measurements and modelling. It is shown that air–sea moisture fluxes induced by this horizontal temperature advection lead to the strong variability observed in the isotopic composition of water vapour in the marine boundary layer.
Masa Kageyama, Louise C. Sime, Marie Sicard, Maria-Vittoria Guarino, Anne de Vernal, Ruediger Stein, David Schroeder, Irene Malmierca-Vallet, Ayako Abe-Ouchi, Cecilia Bitz, Pascale Braconnot, Esther C. Brady, Jian Cao, Matthew A. Chamberlain, Danny Feltham, Chuncheng Guo, Allegra N. LeGrande, Gerrit Lohmann, Katrin J. Meissner, Laurie Menviel, Polina Morozova, Kerim H. Nisancioglu, Bette L. Otto-Bliesner, Ryouta O'ishi, Silvana Ramos Buarque, David Salas y Melia, Sam Sherriff-Tadano, Julienne Stroeve, Xiaoxu Shi, Bo Sun, Robert A. Tomas, Evgeny Volodin, Nicholas K. H. Yeung, Qiong Zhang, Zhongshi Zhang, Weipeng Zheng, and Tilo Ziehn
Clim. Past, 17, 37–62, https://doi.org/10.5194/cp-17-37-2021, https://doi.org/10.5194/cp-17-37-2021, 2021
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The Last interglacial (ca. 127 000 years ago) is a period with increased summer insolation at high northern latitudes, resulting in a strong reduction in Arctic sea ice. The latest PMIP4-CMIP6 models all simulate this decrease, consistent with reconstructions. However, neither the models nor the reconstructions agree on the possibility of a seasonally ice-free Arctic. Work to clarify the reasons for this model divergence and the conflicting interpretations of the records will thus be needed.
Kaveh Purkiani, André Paul, Annemiek Vink, Maren Walter, Michael Schulz, and Matthias Haeckel
Biogeosciences, 17, 6527–6544, https://doi.org/10.5194/bg-17-6527-2020, https://doi.org/10.5194/bg-17-6527-2020, 2020
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There has been a steady increase in interest in mining of deep-sea minerals in the eastern Pacific Ocean recently. The ocean state in this region is known to be highly influenced by rotating bodies of water (eddies), some of which can travel long distances in the ocean and impact the deeper layers of the ocean. Better insight into the variability of eddy activity in this region is of great help to mitigate the impact of the benthic ecosystem from future potential deep-sea mining activity.
Jesper Sjolte, Florian Adolphi, Bo M. Vinther, Raimund Muscheler, Christophe Sturm, Martin Werner, and Gerrit Lohmann
Clim. Past, 16, 1737–1758, https://doi.org/10.5194/cp-16-1737-2020, https://doi.org/10.5194/cp-16-1737-2020, 2020
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In this study we investigate seasonal climate reconstructions produced by matching climate model output to ice core and tree-ring data, and we evaluate the model–data reconstructions against meteorological observations. The reconstructions capture the main patterns of variability in sea level pressure and temperature in summer and winter. The performance of the reconstructions depends on seasonal climate variability itself, and definitions of seasons can be optimized to capture this variability.
Jean-Louis Bonne, Hanno Meyer, Melanie Behrens, Julia Boike, Sepp Kipfstuhl, Benjamin Rabe, Toni Schmidt, Lutz Schönicke, Hans Christian Steen-Larsen, and Martin Werner
Atmos. Chem. Phys., 20, 10493–10511, https://doi.org/10.5194/acp-20-10493-2020, https://doi.org/10.5194/acp-20-10493-2020, 2020
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This study introduces 2 years of continuous near-surface in situ observations of the stable isotopic composition of water vapour in parallel with precipitation in north-eastern Siberia. We evaluate the atmospheric transport of moisture towards the region of our observations with simulations constrained by meteorological reanalyses and use this information to interpret the temporal variations of the vapour isotopic composition from seasonal to synoptic timescales.
Heike H. Zimmermann, Kathleen R. Stoof-Leichsenring, Stefan Kruse, Juliane Müller, Ruediger Stein, Ralf Tiedemann, and Ulrike Herzschuh
Ocean Sci., 16, 1017–1032, https://doi.org/10.5194/os-16-1017-2020, https://doi.org/10.5194/os-16-1017-2020, 2020
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This study targets high-resolution, diatom-specific sedimentary ancient DNA using a DNA metabarcoding approach. Diatom DNA has been preserved with substantial taxonomic richness in the eastern Fram Strait over the past 30 000 years with taxonomic composition being dominated by cold-water and sea-ice-associated diatoms. Taxonomic reorganisations took place after the Last Glacial Maximum and after the Younger Dryas. Peak proportions of pennate diatoms might indicate past sea-ice presence.
Lukas Jonkers, Olivier Cartapanis, Michael Langner, Nick McKay, Stefan Mulitza, Anne Strack, and Michal Kucera
Earth Syst. Sci. Data, 12, 1053–1081, https://doi.org/10.5194/essd-12-1053-2020, https://doi.org/10.5194/essd-12-1053-2020, 2020
Takasumi Kurahashi-Nakamura, André Paul, Guy Munhoven, Ute Merkel, and Michael Schulz
Geosci. Model Dev., 13, 825–840, https://doi.org/10.5194/gmd-13-825-2020, https://doi.org/10.5194/gmd-13-825-2020, 2020
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Chemical processes in ocean-floor sediments have a large influence on the marine carbon cycle, hence the global climate, at long timescales. We developed a new coupling scheme for a chemical sediment model and a comprehensive climate model. The new coupled model outperformed the original uncoupled climate model in reproducing the global distribution of sediment properties. The sediment model will also act as a
bridgebetween the ocean model and paleoceanographic data.
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.
