This research used the geostatistical analysis of snow cover samples taken in 2017–2022 in the Baikal basin. Groups of snow cover pollution sources were identified by the method of empirical Bayesian ...kriging (ArcMap software) and mathematical data processing. The studied area was divided into fourteen districts. Geovisualization of marker substances accumulated in the snow cover allowed for the zoning of the studied area according to the degree of anthropogenic load. It was revealed that the atmospheric pollution of the territory from local sources extended for tens of kilometers along the prevailing wind direction. The maximum concentrations of anthropogenic aerosols in the snow cover were determined in towns that were sources of pollution and near settlements located on the coast of Lake Baikal and at the Selenga River mouth. The industrial centers of the region and the southern basin of Baikal, being affected by the air emissions from the Irkutsk agglomeration, were determined to be the most susceptible to anthropogenic pollution. The middle and northern basins could be attributed to the background regions being affected only by local heating sources and the natural background. The main atmospheric pollutants and the areas of their distribution were established. The main sources of snow cover pollution in the region, in addition to the natural background, were emissions from thermal power plants and motor vehicles.
This paper analyzes the results of the automatic (in situ) recording of the regional transport of pollutants from the large regional coal-fired thermal power plants in the atmospheric boundary layer ...above the southern basin of Lake Baikal. Due to high stacks (about 200 m), emissions from large thermal power plants rise to the altitudes of several hundreds of meters and spread over long distances from their source by tens and hundreds of kilometers. The continuous automatic monitoring of the atmosphere in the southern basin of Lake Baikal on top of the coastal hill (200 m above the lake) revealed the transport of a large number of sulfur oxides and nitrogen oxides in the form of high-altitude plumes from thermal power plants of the large cities located 70 to 100 km to the northwest of the lake (Irkutsk and Angarsk). The consequence of such transport is the increased acidity of precipitation in the southern basin of Lake Baikal and the additional influx of biogenic nitrogen compounds to the lake ecosystem. The spatial scale and possible risks of such regional transport of air pollution for the lake ecosystem require further closer study.
A precipitation monitoring station in Listvyanka was set up to determine the potential impact of the coastal area on the state of the adjacent air environment above Lake Baikal on its southwest ...coast. This article presents the results of studying the chemical composition of atmospheric deposition (aerosols and precipitation) at this station in 2020, and of their comparison with the data from previous years (from 2000 to 2019). In 2020, the ionic composition of atmospheric aerosols and precipitation had changed compared to previous years. In the modern period, the total amount of ions in aerosols, accounting for 0.46 ± 0.40 μg∙m−3, was lower by an order of magnitude than between 2000 and 2004. The average annual total amount of ions in precipitation in Listvyanka was almost unchanged from the average values in 2000–2010 and was 10% lower than that from 2011 to 2019 (7.3 mg/L). The ratio of major ions of sulphates and ammonium changed in the aerosol composition: compared to the period from 2000 to 2004, in 2020, the contribution of ammonium ions had decreased significantly, from 32% to 24%; the contribution of sulphates had increased to 43%, and the contribution of calcium had increased from 8 to 13%. Since 2010, the contribution of K+ ions has increased to 8–10%, indicating the effect of smoke aerosols from wildfires. In precipitation, despite the dominance of sulphates (26%) and calcium (18%) throughout the year, the contribution of nitrates increases to 19% during the cold season (from October to March), while the contribution of ammonium ions and hydrogen ions increases to 13% and 17%, respectively, in the warm season (from April to September). In 2020, as in previous research years, the acidity of precipitation at the Listvyanka station was elevated (pH 5.1 ± 0.5); 50% of precipitation in 2020 had pH ˂ 5. We quantified ions in atmospheric aerosols and precipitation on the underlying surface of the coastal southwestern part of Lake Baikal. Ion fluxes with precipitation were the highest in the warm season, which corresponds to the annual maximum precipitation. Unlike previous years (from 2000 to 2010 and from 2011 to 2019), wet deposition of most ions—especially calcium, ammonium and nitrates—had decreased in 2020. There was a 35-fold decrease in nitrogen fluxes and a 5-fold decrease in sulphur fluxes in aerosols, as well as 1.6-fold and 1.3-fold decreases, respectively, in precipitation.
The aim of this study was to identify particulate matter (PM) sources and to evaluate their contributions to PM in the snowpack of three East Siberian cities. That was the first time when the PM ...accumulated in the snowpack during the winter was used as the object for source apportionment study in urban environment. The use of long-term integrated PM samples allowed to exclude the influence of short-term weather conditions and anthropogenic activities on PM chemistry. To ascertain the real number of PM sources and their contributions to air pollution the results of source apportionment using positive matrix factorization model (PMF) were for the first time compared to the results obtained using end-member mixing analysis (EMMA). It was found that Si, Fe and Ca were the tracers of aluminosilicates, non-exhaust traffic emissions and concrete deterioration respectively. Aluminum was found to be the tracer of both fossil fuel combustion and aluminum production. The results obtained using EMMA were in good agreement with those obtained using PMF. However, in some cases, the non-point sources identified using PMF were the combinations of two single non-point sources identified using EMMA, whereas the non-point sources identified using EMMA were split by PMF into two single non-point sources. The point sources were clearly identified using both techniques.
