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| Titel |
Ecosystem resilience to abrupt late Quaternary change in continental southern Siberia |
| VerfasserIn |
Poppy Harding, Anson Mackay, Elena Bezrukova, Alexander Shchetnikov |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250144815
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| Publikation (Nr.) |
 EGU/EGU2017-8684.pdf |
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| Zusammenfassung |
| Quaternary climate variability is dominated by long term orbital forcing along with abrupt
sub-Milankovitch events on the scales of millennia to centuries, driven by internal feedback
mechanisms, volcanic forcing and fluctuating solar activity. Although these are well
documented in the North Atlantic region, their expression is poorly understood in Siberia,
particularly in relation to abrupt climatic events. Siberia has the world’s highest level of
continentality offering an opportunity to study changes remote from oceanic influences and
improving understanding of interactions between the Siberian High and other atmospheric
systems including the Aleutian Low, Arctic oscillation and Icelandic Low1 and
ENSO2.
Understanding of palaeoenvironmental change in Siberia is essential due to the region’s
high sensitivity to climatic change, with warming rates considerably higher than the global
average over the past 50 years3, triggering significant environmental changes, including
permafrost degradation, shifts in the forest–steppe biome, increases in forest fires and
warming of seasonally ice-covered lakes. Additionally, the region provides essential
palaeoenvironmental context for early hominins, for example at globally important sites such
as Denisova cave4, and megafauna extinctions5.
This presentation outlines ongoing work at Lake Baunt, SE Siberia including: key
quaternary climate forcings, the site and its regional context, the key methods and preliminary
results. These include a dated record back to ∼30ka BP (based on multiple 14C dates and
Bayesian age modelling), multiproxy indicators of palaeoproductivity (e.g. biogenic silica
and diatom analyses) and lake mixing regimes (inferred from diatom analyses). Together
these highlight several key Quaternary fluctuations potentially correlated to events recorded
in Greenland Ice Cores (GS2, GS2.1, GI1, GS1), and these are considered against key
Quaternary records including those from nearby Lake Baikal and Hulu Cave in
east China. Our analyses suggest that teleconnections between the Siberian High
and the East Asian monsoon are also significant for this study, with Lake Baunt
showing a relationship between productivity and variability in strength of the Siberian
High.
References:
1. Tubi, A. & Dayan, U. (2013). Int. J. Climatol. 33, 1357–1366.
2. Park, T.-W. et al. (2014). Clim. Dyn. 45, 1207–1217.
3. Tingley, M. P. & Huybers, P. (2013). Nature 496, 201–5.
4. Krause, J. et al.. (2010). Nature 464, 894–7.
5. Stuart, A. J. et al. (2004). Nature 431, 684–9. |
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