Alexandre Cauquoin, Martin Werner, and Gerrit Lohmann
Clim. Past, 15, 1913–1937, https://doi.org/10.5194/cp-15-1913-2019, https://doi.org/10.5194/cp-15-1913-2019, 2019
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We present here the first model results of a newly developed isotope-enhanced version of the Earth system model MPI-ESM. Our model setup has a finer spatial resolution compared to other isotope-enabled fully coupled models. We evaluate the model for preindustrial and mid-Holocene climate conditions. Our analyses show a good to very good agreement with various isotopic data. The spatial and temporal links between isotopes and climate variables under warm climatic conditions are also analyzed.
Laia Comas-Bru, Sandy P. Harrison, Martin Werner, Kira Rehfeld, Nick Scroxton, Cristina Veiga-Pires, and SISAL working group members
Clim. Past, 15, 1557–1579, https://doi.org/10.5194/cp-15-1557-2019, https://doi.org/10.5194/cp-15-1557-2019, 2019
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We use an updated version of the Speleothem Isotopes Synthesis and Analysis (SISAL) database and palaeoclimate simulations generated using the ECHAM5-wiso isotope-enabled climate model to provide a protocol for using speleothem isotopic data for model evaluation, including screening the observations and the optimum period for the modern observational baseline. We also illustrate techniques through which the absolute isotopic values during any time period could be used for model evaluation.
Charlotte Breitkreuz, André Paul, and Michael Schulz
Clim. Past Discuss., https://doi.org/10.5194/cp-2019-52, https://doi.org/10.5194/cp-2019-52, 2019
Publication in CP not foreseen
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We combined a model simulation of the Last Glacial Maximum ocean with sea surface temperature and calcite oxygen isotope data through data assimilation. The reconstructed ocean state is very similar to the modern and it follows that the employed proxy data do not require an ocean state very different from today's. Sensitivity experiments reveal that data from the deep North Atlantic but also from the global deep Southern Ocean are most important to constrain the Atlantic overturning circulation.
Sentia Goursaud, Valérie Masson-Delmotte, Vincent Favier, Suzanne Preunkert, Michel Legrand, Bénédicte Minster, and Martin Werner
The Cryosphere, 13, 1297–1324, https://doi.org/10.5194/tc-13-1297-2019, https://doi.org/10.5194/tc-13-1297-2019, 2019
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We report new water stable isotope records from the first highly resolved firn core drilled in Adélie Land and covering 1998–2014. Using an updated database, we show that mean values are in line with the range of coastal values. Statistical analyses show no relationship between our record and local surface air temperature. Atmospheric back trajectories and isotopic simulations suggest that water stable isotopes in Adélie provide a fingerprint of the variability of atmospheric dynamics.
François Klein, Nerilie J. Abram, Mark A. J. Curran, Hugues Goosse, Sentia Goursaud, Valérie Masson-Delmotte, Andrew Moy, Raphael Neukom, Anaïs Orsi, Jesper Sjolte, Nathan Steiger, Barbara Stenni, and Martin Werner
Clim. Past, 15, 661–684, https://doi.org/10.5194/cp-15-661-2019, https://doi.org/10.5194/cp-15-661-2019, 2019
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Antarctic temperature changes over the past millennia have been reconstructed from isotope records in ice cores in several studies. However, the link between both variables is complex. Here, we investigate the extent to which this affects the robustness of temperature reconstructions using pseudoproxy and data assimilation experiments. We show that the reconstruction skill is limited, especially at the regional scale, due to a weak and nonstationary covariance between δ18O and temperature.
Charlotte Breitkreuz, André Paul, Stefan Mulitza, Javier García-Pintado, and Michael Schulz
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2019-32, https://doi.org/10.5194/gmd-2019-32, 2019
Publication in GMD not foreseen
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We present a technique for ocean state estimation based on the combination of a simple data assimilation method with a state reduction approach. The technique proves to be very efficient and successful in reducing the model-data misfit and reconstructing a target ocean circulation from synthetic observations. In an application to Last Glacial Maximum proxy data the model-data misfit is greatly reduced but some misfit remains. Two different ocean states are found with similar model-data misfit.
Javier García-Pintado and André Paul
Geosci. Model Dev., 11, 5051–5084, https://doi.org/10.5194/gmd-11-5051-2018, https://doi.org/10.5194/gmd-11-5051-2018, 2018
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Earth system models (ESMs) integrate interactions of atmosphere, ocean, land, ice, and biosphere to estimate the state of regional and global climate under a variety of conditions. Past climate field reconstructions with deterministic ESMs through the assimilation of climate proxies need to consider the required high computations and model non-linearity. Our tests indicate that iterative schemes based on the Kalman filter and careful sensitivity analysis are adequate for approaching the problem.
Jesper Sjolte, Christophe Sturm, Florian Adolphi, Bo M. Vinther, Martin Werner, Gerrit Lohmann, and Raimund Muscheler
Clim. Past, 14, 1179–1194, https://doi.org/10.5194/cp-14-1179-2018, https://doi.org/10.5194/cp-14-1179-2018, 2018
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Tropical volcanic eruptions and variations in solar activity have been suggested to influence the strength of westerly winds across the North Atlantic. We use Greenland ice core records together with a climate model simulation, and find stronger westerly winds for five winters following tropical volcanic eruptions. We see a delayed response to solar activity of 5 years, and the response to solar minima corresponds well to the cooling pattern during the period known as the Little Ice Age.
Sentia Goursaud, Valérie Masson-Delmotte, Vincent Favier, Anaïs Orsi, and Martin Werner
Clim. Past, 14, 923–946, https://doi.org/10.5194/cp-14-923-2018, https://doi.org/10.5194/cp-14-923-2018, 2018
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Atmospheric general circulation models equipped with water stable isotopes are key tools to explore the links between climate variables and precipitation isotopic composition and thus to quantify past temperature changes using ice core records. Here, we evaluate the skills of ECHAM5-wiso to simulate the spatio-temporal characteristics of Antarctic climate and precipitation isotopic composition at the regional scale, thanks to a database of precipitation and ice core records.
