GER 1500 spectrometer (GFZ Potsdam) and water sampling activities (IGB Berlin) on board of the Russian research vessel Vereshchagin (SB Russian Academy of Sciences)
CONTINENT (High Resolution CONTINENTal Palaeoclimate Record from Lake Baikal) is an EU-Project on the climatic history of Lake Baikal, Siberia, Russia. The objective of the project is to span the last 150,000 years with a continuous high resolution palaeoclimate record from a high mid-latitude continental setting.
The set of actuo-reference data of climate proxies for Lake Baikal is created by limnological, sedimentological and geochemical examination on the CONTINENT field expeditions 2001 to 2003. When no field data are available, the occurrence and behavior of climate proxie such as algae pigment concentration,phytoplankton composition, and detrital input can be monitored over space and time by continuously acquired Ocean Colour satellite data (SeaWIFS and MODIS, NASA).
During the ship cruises on Lake Baikal in Summer 2001 and 2002 the GFZ Potsdam simultaneously carried out optical in-situ measurements with the GER 1500 field spectrometer together with water sampling activities for suspended matter, algae pigment, algae species, and coloured dissolved organic matter concentration.
Lake Baikal is a bio-optical very complex case 2 water body. The high fluvial input of terrigenous dissolved and particulate matter do not spatially correlate with the autochthonous Lake Baikal phytoplankton production and all components do strongly optically interact with each other. Due to this restriction for the classical empirical algorithm approach, we had to set up a semi-analytical inverse model approach. We have to extract the Lake Baikal specific absorption and backscattering coefficients (derived from field and labaratory measurements) to implement them into the Water Colour Simulater WASI from the German Space Agency (DLR
). For bio-optical algorithm developement first we will specify a new specific phytoplankton absorption coefficient (a*phyto) including the dominant cyanobacteria picoplankton species of Lake Baikal. Second we have to extract the Lake Baikal specific slope value S for the exponentiell cDOM absorption (a cDOM). Third we have to define a new specific scattering coefficient (b*SPM) for the typical size range and distribution of suspended matter in Lake Baikal such as terrestrious clay particles and the biogenic matter, such as big diatom species in the Northern basin and picoplankton in the South.
As the result of inverse modelling of SeaWiFS data we will provide the spatial and temporal overview of the quantified sedimentary input, and the dynamic of algae biomass for the time span from 2001 to 2003. Qualitatively and semi-quantitatively maps of these water consitutents classified by Principal component analysis, veryfied by ground truth data are yet produced.