Quantification of Past Ocean Dynamics.

• Applicant: Dr. Jörg Lippold
• Subject Area: Palaeontology ; Mineralogy, Petrology and Geochemistry ; Oceanography
• Term: from 2016 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 277128673

• Final Report Year: 2023

Final Report Abstract

The Atlantic meridional overturning circulation (AMOC) represents a potentially vulnerable component of the climate system. A forthcoming collapse of the AMOC under anthropogenic greenhouse forcing is thus a major concern. In order to enhance our understanding of the AMOC behaviour, the main goal of the project was to reconstruct past ocean dynamics by providing quantitative estimates from both proxy observations and model attempts. Here, the temporal focus of the investigations was set on the last glacial, the deglacial period, and the Holocene. In a first step, improvements of the proxy methodologies were implemented followed by intensive acquisition of observational proxy data with focus on the kinematic 231Pa/230Th circulation proxy and the εNd water mass tag. This new database served as the starting point for better understanding of AMOC-related and AMOC-unrelated processes influencing the proxies. As a main objective, this new database allowed for identifying the most likely AMOC scenarios for the variable climate conditions of the past by applying the Bern3D climate model. We found a shallow and weak Atlantic overturning circulation during the Last Glacial Maximum reconciling former and apparently conflicting proxy evidence. Model–data comparison of the last deglaciation indicates a highly variable AMOC, strongly dependent on the climatic and oceanic background state. In contrast, no significant variations were observed for the whole Holocene and yet during distinct climatic events within the last ~10,000 years, despite extraordinary high temporal observational sample resolution.

Publications

• Extracting foraminiferal seawater Nd isotope signatures from bulk deep sea sediment by chemical leaching. Chemical Geology, 439, 189-204.
  Blaser, Patrick; Lippold, Jörg; Gutjahr, Marcus; Frank, Norbert; Link, Jasmin M. & Frank, Martin
  
• New insights into cycling of 231 Pa and 230 Th in the Atlantic Ocean. Earth and Planetary Science Letters, 468, 27-37.
  Rempfer, Johannes; Stocker, Thomas F.; Joos, Fortunat; Lippold, Jörg & Jaccard, Samuel L.
  
• Synchronous and proportional deglacial changes in Atlantic meridional overturning and northeast Brazilian precipitation. Paleoceanography, 32(6), 622-633.
  Mulitza, Stefan; Chiessi, Cristiano M.; Schefuß, Enno; Lippold, Jörg; Wichmann, David; Antz, Benny; Mackensen, Andreas; Paul, André; Prange, Matthias; Rehfeld, Kira; Werner, Martin; Bickert, Torsten; Frank, Norbert; Kuhnert, Henning; Lynch‐Stieglitz, Jean; Portilho‐Ramos, Rodrigo C.; Sawakuchi, André O.; Schulz, Michael; Schwenk, Tilmann ... & Zhang, Yancheng
  
• Variability in mid‐depth ventilation of the western Atlantic Ocean during the last deglaciation. Paleoceanography, 32(9), 948-965.
  Voigt, I.; Cruz, A. P. S.; Mulitza, S.; Chiessi, C. M.; Mackensen, A.; Lippold, J.; Antz, B.; Zabel, M.; Zhang, Y.; Barbosa, C. F. & Tisserand, A. A.
  
• Atlantic deep water circulation during the last interglacial. Scientific Reports, 8(1).
  Luo, Yiming; Tjiputra, Jerry; Guo, Chuncheng; Zhang, Zhongshi & Lippold, Jörg
  
• Improved Separation of Pa from Th and U in Marine Sediments with TK400 Resin. Analytical Chemistry, 90(2), 1395-1401.
  Süfke, Finn; Lippold, Jörg & Happel, Steffen
  
• Origin of Abyssal NW Atlantic Water Masses Since the Last Glacial Maximum. Paleoceanography and Paleoclimatology, 33(5), 530-543.
  Pöppelmeier, F.; Gutjahr, M.; Blaser, P.; Keigwin, L. D. & Lippold, J.
  