Sebastian G. Mutz, Todd A. Ehlers, Martin Werner, Gerrit Lohmann, Christian Stepanek, and Jingmin Li
Earth Surf. Dynam., 6, 271–301, https://doi.org/10.5194/esurf-6-271-2018, https://doi.org/10.5194/esurf-6-271-2018, 2018
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We use a climate model and statistics to provide an overview of regional climates from different times in the late Cenozoic. We focus on tectonically active mountain ranges in particular. Our results highlight significant changes in climates throughout the late Cenozoic, which should be taken into consideration when interpreting erosion rates. We also document the differences between model- and proxy-based estimates for late Cenozoic climate change in South America and Tibet.
Martin Bartels, Jürgen Titschack, Kirsten Fahl, Rüdiger Stein, Marit-Solveig Seidenkrantz, Claude Hillaire-Marcel, and Dierk Hebbeln
Clim. Past, 13, 1717–1749, https://doi.org/10.5194/cp-13-1717-2017, https://doi.org/10.5194/cp-13-1717-2017, 2017
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Multi-proxy analyses (i.a., benthic foraminiferal assemblages and sedimentary properties) of a marine record from Woodfjorden at the northern Svalbard margin (Norwegian Arctic) illustrate a significant contribution of relatively warm Atlantic water to the destabilization of tidewater glaciers, especially during the deglaciation and early Holocene (until ~ 7800 years ago), whereas its influence on glacier activity has been fading during the last 2 millennia, enabling glacier readvances.
Barbara Stenni, Mark A. J. Curran, Nerilie J. Abram, Anais Orsi, Sentia Goursaud, Valerie Masson-Delmotte, Raphael Neukom, Hugues Goosse, Dmitry Divine, Tas van Ommen, Eric J. Steig, Daniel A. Dixon, Elizabeth R. Thomas, Nancy A. N. Bertler, Elisabeth Isaksson, Alexey Ekaykin, Martin Werner, and Massimo Frezzotti
Clim. Past, 13, 1609–1634, https://doi.org/10.5194/cp-13-1609-2017, https://doi.org/10.5194/cp-13-1609-2017, 2017
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Within PAGES Antarctica2k, we build an enlarged database of ice core water stable isotope records. We produce isotopic composites and temperature reconstructions since 0 CE for seven distinct Antarctic regions. We find a significant cooling trend from 0 to 1900 CE across all regions. Since 1900 CE, significant warming trends are identified for three regions. Only for the Antarctic Peninsula is this most recent century-scale trend unusual in the context of last-2000-year natural variability.
Rike Völpel, André Paul, Annegret Krandick, Stefan Mulitza, and Michael Schulz
Geosci. Model Dev., 10, 3125–3144, https://doi.org/10.5194/gmd-10-3125-2017, https://doi.org/10.5194/gmd-10-3125-2017, 2017
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This study presents the implementation of stable water isotopes in the MITgcm and describes the results of an equilibrium simulation under pre-industrial conditions. The model compares well to observational data and measurements of plankton tow records and thus opens wide prospects for long-term simulations in a paleoclimatic context.
Raphaël Morard, Franck Lejzerowicz, Kate F. Darling, Béatrice Lecroq-Bennet, Mikkel Winther Pedersen, Ludovic Orlando, Jan Pawlowski, Stefan Mulitza, Colomban de Vargas, and Michal Kucera
Biogeosciences, 14, 2741–2754, https://doi.org/10.5194/bg-14-2741-2017, https://doi.org/10.5194/bg-14-2741-2017, 2017
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The exploitation of deep-sea sedimentary archive relies on the recovery of mineralized skeletons of pelagic organisms. Planktonic groups leaving preserved remains represent only a fraction of the total marine diversity. Environmental DNA left by non-fossil organisms is a promising source of information for paleo-reconstructions. Here we show how planktonic-derived environmental DNA preserves ecological structure of planktonic communities. We use planktonic foraminifera as a case study.
Shuwen Sun, Enno Schefuß, Stefan Mulitza, Cristiano M. Chiessi, André O. Sawakuchi, Matthias Zabel, Paul A. Baker, Jens Hefter, and Gesine Mollenhauer
Biogeosciences, 14, 2495–2512, https://doi.org/10.5194/bg-14-2495-2017, https://doi.org/10.5194/bg-14-2495-2017, 2017
Matthias Schneider, Christian Borger, Andreas Wiegele, Frank Hase, Omaira E. García, Eliezer Sepúlveda, and Martin Werner
Atmos. Meas. Tech., 10, 507–525, https://doi.org/10.5194/amt-10-507-2017, https://doi.org/10.5194/amt-10-507-2017, 2017
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The characteristics of {H2O,δD} pair space-based remote sensing data depend on the atmospheric and surface conditions, which compromises their usage for model evaluation studies. This paper shows how the problem can be overcome by simulating MUSICA MetOp/IASI {H2O,δD} remote sensing products for any given model atmosphere. The remote sensing retrieval simulator is freely provided as a MATLAB and Python routine.
Sentia Goursaud, Valérie Masson-Delmotte, Vincent Favier, Susanne Preunkert, Michel Fily, Hubert Gallée, Bruno Jourdain, Michel Legrand, Olivier Magand, Bénédicte Minster, and Martin Werner
The Cryosphere, 11, 343–362, https://doi.org/10.5194/tc-11-343-2017, https://doi.org/10.5194/tc-11-343-2017, 2017
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Uncertainty of sea level changes is a challenge. As Antarctica is the biggest water reservoir, it is necessary to know how it will contribute. To be able to simulate it, an understanding of past climate is to be achieved, for instance, by studying the ice cores. As climate change is different in different regions, observations are needed all over the continent. Studying an ice core in Adélie Land, we can conclude that there are no changes there at decadal scale over the period 1947–2007.
