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abstracts
Long term seasonality changes and abrupt climate shifts recorded in highly resolved dust/loess sequences across Eurasia
Björn Machalett
The distribution of Eurasian loess deposits allows interregional palaeoclimatic investigations along a west-east transect across the entire Eurasian loess belt of the Northern Hemisphere, offering the potential to reconstruct Pleistocene atmospheric circulation patterns and aeolian dust dynamics on a wide spatial scale.
High resolution proxy data from several loess sequences across Eurasia (Serbia, Romania, Uzbekistan & Kazakhstan) provide a detailed signal of glacial-interglacial atmospheric dynamics and long term, semi-continuous trends in the aeolian dust record since marine isotope stage 10. In consideration of the modern synoptic atmospheric circulation patterns and aeolian dust transport across the Eurasian landmass, we propose that the data reflect oscillations superimposed on a long term signal of seasonality, triggered by changes in duration and permanency of the seasonal shift of the Eurasian polar front during the middle to late Pleistocene.
Unlike the similarities in long term seasonality changes across Eurasia, there are distinct differences in short-term climate variability along the studied transect from SE Europe to Central Asia. While the records in SE Europe seem to reflect short term climate oscillations controlled by regional climate dynamics and local wind systems, the highly resolved Central Asian dust archives suggest a clear pattern of rapid warming and gradual cooling, indicating a teleconnection with D/O events of the last glacial cycle.
This study aims to reconstruct long-term aeolian dust dynamics and climate variability recorded in high-resolution loess records across Eurasia, linking inter-hemispheric climates on time scales ranging from glacial-interglacial to (sub)millennial.
Björn Machalett, Department of Geography, Humboldt University of Berlin,Unter den Linden 6, Berlin, 10099, Germany, b.machalett@nakula.de
Session: F3: Global Earth-System Dynamics
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