Pollen from the Deep-Sea: A Breakthrough in the Mystery of the Ice Ages

• Published in: Frontiers in Plant Science
• Main Authors: Sanchez Goni, Maria Fernanda, Desprat, Stephanie, Fletcher, William J., Morales-Molino, Cesar, Naughton, Filipa, Oliveira, Dulce, Urrego, Dunia H., Zorzi, Coralie
• Other Authors: Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: vegetation; millennial-scale climate variability; Dansgaard-Oeschger cycles; Heinrich events; glaciations; interglacials; Europe; Quaternary; [SDE]Environmental Sciences; Greenland; North Atlantic
• Online Access: https://hal.science/hal-04487976; https://hal.science/hal-04487976/document; https://hal.science/hal-04487976/file/EPOC_20218_Front.%20Plant%20Sci._Sanchez%20Goni.pdf; https://doi.org/10.3389/fpls.2018.00038

International audience Pollen from deep-sea sedimentary sequences provides an integrated regionalreconstruction of vegetation and climate (temperature, precipitation, and seasonality)on the adjacent continent. More importantly, the direct correlation of pollen, marineand ice indicators allows comparison of the atmospheric climatic changes that haveaffected the continent with the response of the Earth’s other reservoirs, i.e., the oceansand cryosphere, without any chronological uncertainty. The study of long continuouspollen records from the European margin has revealed a changing and complex interplaybetween European climate, North Atlantic sea surface temperatures (SSTs), ice growthand decay, and high- and low-latitude forcing at orbital and millennial timescales.These records have shown that the amplitude of the last five terrestrial interglacialswas similar above 40 N, while below 40 N their magnitude differed due to precessionmodulatedchanges in seasonality and, particularly, winter precipitation. These recordsalso showed that vegetation response was in dynamic equilibrium with rapid climatechanges such as the Dangaard-Oeschger (D-O) cycles and Heinrich events, similar inmagnitude and velocity to the ongoing global warming. However, the magnitude ofthe millennial-scale warming events of the last glacial period was regionally-specific.Precession seems to have imprinted regions below 40 N while obliquity, which controlsaverage annual temperature, probably mediated the impact of D-O warming eventsabove 40 N. A decoupling between high- and low-latitude climate was also observedwithin last glacial warm (Greenland interstadials) and cold phases (Greenland stadials).The synchronous response of western European vegetation/climate and eastern NorthAtlantic SSTs to D-O cycles was not a pervasive feature throughout the Quaternary.During periods of ice growth such as MIS 5a/4, MIS 11c/b and MIS 19c/b, repeatedmillennial-scale cold-air/warm-sea decoupling events occurred on the European marginsuperimposed to a ...