Nitrogen oxides in the atmosphere of coastal areas of Lake Baikal. Sources and possible impact on the ecosystem of the lake

摘要

The research is focused on the distribution of nitrogen oxide concentrations in the atmosphere above Lake Baikal, thedetermination of the largest sources of emission, and a quantitative assessment of their possible contribution to thecontent of nitrates in the near shore waters of the lake. The paper presents the results of measurements of nitrogen oxideconcentrations above the water area of the Baikal in the summer. In general, low background concentrations of nitrogenoxides prevailed, the excess was recorded in the northern part of the lake. An analysis and a calculation of emissions intothe atmosphere from power facilities in the near-shore areas of the lake were carried out. In the northern part of LakeBaikal, the central coal-fired boiler plant in the town of Severobaikalsk could become a source of nitrogen oxidesemission. The plume from the boiler was visually observed above the near shore waters. This boiler plant is the largestenergy facility and the main source of emissions of pollutants into the atmosphere. Deposition of nitrogen oxides fromsuch plumes can temporarily and locally cause an increase in nitrate concentrations in the near shore waters by 3-5% perday. In turn, the high content of nitrates in the water contributes to the growth of biomass of some algae species and thusaffects the entire ecosystem of the lake. Water transport can also be a significant source of nitrogen oxides above thewater area of the lake, but its contribution to the pollution of Lake Baikal is not sufficiently investigated.