Michael Deininger, Martin Werner, and Frank McDermott
Clim. Past, 12, 2127–2143, https://doi.org/10.5194/cp-12-2127-2016, https://doi.org/10.5194/cp-12-2127-2016, 2016
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This study investigates the NAO (Northern Atlantic Oscillation)-related mechanisms that control winter precipitation stable oxygen and hydrogen isotope gradients across Europe. The results show that past longitudinal stable oxygen and hydrogen isotope gradients in European rainfall stored in palaeoclimate archives (e.g. speleothems) can be used to infer the past winter NAO modes from its variations.
François Ritter, Hans Christian Steen-Larsen, Martin Werner, Valérie Masson-Delmotte, Anais Orsi, Melanie Behrens, Gerit Birnbaum, Johannes Freitag, Camille Risi, and Sepp Kipfstuhl
The Cryosphere, 10, 1647–1663, https://doi.org/10.5194/tc-10-1647-2016, https://doi.org/10.5194/tc-10-1647-2016, 2016
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We present successful continuous measurements of water vapor isotopes performed in Antarctica in January 2013. The interest is to understand the impact of the water vapor isotopic composition on the near-surface snow isotopes. Our study reveals a diurnal cycle in the snow isotopic composition in phase with the vapor. This finding suggests fractionation during the sublimation of the ice, which has an important consequence on the interpretation of water isotope variations in ice cores.
Anna Dittmann, Elisabeth Schlosser, Valérie Masson-Delmotte, Jordan G. Powers, Kevin W. Manning, Martin Werner, and Koji Fujita
Atmos. Chem. Phys., 16, 6883–6900, https://doi.org/10.5194/acp-16-6883-2016, https://doi.org/10.5194/acp-16-6883-2016, 2016
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For a better understanding of the stable water isotope data from ice cores, recent time periods have to be analysed, where both measurements and model simulations are available. This was done for Dome Fuji by combining observations, synoptic analysis, back trajectories, and isotopic modelling. It was found that a more northerly moisture source does not necessarily mean a larger temperature difference between source area and deposition site and thus precipitation more depleted in heavy isotopes.
M. Werner, B. Haese, X. Xu, X. Zhang, M. Butzin, and G. Lohmann
Geosci. Model Dev., 9, 647–670, https://doi.org/10.5194/gmd-9-647-2016, https://doi.org/10.5194/gmd-9-647-2016, 2016
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This paper presents the first results of a new isotope-enabled GCM set-up, based on the ECHAM5/MPI-OM fully coupled atmosphere-ocean model. Results of two equilibrium simulations under pre-industrial and Last Glacial Maximum conditions reveal a good to very good agreement with many delta O-18 and delta D observational records, and a remarkable improvement for the modelling of the deuterium excess signal in Antarctic ice cores.
S. Jasechko, A. Lechler, F. S. R. Pausata, P. J. Fawcett, T. Gleeson, D. I. Cendón, J. Galewsky, A. N. LeGrande, C. Risi, Z. D. Sharp, J. M. Welker, M. Werner, and K. Yoshimura
Clim. Past, 11, 1375–1393, https://doi.org/10.5194/cp-11-1375-2015, https://doi.org/10.5194/cp-11-1375-2015, 2015
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In this study we compile global isotope proxy records of climate changes from the last ice age to the late-Holocene preserved in cave calcite, glacial ice and groundwater aquifers. We show that global patterns of late-Pleistocene to late-Holocene precipitation isotope shifts are consistent with stronger-than-modern isotopic distillation of air masses during the last ice age, likely impacted by larger global temperature differences between the tropics and the poles.
V. Masson-Delmotte, H. C. Steen-Larsen, P. Ortega, D. Swingedouw, T. Popp, B. M. Vinther, H. Oerter, A. E. Sveinbjornsdottir, H. Gudlaugsdottir, J. E. Box, S. Falourd, X. Fettweis, H. Gallée, E. Garnier, V. Gkinis, J. Jouzel, A. Landais, B. Minster, N. Paradis, A. Orsi, C. Risi, M. Werner, and J. W. C. White
The Cryosphere, 9, 1481–1504, https://doi.org/10.5194/tc-9-1481-2015, https://doi.org/10.5194/tc-9-1481-2015, 2015
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The deep NEEM ice core provides the oldest Greenland ice core record, enabling improved understanding of the response of ice core records to local climate. Here, we focus on shallow ice cores providing a stack record of accumulation and water-stable isotopes spanning the past centuries. For the first time, we document the ongoing warming in a Greenland ice core. By combining our data with other Greenland ice cores and model results, we characterise the spatio-temporal patterns of variability.
R. Eichinger, P. Jöckel, S. Brinkop, M. Werner, and S. Lossow
Atmos. Chem. Phys., 15, 5537–5555, https://doi.org/10.5194/acp-15-5537-2015, https://doi.org/10.5194/acp-15-5537-2015, 2015
A. Cauquoin, A. Landais, G. M. Raisbeck, J. Jouzel, L. Bazin, M. Kageyama, J.-Y. Peterschmitt, M. Werner, E. Bard, and ASTER Team
Clim. Past, 11, 355–367, https://doi.org/10.5194/cp-11-355-2015, https://doi.org/10.5194/cp-11-355-2015, 2015
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We present a new 10Be record at EDC between 269 and 355ka. Our 10Be-based accumulation rate is in good agreement with the one associated with the EDC3 timescale except for the warm MIS 9.3 optimum. This suggests that temperature reconstruction from water isotopes may be underestimated by 2.4K for the difference between the MIS 9.3 and present day. The CMIP5-PMIP3 models do not quantitatively reproduce changes in precipitation vs. temperature increase during glacial–interglacial transitions.
