Articles | Volume 17, issue 2
https://doi.org/10.5194/cp-17-703-2021
© 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-17-703-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Atmospheric carbon dioxide variations across the middle Miocene climate transition
MARUM – Zentrum für Marine Umweltwissenschaften, Universität Bremen, Leobener Straße 8, 28359 Bremen, Germany
Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und
Meeresforschung, Am Handelshafen 12, 27570 Bremerhaven, Germany
Jelle Bijma
Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und
Meeresforschung, Am Handelshafen 12, 27570 Bremerhaven, Germany
Torsten Bickert
MARUM – Zentrum für Marine Umweltwissenschaften, Universität Bremen, Leobener Straße 8, 28359 Bremen, Germany
Michael Schulz
MARUM – Zentrum für Marine Umweltwissenschaften, Universität Bremen, Leobener Straße 8, 28359 Bremen, Germany
Ann Holbourn
Institut für Geowissenschaften, Christian-Albrechts-Universität, 24118 Kiel, Germany
Michal Kučera
MARUM – Zentrum für Marine Umweltwissenschaften, Universität Bremen, Leobener Straße 8, 28359 Bremen, Germany
Related authors
Markus Raitzsch, Claire Rollion-Bard, Ingo Horn, Grit Steinhoefel, Albert Benthien, Klaus-Uwe Richter, Matthieu Buisson, Pascale Louvat, and Jelle Bijma
Biogeosciences, 17, 5365–5375, https://doi.org/10.5194/bg-17-5365-2020, https://doi.org/10.5194/bg-17-5365-2020, 2020
Short summary
Short summary
The isotopic composition of boron in carbonate shells of marine unicellular organisms is a popular tool to estimate seawater pH. Usually, many shells need to be dissolved and measured for boron isotopes, but the information on their spatial distribution is lost. Here, we investigate two techniques that allow for measuring boron isotopes within single shells and show that they yield robust mean values but provide additional information on the heterogeneity within and between single shells.
Brian R. Crow, Lev Tarasov, Michael Schulz, and Matthias Prange
Clim. Past, 20, 281–296, https://doi.org/10.5194/cp-20-281-2024, https://doi.org/10.5194/cp-20-281-2024, 2024
Short summary
Short summary
An abnormally warm period around 400,000 years ago is thought to have resulted in a large melt event for the Greenland Ice Sheet. Using a sequence of climate model simulations connected to an ice model, we estimate a 50 % melt of Greenland compared to today. Importantly, we explore how the exact methodology of connecting the temperatures and precipitation from the climate model to the ice sheet model can influence these results and show that common methods could introduce errors.
Sabrina Hohmann, Michal Kucera, and Anne de Vernal
Clim. Past, 19, 2027–2051, https://doi.org/10.5194/cp-19-2027-2023, https://doi.org/10.5194/cp-19-2027-2023, 2023
Short summary
Short summary
Drivers for dinocyst assemblage compositions differ regionally and through time. Shifts in the assemblages can sometimes only be interpreted robustly by locally and sometimes globally calibrated transfer functions, questioning the reliability of environmental reconstructions. We suggest the necessity of a thorough evaluation of transfer function performance and significance for downcore applications to disclose the drivers for present and fossil dinocyst assemblages in a studied core location.
Michal Kučera and Geert-Jan A. Brummer
J. Micropalaeontol., 42, 33–34, https://doi.org/10.5194/jm-42-33-2023, https://doi.org/10.5194/jm-42-33-2023, 2023
Pauline Cornuault, Thomas Westerhold, Heiko Pälike, Torsten Bickert, Karl-Heinz Baumann, and Michal Kucera
Biogeosciences, 20, 597–618, https://doi.org/10.5194/bg-20-597-2023, https://doi.org/10.5194/bg-20-597-2023, 2023
Short summary
Short summary
We generated high-resolution records of carbonate accumulation rate from the Miocene to the Quaternary in the tropical Atlantic Ocean to characterize the variability in pelagic carbonate production during warm climates. It follows orbital cycles, responding to local changes in tropical conditions, as well as to long-term shifts in climate and ocean chemistry. These changes were sufficiently large to play a role in the carbon cycle and global climate evolution.
Franziska Tell, Lukas Jonkers, Julie Meilland, and Michal Kucera
Biogeosciences, 19, 4903–4927, https://doi.org/10.5194/bg-19-4903-2022, https://doi.org/10.5194/bg-19-4903-2022, 2022
Short summary
Short summary
This study analyses the production of calcite shells formed by one of the main Arctic pelagic calcifiers, the foraminifera N. pachyderma. Using vertically resolved profiles of shell concentration, size and weight, we show that calcification occurs throughout the upper 300 m with an average production flux below the calcification zone of 8 mg CaCO3 m−2 d−1 representing 23 % of the total pelagic biogenic carbonate production. The production flux is attenuated in the twilight zone by dissolution.
Takasumi Kurahashi-Nakamura, André Paul, Ute Merkel, and Michael Schulz
Clim. Past, 18, 1997–2019, https://doi.org/10.5194/cp-18-1997-2022, https://doi.org/10.5194/cp-18-1997-2022, 2022
Short summary
Short summary
With a comprehensive Earth-system model including the global carbon cycle, we simulated the climate state during the last glacial maximum. We demonstrated that the CO2 concentration in the atmosphere both in the modern (pre-industrial) age (~280 ppm) and in the glacial age (~190 ppm) can be reproduced by the model with a common configuration by giving reasonable model forcing and total ocean inventories of carbon and other biogeochemical matter for the respective ages.
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
Short summary
Short summary
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.
Brian R. Crow, Matthias Prange, and Michael Schulz
Clim. Past, 18, 775–792, https://doi.org/10.5194/cp-18-775-2022, https://doi.org/10.5194/cp-18-775-2022, 2022
Short summary
Short summary
To better understand the climate conditions which lead to extensive melting of the Greenland ice sheet, we used climate models to reconstruct the climate conditions of the warmest period of the last 800 000 years, which was centered around 410 000 years ago. Surprisingly, we found that atmospheric circulation changes may have acted to reduce the melt of the ice sheet rather than enhance it, despite the extensive warmth of the time.
Geert-Jan A. Brummer and Michal Kučera
J. Micropalaeontol., 41, 29–74, https://doi.org/10.5194/jm-41-29-2022, https://doi.org/10.5194/jm-41-29-2022, 2022
Short summary
Short summary
To aid researchers working with living planktonic foraminifera, we provide a comprehensive review of names that we consider appropriate for extant species. We discuss the reasons for the decisions we made and provide a list of species and genus-level names as well as other names that have been used in the past but are considered inappropriate for living taxa, stating the reasons.
Lukas Jonkers, Geert-Jan A. Brummer, Julie Meilland, Jeroen Groeneveld, and Michal Kucera
Clim. Past, 18, 89–101, https://doi.org/10.5194/cp-18-89-2022, https://doi.org/10.5194/cp-18-89-2022, 2022
Short summary
Short summary
The variability in the geochemistry among individual foraminifera is used to reconstruct seasonal to interannual climate variability. This method requires that each foraminifera shell accurately records environmental conditions, which we test here using a sediment trap time series. Even in the absence of environmental variability, planktonic foraminifera display variability in their stable isotope ratios that needs to be considered in the interpretation of individual foraminifera data.
Lukas Jonkers, Oliver Bothe, and Michal Kucera
Clim. Past, 17, 2577–2581, https://doi.org/10.5194/cp-17-2577-2021, https://doi.org/10.5194/cp-17-2577-2021, 2021
Julie Meilland, Michael Siccha, Maike Kaffenberger, Jelle Bijma, and Michal Kucera
Biogeosciences, 18, 5789–5809, https://doi.org/10.5194/bg-18-5789-2021, https://doi.org/10.5194/bg-18-5789-2021, 2021
Short summary
Short summary
Planktonic foraminifera population dynamics has long been assumed to be controlled by synchronous reproduction and ontogenetic vertical migration (OVM). Due to contradictory observations, this concept became controversial. We here test it in the Atlantic ocean for four species of foraminifera representing the main clades. Our observations support the existence of synchronised reproduction and OVM but show that more than half of the population does not follow the canonical trajectory.
Jutta E. Wollenburg, Jelle Bijma, Charlotte Cremer, Ulf Bickmeyer, and Zora Mila Colomba Zittier
Biogeosciences, 18, 3903–3915, https://doi.org/10.5194/bg-18-3903-2021, https://doi.org/10.5194/bg-18-3903-2021, 2021
Short summary
Short summary
Cultured at in situ high-pressure conditions Cibicides and Cibicidoides taxa develop lasting ectoplasmic structures that cannot be retracted or resorbed. An ectoplasmic envelope surrounds their test and may protect the shell, e.g. versus carbonate aggressive bottom water conditions. Ectoplasmic roots likely anchor the specimens in areas of strong bottom water currents, trees enable them to elevate themselves above ground, and twigs stabilize and guide the retractable pseudopodial network.
Charlotte L. Spencer-Jones, Erin L. McClymont, Nicole J. Bale, Ellen C. Hopmans, Stefan Schouten, Juliane Müller, E. Povl Abrahamsen, Claire Allen, Torsten Bickert, Claus-Dieter Hillenbrand, Elaine Mawbey, Victoria Peck, Aleksandra Svalova, and James A. Smith
Biogeosciences, 18, 3485–3504, https://doi.org/10.5194/bg-18-3485-2021, https://doi.org/10.5194/bg-18-3485-2021, 2021
Short summary
Short summary
Long-term ocean temperature records are needed to fully understand the impact of West Antarctic Ice Sheet collapse. Glycerol dialkyl glycerol tetraethers (GDGTs) are powerful tools for reconstructing ocean temperature but can be difficult to apply to the Southern Ocean. Our results show active GDGT synthesis in relatively warm depths of the ocean. This research improves the application of GDGT palaeoceanographic proxies in the Southern Ocean.
Delphine Dissard, Gert Jan Reichart, Christophe Menkes, Morgan Mangeas, Stephan Frickenhaus, and Jelle Bijma
Biogeosciences, 18, 423–439, https://doi.org/10.5194/bg-18-423-2021, https://doi.org/10.5194/bg-18-423-2021, 2021
Short summary
Short summary
Results from a data set acquired from living foraminifera T. sacculifer collected from surface waters are presented, allowing us to establish a new Mg/Ca–Sr/Ca–temperature equation improving temperature reconstructions. When combining equations, δ18Ow can be reconstructed with a precision of ± 0.5 ‰, while successive reconstructions involving Mg/Ca and δ18Oc preclude salinity reconstruction with a precision better than ± 1.69. A new direct linear fit to reconstruct salinity could be established.
