Articles | Volume 12, issue 6
https://doi.org/10.5194/cp-12-1281-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/cp-12-1281-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
02 Jun 2016
Research article |
| 02 Jun 2016
Last Glacial Maximum and deglacial abyssal seawater oxygen isotopic ratios
Department of Earth and Planetary Sciences, Harvard University, Cambridge, USA
also at: Department of Earth, Atmospheric and Planetary Sciences, MIT, Cambridge, USA
Related authors
Carl Wunsch, Sarah Williamson, and Patrick Heimbach
Ocean Sci., 19, 1253–1275, https://doi.org/10.5194/os-19-1253-2023, https://doi.org/10.5194/os-19-1253-2023, 2023
Short summary
Short summary
Data assimilation methods that couple observations with dynamical models are essential for understanding climate change. Here,
climateincludes all sub-elements (ocean, atmosphere, ice, etc.). A common form of combination arises from sequential estimation theory, a methodology susceptible to a variety of errors that can accumulate through time for long records. Using two simple analogs, examples of these errors are identified and discussed, along with suggestions for accommodating them.
Carl Wunsch
Ocean Sci. Discuss., https://doi.org/10.5194/os-2021-113, https://doi.org/10.5194/os-2021-113, 2021
Preprint withdrawn
Short summary
Short summary
Combinations of observations with dynamical, chemical, etc, models are essential tools for understanding of climate change. By "climate" is meant all of the sub-elements including ocean, atmosphere, ice, et al. A common form of combination arises from sequential estimation theory, a methodology susceptible to a variety of errors that can accumulate through time for long records. Using two simple analogues, many of these errors are identified here, with suggestions for accommodating them.
G. Forget, J.-M. Campin, P. Heimbach, C. N. Hill, R. M. Ponte, and C. Wunsch
Geosci. Model Dev., 8, 3071–3104, https://doi.org/10.5194/gmd-8-3071-2015, https://doi.org/10.5194/gmd-8-3071-2015, 2015
Short summary
Short summary
The ECCO v4 non-linear inverse modeling framework and its reference solution are made publicly available. The inverse estimate of ocean physics and atmospheric forcing yields a dynamically consistent and global state estimate without unidentified sources of heat and salt that closely fits in situ and satellite data. Any user can reproduce it accurately. Parametric and external model uncertainties are of comparable magnitudes and generally exceed structural model uncertainties.
Carl Wunsch, Sarah Williamson, and Patrick Heimbach
Ocean Sci., 19, 1253–1275, https://doi.org/10.5194/os-19-1253-2023, https://doi.org/10.5194/os-19-1253-2023, 2023
Short summary
Short summary
Data assimilation methods that couple observations with dynamical models are essential for understanding climate change. Here,
climateincludes all sub-elements (ocean, atmosphere, ice, etc.). A common form of combination arises from sequential estimation theory, a methodology susceptible to a variety of errors that can accumulate through time for long records. Using two simple analogs, examples of these errors are identified and discussed, along with suggestions for accommodating them.
Carl Wunsch
Ocean Sci. Discuss., https://doi.org/10.5194/os-2021-113, https://doi.org/10.5194/os-2021-113, 2021
Preprint withdrawn
Short summary
Short summary
Combinations of observations with dynamical, chemical, etc, models are essential tools for understanding of climate change. By "climate" is meant all of the sub-elements including ocean, atmosphere, ice, et al. A common form of combination arises from sequential estimation theory, a methodology susceptible to a variety of errors that can accumulate through time for long records. Using two simple analogues, many of these errors are identified here, with suggestions for accommodating them.
G. Forget, J.-M. Campin, P. Heimbach, C. N. Hill, R. M. Ponte, and C. Wunsch
Geosci. Model Dev., 8, 3071–3104, https://doi.org/10.5194/gmd-8-3071-2015, https://doi.org/10.5194/gmd-8-3071-2015, 2015
Short summary
Short summary
The ECCO v4 non-linear inverse modeling framework and its reference solution are made publicly available. The inverse estimate of ocean physics and atmospheric forcing yields a dynamically consistent and global state estimate without unidentified sources of heat and salt that closely fits in situ and satellite data. Any user can reproduce it accurately. Parametric and external model uncertainties are of comparable magnitudes and generally exceed structural model uncertainties.