N. V. Rokotyan, V. I. Zakharov, K. G. Gribanov, M. Schneider, F.-M. Bréon, J. Jouzel, R. Imasu, M. Werner, M. Butzin, C. Petri, T. Warneke, and J. Notholt
Atmos. Meas. Tech., 7, 2567–2580, https://doi.org/10.5194/amt-7-2567-2014, https://doi.org/10.5194/amt-7-2567-2014, 2014
K. Gribanov, J. Jouzel, V. Bastrikov, J.-L. Bonne, F.-M. Breon, M. Butzin, O. Cattani, V. Masson-Delmotte, N. Rokotyan, M. Werner, and V. Zakharov
Atmos. Chem. Phys., 14, 5943–5957, https://doi.org/10.5194/acp-14-5943-2014, https://doi.org/10.5194/acp-14-5943-2014, 2014
M. Butzin, M. Werner, V. Masson-Delmotte, C. Risi, C. Frankenberg, K. Gribanov, J. Jouzel, and V. I. Zakharov
Atmos. Chem. Phys., 14, 5853–5869, https://doi.org/10.5194/acp-14-5853-2014, https://doi.org/10.5194/acp-14-5853-2014, 2014
T. Kurahashi-Nakamura, M. Losch, and A. Paul
Geosci. Model Dev., 7, 419–432, https://doi.org/10.5194/gmd-7-419-2014, https://doi.org/10.5194/gmd-7-419-2014, 2014
B. Haese, M. Werner, and G. Lohmann
Geosci. Model Dev., 6, 1463–1480, https://doi.org/10.5194/gmd-6-1463-2013, https://doi.org/10.5194/gmd-6-1463-2013, 2013
D. Handiani, A. Paul, M. Prange, U. Merkel, L. Dupont, and X. Zhang
Clim. Past, 9, 1683–1696, https://doi.org/10.5194/cp-9-1683-2013, https://doi.org/10.5194/cp-9-1683-2013, 2013
J. A. Collins, A. Govin, S. Mulitza, D. Heslop, M. Zabel, J. Hartmann, U. Röhl, and G. Wefer
Clim. Past, 9, 1181–1191, https://doi.org/10.5194/cp-9-1181-2013, https://doi.org/10.5194/cp-9-1181-2013, 2013
J. C. Hargreaves, J. D. Annan, R. Ohgaito, A. Paul, and A. Abe-Ouchi
Clim. Past, 9, 811–823, https://doi.org/10.5194/cp-9-811-2013, https://doi.org/10.5194/cp-9-811-2013, 2013
G. Lohmann, A. Wackerbarth, P. M. Langebroek, M. Werner, J. Fohlmeister, D. Scholz, and A. Mangini
Clim. Past, 9, 89–98, https://doi.org/10.5194/cp-9-89-2013, https://doi.org/10.5194/cp-9-89-2013, 2013
S. Dietrich, M. Werner, T. Spangehl, and G. Lohmann
Clim. Past, 9, 13–26, https://doi.org/10.5194/cp-9-13-2013, https://doi.org/10.5194/cp-9-13-2013, 2013
Related subject area
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
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
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
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.
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
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
Cited articles
Beckers, J.-M., Barth, A., Troupin, C., and Alvera-Azcárate, A.: Approximate and Efficient Methods to Assess Error Fields in Spatial Gridding with Data Interpolating Variational Analysis (DIVA), J. Atmos. Ocean. Technol., 31, 515–530, https://doi.org/10.1175/JTECH-D-13-00130.1, 2014. a, b
Bendle, J. and Rosell-Melé, A.: Distributions of UK37 and UK'37 in the surface waters and sediments of the Nordic Seas: Implications for paleoceanography, Geochem. Geophy. Geosy., 5, https://doi.org/10.1029/2004GC000741, 2004. a, b
Braconnot, P., Otto-Bliesner, B., Harrison, S., Joussaume, S., Peterchmitt, J.-Y., Abe-Ouchi, A., Crucifix, M., Driesschaert, E., Fichefet, Th., Hewitt, C. D., Kageyama, M., Kitoh, A., Laîné, A., Loutre, M.-F., Marti, O., Merkel, U., Ramstein, G., Valdes, P., Weber, S. L., Yu, Y., and Zhao, Y.: Results of PMIP2 coupled simulations of the Mid-Holocene and Last Glacial Maximum – Part 1: experiments and large-scale features, Clim. Past, 3, 261–277, https://doi.org/10.5194/cp-3-261-2007, 2007. a
CLIMAP Project Members: The Surface of the Ice-Age Earth, Science, 191, 1131, https://doi.org/10.1126/science.191.4232.1131, 1976. a, b
Collins, M., Knutti, R., Arblaster, J., Dufresne, J.-L., Fichefet, T., Friedlingstein, P., Gao, X., Gutowski, W., Johns, T., Krinner, G., Shongwe, M., Tebaldi, C., Weaver, A., and Wehner, M.: Long-term Climate Change: Projections, Commitments and Irreversibility, in: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, edited by Stocker, T., Qin, D., Plattner, G.-K., Tignor, M., Allen, S., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P., 1029–1136, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2013. a
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, Q02 005, https://doi.org/10.1029/2005GC001054, 2006. a
Dail, H. and Wunsch, C.: Dynamical Reconstruction of Upper-Ocean Conditions in the Last Glacial Maximum Atlantic, J. Clim., 27, 807–823, https://doi.org/10.1175/JCLI-D-13-00211.1, 2014. a
Dale, B.: The sedimentary record of dinoflagellate cysts: Looking back into the future of phytoplankton blooms, Sci. Mar., 65, 257–272, 2001. a