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
Short summary
Short summary
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.
Markus Raitzsch, Claire Rollion-Bard, Ingo Horn, Grit Steinhoefel, Albert Benthien, Klaus-Uwe Richter, Matthieu Buisson, Pascale Louvat, and Jelle Bijma
Biogeosciences, 17, 5365–5375, https://doi.org/10.5194/bg-17-5365-2020, https://doi.org/10.5194/bg-17-5365-2020, 2020
Short summary
Short summary
The isotopic composition of boron in carbonate shells of marine unicellular organisms is a popular tool to estimate seawater pH. Usually, many shells need to be dissolved and measured for boron isotopes, but the information on their spatial distribution is lost. Here, we investigate two techniques that allow for measuring boron isotopes within single shells and show that they yield robust mean values but provide additional information on the heterogeneity within and between single shells.
Catarina Cavaleiro, Antje H. L. Voelker, Heather Stoll, Karl-Heinz Baumann, and Michal Kucera
Clim. Past, 16, 2017–2037, https://doi.org/10.5194/cp-16-2017-2020, https://doi.org/10.5194/cp-16-2017-2020, 2020
Douglas Lessa, Raphaël Morard, Lukas Jonkers, Igor M. Venancio, Runa Reuter, Adrian Baumeister, Ana Luiza Albuquerque, and Michal Kucera
Biogeosciences, 17, 4313–4342, https://doi.org/10.5194/bg-17-4313-2020, https://doi.org/10.5194/bg-17-4313-2020, 2020
Short summary
Short summary
We observed that living planktonic foraminifera had distinct vertically distributed communities across the Subtropical South Atlantic. In addition, a hierarchic alternation of environmental parameters was measured to control the distribution of planktonic foraminifer's species depending on the water depth. This implies that not only temperature but also productivity and subsurface processes are signed in fossil assemblages, which could be used to perform paleoceanographic reconstructions.
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
Sebastian Beil, Wolfgang Kuhnt, Ann Holbourn, Florian Scholz, Julian Oxmann, Klaus Wallmann, Janne Lorenzen, Mohamed Aquit, and El Hassane Chellai
Clim. Past, 16, 757–782, https://doi.org/10.5194/cp-16-757-2020, https://doi.org/10.5194/cp-16-757-2020, 2020
Short summary
Short summary
Comparison of Cretaceous OAE1a and OAE2 in two drill cores with unusually high sedimentation rates shows that long-lasting negative δ13C excursions precede the positive δ13C excursions and that the evolution of the marine δ13C positive excursions is similar during both OAEs, although the durations of individual phases differ substantially. Phosphorus speciation data across OAE2 and the Mid-Cenomanian Event suggest a positive feedback loop, enhancing marine productivity during OAEs.
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
Short summary
Short summary
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.
Jan Goleń, Jarosław Tyszka, Ulf Bickmeyer, and Jelle Bijma
Biogeosciences, 17, 995–1011, https://doi.org/10.5194/bg-17-995-2020, https://doi.org/10.5194/bg-17-995-2020, 2020
Short summary
Short summary
We studied the organisation and dynamics of actin in foraminifera. Actin is one of the key structural proteins in most lifeforms. Our investigations show that in foraminifera it forms small granules, around 1 µm in diameter, that display rapid movement. This granularity is unusual in comparison to other organisms. We suppose that these granules are most likely involved in the formation of all types of pseudopods responsible for movement, food capturing, biomineralisation, and other functions.
Anna Jentzen, Joachim Schönfeld, Agnes K. M. Weiner, Manuel F. G. Weinkauf, Dirk Nürnberg, and Michal Kučera
J. Micropalaeontol., 38, 231–247, https://doi.org/10.5194/jm-38-231-2019, https://doi.org/10.5194/jm-38-231-2019, 2019
Short summary
Short summary
The study assessed the population dynamics of living planktic foraminifers on a weekly, seasonal, and interannual timescale off the coast of Puerto Rico to improve our understanding of short- and long-term variations. The results indicate a seasonal change of the faunal composition, and over the last decades. Lower standing stocks and lower stable carbon isotope values of foraminifers in shallow waters can be linked to the hurricane Sandy, which passed the Greater Antilles during autumn 2012.
Mattia Greco, Lukas Jonkers, Kerstin Kretschmer, Jelle Bijma, and Michal Kucera
Biogeosciences, 16, 3425–3437, https://doi.org/10.5194/bg-16-3425-2019, https://doi.org/10.5194/bg-16-3425-2019, 2019
Short summary
Short summary
To be able to interpret the paleoecological signal contained in N. pachyderma's shells, its habitat depth must be known. Our investigation on 104 density profiles of this species from the Arctic and North Atlantic shows that specimens reside closer to the surface when sea-ice and/or surface chlorophyll concentrations are high. This is in contrast with previous investigations that pointed at the position of the deep chlorophyll maximum as the main driver of N. pachyderma vertical distribution.
Haruka Takagi, Katsunori Kimoto, Tetsuichi Fujiki, Hiroaki Saito, Christiane Schmidt, Michal Kucera, and Kazuyoshi Moriya
Biogeosciences, 16, 3377–3396, https://doi.org/10.5194/bg-16-3377-2019, https://doi.org/10.5194/bg-16-3377-2019, 2019
Short summary
Short summary
Photosymbiosis (endosymbiosis with algae) is an evolutionary important ecology for many marine organisms but has poorly been identified among planktonic foraminifera. In this study, we identified and characterized photosymbiosis of various species of planktonic foraminifera by focusing on their photosynthesis–related features. We finally proposed a new framework showing a potential strength of photosymbiosis, which will serve as a basis for future ecological studies of planktonic foraminifera.
Andreia Rebotim, Antje Helga Luise Voelker, Lukas Jonkers, Joanna J. Waniek, Michael Schulz, and Michal Kucera
J. Micropalaeontol., 38, 113–131, https://doi.org/10.5194/jm-38-113-2019, https://doi.org/10.5194/jm-38-113-2019, 2019
Short summary
Short summary
To reconstruct subsurface water conditions using deep-dwelling planktonic foraminifera, we must fully understand how the oxygen isotope signal incorporates into their shell. We report δ18O in four species sampled in the eastern North Atlantic with plankton tows. We assess the size and crust effect on the isotopic δ18O and compared them with predictions from two equations. We reveal different patterns of calcite addition with depth, highlighting the need to perform species-specific calibrations.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Eveline M. Mezger, Lennart J. de Nooijer, Jacqueline Bertlich, Jelle Bijma, Dirk Nürnberg, and Gert-Jan Reichart
Biogeosciences, 16, 1147–1165, https://doi.org/10.5194/bg-16-1147-2019, https://doi.org/10.5194/bg-16-1147-2019, 2019
Short summary
Short summary
Seawater salinity is an important factor when trying to reconstruct past ocean conditions. Foraminifera, small organisms living in the sea, produce shells that incorporate more Na at higher salinities. The accuracy of reconstructions depends on the fundamental understanding involved in the incorporation and preservation of the original Na of the shell. In this study, we unravel the Na composition of different components of the shell and describe the relative contribution of these components.
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
Short summary
Short summary
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.
Nadia Al-Sabouni, Isabel S. Fenton, Richard J. Telford, and Michal Kučera
J. Micropalaeontol., 37, 519–534, https://doi.org/10.5194/jm-37-519-2018, https://doi.org/10.5194/jm-37-519-2018, 2018
Short summary
Short summary
In this study we investigate consistency in species-level identifications and whether disagreements are predictable. Overall, 21 researchers from across the globe identified sets of 300 specimens or digital images of planktonic foraminifera. Digital identifications tended to be more disparate. Participants trained by the same person often had more similar identifications. Disagreements hardly affected transfer-function temperature estimates but produced larger differences in diversity metrics.
Jacqueline Bertlich, Dirk Nürnberg, Ed C. Hathorne, Lennart J. de Nooijer, Eveline M. Mezger, Markus Kienast, Steffanie Nordhausen, Gert-Jan Reichart, Joachim Schönfeld, and Jelle Bijma
Biogeosciences, 15, 5991–6018, https://doi.org/10.5194/bg-15-5991-2018, https://doi.org/10.5194/bg-15-5991-2018, 2018
Andrea Klus, Matthias Prange, Vidya Varma, Louis Bruno Tremblay, and Michael Schulz
Clim. Past, 14, 1165–1178, https://doi.org/10.5194/cp-14-1165-2018, https://doi.org/10.5194/cp-14-1165-2018, 2018
Short summary
Short summary
Numerous proxy records from the northern North Atlantic suggest substantial climate variability including the occurrence of multi-decadal-to-centennial cold events during the Holocene. We analyzed two abrupt cold events in a Holocene simulation using a comprehensive climate model. It is shown that the events were ultimately triggered by prolonged phases of positive North Atlantic Oscillation causing changes in ocean circulation followed by severe cooling, freshening, and expansion of sea ice.
Kerstin Kretschmer, Lukas Jonkers, Michal Kucera, and Michael Schulz
Biogeosciences, 15, 4405–4429, https://doi.org/10.5194/bg-15-4405-2018, https://doi.org/10.5194/bg-15-4405-2018, 2018
Short summary
Short summary
The fossil shells of planktonic foraminifera are widely used to reconstruct past climate conditions. To do so, information about their seasonal and vertical habitat is needed. Here we present an updated version of a planktonic foraminifera model to better understand species-specific habitat dynamics under climate change. This model produces spatially and temporally coherent distribution patterns, which agree well with available observations, and can thus aid the interpretation of proxy records.
Amanda Frigola, Matthias Prange, and Michael Schulz
Geosci. Model Dev., 11, 1607–1626, https://doi.org/10.5194/gmd-11-1607-2018, https://doi.org/10.5194/gmd-11-1607-2018, 2018
Short summary
Short summary
The application of climate models to study the Middle Miocene Climate Transition, characterized by major Antarctic ice-sheet expansion and global cooling at the interval 15–13 million years ago, is currently hampered by the lack of boundary conditions. To fill this gap, we compiled two internally consistent sets of boundary conditions, including global topography, bathymetry, vegetation and ice volume, for the periods before and after the transition.
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
Short summary
Short summary
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.