Related subject area
Subject: Ocean Dynamics | Archive: Marine Archives | Timescale: Pleistocene
Sea-level and monsoonal control on the Maldives carbonate platform (Indian Ocean) over the last 1.3 million years
Planktonic foraminiferal assemblages as tracers of paleoceanographic changes within the Northern Benguela current system since the Early Pleistocene
Changes in the Red Sea overturning circulation during Marine Isotope Stage 3
Glacial-interglacial Circumpolar Deep Water temperatures during the last 800,000 years: estimates from a synthesis of bottom water temperature reconstructions
Bottom water oxygenation changes in the southwestern Indian Ocean as an indicator for enhanced respired carbon storage since the last glacial inception
An Intertropical Convergence Zone shift controlled the terrestrial material supply on the Ninetyeast Ridge
Sea ice changes in the southwest Pacific sector of the Southern Ocean during the last 140 000 years
Summer sea-ice variability on the Antarctic margin during the last glacial period reconstructed from snow petrel (Pagodroma nivea) stomach-oil deposits
Variations in export production, lithogenic sediment transport and iron fertilization in the Pacific sector of the Drake Passage over the past 400 kyr
Lower oceanic δ13C during the last interglacial period compared to the Holocene
Change in the North Atlantic circulation associated with the mid-Pleistocene transition
Thermocline state change in the eastern equatorial Pacific during the late Pliocene/early Pleistocene intensification of Northern Hemisphere glaciation
A multi-proxy analysis of Late Quaternary ocean and climate variability for the Maldives, Inner Sea
Central Arctic Ocean paleoceanography from ∼ 50 ka to present, on the basis of ostracode faunal assemblages from the SWERUS 2014 expedition
Deglacial sea level history of the East Siberian Sea and Chukchi Sea margins
Mediterranean Outflow Water variability during the Early Pleistocene
Subsurface North Atlantic warming as a trigger of rapid cooling events: evidence from the early Pleistocene (MIS 31–19)
Photic zone changes in the north-west Pacific Ocean from MIS 4–5e
Seasonal changes in glacial polynya activity inferred from Weddell Sea varves
High-latitude obliquity as a dominant forcing in the Agulhas current system
Sensitivity of Red Sea circulation to sea level and insolation forcing during the last interglacial
Sea-surface salinity variations in the northern Caribbean Sea across the Mid-Pleistocene Transition
Oceanic tracer and proxy time scales revisited
Variations in mid-latitude North Atlantic surface water properties during the mid-Brunhes (MIS 9–14) and their implications for the thermohaline circulation
A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic δ13C gradient
High Arabian Sea productivity conditions during MIS 13 – odd monsoon event or intensified overturning circulation at the end of the Mid-Pleistocene transition?
Montserrat Alonso-Garcia, Jesus Reolid, Francisco J. Jimenez-Espejo, Or M. Bialik, Carlos A. Alvarez Zarikian, Juan Carlos Laya, Igor Carrasquiera, Luigi Jovane, John J. G. Reijmer, Gregor P. Eberli, and Christian Betzler
Clim. Past, 20, 547–571, https://doi.org/10.5194/cp-20-547-2024, https://doi.org/10.5194/cp-20-547-2024, 2024
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The Maldives Inner Sea (northern Indian Ocean) offers an excellent study site to explore the impact of climate and sea-level changes on carbonate platforms. The sediments from International Ocean Discovery Program (IODP) Site U1467 have been studied to determine the drivers of carbonate production in the atolls over the last 1.3 million years. Even though sea level is important, the intensity of the summer monsoon and the Indian Ocean dipole probably modulated the production at the atolls.
Arianna Valentina Del Gaudio, Aaron Avery, Gerald Auer, Werner Erwin Piller, and Walter Kurz
Clim. Past Discuss., https://doi.org/10.5194/cp-2024-16, https://doi.org/10.5194/cp-2024-16, 2024
Revised manuscript accepted for CP
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The Benguela Upwelling System is a region in the SE Atlantic Ocean of high biological productivity. It comprises several water masses such as the Benguela Current, the South Atlantic Central Water and the Indian Ocean Agulhas waters. We analyzed planktonic foraminifera from IODP Sites U1575-U1576 to characterize the water masses and their interplay in the Pleistocene. This defined changes in the local thermocline, which were linked to long-term Benguela Niño/Niña-like and deglaciation events.
Raphaël Hubert-Huard, Nils Andersen, Helge W. Arz, Werner Ehrmann, and Gerhard Schmiedl
Clim. Past, 20, 267–280, https://doi.org/10.5194/cp-20-267-2024, https://doi.org/10.5194/cp-20-267-2024, 2024
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We have studied the geochemistry of benthic foraminifera (micro-fossils) from a sediment core from the Red Sea. Our data show that the circulation and carbon cycling of the Red Sea during the last glacial period responded to high-latitude millennial-scale climate variability and to the orbital influence of the African–Indian monsoon system. This implies a sensitive response of the Red Sea to climate changes.