• Relative timing of precipitation and ocean circulation changes in the western equatorial Atlantic over the last 45 kyr. Climate of the Past, 14(9), 1315-1330.
  Waelbroeck, Claire; Pichat, Sylvain; Böhm, Evelyn; Lougheed, Bryan C.; Faranda, Davide; Vrac, Mathieu; Missiaen, Lise; Vazquez, Riveiros Natalia; Burckel, Pierre; Lippold, Jörg; Arz, Helge W.; Dokken, Trond; Thil, François & Dapoigny, Arnaud
  
• Constraining the Variability of the Atlantic Meridional Overturning Circulation During the Holocene. Geophysical Research Letters, 46(20), 11338-11346.
  Lippold, Jörg; Pöppelmeier, Frerk; Süfke, Finn; Gutjahr, Marcus; Goepfert, Tyler J.; Blaser, Patrick; Friedrich, Oliver; Link, Jasmin M.; Wacker, Lukas; Rheinberger, Stefan & Jaccard, Samuel L.
  
• Constraints on the Northwestern Atlantic Deep Water Circulation From 231Pa/230Th During the Last 30,000 Years. Paleoceanography and Paleoclimatology, 34(12), 1945-1958.
  Süfke, Finn; Pöppelmeier, Frerk; Goepfert, Tyler Jay; Regelous, Marcel; Koutsodendris, Andreas; Blaser, Patrick; Gutjahr, Marcus & Lippold, Jörg
  
• Influence of Ocean Circulation and Benthic Exchange on Deep Northwest Atlantic Nd Isotope Records During the Past 30,000 Years. Geochemistry, Geophysics, Geosystems, 20(9), 4457-4469.
  Pöppelmeier, F.; Blaser, P.; Gutjahr, M.; Süfke, F.; Thornalley, D. J. R.; Grützner, J.; Jakob, K. A.; Link, J. M.; Szidat, S. & Lippold, J.
  
• Revealing past ocean circulation with neodymium isotopes. Past Global Changes Magazine, 27(2).
  Blaser P.; Frank, M. & Flierdt, T. v. d.
  
• The resilience and sensitivity of Northeast Atlantic deep water εNd to overprinting by detrital fluxes over the past 30,000 years. Geochimica et Cosmochimica Acta, 245, 79-97.
  Blaser, P.; Pöppelmeier, F.; Schulz, H.; Gutjahr, M.; Frank, M.; Lippold, J.; Heinrich, H.; Link, J.M.; Hoffmann, J.; Szidat, S. & Frank, N.
  
• Ice-rafted debris as a source of non-conservative behaviour for the εNd palaeotracer: insights from a simple model. Geo-Marine Letters, 40(3), 325-340.
  Vogt-Vincent, Noam; Lippold, Jörg; Kaboth-Bahr, Stefanie & Blaser, Patrick
  
• Influence of Elevated Nd Fluxes on the Northern Nd Isotope End Member of the Atlantic During the Early Holocene. Paleoceanography and Paleoclimatology, 35(11).
  Pöppelmeier, Frerk; Scheen, Jeemijn; Blaser, Patrick; Lippold, Jörg; Gutjahr, Marcus & Stocker, Thomas F.
  
• Inverse response of 231Pa/230Th to variations of the Atlantic meridional overturning circulation in the North Atlantic intermediate water. Geo-Marine Letters, 40(1), 75-87.
  Süfke, Finn; Schulz, Hartmut; Scheen, Jeemijn; Szidat, Sönke; Regelous, Marcel; Blaser, Patrick; Pöppelmeier, Frerk; Goepfert, Tyler J.; Stocker, Thomas F. & Lippold, Jörg
  
• Labrador Sea bottom water provenance and REE exchange during the past 35,000 years. Earth and Planetary Science Letters, 542, 116299.
  Blaser, Patrick; Gutjahr, Marcus; Pöppelmeier, Frerk; Frank, Martin; Kaboth-Bahr, Stefanie & Lippold, Jörg
  
• Northern-sourced water dominated the Atlantic Ocean during the Last Glacial Maximum. Geology, 48(8), 826-829.
  Pöppelmeier, F.; Blaser, P.; Gutjahr, M.; Jaccard, S.L.; Frank, M.; Max, L. & Lippold, J.
  
