Browsing by Author "Waelbroeck, Claire"
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- Consistently dated Atlantic sediment cores over the last 40 thousand yearsPublication . Waelbroeck, Claire; Lougheed, Bryan C.; Vazquez Riveiros, Natalia; Missiaen, Lise; Pedro, Joel; Dokken, Trond; Hajdas, Irka; Wacker, Lukas; Abbott, Peter; Dumoulin, Jean-Pascal; Thil, François; Eynaud, Frédérique; Rossignol, Linda; Fersi, Wiem; Albuquerque, Ana Luiza; Arz, Helge; Austin, William E. N.; Came, Rosemarie; Carlson, Anders E.; Collins, James A.; Dennielou, Bernard; Desprat, Stéphanie; Dickson, Alex; Elliot, Mary; Farmer, Christa; Giraudeau, Jacques; Gottschalk, Julia; Henderiks, Jorijntje; Hughen, Konrad; Jung, Simon; Knutz, Paul; Lebreiro, Susana; Lund, David C.; Lynch-Stieglitz, Jean; Malaizé, Bruno; Marchitto, Thomas; Martínez-Méndez, Gema; Mollenhauer, Gesine; Naughton, Filipa; Nave, Silvia; Nürnberg, Dirk; Oppo, Delia; Peck, Victoria; Peeters, Frank J. C.; Penaud, Aurélie; Portilho-Ramos, Rodrigo da Costa; Repschläger, Janne; Roberts, Jenny; Rühlemann, Carsten; Salgueiro, Emilia; Sanchez Goni, Maria Fernanda; Schönfeld, Joachim; Scussolini, Paolo; Skinner, Luke C.; Skonieczny, Charlotte; Thornalley, David; Toucanne, Samuel; Rooij, David Van; Vidal, Laurence; Voelker, Antje; Wary, Mélanie; Weldeab, Syee; Ziegler, MartinRapid changes in ocean circulation and climate have been observed in marine-sediment and ice cores over the last glacial period and deglaciation, highlighting the non-linear character of the climate system and underlining the possibility of rapid climate shifts in response to anthropogenic greenhouse gas forcing. To date, these rapid changes in climate and ocean circulation are still not fully explained. One obstacle hindering progress in our understanding of the interactions between past ocean circulation and climate changes is the difficulty of accurately dating marine cores. Here, we present a set of 92 marine sediment cores from the Atlantic Ocean for which we have established age-depth models that are consistent with the Greenland GICC05 ice core chronology, and computed the associated dating uncertainties, using a new deposition modeling technique. This is the first set of consistently dated marine sediment cores enabling paleoclimate scientists to evaluate leads/lags between circulation and climate changes over vast regions of the Atlantic Ocean. Moreover, this data set is of direct use in paleoclimate modeling studies.
- A global synthesis of high-resolution stable isotope data from benthic foraminifera of the last deglaciationPublication . 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; Voelker, Antje; Zhao, NingWe present the first version of the Ocean Circulation and Carbon Cycling (OC3) working group database, of oxygen and carbon stable isotope ratios from benthic foraminifera in deep ocean sediment cores from the Last Glacial Maximum (LGM, 23-19 ky) to the Holocene (<10 ky) with a particular focus on the early last deglaciation (19-15 ky BP). It includes 287 globally distributed coring sites, with metadata, isotopic and chronostratigraphic information, and age models. A quality check was performed for all data and age models, and sites with at least millennial resolution were preferred. Deep water mass structure as well as differences between the early deglaciation and LGM are captured by the data, even though its coverage is still sparse in many regions. We find high correlations among time series calculated with different age models at sites that allow such analysis. The database provides a useful dynamical approach to map physical and biogeochemical changes of the ocean throughout the last deglaciation.
- Technical note: large offsets between different datasets of seawater isotopic composition – an illustration of the need to reinforce intercalibration effortsPublication . Reverdin, Gilles; Waelbroeck, Claire; Voelker, Antje; Meyer, HannoWe illustrate offsets in surface seawater isotopic composition between recent public datasets from the Atlantic Ocean and the subtropical southeastern Indian Ocean. The observed offsets between datasets often exceed 0.10 parts per thousand in delta 18O and 0.50 parts per thousand in delta 2H. They might in part originate from different sampling of seasonal, interannual, or spatial variability. However, they likely mostly originate from different instrumentations and protocols used to measure the water samples. Estimation of the systematic offsets is required before merging the different datasets in order to investigate the spatiotemporal variability of isotopic composition in the world ocean surface waters. This highlights the need to actively share seawater isotopic composition samples dedicated to specific intercomparison of data produced in different laboratories and to promote best practices, a task to be addressed by the new Scientific Committee of Oceanic Research (SCOR) working group 171.