David M. Chandler and Petra M. Langebroek
EGUsphere, https://doi.org/10.5194/egusphere-2023-850, https://doi.org/10.5194/egusphere-2023-850, 2023
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Sea-level rise and global climate change caused by ice melt in Antarctica is a puzzle of feedbacks between the climate, ocean and ice sheets, over tens to thousands of years. Antarctic Ice Sheet melting is caused mainly by warm deep water from the Southern Ocean. Here, we analyse close relationships between deep water temperatures and global climate in the last 800,000 years. This knowledge can help us to better understanding how climate and sea-level are likely to change in the future.
Helen Eri Amsler, Lena Mareike Thöle, Ingrid Stimac, Walter Geibert, Minoru Ikehara, Gerhard Kuhn, Oliver Esper, and Samuel Laurent Jaccard
Clim. Past, 18, 1797–1813, https://doi.org/10.5194/cp-18-1797-2022, https://doi.org/10.5194/cp-18-1797-2022, 2022
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We present sedimentary redox-sensitive trace metal records from five sediment cores retrieved from the SW Indian Ocean. These records are indicative of oxygen-depleted conditions during cold periods and enhanced oxygenation during interstadials. Our results thus suggest that deep-ocean oxygenation changes were mainly controlled by ocean ventilation and that a generally more sluggish circulation contributed to sequestering remineralized carbon away from the atmosphere during glacial periods.
Xudong Xu, Jianguo Liu, Yun Huang, Lanlan Zhang, Liang Yi, Shengfa Liu, Yiping Yang, Li Cao, and Long Tan
Clim. Past, 18, 1369–1384, https://doi.org/10.5194/cp-18-1369-2022, https://doi.org/10.5194/cp-18-1369-2022, 2022
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Terrestrial materials in marine environments record source information and help us understand how climate and ocean impact sediment compositions. Here, we use evidence on the Ninetyeast Ridge to analyze the relationship between terrestrial material supplementation and climatic change. We find that the ITCZ controlled the rainfall in the Burman source area and that closer connections occurred between the Northern–Southern Hemisphere in the eastern Indian Ocean during the late LGM.
Jacob Jones, Karen E. Kohfeld, Helen Bostock, Xavier Crosta, Melanie Liston, Gavin Dunbar, Zanna Chase, Amy Leventer, Harris Anderson, and Geraldine Jacobsen
Clim. Past, 18, 465–483, https://doi.org/10.5194/cp-18-465-2022, https://doi.org/10.5194/cp-18-465-2022, 2022
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We provide new winter sea ice and summer sea surface temperature estimates for marine core TAN1302-96 (59° S, 157° E) in the Southern Ocean. We find that sea ice was not consolidated over the core site until ~65 ka and therefore believe that sea ice may not have been a major contributor to early glacial CO2 drawdown. Sea ice does appear to have coincided with Antarctic Intermediate Water production and subduction, suggesting it may have influenced intermediate ocean circulation changes.
Erin L. McClymont, Michael J. Bentley, Dominic A. Hodgson, Charlotte L. Spencer-Jones, Thomas Wardley, Martin D. West, Ian W. Croudace, Sonja Berg, Darren R. Gröcke, Gerhard Kuhn, Stewart S. R. Jamieson, Louise Sime, and Richard A. Phillips
Clim. Past, 18, 381–403, https://doi.org/10.5194/cp-18-381-2022, https://doi.org/10.5194/cp-18-381-2022, 2022
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Sea ice is important for our climate system and for the unique ecosystems it supports. We present a novel way to understand past Antarctic sea-ice ecosystems: using the regurgitated stomach contents of snow petrels, which nest above the ice sheet but feed in the sea ice. During a time when sea ice was more extensive than today (24 000–30 000 years ago), we show that snow petrel diet had varying contributions of fish and krill, which we interpret to show changing sea-ice distribution.
María H. Toyos, Gisela Winckler, Helge W. Arz, Lester Lembke-Jene, Carina B. Lange, Gerhard Kuhn, and Frank Lamy
Clim. Past, 18, 147–166, https://doi.org/10.5194/cp-18-147-2022, https://doi.org/10.5194/cp-18-147-2022, 2022
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Past export production in the southeast Pacific and its link to Patagonian ice dynamics is unknown. We reconstruct biological productivity changes at the Pacific entrance to the Drake Passage, covering the past 400 000 years. We show that glacial–interglacial variability in export production responds to glaciogenic Fe supply from Patagonia and silica availability due to shifts in oceanic fronts, whereas dust, as a source of lithogenic material, plays a minor role.