Lennart J. de Nooijer, Anieke Brombacher, Antje Mewes, Gerald Langer, Gernot Nehrke, Jelle Bijma, and Gert-Jan Reichart
Biogeosciences, 14, 3387–3400, https://doi.org/10.5194/bg-14-3387-2017, https://doi.org/10.5194/bg-14-3387-2017, 2017
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Philipp M. Munz, Stephan Steinke, Anna Böll, Andreas Lückge, Jeroen Groeneveld, Michal Kucera, and Hartmut Schulz
Clim. Past, 13, 491–509, https://doi.org/10.5194/cp-13-491-2017, https://doi.org/10.5194/cp-13-491-2017, 2017
Short summary
Short summary
We present the results of several independent proxies of summer SST and upwelling SST from the Oman margin indicative of monsoon strength during the early Holocene. In combination with indices of carbonate preservation and bottom water redox conditions, we demonstrate that a persistent solar influence was modulating summer monsoon intensity. Furthermore, bottom water conditions are linked to atmospheric forcing, rather than changes of intermediate water masses.
Andreia Rebotim, Antje H. L. Voelker, Lukas Jonkers, Joanna J. Waniek, Helge Meggers, Ralf Schiebel, Igaratza Fraile, Michael Schulz, and Michal Kucera
Biogeosciences, 14, 827–859, https://doi.org/10.5194/bg-14-827-2017, https://doi.org/10.5194/bg-14-827-2017, 2017
Short summary
Short summary
Planktonic foraminifera species depth habitat remains poorly constrained and the existing conceptual models are not sufficiently tested by observational data. Here we present a synthesis of living planktonic foraminifera abundance data in the subtropical eastern North Atlantic from vertical plankton tows. We also test potential environmental factors influencing the species depth habitat and investigate yearly or lunar migration cycles. These findings may impact paleoceanographic studies.
Ella L. Howes, Karina Kaczmarek, Markus Raitzsch, Antje Mewes, Nienke Bijma, Ingo Horn, Sambuddha Misra, Jean-Pierre Gattuso, and Jelle Bijma
Biogeosciences, 14, 415–430, https://doi.org/10.5194/bg-14-415-2017, https://doi.org/10.5194/bg-14-415-2017, 2017
Short summary
Short summary
To calculate the seawater carbonate system, proxies for 2 out of 7 parameters are required. The boron isotopic composition of foraminifera shells can be used as a proxy for pH and it has been suggested that B / Ca ratios may act as a proxy for carbonate ion concentration. However, differentiating between the effects of pH and [CO32−] is problematic, as they co-vary in natural systems. To deconvolve the effects, we conducted culture experiments with the planktonic foraminifer Orbulina universa.
Vidya Varma, Matthias Prange, and Michael Schulz
Geosci. Model Dev., 9, 3859–3873, https://doi.org/10.5194/gmd-9-3859-2016, https://doi.org/10.5194/gmd-9-3859-2016, 2016
Short summary
Short summary
We compare the results from simulations of the present and the last interglacial, with and without acceleration of the orbital forcing, using a comprehensive coupled climate model. In low latitudes, the simulation of long-term variations in interglacial surface climate is not significantly affected by the use of the acceleration technique and hence model–data comparison of surface variables is therefore not hampered but major repercussions of the orbital forcing are obvious below thermocline.
Rima Rachmayani, Matthias Prange, and Michael Schulz
Clim. Past, 12, 677–695, https://doi.org/10.5194/cp-12-677-2016, https://doi.org/10.5194/cp-12-677-2016, 2016
Short summary
Short summary
A set of 13 interglacial time slice experiments was carried out using a CCSM3-DGVM to study global climate variability between and within the Quaternary interglaciations of MIS 1, 5, 11, 13, and 15. Seasonal surface temperature anomalies can be explained by local insolation anomalies induced by the astronomical forcing in most regions and by GHG forcing at high latitudes and early Bruhnes interglacials. However, climate feedbacks may modify the surface temperature response in specific regions.
G. Dishon, J. Fisch, I. Horn, K. Kaczmarek, J. Bijma, D. F. Gruber, O. Nir, Y. Popovich, and D. Tchernov
Biogeosciences, 12, 5677–5687, https://doi.org/10.5194/bg-12-5677-2015, https://doi.org/10.5194/bg-12-5677-2015, 2015
Short summary
Short summary
This paper offers a new methodology to study paleo-coral bleaching events using high-resolution femtosecond Laser Ablation Multiple Collector Inductively Coupled Plasma Mass Spectrometry. Coral bleaching records only go back several decades, but this new proxy allows the study of bleaching events that occurred tens of thousands of years ago. Unlike other methods, the high-resolution of the method can detect bleaching events that occur over very short time periods, just a few weeks.
L. Jonkers and M. Kučera
Biogeosciences, 12, 2207–2226, https://doi.org/10.5194/bg-12-2207-2015, https://doi.org/10.5194/bg-12-2207-2015, 2015
A. Mewes, G. Langer, S. Thoms, G. Nehrke, G.-J. Reichart, L. J. de Nooijer, and J. Bijma
Biogeosciences, 12, 2153–2162, https://doi.org/10.5194/bg-12-2153-2015, https://doi.org/10.5194/bg-12-2153-2015, 2015
Short summary
Short summary
A culture study with the benthic foraminifer Amphistegina lessonii was conducted at varying seawater [Ca2+] and constant [Mg2+]. Results showed optimum growth rates and test thickness at ambient seawater Mg/Ca and a calcite Mg/Ca which is controlled by the relative seawater ratio. Results support the conceptual biomineralization model by Nehrke et al. (2013); however, our refined flux-based model suggests transmembrane transport fractionation that is slightly weaker than expected.
K. Kaczmarek, G. Langer, G. Nehrke, I. Horn, S. Misra, M. Janse, and J. Bijma
Biogeosciences, 12, 1753–1763, https://doi.org/10.5194/bg-12-1753-2015, https://doi.org/10.5194/bg-12-1753-2015, 2015
Short summary
Short summary
Culture experiments based on a decoupled pH and CO32- chemistry indicate that the δ11B of the test of A. lessonii is related to pH whereas the B/Ca of the foraminiferal shells show a positive correlation with B(OH)4-/HCO3-. The latter observation suggests a competition between B(OH)4- and HCO3- of the culture media for B uptake into the test.
R. Rachmayani, M. Prange, and M. Schulz
Clim. Past, 11, 175–185, https://doi.org/10.5194/cp-11-175-2015, https://doi.org/10.5194/cp-11-175-2015, 2015
Short summary
Short summary
The role of vegetation-precipitation feedbacks in modifying the North African rainfall response to enhanced early to mid-Holocene summer insolation is analysed using the climate-vegetation model CCSM3-DGVM. Dynamic vegetation amplifies the positive early to mid-Holocene summer precipitation anomaly by ca. 20% in the Sahara-Sahel region. The primary vegetation feedback operates through surface latent heat flux anomalies by canopy evapotranspiration and their effect on the African easterly jet.
G. Langer, G. Nehrke, C. Baggini, R. Rodolfo-Metalpa, J. M. Hall-Spencer, and J. Bijma
Biogeosciences, 11, 7363–7368, https://doi.org/10.5194/bg-11-7363-2014, https://doi.org/10.5194/bg-11-7363-2014, 2014
Short summary
Short summary
Specimens of the patellogastropod limpet Patella caerulea were collected within and outside a CO2 vent site at Ischia, Italy. The distribution of different crystal structures across shell sections was analysed. Patella caerulea counteracts shell dissolution in corrosive waters by enhanced production of aragonitic parts of the shell. We conclude that it is not possible to predict the dissolution behaviour of a composite biomineral on the basis of the properties of its constituent mineral.
I. Hessler, S. P. Harrison, M. Kucera, C. Waelbroeck, M.-T. Chen, C. Anderson, A. de Vernal, B. Fréchette, A. Cloke-Hayes, G. Leduc, and L. Londeix
Clim. Past, 10, 2237–2252, https://doi.org/10.5194/cp-10-2237-2014, https://doi.org/10.5194/cp-10-2237-2014, 2014
A. J. Enge, U. Witte, M. Kucera, and P. Heinz
Biogeosciences, 11, 2017–2026, https://doi.org/10.5194/bg-11-2017-2014, https://doi.org/10.5194/bg-11-2017-2014, 2014
G. Nehrke, N. Keul, G. Langer, L. J. de Nooijer, J. Bijma, and A. Meibom
Biogeosciences, 10, 6759–6767, https://doi.org/10.5194/bg-10-6759-2013, https://doi.org/10.5194/bg-10-6759-2013, 2013
M. F. G. Weinkauf, T. Moller, M. C. Koch, and M. Kučera
Biogeosciences, 10, 6639–6655, https://doi.org/10.5194/bg-10-6639-2013, https://doi.org/10.5194/bg-10-6639-2013, 2013
Y. Milker, R. Rachmayani, M. F. G. Weinkauf, M. Prange, M. Raitzsch, M. Schulz, and M. Kučera
Clim. Past, 9, 2231–2252, https://doi.org/10.5194/cp-9-2231-2013, https://doi.org/10.5194/cp-9-2231-2013, 2013
N. Keul, G. Langer, L. J. de Nooijer, and J. Bijma
Biogeosciences, 10, 6185–6198, https://doi.org/10.5194/bg-10-6185-2013, https://doi.org/10.5194/bg-10-6185-2013, 2013
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
P. Bakker, E. J. Stone, S. Charbit, M. Gröger, U. Krebs-Kanzow, S. P. Ritz, V. Varma, V. Khon, D. J. Lunt, U. Mikolajewicz, M. Prange, H. Renssen, B. Schneider, and M. Schulz
Clim. Past, 9, 605–619, https://doi.org/10.5194/cp-9-605-2013, https://doi.org/10.5194/cp-9-605-2013, 2013
Related subject area
Subject: Proxy Use-Development-Validation | Archive: Marine Archives | Timescale: Cenozoic
A clumped isotope calibration of coccoliths at well-constrained culture temperatures for marine temperature reconstructions
Can we reliably reconstruct the mid-Pliocene Warm Period with sparse data and uncertain models?
Paleocene–Eocene age glendonites from the Mid-Norwegian Margin – indicators of cold snaps in the hothouse?
