Synchronisierte holozäne Archive zirkumbaltischer Umweltveränderungen
Zusammenfassung der Projektergebnisse
The Circum-Baltic ecosystems are sensitive to both natural climate forcing and human impact. Their evolution since the last deglaciation is documented in sediments from the Baltic Sea itself, as well as in surrounding terrestrial sediment archives. Existing studies point to complex interactions of various climate forcing, as well as different timings of proxy responses in marine and terrestrial environmental archives. However, the detailed investigation of such variations is limited by the availability of high-resolution paleoclimate archives from this region, as well as chronological uncertainties between the investigated records. Main scientific objectives of this project were (i) the establishment of a new lake sediment record of Holocene paleoenvironmental variability for the western Baltic region and (ii) a step towards a synchronous network of natural environmental archives in the Baltic region, applying globally common production rate variations of the cosmogenic radionuclide 10Be. Therefore, we first, investigated the sediment record from Lake Kälksjön in central Sweden to establish time-series of the unique western ‘Scandinavian’ expression of Circum-Baltic climate variability during the last 9600 years. Productivity increases in KKJ reflected by co-varying TOC and δ13Corg contents are interpreted to be driven by the progressive millennial-scale winter warming in north-western Europe, following the increasing Northern Hemisphere winter insolation, and decadal to centennial periods of a more positive NAO polarity. Strengthened productivity variability since ~5450 cal. a BP is hypothesized to reflect a reinforcement of NAO-like atmospheric circulation, concurrent with the onset of more vigorous variations in North Atlantic deep-water formation. To synchronize the terrestrial Lake Kälksjön and brackish Western Gotland Basin (Baltic Sea) sediment records, we measured 10Be time-series covering the periods from 6400 to 5200 a BP and 2000 a BP until today. 10Be/9Be ratios and environmental proxy records from the same archive were used to determine the depositional mechanisms and reduce non-production variability in the 10Be time-series from KKJ and WGB sediments. The preserved 10Be production signal allowed the synchronization of both records using semi-automated curve fitting and to reduce the centennial chronological uncertainties of both archives to a few decades. Integrating proxy records from the synchronized sediment archives points to the combined influences of cooler summers and winters on deep water formation and oxygenation in the central Baltic Sea basins during a 250-year-long period within the Holocene Thermal Maximum. In conclusion, the project outcome presents a step towards the construction of a synchronous network of paleoenvironmental archives for the marine-terrestrial Baltic Sea environment based on the 10Be synchronization tool and multi-archive investigations of paleoclimate changes at very high chronological precision.
Projektbezogene Publikationen (Auswahl)
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Lagged atmospheric circulation response in the Black Sea region to Greenland Interstadial 10. Proceedings of the National Academy of Sciences, 117(46), 28649-28654.
Czymzik, Markus; Nowaczyk, Norbert R.; Dellwig, Olaf; Wegwerth, Antje; Muscheler, Raimund; Christl, Marcus & Arz, Helge W.
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Radionuclide wiggle matching reveals a nonsynchronous early Holocene climate oscillation in Greenland and western Europe around a grand solar minimum. Climate of the Past, 16(4), 1145-1157.
Mekhaldi, Florian; Czymzik, Markus; Adolphi, Florian; Sjolte, Jesper; Björck, Svante; Aldahan, Ala; Brauer, Achim; Martin-Puertas, Celia; Possnert, Göran & Muscheler, Raimund
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Relationship between precipitation and 10Be and impacts on soil dynamics. CATENA, 195 (2020, 12), 104748.
Chen, Peng; Yi, Peng; Czymzik, Markus; Aldahan, Ala; Ljung, Karl; Yu, Zhongbo; Hou, Xiaolin; Zheng, Minjie; Chen, Xuegao & Possnert, Göran
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Mid-Holocene reinforcement of North Atlantic atmospheric circulation variability from a western Baltic lake sediment record. Climate of the Past, 19(1), 233-248.
Czymzik, Markus; Tjallingii, Rik; Plessen, Birgit; Feldens, Peter; Theuerkauf, Martin; Moros, Matthias; Schwab, Markus J.; Nantke, Carla K. M.; Pinkerneil, Silvia; Brauer, Achim & Arz, Helge W.
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Tendency of soil erosion dynamics by coupling radioisotopes and RUSLE model on the Southeastern Tibetan Plateau in response to climate warming and human activity. CATENA, 223, 106954.
Chen, Peng; Czymzik, Markus; Yu, Zhongbo; Aldahan, Ala; Wang, Jinguo; Yi, Peng; Hou, Xiaolin; Guo, Shouyan & Zheng, Minjie
