Home – Home – Jornals – Atmospheric and Oceanic Optics 2022 number 6

We consider the usefulness of satellite data to estimate atmospheric instability and precipitable water vapor for the cases with severe convective events occurred over the European Russia and the Ural region. The initial sample includes 305 squalls, tornado, and large hail events. We evaluated the values of the instability parameter Lifted Index (LI) and precipitable water vapor (PW) using MODIS Atmospheric Profile Product data as well as the ERA5 reanalysis data. It was found that the median values of LI and PW according to the MODIS and ERA5 data are rather close, while the extreme values substantially differ. Local areas with very strong instability and high PW were identified from MODIS data, but not detected according to the reanalysis data. We found major limitations of the MODIS data associated with rather low frequency of imagery and the lack of information on the instability parameters for cloudy pixels. In particular, it reduced the sample size from 305 to 95 cases.

The results of the complex study of the composition and temporal variability of urban aerosol in near-surface air in the center of Moscow during two winter seasons (2019/2020 and 2020/2021) are discussed. Daily data on PM₁₀ and PM_2.5 concentrations and the total aerosol mass concentration (by gravimetric method) and 65 chemical elements included in its composition measured for 35-40 days every season are considered. The aerosol composition is compared with the meteorological parameters in near surface air in Moscow, the direction of long-range air mass transport to the Moscow region, and the distribution of dust in near-surface air over the European Russia (according to the MERRA-2 reanalysis). The detailed study of the aerosol elemental composition in Moscow allowed us to identify the elements of global/local distribution and of natural/anthropogenic genesis. Concentrations of all aerosol components under study in Moscow in winter did not exceed the corresponding daily average MPC values for the air of residential areas. It is shown that PM₁₀ and PM_2.5 are accumulated in the near-surface air of the city in calm conditions. The maximal levels of aerosol pollution were observed in the first part of December 2020 with south-easterly winds, when long-range atmospheric transport of impurities to Moscow took place from sources located in the arid south zones of European Russia, in the Caspian Lowland and in western Kazakhstan.

We discuss the results from measurements of aerosol physicochemical characteristics in summer 2021 in the Greenland-Kara sector of the Arctic Ocean (83rd and 84th cruises of RV “Akademik Mstislav Keldysh”). The studied characteristics included: the aerosol optical depth of the atmosphere, the aerosol and black carbon concentrations, as well as the chemical composition of aerosol samples, i.e., the concentrations of main elements, the concentrations of organic and elemental carbon, and the isotopic composition of carbon. For the most aerosol characteristics we noted lower average values as compared to the three preceding expeditions. Data from five expeditions are used to estimate the differences in the aerosol and black carbon concentrations among the Kara, Barents, Norwegian, and Greenland Seas.

The results of long-term (2007-2021) complex experimental studies of microphysical parameters, mass concentration and elemental composition of aerosol particles in the surface air layer of semiarid zones in the south of European Russia are presented. Background values of the daily average mass concentration of near-surface aerosols in the deserted areas of Kalmykia and dry-steppe zone of Rostov region are estimated for the hot summer period: 125 and 34 mg/m³, respectively. The particle size distribution functions typical for atmospheric aerosols of the regions under study are determined. The processes of aerosol particle removal are studied in connection with the main atmospheric processes. Insignificant variations in the mass concentration of only Cd, Hg, and Cu are revealed in aerosols in Rostov region. The elemental composition of Kalmykia aerosols is more variable in both natural and man-made elements, mainly in chemical elements of salt balance and heavy metals. It is shown that most elements are weakly accumulated in aerosols, and their differentiation depends more on the mosaic of the underlying surface. During the long-term period under study, a trend toward purifying the deserted territories of the south of European Russia from harmful atmospheric impurities is found, presumably as a result of reducing climate aridization and/or anthropogenic effect.

Microorganisms of atmospheric aerosols sampled at four stationary points with different anthropogenic load in Novosibirsk in the period from September 2020 to December 2021 are studied. Atmospheric aerosols were monthly sampled by atmospheric air filtration at reinforced Teflon membranes Sartorius for 12 h, with a two week lags. Under those sampling conditions, spore-forming bacteria of the genus Bacillus and cocci of the genera Staphylococcus and Micrococcus predominated among the cultured bacteria in winter. In the spring-summer and autumn samples of atmospheric aerosols, the concentrations and diversity of coccal forms, spore-forming and non-spore-forming bacteria, actinomycetes, and fungi sharply increased. We have identified a significant number of hemolytic spore-forming bacteria and staphylococci, which are multi-resistant to antibiotics and have enzymes contributing to infectious process development.

