RUSALCA Expedition
HSR members Prof. Dr Sergey Alexeev, Prof. Dr Nikolay Neronov and Alexander Fyodorov, and head of expedition Dr Vladimir Smolin took part in preparation and carrying out of the third Russian-American Expedition in the Bering Strait, the Bering Sea, and the Chuckchee Sea. This, under the auspices of the Joint Russian-American Long-term Census of the Arctic (RUSALCA) was successfully realised between 18th August and 5th September 2006. The long-term purpose of this programme is the performance of long-term and detailed monitoring of indicators of climatic changes in the Arctic, including monitoring of the Bering Strait.
Researches in 2006 were performed on the Russian Navy hydrographic vessel Sever with financial support from NOAA Department of Arctic Research and the Russian Academy of Science. The research was aimed at obtaining comprehensive information about the condition of natural systems in the Bering Strait and Chuckchee Sea, correlation of their main components, and their influence on forming climatic signals in northern Polar Regions. The acquisition of hydrological, biochemical and hydro-biological data for American and Russian databases serves as a basis for joint evaluation of climate change, water exchange and contents of biocenose in the Arctic.

The main results of the exped–ition may be formulated as follows. First, three American buoy-based stations were successfully erected in the western part of the Bering Strait. In spite of loss of data from the American current meter, American scientists will get access to data provided by the Russian current meter installed at the same buoy-based station. This data represents annual series of current measurements and other parameters.

Secondly, three autonomous buoy-based station, equipped with American and Russian equipment were successfully installed in the western part of the Bering Strait. All stations are set for an annual term of measurements. The next data processing will provide unique material for evaluation of space and time hydrogeological characteristics, and description of the processes in time scales varying from one hour to one year.

Third, the presence of an area with high biomass of bottom invertebrates has been confirmed in the south-western area of the Chuckchee Sea. The existence of rich bottom communities in this area of the sea obviously results from vortex circulation originating in the Chuckchee Sea westwards of the Bering Strait.

Fourthly, for the first time in the Chuckchee Sea, experimental data was obtained about levels of acoustic back scattering at frequency 12kHz. This may be used for evaluation of coefficients of reflection and other characteristics of bottom.

And finally, mercury levels in the air along the transit route Petropavlovsk-Kamchatskiy to Nom were noted to be within the limits, considering the regional background. Separate areas in the Bering Sea and Chuckchee Sea where episodic sudden increase in mercury levels are noted stand out against a background of otherwise low levels. It is supposed that the majority of local increases in level are determined by entry of mercury from the earth’s crust and its bearing out through matter to the atmosphere.

Nikolay Neronov confirmed that researches under the RUSALKA programme would be continued.