The results of continuous observations of the mass concentration of black carbon (BC) and PM10 and PM2.5 aerosols in the near-surface layer of the atmosphere in the center of Moscow metropolis in 2022 are considered. The results are interpreted applying meteorological data, backward trajectories of air mass transport to Moscow, and MERRA-2 reanalysis data on the spatial distribution of dust and BC in near-surface air of the center of European Russia. The days (less than 9

An Erratum to this paper has been published: https://doi.org/10.1134/S1028334X2307005X

Outflows of absorbing aerosol (black carbon) from continental regions of midlatitudes affect appreciably the climate and ecological state of the Arctic Ocean. We present a statistical generalization of the absorbing sub-stance concentrations was measured in the equivalent of black carbon (eBC) in the atmosphere of the Eurasian sector of the Arctic Ocean (from the Greenland to Chukchi Seas), which is based on the largest amount of in-situ measurements in 28 marine expeditions. Our research results show a common regularity for all investigated regions of the Arctic Ocean with eBC decreasing with latitude rising (increasing distance from continent). The average decreasing gradient of the eBC concentrations per 1 degrees latitude is 3.2 ng/m3 over the Barents Sea and 1.3 ng/m3 over the Kara Sea. The atmosphere of the Barents Sea stands out in the largest black carbon content: the average and modal eBC values are 56 and 15 ng/m3 respectively. Relative to the maximum over the Barents Sea, the eBC concentrations decrease to 20 ng/m3, in both the western (the Greenland Sea) and eastern directions (the East Siberian and Chukchi Seas). More than a factor of two decrease in the eBC concentrations from the Barents sea to Far East seas indicates that the total contribution of outflows of absorbing aerosol from Asian part is smaller than from the north of Europe. Episodic outflows of the strongest pollution (more than 150 ng/m3) are noted to have a significant effect on the statistical characteristics of black carbon. These situations are observed most often in the atmosphere of the Barents and Kara Seas. Under the influence of these anomalies, the average eBC concentrations increase by a factor of 1.5, and the coefficients of variations by a factor of 1.7-2.4. The maps of the average spatial distribution of the eBC concentrations, measured in marine expeditions, qualitatively agree with multiyear data from model calculations (MERRA-2 reanalysis). The main difference is the higher model eBC values in the southern part of the Laptev Sea and the East Siberian Sea. A comparison of the two data types in these regions, matched to be coincident in time and collocated in space, confirmed that the model eBC con-centrations overestimate measurements by 5.68 ng/m3 on the average. Of two reasons for this difference, more probable (as the authors think) is that the model calculations overestimate the outflows of absorbing aerosol to the eastern sector of the Arctic Ocean.

According to the monitoring data of the optical and microphysical characteristics of smoke aerosol at AERONET stations during forest fires in the summer of 2019 in Alaska, the anomalous selective absorption of smoke aerosol has been detected in the visible and near-infrared spectral range from 440 to 1020 nm. With anomalous selective absorption, the imaginary part of the refractive index of smoke aerosol reached 0.315 at a wavelength of 1020 nm. A power-law approximation of the spectral dependence of the imaginary part of the refractive index with an exponent from 0.26 to 2.35 is proposed. It is shown that, for anomalous selective absorption, power-law approximations of the spectral dependences of the aerosol optical extinction and absorption depths are applicable with an Ångström exponent from 0.96 to 1.65 for the aerosol optical extinction depth and from 0.97 to –0.89 for the aerosol optical absorption depth, which reached 0.72. Single scattering albedo varied from 0.62 to 0.96. In the size distribution of smoke aerosol particles with anomalous selective absorption, the fine fraction of particles of condensation origin dominated. The similarity of the fraction of particles distinguished by anomalous selective absorption with the fraction of tar balls (TBs) detected by electron microscopy in smoke aerosol, which, apparently, arise during the condensation of terpenes and their oxygen-containing derivatives, is noted.