The long-term temporal variability of the microstructural characteristics of aerosol in the surface air layer, measured in the monitoring mode at the aerosol station of IAO SB RAS in 2000-2020, is analyzed. Estimates are made on the basis of the concentrations of submicron ( N_f ) and coarse ( N_c ) particles and their ratio N_f / N_c . Two data arrays are considered: “full” and for the “background” aerosol weather type. The range of variations in the annual average values of the total concentration of particles N ( r > 0.2 mm) is found to be 8-50 cm^-3, and for background situations, 5-30 cm^-3. No reliable long-term trends in the characteristics under study are revealed. Spectral analysis of the monthly average concentrations for the “background” array shows the presence of a significant (with a probability of 0,95) time period of about a year for N_f / N_c and N_f and its absence for N_c .

The chemical composition of dry deposition in the industrial center of Eastern Siberia, Irkutsk (Russia) in 2020 is analyzed. In the warm season, the content of PO₄³_¯ in the dry deposition was increased, especially in calm weather. In autumn, the average concentration of NH₄⁺ was three time higher as compared to August; Si²⁺, two time higher, and PO₄³_¯, three time lower.

The results of the study of pollen emission into the atmosphere of 24 anemophilic plant species and 3 entomophilic plant species for which optional anemophilia is possible are given. The percentage of clusters of two or more pollen grains of the total number of pollen particles entering the atmosphere is estimated. It is shown that such clusters were formed in significant quantities in all series of experiments. The percentage of pollen clusters attained ~ 71% of the total number of pollen particles, and of pollen grains in the clusters, ~ 94% of the total number of pollen grains.

Physicochemical and toxicological properties of biomass burning are of a big importance for assessment of wildfire impact on environment. However, the data on Siberian wildfires are much limited. The composition of Siberian biomass burning is studied in the Large Aerosol Chamber (LAC) of Institute Atmospheric Optics, Siberian Branch, Russian Academy of Sciences (Tomsk). Here, we present FTIR spectroscopy, gas chromatography-mass spectrometry, and liquid chromatography experimental data on composition of organic compounds in Siberian pine and forest debris smoke produced at smoldering and flaming phases and due to aging. Markers which allow identifying the combustion conditions and biomass type are established, namely, characteristic absorption bands, ratios of carboxyl and aliphatic functionalities, diagnostic ratios of polycyclic aromatic hydrocarbons (PAHs). Emission factors and carcinogenic risk for smoke PAH are assessed.

The results of experimental and numerical studies of long-term atmospheric contamination of the cement plant environ in the Iskitim city of Novosibirsk region are discussed. The object under the study is the snow cover. There are the data of network measurements of hydrogen value (pH), ionic components, suspended matter content accumulated for winter 2018/19. The numerical reconstruction of the pollution fields was carried out using low-parameter models in the approximations of a light and monodisperse impurity. A statistical analysis of the relationship between the content of impurities in snow samples and the values of the snow index (NDSI) calculated from high-resolution satellite images was carried out.

We consider the application of MODIS satellite data to the analysis of the condition of oil-producing Arctic territories. The state of the vegetation cover of the hydrocarbon fields in the Purovsky region of Yamalo-Nenets Autonomous Okrug: East-Tarkosalinskoye, Vyngayakhinskoye and Tarasovskoye for the period 2013-2020 are studied. Based on Terra/MODIS satellite data and ArcGis geoinformation system, we calculated the average values of the vegetation index EVI (Enhanced Vegetation Index) for the areas under study. The anthropogenic load on the oil and gas complex is mapped, and the dynamics of the vegetation of the territories of oil and gas fields in the Yamalo-Nenets Autonomous Okrug is analyzed.

The problem of revealing relationships between atmospheric parameters measured with GNSS receivers and characteristics of convective processes based on monitoring data in Kazan for 2010-2020 is solved in the work. Coherence and synchrony of variations in the precipitation intensity and potentially available convective energy with variations in the zenith tropospheric delay are most often detected on time scales smaller than 4 hours, with the wavelet correlation level higher than 0.8 in most cases.

Method for studying the effect of the mass flow from the particle surface on the drag coefficient in a wide range of Reynolds numbers is suggested. For this, two experimental setups have been developed and used for the study of the effect of air injection from the surface of a solid perforated sphere on the drag coefficient at various values of the velocity of injection flow in the range of Reynolds numbers of the airflow around a particle from 133 to 9900. It is shown that the drag coefficient of the particle decreases with an increase in the velocity of the gas injected from the surface of a solid spherical particle. The empirical equation for calculating the drag coefficient of a solid sphere in the self-similar regime depending on the ratio of the gas injection velocity and the airflow velocity has been derived from the regression analysis.