Assessing environmental change associated with early Eocene hyperthermals in the Atlantic Coastal Plain, USA
Technical note: A new online tool for δ18O–temperature conversions
A 15-million-year surface- and subsurface-integrated TEX86 temperature record from the eastern equatorial Atlantic
Sclerochronological evidence of pronounced seasonality from the late Pliocene of the southern North Sea basin and its implications
Pliocene evolution of the tropical Atlantic thermocline depth
Maastrichtian–Rupelian paleoclimates in the southwest Pacific – a critical re-evaluation of biomarker paleothermometry and dinoflagellate cyst paleoecology at Ocean Drilling Program Site 1172
Southern Ocean bottom-water cooling and ice sheet expansion during the middle Miocene climate transition
Rapid and sustained environmental responses to global warming: the Paleocene–Eocene Thermal Maximum in the eastern North Sea
OPTiMAL: a new machine learning approach for GDGT-based palaeothermometry
Technical note: A new automated radiolarian image acquisition, stacking, processing, segmentation and identification workflow
Late Paleocene–early Eocene Arctic Ocean sea surface temperatures: reassessing biomarker paleothermometry at Lomonosov Ridge
Surface-circulation change in the southwest Pacific Ocean across the Middle Eocene Climatic Optimum: inferences from dinoflagellate cysts and biomarker paleothermometry
A new age model for the Pliocene of the southern North Sea basin: a multi-proxy climate reconstruction
Joint inversion of proxy system models to reconstruct paleoenvironmental time series from heterogeneous data
Mercury anomalies across the Palaeocene–Eocene Thermal Maximum
Reinforcing the North Atlantic backbone: revision and extension of the composite splice at ODP Site 982
Highly variable Pliocene sea surface conditions in the Norwegian Sea
The PRISM4 (mid-Piacenzian) paleoenvironmental reconstruction
Revisiting carbonate chemistry controls on planktic foraminifera Mg / Ca: implications for sea surface temperature and hydrology shifts over the Paleocene–Eocene Thermal Maximum and Eocene–Oligocene transition
The Paleocene–Eocene Thermal Maximum at DSDP Site 277, Campbell Plateau, southern Pacific Ocean
The bivalve Glycymeris planicostalis as a high-resolution paleoclimate archive for the Rupelian (Early Oligocene) of central Europe
Pliocene diatom and sponge spicule oxygen isotope ratios from the Bering Sea: isotopic offsets and future directions
Re-evaluation of the age model for North Atlantic Ocean Site 982 – arguments for a return to the original chronology
Exploring the controls on element ratios in middle Eocene samples of the benthic foraminifera Oridorsalis umbonatus
Application of Fourier Transform Infrared Spectroscopy (FTIR) for assessing biogenic silica sample purity in geochemical analyses and palaeoenvironmental research
Alexander J. Clark, Ismael Torres-Romero, Madalina Jaggi, Stefano M. Bernasconi, and Heather M. Stoll
Clim. Past, 20, 2081–2101, https://doi.org/10.5194/cp-20-2081-2024, https://doi.org/10.5194/cp-20-2081-2024, 2024
Short summary
Short summary
Coccoliths are abundant in sediments across the world’s oceans, yet it is difficult to apply traditional carbon or oxygen isotope methodologies for temperature reconstructions. We show that our coccolith clumped isotope temperature calibration with well-constrained temperatures systematically differs from inorganic carbonate calibrations. We suggest the use of our well-constrained calibration for future coccolith carbonate temperature reconstructions.
James D. Annan, Julia C. Hargreaves, Thorsten Mauritsen, Erin McClymont, and Sze Ling Ho
Clim. Past, 20, 1989–1999, https://doi.org/10.5194/cp-20-1989-2024, https://doi.org/10.5194/cp-20-1989-2024, 2024
Short summary
Short summary
We have created a new global surface temperature reconstruction of the climate of the mid-Pliocene Warm Period, representing the period roughly 3.2 million years before the present day. We estimate that the globally averaged mean temperature was around 3.9 °C warmer than it was in pre-industrial times, but there is significant uncertainty in this value.
Madeleine L. Vickers, Morgan T. Jones, Jack Longman, David Evans, Clemens V. Ullmann, Ella Wulfsberg Stokke, Martin Vickers, Joost Frieling, Dustin T. Harper, Vincent J. Clementi, and IODP Expedition 396 Scientists
Clim. Past, 20, 1–23, https://doi.org/10.5194/cp-20-1-2024, https://doi.org/10.5194/cp-20-1-2024, 2024
Short summary
Short summary
The discovery of cold-water glendonite pseudomorphs in sediments deposited during the hottest part of the Cenozoic poses an apparent climate paradox. This study examines their occurrence, association with volcanic sediments, and speculates on the timing and extent of cooling, fitting this with current understanding of global climate during this period. We propose that volcanic activity was key to both physical and chemical conditions that enabled the formation of glendonites in these sediments.
William Rush, Jean Self-Trail, Yang Zhang, Appy Sluijs, Henk Brinkhuis, James Zachos, James G. Ogg, and Marci Robinson
Clim. Past, 19, 1677–1698, https://doi.org/10.5194/cp-19-1677-2023, https://doi.org/10.5194/cp-19-1677-2023, 2023
Short summary
Short summary
The Eocene contains several brief warming periods referred to as hyperthermals. Studying these events and how they varied between locations can help provide insight into our future warmer world. This study provides a characterization of two of these events in the mid-Atlantic region of the USA. The records of climate that we measured demonstrate significant changes during this time period, but the type and timing of these changes highlight the complexity of climatic changes.
Daniel E. Gaskell and Pincelli M. Hull
Clim. Past, 19, 1265–1274, https://doi.org/10.5194/cp-19-1265-2023, https://doi.org/10.5194/cp-19-1265-2023, 2023
Short summary
Short summary
One of the most common ways of reconstructing temperatures in the geologic past is by analyzing oxygen isotope ratios in fossil shells. However, converting these data to temperatures can be a technically complicated task. Here, we present a new online tool that automates this task.
Carolien M. H. van der Weijst, Koen J. van der Laan, Francien Peterse, Gert-Jan Reichart, Francesca Sangiorgi, Stefan Schouten, Tjerk J. T. Veenstra, and Appy Sluijs
Clim. Past, 18, 1947–1962, https://doi.org/10.5194/cp-18-1947-2022, https://doi.org/10.5194/cp-18-1947-2022, 2022
Short summary
Short summary
The TEX86 proxy is often used by paleoceanographers to reconstruct past sea-surface temperatures. However, the origin of the TEX86 signal in marine sediments has been debated since the proxy was first proposed. In our paper, we show that TEX86 carries a mixed sea-surface and subsurface temperature signal and should be calibrated accordingly. Using our 15-million-year record, we subsequently show how a TEX86 subsurface temperature record can be used to inform us on past sea-surface temperatures.
Andrew L. A. Johnson, Annemarie M. Valentine, Bernd R. Schöne, Melanie J. Leng, and Stijn Goolaerts
Clim. Past, 18, 1203–1229, https://doi.org/10.5194/cp-18-1203-2022, https://doi.org/10.5194/cp-18-1203-2022, 2022
Short summary
Short summary
Determining seasonal temperatures demands proxies that record the highest and lowest temperatures over the annual cycle. Many record neither, but oxygen isotope profiles from shells in principle record both. Oxygen isotope data from late Pliocene bivalve molluscs of the southern North Sea basin show that the seasonal temperature range was at times much higher than previously estimated and higher than now. This suggests reduced oceanic heat supply, in contrast to some previous interpretations.
Carolien M. H. van der Weijst, Josse Winkelhorst, Wesley de Nooijer, Anna von der Heydt, Gert-Jan Reichart, Francesca Sangiorgi, and Appy Sluijs
Clim. Past, 18, 961–973, https://doi.org/10.5194/cp-18-961-2022, https://doi.org/10.5194/cp-18-961-2022, 2022
Short summary
Short summary
A hypothesized link between Pliocene (5.3–2.5 million years ago) global climate and tropical thermocline depth is currently only backed up by data from the Pacific Ocean. In our paper, we present temperature, salinity, and thermocline records from the tropical Atlantic Ocean. Surprisingly, the Pliocene thermocline evolution was remarkably different in the Atlantic and Pacific. We need to reevaluate the mechanisms that drive thermocline depth, and how these are tied to global climate change.
Peter K. Bijl, Joost Frieling, Marlow Julius Cramwinckel, Christine Boschman, Appy Sluijs, and Francien Peterse
Clim. Past, 17, 2393–2425, https://doi.org/10.5194/cp-17-2393-2021, https://doi.org/10.5194/cp-17-2393-2021, 2021
Short summary
Short summary
Here, we use the latest insights for GDGT and dinocyst-based paleotemperature and paleoenvironmental reconstructions in late Cretaceous–early Oligocene sediments from ODP Site 1172 (East Tasman Plateau, Australia). We reconstruct strong river runoff during the Paleocene–early Eocene, a progressive decline thereafter with increased wet/dry seasonality in the northward-drifting hinterland. Our critical review leaves the anomalous warmth of the Eocene SW Pacific Ocean unexplained.
Thomas J. Leutert, Sevasti Modestou, Stefano M. Bernasconi, and A. Nele Meckler
Clim. Past, 17, 2255–2271, https://doi.org/10.5194/cp-17-2255-2021, https://doi.org/10.5194/cp-17-2255-2021, 2021
Short summary
Short summary
The Miocene climatic optimum associated with high atmospheric CO2 levels (~17–14 Ma) was followed by a period of dramatic climate change. We present a clumped isotope-based bottom-water temperature record from the Southern Ocean covering this key climate transition. Our record reveals warm conditions and a substantial cooling preceding the main ice volume increase, possibly caused by thresholds involved in ice growth and/or regional effects at our study site.
Ella W. Stokke, Morgan T. Jones, Lars Riber, Haflidi Haflidason, Ivar Midtkandal, Bo Pagh Schultz, and Henrik H. Svensen
Clim. Past, 17, 1989–2013, https://doi.org/10.5194/cp-17-1989-2021, https://doi.org/10.5194/cp-17-1989-2021, 2021
Short summary
Short summary
In this paper, we present new sedimentological, geochemical, and mineralogical data exploring the environmental response to climatic and volcanic impact during the Paleocene–Eocene Thermal Maximum (~55.9 Ma; PETM). Our data suggest a rise in continental weathering and a shift to anoxic–sulfidic conditions. This indicates a rapid environmental response to changes in the carbon cycle and temperatures and highlights the important role of shelf areas as carbon sinks driving the PETM recovery.
Tom Dunkley Jones, Yvette L. Eley, William Thomson, Sarah E. Greene, Ilya Mandel, Kirsty Edgar, and James A. Bendle
Clim. Past, 16, 2599–2617, https://doi.org/10.5194/cp-16-2599-2020, https://doi.org/10.5194/cp-16-2599-2020, 2020
Short summary
Short summary
We explore the utiliity of the composition of fossil lipid biomarkers, which are commonly preserved in ancient marine sediments, in providing estimates of past ocean temperatures. The group of lipids concerned show compositional changes across the modern oceans that are correlated, to some extent, with local surface ocean temperatures. Here we present new machine learning approaches to improve our understanding of this temperature sensitivity and its application to reconstructing past climates.
