Distribution of the Barguzin River waters in the Barguzin Bay estimated by the content of dissolved methane

Abstract

Within the framework of many-year studies of the carbon cycle in the water-atmosphere system and in order to determine high-priority measures for conservation of the unique ecosystem of Lake Baikal, the specialized combined expedition was carried out in August 2019 in Barguzin and Chivyrkuy Bays of Lake Baikal. With the unique onboard instrumentation system, we have measured the gas content in the surface water and the near-water atmosphere, as well as concentrations of biogenic elements and organic matter at the sampling stations. The spatial distribution of the increased methane concentrations in the surface water of Barguzin Bay has been analyzed to determine the main direction of the Barguzin River’s water inflow into the bay. The observational data were compared with the results of scenario calculations by a large-scale model of currents in the lake. This model gives us some understanding of a general nature of water mass circulation in the bay. For modelling small-scale manifestations in the near shore zones, it is necessary to use higher resolution models for nested regions.