Seasonal, Weekly, and Diurnal Black Carbon in Moscow Megacity Background under Impact of Urban and Regional Sources

Abstract

Moscow megacity has a big gap in assessment of air quality, resulting in severe aerosol pollution. Black carbon (BC) concentrations over different timescales, including weekly and diurnal, are studied during four seasons of 2019–2020 at urban background site. Seasonal BC varies from 0.9 to 25.5 μg/m3 with a mean of 1.7 ± 1.4 μg/m3. Maximum mean BC equal to 2.2 ± 1.8 μg/m3 was observed in spring. Diurnal trends of black carbon concentrations differ in spring/summer and autumn/winter periods, they exhibit morning and evening peaks corresponding to traffic combined with the boundary layer height effect. The weekly cycle of BC characterizes the highest amount of combustion-related pollution on working days and the characteristics of population migration from a city for weekend. Seasonal pollution roses show the direction of the highest BC contamination. For identification of BC sources relating to traffic, heat and power plants, and industry around the site, polar plots are used. The spectral dependence of the aerosol light attenuation provides the estimate for Absorption Angstrom Exponent (AAE). We use the AAE above 1.3 and high frequency of AAE observation above 1 in order to support the assessment for a contribution of biomass burning in the region around Moscow in autumn and winter as well as of agriculture fires and wildfires in warm seasons. Air masses arriving to a city from fire-affected regions in spring and summer impact urban air pollution.

Columnar and surface urban aerosol in the Moscow megacity according to measurements and simulations with the COSMO-ART model

“…BC measurements in the center of Moscow have revealed substantially lower levels of air pollution than in Beijing (Golitsyn et al, 2015). The levels of BC concentration are similar to those in European cities, which indicates the comparable impacts of major urban sources such as traffic with intensive implementation of modern environmental requirements, heating power plants and manufacturing industries (Popovicheva et al, 2020(Popovicheva et al, , 2022.…”

“…The pronounced negative correlations with wind speed were found for surface aerosol species, such as PM 10 and, especially, BC. Negative correlation between BC and wind speed was also shown in Chen et al (2014) and Popovicheva et al (2020). Note that the observed negative correlation of the BC/PM 10 ratio with wind speed may lead to the decrease in the absorbing properties of the atmosphere in case of high wind speed.…”

“…There is the absence of a morning BC maximum in Moscow during rush hours, which was observed in many other cities, for example, in Tomsk (Kozlov et al, 2011), in Ahmedabad (Ramachandran andRajesh, 2007) and in Athens (Diapouli et al, 2017). It can be explained by the specific regulation of diesel-heavy trucks, which have permission of entry only at night in Moscow (Popovicheva et al, 2020). In addition, it is necessary to account for a specific location of the MSU MO at a distance from the direct sources of urban emissions (highways).…”

“…The calibration parameter for quantification of eBC mass was derived during parallel longterm measurements against an AE33 aethalometer (Magee Scientific) that operates at the same three wavelengths. More details can be found in Popovicheva et al (2020).…”

Ecological Zoning of the Baikal Basin Based on the Results of Chemical Analysis of the Composition of Atmospheric Precipitation Accumulated in the Snow Cover

“…Studies on snow cover monitoring can be divided into several groups: local, regional, or global. Most of them are devoted to the state of the environment in industrial centers [14][15][16][17][18][19][20]. Some studies assess the impact of a specific industrial group of sources [21][22][23][24][25][26] or a certain anthropogenic substance [27,28] on the environment by means of snow cover analysis.…”