Martin Tetard, Ross Marchant, Giuseppe Cortese, Yves Gally, Thibault de Garidel-Thoron, and Luc Beaufort
Clim. Past, 16, 2415–2429, https://doi.org/10.5194/cp-16-2415-2020, https://doi.org/10.5194/cp-16-2415-2020, 2020
Short summary
Short summary
Radiolarians are marine micro-organisms that produce a siliceous shell that is preserved in the fossil record and can be used to reconstruct past climate variability. However, their study is only possible after a time-consuming manual selection of their shells from the sediment followed by their individual identification. Thus, we develop a new fully automated workflow consisting of microscopic radiolarian image acquisition, image processing and identification using artificial intelligence.
Appy Sluijs, Joost Frieling, Gordon N. Inglis, Klaas G. J. Nierop, Francien Peterse, Francesca Sangiorgi, and Stefan Schouten
Clim. Past, 16, 2381–2400, https://doi.org/10.5194/cp-16-2381-2020, https://doi.org/10.5194/cp-16-2381-2020, 2020
Short summary
Short summary
We revisit 15-year-old reconstructions of sea surface temperatures in the Arctic Ocean for the late Paleocene and early Eocene epochs (∼ 57–53 million years ago) based on the distribution of fossil membrane lipids of archaea preserved in Arctic Ocean sediments. We find that improvements in the methods over the past 15 years do not lead to different results. However, data quality is now higher and potential biases better characterized. Results confirm remarkable Arctic warmth during this time.
Marlow Julius Cramwinckel, Lineke Woelders, Emiel P. Huurdeman, Francien Peterse, Stephen J. Gallagher, Jörg Pross, Catherine E. Burgess, Gert-Jan Reichart, Appy Sluijs, and Peter K. Bijl
Clim. Past, 16, 1667–1689, https://doi.org/10.5194/cp-16-1667-2020, https://doi.org/10.5194/cp-16-1667-2020, 2020
Short summary
Short summary
Phases of past transient warming can be used as a test bed to study the environmental response to climate change independent of tectonic change. Using fossil plankton and organic molecules, here we reconstruct surface ocean temperature and circulation in and around the Tasman Gateway during a warming phase 40 million years ago termed the Middle Eocene Climatic Optimum. We find that plankton assemblages track ocean circulation patterns, with superimposed variability being related to temperature.
Emily Dearing Crampton-Flood, Lars J. Noorbergen, Damian Smits, R. Christine Boschman, Timme H. Donders, Dirk K. Munsterman, Johan ten Veen, Francien Peterse, Lucas Lourens, and Jaap S. Sinninghe Damsté
Clim. Past, 16, 523–541, https://doi.org/10.5194/cp-16-523-2020, https://doi.org/10.5194/cp-16-523-2020, 2020
Short summary
Short summary
The mid-Pliocene warm period (mPWP; 3.3–3.0 million years ago) is thought to be the last geological interval with similar atmospheric carbon dioxide concentrations as the present day. Further, the mPWP was 2–3 °C warmer than present, making it a good analogue for estimating the effects of future climate change. Here, we construct a new precise age model for the North Sea during the mPWP, and provide a detailed reconstruction of terrestrial and marine climate using a multi-proxy approach.
Gabriel J. Bowen, Brenden Fischer-Femal, Gert-Jan Reichart, Appy Sluijs, and Caroline H. Lear
Clim. Past, 16, 65–78, https://doi.org/10.5194/cp-16-65-2020, https://doi.org/10.5194/cp-16-65-2020, 2020
Short summary
Short summary
Past climate conditions are reconstructed using indirect and incomplete geological, biological, and geochemical proxy data. We propose that such reconstructions are best obtained by statistical inversion of hierarchical models that represent how multi–proxy observations and calibration data are produced by variation of environmental conditions in time and/or space. These methods extract new information from traditional proxies and provide robust, comprehensive estimates of uncertainty.
Morgan T. Jones, Lawrence M. E. Percival, Ella W. Stokke, Joost Frieling, Tamsin A. Mather, Lars Riber, Brian A. Schubert, Bo Schultz, Christian Tegner, Sverre Planke, and Henrik H. Svensen
Clim. Past, 15, 217–236, https://doi.org/10.5194/cp-15-217-2019, https://doi.org/10.5194/cp-15-217-2019, 2019
Short summary
Short summary
Mercury anomalies in sedimentary rocks are used to assess whether there were periods of elevated volcanism in the geological record. We focus on five sites that cover the Palaeocene–Eocene Thermal Maximum, an extreme global warming event that occurred 55.8 million years ago. We find that sites close to the eruptions from the North Atlantic Igneous Province display significant mercury anomalies across this time interval, suggesting that magmatism played a role in the global warming event.
Anna Joy Drury, Thomas Westerhold, David Hodell, and Ursula Röhl
Clim. Past, 14, 321–338, https://doi.org/10.5194/cp-14-321-2018, https://doi.org/10.5194/cp-14-321-2018, 2018
Short summary
Short summary
North Atlantic Site 982 is key to our understanding of climate evolution over the past 12 million years. However, the stratigraphy and age model are unverified. We verify the composite splice using XRF core scanning data and establish a revised benthic foraminiferal stable isotope astrochronology from 8.0–4.5 million years ago. Our new stratigraphy accurately correlates the Atlantic and the Mediterranean and suggests a connection between late Miocene cooling and dynamic ice sheet expansion.
Paul E. Bachem, Bjørg Risebrobakken, Stijn De Schepper, and Erin L. McClymont
Clim. Past, 13, 1153–1168, https://doi.org/10.5194/cp-13-1153-2017, https://doi.org/10.5194/cp-13-1153-2017, 2017
Short summary
Short summary
We present a high-resolution multi-proxy study of the Norwegian Sea, covering the 5.33 to 3.14 Ma time window within the Pliocene. We show that large-scale climate transitions took place during this warmer than modern time, most likely in response to ocean gateway transformations. Strong warming at 4.0 Ma in the Norwegian Sea, when regions closer to Greenland cooled, indicate that increased northward ocean heat transport may be compatible with expanding glaciation and Arctic sea ice growth.
Harry Dowsett, Aisling Dolan, David Rowley, Robert Moucha, Alessandro M. Forte, Jerry X. Mitrovica, Matthew Pound, Ulrich Salzmann, Marci Robinson, Mark Chandler, Kevin Foley, and Alan Haywood
Clim. Past, 12, 1519–1538, https://doi.org/10.5194/cp-12-1519-2016, https://doi.org/10.5194/cp-12-1519-2016, 2016
Short summary
Short summary
Past intervals in Earth history provide unique windows into conditions much different than those observed today. We investigated the paleoenvironments of a past warm interval (~ 3 million years ago). Our reconstruction includes data sets for surface temperature, vegetation, soils, lakes, ice sheets, topography, and bathymetry. These data are being used along with global climate models to expand our understanding of the climate system and to help us prepare for future changes.
David Evans, Bridget S. Wade, Michael Henehan, Jonathan Erez, and Wolfgang Müller
Clim. Past, 12, 819–835, https://doi.org/10.5194/cp-12-819-2016, https://doi.org/10.5194/cp-12-819-2016, 2016
Short summary
Short summary
We show that seawater pH exerts a substantial control on planktic foraminifera Mg / Ca, a widely applied palaeothermometer. As a result, temperature reconstructions based on this proxy are likely inaccurate over climatic events associated with a significant change in pH. We examine the implications of our findings for hydrological and temperature shifts over the Paleocene-Eocene Thermal Maximum and for the degree of surface ocean precursor cooling before the Eocene-Oligocene transition.
C. J. Hollis, B. R. Hines, K. Littler, V. Villasante-Marcos, D. K. Kulhanek, C. P. Strong, J. C. Zachos, S. M. Eggins, L. Northcote, and A. Phillips
Clim. Past, 11, 1009–1025, https://doi.org/10.5194/cp-11-1009-2015, https://doi.org/10.5194/cp-11-1009-2015, 2015
Short summary
Short summary
Re-examination of a Deep Sea Drilling Project sediment core (DSDP Site 277) from the western Campbell Plateau has identified the initial phase of the Paleocene-Eocene Thermal Maximum (PETM) within nannofossil chalk, the first record of the PETM in an oceanic setting in the southern Pacific Ocean (paleolatitude of ~65°S). Geochemical proxies indicate that intermediate and surface waters warmed by ~6° at the onset of the PETM prior to the full development of the negative δ13C excursion.
E. O. Walliser, B. R. Schöne, T. Tütken, J. Zirkel, K. I. Grimm, and J. Pross
Clim. Past, 11, 653–668, https://doi.org/10.5194/cp-11-653-2015, https://doi.org/10.5194/cp-11-653-2015, 2015
A. M. Snelling, G. E. A. Swann, J. Pike, and M. J. Leng
Clim. Past, 10, 1837–1842, https://doi.org/10.5194/cp-10-1837-2014, https://doi.org/10.5194/cp-10-1837-2014, 2014
K. T. Lawrence, I. Bailey, and M. E. Raymo
Clim. Past, 9, 2391–2397, https://doi.org/10.5194/cp-9-2391-2013, https://doi.org/10.5194/cp-9-2391-2013, 2013
C. F. Dawber and A. K. Tripati
Clim. Past, 8, 1957–1971, https://doi.org/10.5194/cp-8-1957-2012, https://doi.org/10.5194/cp-8-1957-2012, 2012
G. E. A. Swann and S. V. Patwardhan
Clim. Past, 7, 65–74, https://doi.org/10.5194/cp-7-65-2011, https://doi.org/10.5194/cp-7-65-2011, 2011
Cited articles
Abels, H. A., Hilgen, F. J., Krijgsman, W., Kruk, R. W., Raffi, I., Turco,
E., and Zachariasse, W. J.: Long-period orbital control on middle Miocene
global cooling: Integrated stratigraphy and astronomical tuning of the Blue
Clay Formation on Malta, Paleoceanography, 20, PA4012,
https://doi.org/10.1029/2004PA001129, 2005.