de Garidel-Thoron, T., Rosenthal, Y., Beaufort, L., Bard, E., Sonzogni, C., and Mix, A. C.: A multiproxy assessment of the western equatorial Pacific hydrography during the last 30 kyr, Paleoceanography, 22, PA3204, https://doi.org/10.1029/2006PA001269, 2007. a, b, c
de Vernal, A., Eynaud, F., Henry, M., Hillaire-Marcel, C., Londeix, L., Mangin, S., Mathiessen, J., Marret, F., Radi, T., Rochon, A., Solignac, S., and Turon, J.-L.: Reconstruction of sea-surface conditions at middle to high latitudes of the Northern Hemisphere during the Last Glacial Maximum (LGM) based on dinoflagellate cyst assemblages, Quat. Sci. Rev., 24, 897–924, https://doi.org/10.1016/j.quascirev.2004.06.014, 2005. a, b, c
de Vernal, A., Rosell-Melé, A., Kucera, M., Hillaire-Marcel, C., Eynaud, F., Weinelt, M., Dokken, T., and Kageyama, M.: Comparing proxies for the reconstruction of LGM sea-surface conditions in the northern North Atlantic, Quat. Sci. Rev., 25, 2820–2834, https://doi.org/10.1016/j.quascirev.2006.06.006, 2006. a, b, c, d, e, f
Deutsch, C. V. and Journel, A. G.: GSLIB, Geostatistical Software Library and User's Guide, Oxford University Press, New York, Oxford, 1992. a
Eisenman, I.: Geographic muting of changes in the Arctic sea ice cover, Geophys. Res. Lett., 37, L16501, https://doi.org/10.1029/2010GL043741, 2010. a
Filippova, A., Kienast, M., Frank, M., and Schneider, R. R.: Alkenone paleothermometry in the North Atlantic: A review and synthesis of surface sediment data and calibrations, Geochem. Geophy. Geosy., 17, 1370–1382, https://doi.org/10.1002/2015GC006106, 2016. a, b
Fischer, G., Gersonde, R., and Wefer, G.: Organic carbon, biogenic silica and diatom fluxes in the marginal winter sea ice zone and in the Polar Front Region in the Southern Ocean (Atlantic sector): interannual variation and changes in composition, Deep-Sea Res. Pt. II, 49, 1721–1745, https://doi.org/10.1016/S0967-0645(02)00009-7, 2002. a, b
Fraile, I., Mulitza, S., and Schulz, M.: Modeling planktonic foraminiferal seasonality: Implications for sea-surface temperature reconstructions, Mar Micropaleontol., 72, 1–9, https://doi.org/10.1016/j.marmicro.2009.01.003, 2009. a, b
Fraile, I., Schulz, M., Mulitza, S., Merkel, U., Prange, M., and Paul, A.: Modeling the seasonal distribution of planktonic foraminifera during the Last Glacial Maximum, Paleoceanography, 24, PA2216, https://doi.org/10.1029/2008PA001686, 2009b. a
Gersonde, R. and Zielinski, U.: The reconstruction of late Quaternary Antarctic sea-ice distribution – the use of diatoms as proxies for sea-ice, Paleogeography Paleoclimatology Paleoecology, 162, 263–286, https://doi.org/10.1016/S0031-0182(00)00131-0, 2000. a, b
Gersonde, R., Crosta, X., Abelmann, A., and Armand, L.: Sea-surface temperature and sea ice distribution of the Southern Ocean at the EPILOG Last Glacial Maximum – a circum-Antarctic view based on siliceous microfossil records, Quat. Sci. Rev., 24, 869–896, https://doi.org/10.1016/j.quascirev.2004.07.015, 2005. a, b
Giraud, X. and Paul, A.: Interpretation of the paleo–primary production record in the NW African coastal upwelling system as potentially biased by sea level change, Paleoceanography, 25, https://doi.org/10.1029/2009PA001795, 2010. a
Guilderson, T. P., Fairbanks, R. G., and Rubenstone, J. L.: Tropical Temperature Variations Since 20 000 Years Ago: Modulating Interhemispheric Climate Change, Science, 263, 663–665, https://doi.org/10.1126/science.263.5147.663, 1994. a
Jansen, E., Overpeck, J., Briffa, K., Duplessy, J.-C., Joos, F., Masson-Delmotte, V., Olago, D., Otto-Bliesner, B., Peltier, W., Rahmstorf, S., Ramesh, R., Raynaud, D., Rind, D., Solomina, O., Villalba, R., and Zhang, D.: Palaeoclimate, in: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K., Tignor, M., and Miller, H., 447–451, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2007. a, b
Judd, E. J., Bhattacharya, T., and Ivany, L. C.: A Dynamical Framework for Interpreting Ancient SeaSurface Temperature, Geophys. Res. Lett., 47, e2020GL089 044, https://doi.org/10.1029/2020GL089044, 2020. a, b
Kageyama, M., Albani, S., Braconnot, P., Harrison, S. P., Hopcroft, P. O., Ivanovic, R. F., Lambert, F., Marti, O., Peltier, W. R., Peterschmitt, J.-Y., Roche, D. M., Tarasov, L., Zhang, X., Brady, E. C., Haywood, A. M., LeGrande, A. N., Lunt, D. J., Mahowald, N. M., Mikolajewicz, U., Nisancioglu, K. H., Otto-Bliesner, B. L., Renssen, H., Tomas, R. A., Zhang, Q., Abe-Ouchi, A., Bartlein, P. J., Cao, J., Li, Q., Lohmann, G., Ohgaito, R., Shi, X., Volodin, E., Yoshida, K., Zhang, X., and Zheng, W.: The PMIP4 contribution to CMIP6 – Part 4: Scientific objectives and experimental design of the PMIP4-CMIP6 Last Glacial Maximum experiments and PMIP4 sensitivity experiments, Geosci. Model Dev., 10, 4035–4055, https://doi.org/10.5194/gmd-10-4035-2017, 2017. a, b