Shannon A. Bengtson, Laurie C. Menviel, Katrin J. Meissner, Lise Missiaen, Carlye D. Peterson, Lorraine E. Lisiecki, and Fortunat Joos
Clim. Past, 17, 507–528, https://doi.org/10.5194/cp-17-507-2021, https://doi.org/10.5194/cp-17-507-2021, 2021
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The last interglacial was a warm period that may provide insights into future climates. Here, we compile and analyse stable carbon isotope data from the ocean during the last interglacial and compare it to the Holocene. The data show that Atlantic Ocean circulation was similar during the last interglacial and the Holocene. We also establish a difference in the mean oceanic carbon isotopic ratio between these periods, which was most likely caused by burial and weathering carbon fluxes.
Gloria M. Martin-Garcia, Francisco J. Sierro, José A. Flores, and Fátima Abrantes
Clim. Past, 14, 1639–1651, https://doi.org/10.5194/cp-14-1639-2018, https://doi.org/10.5194/cp-14-1639-2018, 2018
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This work documents major oceanographic changes that occurred in the N. Atlantic from 812 to 530 ka and were related to the mid-Pleistocene transition. Since ~ 650 ka, glacials were more prolonged and intense than before. Larger ice sheets may have worked as a positive feedback mechanism to prolong the duration of glacials. We explore the connection between the change in the N. Atlantic oceanography and the enhanced ice-sheet growth, which contributed to the change of cyclicity in climate.
Kim Alix Jakob, Jörg Pross, Christian Scholz, Jens Fiebig, and Oliver Friedrich
Clim. Past, 14, 1079–1095, https://doi.org/10.5194/cp-14-1079-2018, https://doi.org/10.5194/cp-14-1079-2018, 2018
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Eastern equatorial Pacific (EEP) thermocline dynamics during the intensification of Northern Hemisphere glaciation (iNHG; ~ 2.5 Ma) currently remain unclear. In light of this uncertainty, we generated geochemical, faunal and sedimentological data for EEP Site 849 (~ 2.75–2.4 Ma). We recorded a thermocline depth change shortly before the final phase of the iNHG, which supports the hypothesis that tropical thermocline shoaling may have contributed to substantial Northern Hemisphere ice growth.
Dorothea Bunzel, Gerhard Schmiedl, Sebastian Lindhorst, Andreas Mackensen, Jesús Reolid, Sarah Romahn, and Christian Betzler
Clim. Past, 13, 1791–1813, https://doi.org/10.5194/cp-13-1791-2017, https://doi.org/10.5194/cp-13-1791-2017, 2017
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We investigated a sediment core from the Maldives to unravel the interaction between equatorial climate and ocean variability of the past 200 000 years. The sedimentological, geochemical and foraminiferal data records reveal enhanced dust, which was transported by intensified winter monsoon winds during glacial conditions. Precessional fluctuations of bottom water oxygen suggests an expansion of the Arabian Sea OMZ and a varying inflow of Antarctic Intermediate Water.
Laura Gemery, Thomas M. Cronin, Robert K. Poirier, Christof Pearce, Natalia Barrientos, Matt O'Regan, Carina Johansson, Andrey Koshurnikov, and Martin Jakobsson
Clim. Past, 13, 1473–1489, https://doi.org/10.5194/cp-13-1473-2017, https://doi.org/10.5194/cp-13-1473-2017, 2017
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Continuous, highly abundant and well-preserved fossil ostracodes were studied from radiocarbon-dated sediment cores collected on the Lomonosov Ridge (Arctic Ocean) that indicate varying oceanographic conditions during the last ~50 kyr. Ostracode assemblages from cores taken during the SWERUS-C3 2014 Expedition, Leg 2, reflect paleoenvironmental changes during glacial, deglacial, and interglacial transitions, including changes in sea-ice cover and Atlantic Water inflow into the Eurasian Basin.
Thomas M. Cronin, Matt O'Regan, Christof Pearce, Laura Gemery, Michael Toomey, Igor Semiletov, and Martin Jakobsson
Clim. Past, 13, 1097–1110, https://doi.org/10.5194/cp-13-1097-2017, https://doi.org/10.5194/cp-13-1097-2017, 2017
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Global sea level rise during the last deglacial flooded the Siberian continental shelf in the Arctic Ocean. Sediment cores, radiocarbon dating, and microfossils show that the regional sea level in the Arctic rose rapidly from about 12 500 to 10 700 years ago. Regional sea level history on the Siberian shelf differs from the global deglacial sea level rise perhaps due to regional vertical adjustment resulting from the growth and decay of ice sheets.