Eutrophication is a major ecological problem and affects and endangers freshwater bodies, making assessment of the trophic status of water bodies crucial for their restoration and sustainable use. ...Lake Baikal is affected by a number of environmental stressors, including coastal eutrophication. Daily measurements of concentrations of nutrients, dissolved oxygen (DO), chlorophyll-a (Chl-a), weekly measurements of algae abundance and biomass in the open water season in June-December 2020, and measurements of concentrations of nutrients at 2–7-day intervals in June-October 2021 were made in the littoral of the South Baikal for the first time. It was shown that nitrate and phosphate concentrations decreased by July-August, their minimum content was maintained until September, concentrations began to increase in October and reached a maximum in December. The maximum abundance and biomass of algae and chlorophyll concentrations were only observed in early July. Storm situations increased the content of nitrogen, phosphorus and DO in water, the duration of their influence was not more than 2 days. A correlation matrix revealed significant positive correlations of NO3−-DO, phosphate (SPR)-NO3−, SRP-DO and biomass-Chl-a and strong negative correlations between water temperature (Tw)-DO, Tw-NO3−, Tw-total nitrogen (TN) and Tw-SRP. Based on SRP and NO3− concentrations and TN:TP ratios, it was concluded that algal development was limited to nitrogen and phosphorus in summer. The trophic status of the Southern Baikal littoral zone was assessed using classifications based on TN, TP, NO3−, SRP, Chl-a content and algal biomass, as well as the Carlson index (TSI) and probabilistic assessment. The results of assessments using different methods of trophic status determination showed that the Baikal littoral zone in the study area belongs to the oligotrophic type with minor elements of mesotrophy. According to the saprobity index, water purity of littoral waters varies within the oligosaprobic and β-mesosaprobic zones and corresponded to quality classes II and III (clean and moderate purity); the system demonstrates a high capacity for self-purification.
Research has focused on the effect of sulphate and nitrate atmospheric deposition on river water chemistry in the Baikal region. During long-term monitoring it was ascertained that anthropogenic SO
2
...and NO
x
in the plumes emitted from regional coal Power Plants (PPs) cause extra nitrate and sulphate deposition in the Pereemnaya River basin that is located 100-150 km away from the emission sources. As a result, average concentrations of sulphate and nitrate in the water of the Pereemnaya River are 2-3 times higher than those in Lake Baikal, whilst total mineralisation of the river water is approximately 3 times lower. Because of the acidity of atmospheric deposition in the Pereemnaya river basin, pH value of the snow cover and precipitation is about 4.7. That makes the river water pH significantly lower (=6.8) than that in the lake and other tributaries (=7.8). It is recommended to strengthen monitoring of the natural environment in the southern basin of Lake Baikal and to apply measures to reduce pollutant emissions from PPs.
The composition of the snow cover in the Arctic characterizes the winter atmosphere, when long-range and ultra-long-range transport becomes dominant in the influx of aerosols. In addition, when snow ...occurs on the ice of a water body, the “snow — ice — under-ice water” cryosystem is formed. The components of this system mutually influence each other. In March 2023, to research the ionic and algological composition of the snow cover snow samples were taken in the estuaries of three rivers in the Nenets Autonomous Area (the Indiga River, the Pyosha River and the Pechora River). In the field, the characteristics of snow cover were identified. Snow samples were melted at room temperature, after which the pH level and mineralization were determined. Further, the concentrations of the major ions and nutrients were identified in the filtrate, as well as the species composition and abundance of microalgae. It is shown that the snow cover in the river estuaries of the southern-eastern Barents Sea has a unique composition. It is formed in conditions of close interaction with both air and water environments. In winter, in addition to the atmospheric transport of marine aerosol, seawater seeping through the ice can enrich the snow cover with salts, thereby increasing mineralization and pH levels. This effect is most clearly seen in the estuary of the Indiga River, a little less — in the estuary of the Pyosha River. Marine arctic species of diatom microalgae were found in the snow cover in the estuaries of both rivers. The development of diatoms was promoted by the concentration of nutrients, which exceeded the values limiting the development of microalgae. The main channel for the entry of microalgae can be seawater seeping through the ice during high tide.
The relationship between oxygen saturation and the 'a' chlorophyll content in the surface layer of the White Sea is revealed. The possibility of using the oxygen saturation index in estimating the ...trophicity of the White Sea waters is discussed. Data obtained in 2001-2014 is analyzed. Seasonal maps of the indicator distribution are made. A tendency of a general decrease of the oxygen saturation and 'a' chlorophyll content in the surface layer of the White Sea from spring to autumn is noticed. A positive relationship between the oxygen saturation and the 'a' chlorophyll content in the surface waters of the White Sea is shown.
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