Smoothed millennial-scale palaeoclimatic reference data as unconventional comparison targets: Application to European loess records

• Published in: Scientific Reports
• Main Authors: Zeeden, Christian, Obreht, Igor, Veres, Daniel, Kaboth-Bahr, Stefanie, Hošek, Jan, Marković, Slobodan, Bösken, Janina, Lehmkuhl, Frank, Rolf, Christian, Hambach, Ulrich
• Other Authors: Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Leibniz Institute for Applied Geophysics (LIAG), Leibniz Association, University of Bremen, Romanian Academy IASI, Romanian Academy of Sciences, Universität Heidelberg Heidelberg, Universität Potsdam, Czech Technical University in Prague (CTU), Faculty of Sciences University of Novi Sad, University of Novi Sad, RWTH Aachen University, University of Bayreuth
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: Palaeoclimate; Sedimentology; Stratigraphy; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; [PHYS]Physics [physics]; [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]; Greenland; Greenland ice cores
• Online Access: https://hal.sorbonne-universite.fr/hal-02557205; https://hal.sorbonne-universite.fr/hal-02557205/document; https://hal.sorbonne-universite.fr/hal-02557205/file/s41598-020-61528-8.pdf; https://doi.org/10.1038/s41598-020-61528-8

International audience Millennial-scale palaeoclimate variability has been documented in various terrestrial and marine palaeoclimate proxy records throughout the northern Hemisphere for the last glacial cycle. its clear expression and rapid shifts between different states of climate (Greenland Interstadials and Stadials) represents a correlation tool beyond the resolution of e.g. luminescence dating, especially relevant for terrestrial deposits. Usually, comparison of terrestrial proxy datasets and the Greenland ice cores indicates a complex expression of millennial-scale climate variability as recorded in terrestrial geoarchives including loess. Loess is the most widespread terrestrial geoarchive of the Quaternary and especially widespread over Eurasia. However, loess often records a smoothed representation of millennial-scale variability without all fidelity when compared to the Greenland data, this being a relevant limiting feature in integrating loess with other palaeoclimate records. to better understand the loess proxy-response to millennial-scale climate variability, we simulate a proxy signal smoothing by natural processes through application of low-pass filters of δ 18 O data from Greenland, a high-resolution palaeoclimate reference record, alongside speleothem isotope records from the Black Sea-Mediterranean region. We show that low-pass filters represent rather simple models for better constraining the expression of millennial-scale climate variability in low sedimentation environments, and in sediments where proxy-response signals are most likely affected by natural smoothing (by e.g. bioturbation). Interestingly, smoothed datasets from Greenland and the Black Sea-Mediterranean region are most similar in the last ~15 ka and between ~50-30 ka. Between ~30-15 ka, roughly corresponding to the Last Glacial Maximum and the deglaciation, the records show dissimilarities, challenging the construction of robust correlative timescales in this age range. from our analysis it becomes apparent that patterns ...