Stefanie Kaboth, Patrick Grunert, and Lucas Lourens
Clim. Past, 13, 1023–1035, https://doi.org/10.5194/cp-13-1023-2017, https://doi.org/10.5194/cp-13-1023-2017, 2017
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This study is devoted to reconstructing Mediterranean Outflow Water (MOW) variability and the interplay between the Mediterranean and North Atlantic climate systems during the Early Pleistocene. We find indication that the increasing production of MOW aligns with the intensification of the North Atlantic overturning circulation, highlighting the potential of MOW to modulate the North Atlantic salt budget. Our results are based on new stable isotope and grain-size data from IODP 339 Site U1389.
I. Hernández-Almeida, F.-J. Sierro, I. Cacho, and J.-A. Flores
Clim. Past, 11, 687–696, https://doi.org/10.5194/cp-11-687-2015, https://doi.org/10.5194/cp-11-687-2015, 2015
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This manuscript presents new Mg/Ca and previously published δ18O measurements of Neogloboquadrina pachyderma sinistral for MIS 31-19, from a sediment core from the subpolar North Atlantic. The mechanism proposed here involves northward subsurface transport of warm and salty subtropical waters during periods of weaker AMOC, leading to ice-sheet instability and IRD discharge. This is the first time that these rapid climate oscillations are described for the early Pleistocene.
G. E. A. Swann and A. M. Snelling
Clim. Past, 11, 15–25, https://doi.org/10.5194/cp-11-15-2015, https://doi.org/10.5194/cp-11-15-2015, 2015
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New diatom isotope records are presented alongside existing geochemical and isotope records to document changes in the photic zone, including nutrient supply and the efficiency of the soft-tissue biological pump, between MIS 4 and MIS 5e in the subarctic north-west Pacific Ocean. The results provide evidence for temporal changes in the strength and efficiency of the regional soft-tissue biological pump, altering the ratio of regenerated to preformed nutrients in the water.
D. Sprenk, M. E. Weber, G. Kuhn, V. Wennrich, T. Hartmann, and K. Seelos
Clim. Past, 10, 1239–1251, https://doi.org/10.5194/cp-10-1239-2014, https://doi.org/10.5194/cp-10-1239-2014, 2014
T. Caley, J.-H. Kim, B. Malaizé, J. Giraudeau, T. Laepple, N. Caillon, K. Charlier, H. Rebaubier, L. Rossignol, I. S. Castañeda, S. Schouten, and J. S. Sinninghe Damsté
Clim. Past, 7, 1285–1296, https://doi.org/10.5194/cp-7-1285-2011, https://doi.org/10.5194/cp-7-1285-2011, 2011
G. Trommer, M. Siccha, E. J. Rohling, K. Grant, M. T. J. van der Meer, S. Schouten, U. Baranowski, and M. Kucera
Clim. Past, 7, 941–955, https://doi.org/10.5194/cp-7-941-2011, https://doi.org/10.5194/cp-7-941-2011, 2011
S. Sepulcre, L. Vidal, K. Tachikawa, F. Rostek, and E. Bard
Clim. Past, 7, 75–90, https://doi.org/10.5194/cp-7-75-2011, https://doi.org/10.5194/cp-7-75-2011, 2011
C. Siberlin and C. Wunsch
Clim. Past, 7, 27–39, https://doi.org/10.5194/cp-7-27-2011, https://doi.org/10.5194/cp-7-27-2011, 2011
A. H. L. Voelker, T. Rodrigues, K. Billups, D. Oppo, J. McManus, R. Stein, J. Hefter, and J. O. Grimalt
Clim. Past, 6, 531–552, https://doi.org/10.5194/cp-6-531-2010, https://doi.org/10.5194/cp-6-531-2010, 2010
L. E. Lisiecki
Clim. Past, 6, 305–314, https://doi.org/10.5194/cp-6-305-2010, https://doi.org/10.5194/cp-6-305-2010, 2010
M. Ziegler, L. J. Lourens, E. Tuenter, and G.-J. Reichart
Clim. Past, 6, 63–76, https://doi.org/10.5194/cp-6-63-2010, https://doi.org/10.5194/cp-6-63-2010, 2010
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Short summary
This paper examines the oxygen isotope data in several deep-sea cores. The question addressed is whether those data support an inference that the abyssal ocean in the Last Glacial Maximum period was significantly colder than it is today. Along with a separate analysis of salinity data in the same cores, it is concluded that a cold, saline deep ocean is consistent with the available data but so is an abyss much more like that found today. LGM model testers should beware.
This paper examines the oxygen isotope data in several deep-sea cores. The question addressed is...