Kageyama, M., Harrison, S. P., Kapsch, M.-L., Löfverström, M., Lora, J. M., Mikolajewicz, U., Sherriff-Tadano, S., Vadsaria, T., Abe-Ouchi, A., Bouttes, N., Chandan, D., LeGrande, A. N., Lhardy, F., Lohmann, G., Morozova, P. A., Ohgaito, R., Peltier, W. R., Quiquet, A., Roche, D. M., Shi, X., Schmittner, A., Tierney, J. E., and Volodin, E.: The PMIP4-CMIP6 Last Glacial Maximum experiments: preliminary results and comparison with the PMIP3-CMIP5 simulations, Clim. Past Discuss. [preprint], https://doi.org/10.5194/cp-2019-169, in review, 2020. a
Kretschmer, K., Jonkers, L., Kucera, M., and Schulz, M.: Modeling seasonal and vertical habitats of planktonic foraminifera on a global scale, Biogeosciences, 15, 4405–4429, https://doi.org/10.5194/bg-15-4405-2018, 2018. a
Kucera, M., Weinelt, M., Kiefer, T., Pflaumann, U., Hayes, A., Weinelt, M., Chen, M.-T., Mix, A. C., Barrows, T. T., Cortijo, E., Duprat, J., Juggins, S., and Waelbroeck, C.: Reconstruction of sea-surface temperatures from assemblages of planktonic foraminifera: Multi-technique approach based on geographically constrained calibration data sets and its application to glacial Atlantic and Pacific Oceans, Quat. Sci. Rev., 24, 951–998, https://doi.org/10.1016/j.quascirev.2004.07.014, 2005b. a, b, c, d
Leduc, G., de Garidel-Thoron, T., Kaiser, J., Bolton, C., and Contoux, C.: Databases for sea surface paleotemperature based on geochemical proxies from marine sediments: implications for model-data comparisons, Quaternaire, 28, 201–216, https://doi.org/10.4000/quaternaire.8034, 2017. a, b
Lee, K. E., Slowey, N. C., and Herbert, T. D.: Glacial sea surface temperatures in the subtropical North Pacific: A comparison of
Levitus, S.: Climatological Atlas of the World Ocean, Tech. Rep., US Department of Commerce, National Oceanic and Atmospheric Administration, Rockville, MD, USA, 1982. a
Manabe, S. and Broccoli, A. J.: Beyond Global Warming, Princeton University Press, Princeton and Oxford, https://doi.org/10.1515/9780691185163, 2020. a, b, c, d
Marchal, O. and Curry, W. B.: On the Abyssal Circulation in the Glacial Atlantic, J. Phys. Oceanogr., 38, 2014–2037, https://doi.org/10.1175/2008JPO3895.1, 2008. a, b, c
Masson-Delmotte, V., Schulz, M., Abe-Ouchi, A., Beer, J., Ganopolski, A., González Rouco, J., Jansen, E., Lambeck, K., Luterbacher, J., Naish, T., Osborn, T., Otto-Bliesner, B., Quinn, T., Ramesh, R., Rojas, M., Shao, X., and Timmermann, A.: Information from Paleoclimate Archives, in: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, edited by Stocker, T., Qin, D., Plattner, G.-K., Tignor, M., Allen, S., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P., 383–464, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2013. a, b
Méheust, M., Ruediger Stein, R., Fahl, K., Max, L., and Riethdorf, J. R.: High-resolution IP25-based reconstruction of sea-ice variability in the western North Pacific and Bering Sea during the past 18 000 years, Geo-Mar. Lett., 36, 101–111, https://doi.org/10.1007/s00367-015-0432-4, 2016. a, b
Mix, A. C.: The oxygen-isotope record of glaciation, in: North America and adjacent oceans during the last deglaciation, edited by Ruddiman, W. F. and Wright, Jr., H. E., vol. K-3 of The Geology of North America, Geol. Soc. Am., Boulder, CO, https://doi.org/10.1130/DNAG-GNA-K3.111, 1987. a, b
Morey, A. E., Mix, A. C., and Pisias, N. G.: Planktonic foraminiferal assemblages preserved in surface sediments correspond to multiple environmental variables, Quat. Sci. Rev., 24, 925–950, https://doi.org/10.1016/j.quascirev.2003.09.011, 2005. a, b, c
Paul, A. and Schäfer-Neth, C.: Modeling the water masses of the Atlantic Ocean at the Last Glacial Maximum, Paleoceanography, 18, 1058, https://doi.org/10.1029/2002PA000783, 2003. a, b, c, d
Paul, A., Mulitza, S., Stein, R., and Werner, M.: Glacial Ocean Map (GLOMAP), PANGAEA, https://doi.org/10.1594/PANGAEA.923262, 2020. a
Pflaumann, U., Sarnthein, M., Chapman, M., Funnel, B., Huels, M., Kiefer, T., Maslin, M., Schulz, H., Swallow, J., van Kreveld, S., Vautravers, M., Vogelsang, E., and Weinelt, M.: The Glacial North Atlantic: Sea-surface conditions reconstructed by GLAMAP-2000, Paleoceanography, 18, 1065, https://doi.org/10.1029/2002PA00774, 2003. a, b
PMIP: Paleoclimate Modelling Intercomparison Project, https://pmip1.lsce.ipsl.fr/newsletters/newsletter02.html (last access: 30 March 2021), Tech. Rep., 1993. a
