Long-term Dynamics of Sulfur and Nitrogen in the Snow Cover of Minsk

Trends in the levels of sulfur and nitrogen in the snow cover on the territory of Minsk over the 13-year period from 2007 to 2019 have been revealed. The results of observations at permanent sites in various parts of the city were used. Despite a significant interannual variability in the concentrations of sulfur and nitrogen in the snow, a general downward trend in the concentrations of sulfur and nitrogen combined with an upward trend in pH of precipitation was revealed. An average reduction (trend) in the concentration in the snow cover for 2007–2019 was 0.061 mg S/dm³ per year for sulfur, 0.009 mg N/dm³ per year for oxidized nitrogen, 0.003 mg N/dm³ per year for reduced nitrogen. It was found that the average rate of nitrogen reduction in the snow cover in Minsk over the period from 2007 to 2017 was comparable to the rate of reduction of these compounds at the European Monitoring and Evaluation Programme (EMEP) stations in Europe, while the average rate of oxidized sulfur reduction in Minsk exceeded that the respective parameter at the EMEP stations. The levels of the atmospheric inflow of sulfur and nitrogen have been assessed in terms of their spatial heterogeneity in the city, and their links with the level of air pollution and emissions have been described.