The vast landmass of Siberia and the Russian Far East (SRFE) stores carbon in its peatlands and its response to rapid climate warming is of global importance. Unfortunately, very few high-resolution records of climate and environmental change in the past 2000 years are available in the region. This situation also makes it difficult to test our current understanding of the climate system in the region by comparing palaeoenvironmental data with climate model output.
Where data exists, it is suggested that climatic periods such as the Medieval Warm Period and Little Ice Age are recognised in Siberia (Naurzbaev et al 2002), but the exact spatial and temporal extent is not clear. For these reasons, more high-resolution climate reconstructions are urgently required from Central Siberia.
The NERC-funded collaborative DIMA Network (https://research.ncl.ac.uk/dima) for palaeo-environmental science provides an exciting opportunity to work closely with colleagues at Siberian institutes, do fieldwork in a remote part of Siberia, and to apply new techniques for creating high-resolution climate records.
A strong relationship exists between summer temperature and assemblages of Chironomidae (non-biting midges). This relationship can be used to reconstruct past temperatures using chironomid remains in sediment records (Nazarova et al., 2015). Similarly, strong correlations have been observed between climatic variables (temperature and/or precipitation), stable hydrogen isotopes (δD) in n-alkanes (Rach et al., 2017), and stable oxygen isotope ratios (δ18O) measured on aquatic invertebrates (Verbruggen et al., 2010). Combined, these techniques give powerful independent evidence for changes in temperature and moisture variability.
For the most successful application of these techniques, local calibration data material in lake surface sediments (sediment core tops) and modern lake water should be compiled to constrain reconstructions based on remains in sediment records, and this will also be part of this project.
This studentship will address the following research questions:
1. Are temperature changes during the last 2,000 years in Central Siberia synchronous with events like the Little Ice Age and Medieval Warming in other parts of the Northern Hemisphere?
2. How closely linked are chironomid-inferred temperature reconstructions and δ18O/δD records during the past 2,000 years in Central Siberia?
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Coring a lake in Siberia – photograph by Tatiana Blyakharchuk