Allen, K. A., Hönisch, B., Eggins, S. M., and Rosenthal, Y.:
Environmental controls on B/Ca in calcite tests of the tropical planktic
foraminifer species Globigerinoides ruber and Globigerinoides sacculifer, Earth Planet. Sci. Lett., 35/352,
270–280, https://doi.org/10.1016/j.epsl.2012.07.004, 2012.
Auer, G., Piller, W. E., Reuter, M., and Harzhauser, M.: Correlating carbon
and oxygen isotope events in early to middle Miocene shallow marine
carbonates in the Mediterranean region using orbitally tuned
chemostratigraphy and lithostratigraphy, Paleoceanography, 30, 332–352,
https://doi.org/10.1002/2014PA002716, 2015.
Aziz, H. A., Sanz-Rubio, E., Calvo, J. P., Hilgen, F. J., and Krijgsman, W.:
Palaeoenvironmental reconstruction of a middle Miocene alluvial fan to
cyclic shallow lacustrine depositional system in the Calatayud Basin (NE
Spain), Sedimentology, 50, 211–236,
https://doi.org/10.1046/j.1365-3091.2003.00544.x, 2003.
Badger, M. P. S., Lear, C. H., Pancost, R. D., Foster, G. L., Bailey, T. R.,
Leng, M. J., and Abels, H. A.: CO2 drawdown following the middle Miocene
expansion of the Antarctic Ice Sheet, Paleoceanography, 28, 42–53,
https://doi.org/10.1002/palo.20015, 2013.
Badger, M. P. S., Chalk, T. B., Foster, G. L., Bown, P. R., Gibbs, S. J., Sexton, P. F., Schmidt, D. N., Pälike, H., Mackensen, A., and Pancost, R. D.: Insensitivity of alkenone carbon isotopes to atmospheric CO2 at low to moderate CO2 levels, Clim. Past, 15, 539–554, https://doi.org/10.5194/cp-15-539-2019, 2019.
Barker, S., Greaves, M., and Elderfield, H.: A study of cleaning procedures
used for foraminiferal Mg/Ca paleothermometry, Geochem. Geophy. Geosy.,
4, 8407, https://doi.org/10.1029/2003GC000559, 2003.
Betzler, C., Eberli, G. P., Lüdmann, T., Reolid, J., Kroon, D., Reijmer,
J. J. G., Swart, P. K., Wright, J., Young, J. R., Alvarez-Zarikian, C.,
Alonso-García, M., Bialik, O. M., Blättler, C. L., Guo, J. A.,
Haffen, S., Horozal, S., Inoue, M., Jovane, L., Lanci, L., Laya, J. C., Hui
Mee, A. L., Nakakuni, M., Nath, B. N., Niino, K., Petruny, L. M., Pratiwi,
S. D., Slagle, A. L., Sloss, C. R., Su, X., and Yao, Z.: Refinement of
Miocene sea level and monsoon events from the sedimentary archive of the
Maldives (Indian Ocean), Prog. Earth Planet. Sci., 5, 5,
https://doi.org/10.1186/s40645-018-0165-x, 2018.
Boudreau, B. P. and Luo, Y.: Retrodiction of secular variations in deep-sea
CaCO3 burial during the Cenozoic, Earth Planet. Sci. Lett., 474, 1–12,
https://doi.org/10.1016/j.epsl.2017.06.005, 2017.
Boudreau, B. P., Middelburg, J. J., Sluijs, A., and van der Ploeg, R.:
Secular variations in the carbonate chemistry of the oceans over the
Cenozoic, Earth Planet. Sci. Lett., 512, 194–206,
https://doi.org/10.1016/j.epsl.2019.02.004, 2019.
Brennan, S. T., Lowenstein, T. K., and Cendón, D. I.: The major-ion
composition of Cenozoic seawater: The past 36 million years from fluid
inclusions in marine halite, Am. J. Sci., 313, 713–775,
https://doi.org/10.2475/08.2013.01, 2013.
Caves, J. K., Jost, A. B., Lau, K. V., and Maher, K.: Cenozoic carbon cycle
imbalances and a variable weathering feedback, Earth Planet. Sci. Lett.,
450, 152–163, https://doi.org/10.1016/j.epsl.2016.06.035, 2016.
Clift, P. D. and Plumb, R. A.: The Asian Monsoon: Causes, History and
Effects, Cambridge University Press, Cambridge, UK, 2008.
Coxall, H. K., Wilson, P. A., Pälike, H., Lear, C. H., and Backman, J.:
Rapid stepwise onset of Antarctic glaciation and deeper calcite compensation
in the Pacific Ocean, Nature, 433, 53–57, https://doi.org/10.1038/nature03135,
2005.
Diekmann, B., Falker, M., and Kuhn, G.: Environmental history of the
south-eastern South Atlantic since the Middle Miocene: evidence from the
sedimentological records of ODP Sites 1088 and 1092, Sedimentology, 50,
511–529, https://doi.org/10.1046/j.1365-3091.2003.00562.x, 2003.
Dyez, K. A., Hönisch, B., and Schmidt, G. A.: Early Pleistocene
Obliquity-Scale pCO2 Variability at 1.5 Million Years Ago, Paleocean.
Paleoclimat., 33, 1270–1291, https://doi.org/10.1029/2018PA003349,
2018.
Evans, D. and Müller, W.: Deep time foraminifera Mg/Ca paleothermometry:
Nonlinear correction for secular change in seawater Mg/Ca, Paleoceanography,
27, PA4205, https://doi.org/10.1029/2012PA002315, 2012.
Flower, B. P. and Kennett, J. P.: Middle Miocene ocean-climate transition:
High-resolution oxygen and carbon isotopic records from Deep Sea Drilling
Project Site 588A, southwest Pacific, Paleoceanography, 8, 811–843,
https://doi.org/10.1029/93PA02196, 1993.
Flower, B. P. and Kennett, J. P.: The middle Miocene climatic transition:
East Antarctic ice sheet development, deep ocean circulation and global
carbon cycling, Paleogeogr. Paleoclimatol., 108, 537–555,
https://doi.org/10.1016/0031-0182(94)90251-8, 1994.
Foster, G. L., Lear, C. H., and Rae, J. W. B.: The evolution of pCO2, ice
volume and climate during the middle Miocene, Earth Planet. Sci. Lett.,
344, 243–254, https://doi.org/10.1016/j.epsl.2012.06.007, 2012.
François, R., Altabet, M. A., Yu, E.-F., Sigman, D. M., Bacon, M. P.,
Frank, M., Bohrmann, G., Bareille, G., and Labeyrie, L. D.: Contribution of
Southern Ocean surface-water stratification to low atmospheric CO2
concentrations during the last glacial period, Nature, 389, 929–935,
https://doi.org/10.1038/40073, 1997.
Gaillardet, J., Lemarchand, D., Göpel, C., and Manhès, G.: Evaporation and Sublimation of Boric Acid: Application for Boron Purification from Organic Rich Solutions, Geostand. Newsl., 25, 67–75, https://doi.org/10.1111/j.1751-908X.2001.tb00788.x, 2001.
Goyet, C., Healy, R., Ryan, J., and Kozyr, A.: Global Distribution of Total
Inorganic Carbon and Total Alkalinity below the Deepest Winter Mixed Layer
Depths, ORNL/CDIAC-127, NDP-076, Carbon Dioxide Information Analysis
Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge,
USA, available at:
https://digital.library.unt.edu/ark:/67531/metadc724552/m1/7/ (last access: 18 May 2017), 2000.
Gray, W. R. and Evans, D.: Nonthermal Influences on Mg/Ca in Planktonic
Foraminifera: A Review of Culture Studies and Application to the Last
Glacial Maximum, Paleocean. Paleoclimat., 34, 306–315,
https://doi.org/10.1029/2018PA003517, 2019.
Greenop, R., Foster, G. L., Wilson, P. A., and Lear, C. H.: Middle Miocene
climate instability associated with high-amplitude CO2 variability,
Paleoceanography, 29, 2014PA002653, https://doi.org/10.1002/2014PA002653, 2014.
Greenop, R., Hain, M. P., Sosdian, S. M., Oliver, K. I. C., Goodwin, P., Chalk, T. B., Lear, C. H., Wilson, P. A., and Foster, G. L.: A record of Neogene seawater δ11B reconstructed from paired δ11B analyses on benthic and planktic foraminifera, Clim. Past, 13, 149–170, https://doi.org/10.5194/cp-13-149-2017, 2017.
Greenop, R., Sosdian, S. M., Henehan, M. J., Wilson, P. A., Lear, C. H., and
Foster, G. L.: Orbital Forcing, Ice Volume, and CO2 Across the
Oligocene-Miocene Transition, Paleocean. Paleoclimat., 34, 316–328,
https://doi.org/10.1029/2018PA003420, 2019.
Hain, M. P., Sigman, D. M., Higgins, J. A., and Haug, G. H.: The effects of
secular calcium and magnesium concentration changes on the thermodynamics of
seawater acid/base chemistry: Implications for Eocene and Cretaceous ocean
carbon chemistry and buffering, Global Biogeochem. Cy., 29, 517–533,
https://doi.org/10.1002/2014GB004986, 2015.
Hain, M. P., Sigman, D. M., Higgins, J. A., and Haug, G. H.: Response to
Comment by Zeebe and Tyrrell on “The Effects of Secular Calcium and
Magnesium Concentration Changes on the Thermodynamics of Seawater Acid/Base
Chemistry: Implications for the Eocene and Cretaceous Ocean Carbon Chemistry
and Buffering”, Global Biogeochem. Cy., 32, 898–901,
https://doi.org/10.1002/2018GB005931, 2018.
Henehan, M. J., Foster, G. L., Bostock, H. C., Greenop, R., Marshall, B. J.,
and Wilson, P. A.: A new boron isotope-pH calibration for Orbulina universa, with
implications for understanding and accounting for “vital effects”, Earth
Planet. Sci. Lett., 454, 282–292, https://doi.org/10.1016/j.epsl.2016.09.024, 2016.
Heureux, A. M. C. and Rickaby, R. E. M.: Refining our estimate of
atmospheric CO2 across the Eocene-Oligocene climatic transition, Earth
Planet. Sci. Lett., 409, 329–338, https://doi.org/10.1016/j.epsl.2014.10.036, 2015.
Hodell, D. A. and Woodruff, F.: Variations in the strontium isotopic ratio
of seawater during the Miocene: Stratigraphic and geochemical implications,
Paleoceanography, 9, 405–426, https://doi.org/10.1029/94PA00292,
1994.
