Lake Baikal
Lake Baikal represents one of the few Eurasian, continental, lacustrine sites with an extremely long, uninterrupted sedimentary record (spanning potentially 25 million years) that has been exploited for high resolution palaeoclimate studies (ICDP-project). Lake Baikal is an optimal climate archive as the large size and volume of the lake guaranties for stable boundary conditions and it records besides the Chinese Loess-plateau regional and supra-regional temperate climate signals at a continental location.
To understand the dynamic of the present global climate it is important to keep track of teleconnections between major climatic systems in the past. These interactions are relevant for an evaluation of the human influence on climate and measures of the society, which have to be decided on preventing environmental damage. Baikal records involvements of two important weather systems - the Siberian high-pressure zone and the Asian monsoon zone. Accordingly, Baikal is a key area responding to the air mass, which are controlled by the North Atlantic Oscillation (NAO). But Siberia has possibly also a feedback role on the monsoonal system, as moisture distribution (and in particular snow cover), controlling the albedo of this region from early winter through late spring, may regulate the strength of the summer monsoon in SE Asia.
The EU-project CONTINENT aimed to contribute with a multiproxy approach to a better understanding of temperature evolution and moisture regimes in Central Eurasia during two time slices (Holocene and Eemian time equivalents with Terminations I and II) and to compare the Baikal record with climatic archives from Europe and how the transfer models for the Baikal climate proxies should be built.
Therefore we also reconstructed snow cover history as proxy tracing links between Baikal and the W Pacific Ocean using inference models spanning the last 500 years. They have shown that it is indeed possible to reconstruct spring snow cover on Baikal.
The CONTINENT project brought together for the first time new and advanced analytical and modelling methods to combine the understanding of recent processes in Lake Baikal, which lead to sound paleoclimatic interpretation. The approach included among others:
- Understanding dynamics and processes of
- primary producers and their successions in the photic zone (including their biochemical compounds) as responses to ice formation and snow cover and water turbulence
- basin fractionation (chemical and minerogenic fractionation) as response to dynamic processes in the water body during different climatic regimes
- Using tools for numerically reconstructing present and past climates by
- algorithms for chlorophyll input in surface water
- adaptation of transfer functions based on pollen
- development of transfer models based on pigments
- Establishing an age model for the last 150 kys by
- rock magnetic techniques and palaeomagnetic reversals
- Establishing climatic records at a high temporal resolution by
- evaluation of changes in the hydrological regime of the catchment of Lake Baikal from the Late Weichselian through to the Holocene (0-20 kys) by using the stratigraphy and the age model (AMS-14C) of pollen and the reconstruction of the detrital input
- evaluation of temperature and humidity during the Eemian (the Kazantsevo optimum, by far the warmest interglacial and hence a non-analogue situation to the Holocene) and the preceding Termination II which includes Heinrich-event 11.
- Building a new information system for sediment core characterisation, description and computerised core data storage.