Based on monitoring from AERONET stations in the Beijing region in the twenty first century, it is found that, during transport of dust haze with the aerosol optical depth up to 4.0–4.5, the optical and microphysical characteristic of dust aerosol are determined by coarse particles with modal radii of ∼2–4 μm and a mass content of dust aerosol reaching 11–12 g/m2. Data of monitoring from the Beijing and Xinglong stations in April 2006 and from the Beijing-CAMS station in March 2021 indicate that the imaginary part of the refractive index of dust aerosol under the conditions of optically dense dust haze is comparatively small, from 0.0005 to 0.003, with 54 and 77% detection probabilities at the Beijing and Xinglong stations, respectively, in April 2006. The analysis of the spatial distribution of the aerosol optical depth and the wind field reanalysis data showed that the long-range dust aerosol transport from Takla-Makan desert to North China Plain (NCP) was observed in April 2006. The aerosol radiative forcings at the top and bottom of the atmosphere are calculated for the period of dust haze propagation on the territory of China. During intense transports of dust aerosol to the Beijing region, the efficiency of the aerosol radiative forcing is shown to be 85 W/m2 at the top of the atmosphere and 135–140 W/m2 at the bottom of the atmosphere. Using the wind field reanalysis data, aerosol optical depth satellite monitoring data, and retrievals of the optical and microphysical characteristics of the tropospheric aerosol, we estimated the dust aerosol mass flux from Takla-Makan Desert to NCP (∼1.5 ton/s) in April 2006 and the daily total dust aerosol mass transport (∼1.5 million tons).

Using the measurement data in a wind–sand flux on the desertified areas of Astrakhan oblast and Kalmykia, it has been established that the time variability of saltating and dust aerosol particle concentrations, the electric characteristics of the wind–sand flux, including electric currents of saltation, the volume charge of dust aerosol particles, and the electric field intensity in the near-surface layer of the atmosphere within a range of ~30 s to 30 min are determined by the low-frequency variations in the horizontal component of the wind velocity. According to the data of measurements, over the desertified area, the electric charge surface density reaches +25 nC/m2. The empirical probability distribution of a specific charge for sand grains under the condition of quasi-continuous saltation is obtained. A saltation initiation mechanism by electric discharges on the underlayer surface is proposed. An analytical model of particle liftoff to the near-surface layer of the atmosphere by electric discharges on the underlayer surface is presented. It is shown that, during the electric (corona) discharge, the saltating particle launch velocity can exceed 1 m/s.

Measurements of electric currents of saltation in the wind-sand flux and currents caused by the wind transport of dust aerosol particles have been carried out in the desertified territories of Astrakhan oblast and Kalmykia. Empirical distribution functions of the specific charge of saltating particles in a wind-sand flux are presented for the conditions of quasi-continuous and intermittent saltation. It is established that the electric charge surface density reaches +25 nC/m 2 . It is shown that the local electric field on the surface of the saltating particles can exceed 450 kV/m. An abnormal high electrization mechanism of the wind-sand flux is proposed, including the initiation of high-speed saltation: electric (corona) discharges on the underlying surface, which makes it possible to consider the wind-sand flux a dusty plasma. An analytical model has been developed for the escape of saltating particles from the underlying surface during a corona discharge. It is shown that, when saltation is initiated by a corona discharge, the escape velocity of charged particles can exceed 1 m/s.

The characteristics of acoustic-gravity waves (waveforms, time durations, amplitudes, azimuths and horizontal phase speeds) from the eruption of the Hunga-Tonga-Hunga-Hapai volcano detected at different infrasound stations of the Infrasound Monitoring System and at a network of low-frequency microbarographs in the Moscow region are studied. Using the correlation analysis of the signals at different locations, six arrivals of signals from the volcano, which made up to two revolutions around the Earth, were detected. The Lamb mode of acoustic gravity waves from the volcano eruption is identified and the effect of this mode on generation of tsunami waves and variation of aerosol concentration is studied. The energy released from an underwater volcano into the atmosphere is estimated from the parameters of the Lamb wave and compared with the energy released from the most powerful nuclear bomb of 58 Mt TNT.

Data on black carbon (BC) concentration C BC in the air basin of Moscow, and 5-day back trajectories of air mass motion, obtained in the period of 2003–2014, were used to determine the dependence of variations in black carbon concentration in the air basin of Moscow on the direction of air mass transport, and to determine the black carbon source regions. The 12-year measurements of black carbon concentration in Moscow air are used to show that the С BC variations are determined by the character of the air mass circulation in the troposphere. Measurements of black carbon content in the Moscow air basin in June–September 2019 and 10-day back trajectories of air mass transport were used to study the effect of the latter on the air pollution level in Moscow.