Holbourn, A., Kuhnt, W., Simo, J. A., and Li, Q.: Middle Miocene
isotope stratigraphy and paleoceanographic evolution of the northwest and
southwest Australian margins (Wombat Plateau and Great Australian Bight),
Paleogeogr. Paleoclimatol., 208, 1–22,
https://doi.org/10.1016/j.palaeo.2004.02.003, 2004.
Holbourn, A., Kuhnt, W., Schulz, M., and Erlenkeuser, H.: Impacts of orbital
forcing and atmospheric carbon dioxide on Miocene ice-sheet expansion,
Nature, 438, 483–487, https://doi.org/10.1038/nature04123, 2005.
Holbourn, A., Kuhnt, W., Schulz, M., Flores, J.-A., and Andersen, N.:
Orbitally-paced climate evolution during the middle Miocene “Monterey”
carbon-isotope excursion, Earth Planet. Sci. Lett., 261, 534–550,
https://doi.org/10.1016/j.epsl.2007.07.026, 2007.
Holbourn, A., Kuhnt, W., Frank, M., and Haley, B. A.: Changes in Pacific
Ocean circulation following the Miocene onset of permanent Antarctic ice
cover, Earth Planet. Sci. Lett., 365, 38–50,
https://doi.org/10.1016/j.epsl.2013.01.020, 2013.
Holbourn, A., Kuhnt, W., Lyle, M., Schneider, L., Romero, O., and Andersen,
N.: Middle Miocene climate cooling linked to intensification of eastern
equatorial Pacific upwelling, Geology, 42, 19–22, https://doi.org/10.1130/G34890.1,
2014.
Horita, J., Zimmermann, H., and Holland, H. D.: Chemical evolution of
seawater during the Phanerozoic: Implications from the record of marine
evaporites, Geochim. Cosmochim. Ac., 66, 3733–3756,
https://doi.org/10.1016/S0016-7037(01)00884-5, 2002.
Ji, S., Nie, J., Lechler, A., Huntington, K. W., Heitmann, E. O., and
Breecker, D. O.: A symmetrical CO2 peak and asymmetrical climate change
during the middle Miocene, Earth Planet. Sci. Lett., 499, 134–144,
https://doi.org/10.1016/j.epsl.2018.07.011, 2018.
Jonkers, L. and Kučera, M.: Global analysis of seasonality in the shell flux of extant planktonic Foraminifera, Biogeosciences, 12, 2207–2226, https://doi.org/10.5194/bg-12-2207-2015, 2015.
Knorr, G. and Lohmann, G.: Climate warming during Antarctic ice sheet
expansion at the Middle Miocene transition, Nat. Geosci., 7, 376–381,
https://doi.org/10.1038/ngeo2119, 2014.
Kölling, M., Bouimetarhan, I., Bowles, M. W., Felis, T., Goldhammer, T.,
Hinrichs, K.-U., Schulz, M., and Zabel, M.: Consistent CO2 release by
pyrite oxidation on continental shelves prior to glacial terminations,
Nat. Geosci., 12, 929–934, https://doi.org/10.1038/s41561-019-0465-9, 2019.
Kroon, D., Williams, T., Pirmez, C., Spezzaferri, S., Sato, T., and Wright,
J. D.: Coupled early Pliocene-middle Miocene bio-cyclostratigraphy of Site 1006 reveals orbitally induced cyclicity patterns of Great Bahama Bank
carbonate production, Proceedings of the Ocean Drilling Program, 166, 155–166, https://doi.org/10.2973/odp.proc.sr.166.127.2000, 2000.
Kuhnert, H., Bickert, T., and Paulsen, H.: Southern Ocean frontal system
changes precede Antarctic ice sheet growth during the middle Miocene, Earth
Planet. Sci. Lett., 284, 630–638, https://doi.org/10.1016/j.epsl.2009.05.030,
2009.
Kürschner, W. M., Kvaček, Z., and Dilcher, D. L.: The impact of
Miocene atmospheric carbon dioxide fluctuations on climate and the evolution
of terrestrial ecosystems, P. Natl. Acad. Sci., 105, 449–453,
https://doi.org/10.1073/pnas.0708588105, 2008.
Laskar, J., Robutel, P., Joutel, F., Gastineau, M., Correia, A. C. M., and
Levrard, B.: A long-term numerical solution for the insolation quantities of
the Earth, Astron. Astrophys., 428, 25, https://doi.org/10.1051/0004-6361:20041335,
2004.
Lavigne, H., Epitalon, J.-M., and Gattuso, J.-P.: seacarb: seawater carbonate
chemistry with R., available at:
http://CRAN.R-project.org/package=seacarb (last access: 30 October 2020), 2011.
Lear, C. H., Rosenthal, Y., Coxall, H. K., and Wilson, P. A.: Late Eocene to
early Miocene ice sheet dynamics and the global carbon cycle,
Paleoceanography, 19, PA4015, https://doi.org/10.1029/2004PA001039, 2004.
Lear, C. H., Mawbey, E. M., and Rosenthal, Y.: Cenozoic benthic foraminiferal
Mg/Ca and Li/Ca records: Toward unlocking temperatures and saturation
states, Paleoceanography, 25, PA4215, https://doi.org/10.1029/2009PA001880, 2010.
Lemarchand, D., Gaillardet, J., Lewin, É., and Allègre, C. J.: The
influence of rivers on marine boron isotopes and implications for
reconstructing past ocean pH, Nature, 408, 951–954, https://doi.org/10.1038/35050058,
2000.
Leutert, T. J., Auderset, A., Martínez-García, A., Modestou, S.,
and Meckler, A. N.: Coupled Southern Ocean cooling and Antarctic ice sheet
expansion during the middle Miocene, Nat. Geosci., 13, 634–639,
https://doi.org/10.1038/s41561-020-0623-0, 2020.
Lowenstein, T. K., Hardie, L. A., Timofeeff, M. N., and Demicco, R. V.:
Secular variation in seawater chemistry and the origin of calcium chloride
basinal brines, Geology, 31, 857–860, https://doi.org/10.1130/G19728R.1, 2003.
Ma, W., Tian, J., Li, Q., and Wang, P.: Simulation of long eccentricity
(400-kyr) cycle in ocean carbon reservoir during Miocene Climate Optimum:
Weathering and nutrient response to orbital change, Geophys. Res. Lett.,
38, L10701, https://doi.org/10.1029/2011GL047680, 2011.
Ma, X., Tian, J., Ma, W., Li, K., and Yu, J.: Changes of deep Pacific
overturning circulation and carbonate chemistry during middle Miocene East
Antarctic ice sheet expansion, Earth Planet. Sci. Lett., 484, 253–263,
https://doi.org/10.1016/j.epsl.2017.12.002, 2018.
Martínez-Botí, M. A., Marino, G., Foster, G. L., Ziveri, P.,
Henehan, M. J., Rae, J. W. B., Mortyn, P. G., and Vance, D.: Boron isotope
evidence for oceanic carbon dioxide leakage during the last deglaciation,
Nature, 518, 219–222, https://doi.org/10.1038/nature14155, 2015.
Mashiotta, T. A., Lea, D. W., and Spero, H. J.: Glacial-interglacial changes
in Subantarctic sea surface temperature and δ18O-water using
foraminiferal Mg, Earth Planet. Sci Lett., 170, 417–432,
https://doi.org/10.1016/S0012-821X(99)00116-8, 1999.
McKay, D. I. A., Tyrrell, T., and Wilson, P. A.: Global carbon cycle
perturbation across the Eocene-Oligocene climate transition,
Paleoceanography, 31, 311–329, https://doi.org/10.1002/2015PA002818, 2016.
Misra, S., Owen, R., Kerr, J., Greaves, M., and Elderfield, H.: Determination
of δ11B by HR-ICP-MS from mass limited samples: Application to
natural carbonates and water samples, Geochim. Cosmochim. Ac., 140,
531–552, https://doi.org/10.1016/j.gca.2014.05.047, 2014.
Mortyn, P. G. and Charles, C. D.: Planktonic foraminiferal depth habitat and
δ18O calibrations: Plankton tow results from the Atlantic
sector of the Southern Ocean, Paleoceanography, 18, 1037,
https://doi.org/10.1029/2001PA000637, 2003.
Myers, S. R.: Astrochron: An R Package for Astrochronology, available at: https://cran.r-project.org/package=astrochron (last access: 8 January 2019), 2014.
Ohneiser, C. and Wilson, G. S.: Eccentricity-Paced Southern Hemisphere
Glacial-Interglacial Cyclicity Preceding the Middle Miocene Climatic
Transition, Paleocean. Paleoclimat., 33, https://doi.org/10.1029/2017PA003278, 2018.
Pagani, M., Freeman, K. H., and Arthur, M. A.: Late Miocene Atmospheric
CO2 Concentrations and the Expansion of C4 Grasses, Science, 285,
876–879, https://doi.org/10.1126/science.285.5429.876, 1999.
Paillard, D. and Donnadieu, Y.: A 100 Myr history of the carbon cycle based
on the 400 kyr cycle in marine δ13C benthic records,
Paleoceanography, 29, 1249–1255,
https://doi.org/10.1002/2014PA002693, 2014.
Paulsen, H.: Miocene changes in the vertical structure of the Southeast
Atlantic near-surface water column: Influence on the paleoproductivity, PhD
thesis, Universität Bremen, FB Geowissenschaften, Bremen, Germany, available at: https://media.suub.uni-bremen.de/handle/elib/2188 (last access: 24 November 2020), 2005.
Pearson, P. N. and Palmer, M. R.: Atmospheric carbon dioxide concentrations
over the past 60 million years, Nature, 406, 695–699, https://doi.org/10.1038/35021000,
2000.
Pearson, P. N., Foster, G. L., and Wade, B. S.: Atmospheric carbon dioxide
through the Eocene-Oligocene climate transition, Nature, 461,
1110–1113, https://doi.org/10.1038/nature08447, 2009.
Rae, J. W. B., Foster, G. L., Schmidt, D. N., and Elliott, T.: Boron isotopes
and B/Ca in benthic foraminifera: Proxies for the deep ocean carbonate
system, Earth Planet. Sci. Lett., 302, 403–413,
https://doi.org/10.1016/j.epsl.2010.12.034, 2011.
Raitzsch, M. and Hönisch, B.: Cenozoic boron isotope variations in
benthic foraminifers, Geology, 41, 591–594,
https://doi.org/10.1130/G34031.1, 2013.
Raitzsch, M., Kuhnert, H., Groeneveld, J., and Bickert, T.: Benthic
foraminifer Mg/Ca anomalies in South Atlantic core top sediments and their
implications for paleothermometry, Geochem. Geophy. Geosy., 9, Q05010,
https://doi.org/10.1029/2007GC001788, 2008.
