Expedition onboard RV “V.A. Koptyug”, July 24-August 04, 2019

The complex expedition on atmospheric investigations within the framework of programs “Studies of the Composition and Spatio-Temporal Distribution of Aerosol-Gas Impurities of the Atmosphere in the Water Area of Lake Baikal” and “Assessment and Forecast of Ecological State of Lake Baikal and Adjacent Territories under Conditions of Anthropogenic Impact and Climate Change” was carried out onboard RV “V.A. Koptyug”, July 24-August 04, 2019, in South, Central and Northern Baikal. The expedition included the researchers from four institutes of the Russian Federation.

The aim of the expedition was to assess the contribution of anthropogenic sources in the Baikal region and natural hazards (forest and peat fires) to the overall air pollution of Lake Baikal, using the data on experimental observations, to predict possible consequences of aerosols for its ecosystem.

Onboard RV “V.A. Koptyug”, microphysical and optical properties of the aerosol, spatio-temporal distribution and variations of gas impurities in the atmosphere over the Baikal water area were complexly measured using remote sensing of the atmosphere (lidar) and local control of automatic weather stations, a diffusion aerosol spectrometer, gas analyzers, and an aethalometer. Measurements were taken in continuous mode with averaging of two-five minutes, and large data arrays were obtained on the calculated particle concentration by size, the mass concentration of sulfur oxides, nitrogen, ozone, and black carbon (soot). Using low- and high-volume pumps, more than 50 aerosol samples were taken for the analysis of chemical composition: ions, microelements, PAHs, Corg and other organic compounds. Lidar performed vertical and horizontal sensing of the atmosphere at a distance of 5-6 km. The measurements were taken along the course of the vessel throughout the water area and near the local sources of air pollution: Baikalsk and Severobaikalsk towns, Listvyanka, Turka and Nizhneangarsk settlements, Chivyrkuy and Barguzin bays, coves, and estuarine areas of large rivers (the Selenga, the Barguzin and the Turka). The exhaust gases of the vessel were sampled. Smoke from wildfires was observed almost along the entire course of the vessel (there were wildfires in the Republic of Sakha (Yakutia), Krasnoyarsk Krai and the Irkutsk Region). For the first time, the upper atmosphere was filled with smoke aerosol near the Maloye More Strait at heights of 2.5 km, and further to North Baikal and back throughout the lake perimeter, the atmospheric layers from 2.5 to 150 m from the water surface were filled with smoke. There was low atmospheric transparency and smog.

During the expedition, synchronous observations were carried out on the coast of South Baikal, at research stations of Listvyanka, Bolshiye Koty and Boyarsk. Onboard the vessel, workshops and data exchange were held. The planned fieldworks were completely fulfilled.