• Water mass gradients of the mid-depth Southwest Atlantic during the past 25,000 years. Earth and Planetary Science Letters, 531, 115963.
  Pöppelmeier, F.; Gutjahr, M.; Blaser, P.; Oppo, D.W.; Jaccard, S.L.; Regelous, M.; Huang, K.-F.; Süfke, F. & Lippold, J.
  
• Deglacial patterns of South Pacific overturning inferred from 231Pa and 230Th. Scientific Reports, 11(1).
  Ronge, Thomas A.; Lippold, Jörg; Geibert, Walter; Jaccard, Samuel L.; Mieruch-Schnülle, Sebastian; Süfke, Finn & Tiedemann, Ralf
  
• Driving Mechanisms of Sedimentary 230Th and 231Pa Variability in the Western Arctic Ocean Through the Last Glacial Cycle. Paleoceanography and Paleoclimatology, 36(7).
  Xu, Qian; Xiao, Wenshen; Wang, Rujian; Süfke, Finn; Lippold, Jörg & Not, Christelle
  
• Stable Atlantic Deep Water Mass Sourcing on Glacial‐Interglacial Timescales. Geophysical Research Letters, 48(15).
  Pöppelmeier, Frerk; Gutjahr, Marcus; Blaser, Patrick; Schulz, Hartmut; Süfke, Finn & Lippold, Jörg
  
• The influence of deep water circulation on the distribution of 231Pa and 230Th in the Pacific Ocean. Earth and Planetary Science Letters, 554, 116674.
  Luo, Yiming; Lippold, Jörg; Allen, Susan E.; Tjiputra, Jerry; Jaccard, Samuel L. & Francois, Roger
  
• Western boundary current in relation to Atlantic Subtropical Gyre dynamics during abrupt glacial climate fluctuations. Global and Planetary Change, 201, 103497.
  Nürnberg, Dirk; Riff, Tabitha; Bahr, André; Karas, Cyrus; Meier, Karl & Lippold, Jörg
  
• Arctic drainage of Laurentide Ice Sheet meltwater throughout the past 14,700 years. Communications Earth & Environment, 3(1).
  Süfke, Finn; Gutjahr, Marcus; Keigwin, Lloyd D.; Reilly, Brendan; Giosan, Liviu & Lippold, Jörg
  
• Neodymium isotopes as a paleo-water mass tracer: A model-data reassessment. Quaternary Science Reviews, 279, 107404.
  Pöppelmeier, Frerk; Lippold, Jörg; Blaser, Patrick; Gutjahr, Marcus; Frank, Martin & Stocker, Thomas F.
  
• A global synthesis of high-resolution stable isotope data from benthic foraminifera of the last deglaciation. Scientific Data, 10(1).
  Muglia, Juan; Mulitza, Stefan; Repschläger, Janne; Schmittner, Andreas; Lembke-Jene, Lester; Lisiecki, Lorraine; Mix, Alan; Saraswat, Rajeev; Sikes, Elizabeth; Waelbroeck, Claire; Gottschalk, Julia; Lippold, Jörg; Lund, David; Martinez-Mendez, Gema; Michel, Elisabeth; Muschitiello, Francesco; Naik, Sushant; Okazaki, Yusuke; Stott, Lowell ... & Zhao, Ning
  
• Multi-proxy constraints on Atlantic circulation dynamics since the last ice age. Nature Geoscience, 16(4), 349-356.
  Pöppelmeier, Frerk; Jeltsch-Thömmes, Aurich; Lippold, Jörg; Joos, Fortunat & Stocker, Thomas F.
  
• SYSTEMATIC ANALYSES OF RADIOCARBON AGES OF COEXISTING PLANKTONIC FORAMINIFERA. Radiocarbon, 65(4), 876-898.
  Lippold, Jörg; Gottschalk, Julia; Lynch-Stieglitz, Jean; Schmidt, Matthew W.; Szidat, Sönke & Bahr, Andre