Raitzsch, M., Bijma, J., Benthien, A., Richter, K.-U., Steinhoefel, G., and
Kučera, M.: Boron isotope-based seasonal paleo-pH reconstruction for the
Southeast Atlantic – A multispecies approach using habitat preference of
planktonic foraminifera, Earth Planet. Sci. Lett., 487, 138–150,
https://doi.org/10.1016/j.epsl.2018.02.002, 2018.
Raitzsch, M., Rollion-Bard, C., Horn, I., Steinhoefel, G., Benthien, A., Richter, K.-U., Buisson, M., Louvat, P., and Bijma, J.: Technical note: Single-shell δ11B analysis of Cibicidoides wuellerstorfi using femtosecond laser ablation MC-ICPMS and secondary ion mass spectrometry, Biogeosciences, 17, 5365–5375, https://doi.org/10.5194/bg-17-5365-2020, 2020.
Reolid, J., Betzler, C., and Lüdmann, T.: The record of Oligocene –
Middle Miocene paleoenvironmental changes in a carbonate platform (IODP Exp.
359, Maldives, Indian Ocean), Mar. Geol., 412, 199–216,
https://doi.org/10.1016/j.margeo.2019.03.011, 2019.
Reuning, L., Reijmer, J. J. G., and Betzler, C.: Sedimentation cycles and
their diagenesis on the slope of a Miocene carbonate ramp (Bahamas, ODP Leg
166), Mar. Geol., 185, 121–142, https://doi.org/10.1016/S0025-3227(01)00293-6, 2002.
Ridgwell, A.: A Mid Mesozoic Revolution in the regulation of ocean
chemistry, Mar. Geol., 217, 339–357, https://doi.org/10.1016/j.margeo.2004.10.036,
2005.
Shackleton, N. J.: Attainment of isotopic equilibrium between ocean water
and the benthonic foraminifera genus Uvigerina: isotopic changes in the ocean during
the last glacial, Cent. Nat. Rech. Sci. Colloq. Int., 219, 203–209, 1974.
Shevenell, A. E. and Kennett, J. P.: Paleoceanographic Change During the
Middle Miocene Climate Revolution: An Antarctic Stable Isotope Perspective,
in: The Cenozoic Southern Ocean: Tectonics, Sedimentation, and Climate Change
Between Australia and Antarctica, American Geophysical Union, Washington, DC, USA,
235–251, 2004.
Shevenell, A. E., Kennett, J. P., and Lea, D. W.: Middle Miocene Southern
Ocean Cooling and Antarctic Cryosphere Expansion, Science, 305, 1766–1770,
https://doi.org/10.1126/science.1100061, 2004.
Shevenell, A. E., Kennett, J. P., and Lea, D. W.: Middle Miocene ice sheet
dynamics, deep-sea temperatures, and carbon cycling: A Southern Ocean
perspective, Geochem. Geophy. Geosy., 9, Q02006,
https://doi.org/10.1029/2007GC001736, 2008.
Sosdian, S. M. and Lear, C. H.: Initiation of the Western Pacific Warm Pool
at the Middle Miocene Climate Transition?, Paleocean. Paleoclimat., 35,
e2020PA003920, https://doi.org/10.1029/2020PA003920, 2020.
Sosdian, S. M., Greenop, R., Hain, M. P., Foster, G. L., Pearson, P. N., and
Lear, C. H.: Constraining the evolution of Neogene ocean carbonate chemistry
using the boron isotope pH proxy, Earth Planet. Sci. Lett., 498, 362–376,
https://doi.org/10.1016/j.epsl.2018.06.017, 2018.
Sosdian, S. M., Babila, T. L., Greenop, R., Foster, G. L., and Lear, C. H.:
Ocean Carbon Storage across the middle Miocene: a new interpretation for the
Monterey Event, Nat. Commun., 11, 1–11, https://doi.org/10.1038/s41467-019-13792-0,
2020.
Stoll, H. M., Guitian, J., Hernandez-Almeida, I., Mejia, L. M., Phelps, S.,
Polissar, P., Rosenthal, Y., Zhang, H., and Ziveri, P.: Upregulation of
phytoplankton carbon concentrating mechanisms during low CO2 glacial
periods and implications for the phytoplankton pCO2 proxy, Quat. Sci.
Rev., 208, 1–20, https://doi.org/10.1016/j.quascirev.2019.01.012, 2019.
Super, J. R., Thomas, E., Pagani, M., Huber, M., O'Brien, C., and Hull, P.
M.: North Atlantic temperature and pCO2 coupling in the early-middle
Miocene, Geology, 46, 519–522, https://doi.org/10.1130/G40228.1, 2018.
Takahashi, T., Olafsson, J., Goddard, J. G., Chipman, D. W., and Sutherland,
S. C.: Seasonal variation of CO2 and nutrients in the high-latitude
surface oceans: A comparative study, Global Biogeochem. Cy., 7, 843–878,
https://doi.org/10.1029/93GB02263, 1993.
Takahashi, T., Sutherland, S. C., Wanninkhof, R., Sweeney, C., Feely, R. A.,
Chipman, D. W., Hales, B., Friederich, G., Chavez, F., Sabine, C., Watson,
A., Bakker, D. C. E., Schuster, U., Metzl, N., Yoshikawa-Inoue, H., Ishii,
M., Midorikawa, T., Nojiri, Y., Körtzinger, A., Steinhoff, T., Hoppema,
M., Olafsson, J., Arnarson, T. S., Tilbrook, B., Johannessen, T., Olsen, A.,
Bellerby, R., Wong, C. S., Delille, B., Bates, N. R., and de Baar, H. J. W.:
Climatological mean and decadal change in surface ocean pCO2, and net
sea-air CO2 flux over the global oceans, Deep-Sea Res., 56,
554–577, https://doi.org/10.1016/j.dsr2.2008.12.009, 2009.
Tian, J., Shevenell, A., Wang, P., Zhao, Q., Li, Q., and Cheng, X.:
Reorganization of Pacific Deep Waters linked to middle Miocene Antarctic
cryosphere expansion: A perspective from the South China Sea, Paleogeogr.
Paleoclimatol., 284, 375–382,
https://doi.org/10.1016/j.palaeo.2009.10.019, 2009.
Timofeeff, M. N., Lowenstein, T. K., da Silva, M. A. M., and Harris, N. B.:
Secular variation in the major-ion chemistry of seawater: Evidence from
fluid inclusions in Cretaceous halites, Geochim. Cosmochim. Ac., 70,
1977–1994, https://doi.org/10.1016/j.gca.2006.01.020, 2006.
Toggweiler, J. R.: Origin of the 100 000-year timescale in Antarctic
temperatures and atmospheric CO2, Paleoceanography, 23, PA2211,
https://doi.org/10.1029/2006PA001405, 2008.
Tyrrell, T. and Zeebe, R. E.: History of carbonate ion concentration over
the last 100 million years, Geochim. Cosmochim. Ac., 68, 3521–3530,
https://doi.org/10.1016/j.gca.2004.02.018, 2004.
van der Ploeg, R., Boudreau, B. P., Middelburg, J. J., and Sluijs, A.:
Cenozoic carbonate burial along continental margins, Geology, 47,
1025–1028, https://doi.org/10.1130/G46418.1, 2019.
Vincent, E. and Berger, W. H.: Carbon dioxide and polar cooling in the
Miocene: the Monterey hypothesis, in: The Carbon Cycle and Atmospheric
CO2: Natural Variations Archean to Present, edited by: Sundquist, E. T. and Broecker, W. S., American
Geophysical Union, Washington, USA,
455–468,
https://doi.org/10.1029/GM032p0455, 1985.
Wan, S., Kürschner, W. M., Clift, P. D., Li, A., and Li, T.: Extreme
weathering/erosion during the Miocene Climatic Optimum: Evidence from
sediment record in the South China Sea, Geophys. Res. Lett., 36, L19706,
https://doi.org/10.1029/2009GL040279, 2009.
Wang, B.-S., You, C.-F., Huang, K.-F., Wu, S.-F., Aggarwal, S. K., Chung,
C.-H., and Lin, P.-Y.: Direct separation of boron from Na- and Ca-rich
matrices by sublimation for stable isotope measurement by MC-ICP-MS,
Talanta, 82, 1378–1384, https://doi.org/10.1016/j.talanta.2010.07.010, 2010.
Wang, P.: Global monsoon in a geological perspective, Chin. Sci. Bull.,
54, 1113–1136, https://doi.org/10.1007/s11434-009-0169-4, 2009.
Williams, T., Kroon, D., and Spezzaferri, S.: Middle and Upper Miocene
cyclostratigraphy of downhole logs and short- to long-term astronomical
cycles in carbonate production of the Great Bahama Bank, Mar. Geol., 185,
75–93, https://doi.org/10.1016/S0025-3227(01)00291-2, 2002.
Woodruff, F. and Savin, S.: Mid-Miocene isotope stratigraphy in the deep
sea: high resolution correlations, paleoclimatic cycles, and sediment
preservation, Paleoceanography, 6, 755–806,
https://doi.org/10.1029/91PA02561, 1991.
Wright, J. D., Miller, K. G., and Fairbanks, R. G.: Early and Middle Miocene
stable isotopes: Implications for Deepwater circulation and climate,
Paleoceanography, 7, 357–389, https://doi.org/10.1029/92PA00760, 1992.
Zeebe, R. E. and Tyrrell, T.: History of carbonate ion concentration over
the last 100 million years II: Revised calculations and new data, Geochim.
Cosmochim. Ac., 257, 373–392, https://doi.org/10.1016/j.gca.2019.02.041, 2019.
Zeebe, R. E. and Wolf-Gladrow, D. A.: CO2 in Seawater: Equilibrium,
Kinetics, Isotopes, Elsevier Oceanography Series, Amsterdam, the Netherlands, 2001.
Short summary
At approximately 14 Ma, the East Antarctic Ice Sheet expanded to almost its current extent, but the role of CO2 in this major climate transition is not entirely known. We show that atmospheric CO2 might have varied on 400 kyr cycles linked to the eccentricity of the Earth’s orbit. The resulting change in weathering and ocean carbon cycle affected atmospheric CO2 in a way that CO2 rose after Antarctica glaciated, helping to stabilize the climate system on its way to the “ice-house” world.
At approximately 14 Ma, the East Antarctic Ice Sheet expanded to almost its current extent, but...