Prahl, F. G., Muehlhausen, L. A., and Lyle, M.: An organic geochemical assessment of oceanographic conditions at Manop Site C over the past 26 000 years, Paleoceanography, 4, 495–510, https://doi.org/10.1029/PA004i005p00495, 1989. a, b
Ravelo, A. C., Fairbanks, R. G., and Philander, S. G. H.: Reconstructing tropical Atlantic hydrography using planktonic foraminifera and an ocean model, Paleoceanography, 5, 409–431, https://doi.org/10.1029/PA005i003p00409, 1990. a
Roche, D. M., Crosta, X., and Renssen, H.: Evaluating Southern Ocean sea-ice for the Last Glacial Maximum and pre-industrial climates: PMIP-2 models and data evidence, Quat. Sci. Rev., 56, 99–106, https://doi.org/10.1016/j.quascirev.2012.09.020, 2012. a, b
Rühlemann, C. and Butzin, M.: Alkenone temperature anomalies in the Brazil-Malvinas Confluence area caused by lateral advection of suspended particulate material, Geochem. Geophy. Geosy., 7, Q10 015, https://doi.org/10.1029/2006GC001251, 2006. a
Sarnthein, M., Pflaumann, U., and Weinelt, M.: Past extent of sea ice in the northern North Atlantic inferred from foraminiferal paleotemperature estimates, Paleoceanography, 18, 1047, https://doi.org/10.1029/2002PA000771, 2003b. a, b
Schäfer-Neth, C. and Paul, A.: The Atlantic Ocean at the Last Glacial Maximum: 1. Objective mapping of the GLAMAP sea-surface conditions, in: The South Atlantic in the Late Quaternary: Reconstruction of Material Budgets and Current Systems, edited by Wefer, G., Mulitza, S., and Ratmeyer, V., 531–548, Springer-Verlag, Berlin, Heidelberg, 2004. a, b, c, d
Schneider von Deimling, T., Held, H., Ganopolski, A., and Rahmstorf, S.: Climate sensitivity estimated from ensemble simulations of glacial climate, Clim. Dyn., 27, 149–163, https://doi.org/10.1007/s00382-006-0126-8, 2006. a, b, c
Sherwood, S., Webb, M. J., Annan, J. D., Armour, K. C., Forster, P. M., Hargreaves, J. C., Hegerl, G., Klein, S. A., Marvel, K. D., Rohling, E. J., Watanabe, M., Andrews, T., Braconnot, P., Bretherton, C. S., Foster, G. L., Hausfather, Z., Heydt, A. S. v. d., Knutti, R., Mauritsen, T., Norris, J. R., Proistosescu, C., Rugenstein, M., Schmidt, G. A., Tokarska, K. B., and Zelinka, M. D.: An assessment of Earth's climate sensitivity using multiple lines of evidence, Rev. Geophy., 58, e2019RG000678, https://doi.org/10.1029/2019RG000678, 2020. a, b, c, d, e
Takahashi, K. and Be, A. W. H.: Planktonic foraminifera: factors controlling sinking speeds, Deep-Sea Res., 31, 1477–1500, https://doi.org/10.1016/0198-0149(84)90083-9, 1984. a
Telford, R. J., Li, C., and Kucera, M.: Mismatch between the depth habitat of planktonic foraminifera and the calibration depth of SST transfer functions may bias reconstructions, Clim. Past, 9, 859–870, https://doi.org/10.5194/cp-9-859-2013, 2013. a
Troupin, C., Barth, A., Sirjacobs, D., Ouberdous, M., Brankart, J.-M., Brasseur, P., Rixen, M., Alvera-Azcárate, A., Belounis, M., Capet, A., Lenartz, F., Toussaint, M.-E., and Beckers, J.-M.: Generation of analysis and consistent error fields using the Data Interpolating Variational Analysis (DIVA), Ocean Model., 52-53, 90–101, https://doi.org/10.1016/j.ocemod.2012.05.002, 2012. a, b, c, d, e, f, g, h, i, j
Troupin, C., Watelet, S., Ouberdous, M., Sirjacobs, D., Alvera-Azcárate, A., Barth, A., Toussaint, M.-E., and Beckers, J.-M.: Data Interpolating Variational Analysis User Guide, Tech. Rep., GeoHydrodynamics and Environment Research (GHER), Departement of Astrophysics, Geophysics and Oceanography, University of Liège, https://github.com/gher-ulg/Diva-User-Guide/, last access: 3 December 2019.
a, b, c
Tyberghein, L., Verbruggen, H., Pauly, K., Troupin, C., Mineur, F., and De Clerck, O.: Bio-ORACLE: a global environmental dataset for marine species distribution modelling, Global Ecol. Biogeogr., 21, 272–281, https://doi.org/10.1111/j.1466-8238.2011.00656.x, 2012. a, b
Werner, M., Jouzel, J., Masson-Delmotte, V., and Lohmann, G.: Reconciling glacial Antarctic water stable isotopes with ice sheet topography and the isotopic paleothermometer, Nat. Commun., 9, 3537, https://doi.org/10.1038/s41467-018-05430-y, 2018. a
Wessel, P. and Smith, W. H. F.: New, improved version of Generic Mapping Tools released, Eos, 79, p. 579, https://doi.org/10.1029/98EO00426, 1998. a, b
Wunsch, C.: The Ocean Circulation Inverse Problem, Cambridge University Press, New York, 1996. a
Wunsch, C.: Towards determining uncertainties in global oceanic mean values of heat, salt, and surface elevation, Tellus A, 70, 1–14, https://doi.org/10.1080/16000870.2018.1471911, 2018. a, b
Short summary
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.
Maps and fields of near-sea-surface temperature differences between the past and present can be...