In Russian Arctic seas, observations of surface methane concentrations (CH4), ozone, nitrogen and carbon oxides, as well as the content of $${{\delta }^{{13}}}{{{\text{C}}}_{{{\text{C}}{{{\text{H}}}_{4}}}}}$$ isotope and black carbon (BC, soot aerosol), were carried out from onboard of the R/V Academician Mstislav Keldysh. The areas of local methane releasing from bottom sediments were investigated. It was shown that the studied methane releasing on the Arctic shelf are of a local nature and, on the whole, insignificantly affect the composition of the atmosphere in the region. The average concentration of methane in the surface air in the Arctic seas is mainly determined by large-scale processes of air mass transfer. An analysis of the distribution of black carbon along the route of the vessel was carried out. It was found that the excess in the concentration of black carbon over the background values is observed occasionally during advection of air masses from the mainland and from the areas of associated gases burning and forest fires. The effect of emissions from a ship’s chimney on the data obtained was analyzed.

We discuss the measurements of black carbon concentrations in the composition of atmospheric aerosol over the seas of the North Atlantic and European sector of the Arctic Ocean (21 expeditions in 2007–2020). The black carbon concentrations were measured by an aethalometer and filter method. The comparison of the two variants of the measurements of the black carbon concentrations showed that the data acceptably agreed and can be used jointly. It is noted that the spatial distribution of black carbon over the ocean is formed under the influence of outflows of air masses from the direction of continents, where the main sources of emission of absorbing aerosol are concentrated. We analyzed the statistical characteristics of black carbon concentrations in five marine regions, differing by the outflows of continental aerosol. The largest black carbon content is a salient feature of the atmosphere of the North and Baltic Seas, surrounded by land: average values of concentrations are 210 ng/m3, and modal values are 75 ng/m3. In other regions (except in the south of the Barents Sea), the average black carbon concentrations are 37–44 ng/m3 (modal concentrations are 18–26 ng/m3). We discuss the specific features of the spatial (latitude-longitude) distributions of black carbon concentrations, relying on ship-based measurements and model calculations (MERRA-2 reanalysis data). A common regularity of the experimental and model spatial distributions of black carbon is that the concentrations decrease in the northern direction and with the growing distance from the continent: from several hundred ng/m3 in the southern part of the North Sea to values below 50 ng/m3 in polar regions of the ocean.

A comparative analysis of measurements of black carbon concentrations in the composition of atmospheric aerosol is carried out using two aethalometry methods: on the basis of collecting aerosol samples on filters and with the use of aethalometer. The two independent techniques for measuring the black carbon concentrations are shown to well agree: the cross-correlation coefficient is 0.87, the standard deviation is 17 ng/m3, and the systematic component is 0.65 ng/m3.

We discuss the measurements of black carbon concentrations in the composition of atmospheric aerosol over seas of the North Atlantic and European sector of the Arctic Ocean (21 expeditions). A comparative analysis of statistical characteristics, calculated for separate marine regions, is carried out. A higher black carbon content in the atmosphere of the North Sea and in the south of the Barents Sea is noted. We present estimates of the average latitude-longitude distribution of aerosol characteristics, measured in expeditions, in comparison with MERRA-2 reanalysis data.

Automated instruments for measuring of (1) the dust aerosol particle concentrations and the dust aerosol particle size distribution function, (2) the vertical turbulent fluxes of the dust aerosol and (3) the electric characteristics of the windsand flux. The dust aerosol particle concentrations in the range from 0.5 to 5.0 mcm at heights 2 m and 20 cm were measured. The vertical turbulent fluxes and the uplift rate (reached 5 cm/s) of the dust aerosol were determined. Influence of the convective structures on the emission and turbulent fluxes of the dust aerosol was found. It was established that the average volume electric charge of the dust aerosol reached – 70 nC/m3 and the electric charge density at the surface did not exceed + 25 nC/m2 .

According to measurement data on the desertified area in the Astrakhan oblast in the conditions of non-intermittent saltation, a strong influence of convective quasiperiodic structures with periods from 1.5 to 8 minutes on variations of the saltating particle concentrations are found. Statistical characteristics of the saltating particle concentrations variations are received. The vertical profile of the average particle concentration in the height range from 3 to 15 cm is obtained. An exponential approximation of the particle concentration profile with a logarithmic gradient of -0.32 cm−1 is proposed. It is shown that the average particle content in the saltation layer is 8.6 cm−2.

The concentration of black carbon (BC), measured in near-surface air on the territory of the Pechora-Ilych State Natural Biosphere Reserve (PISNBR) on the western side of the Northern Ural Mountains, far from sources, is presented for two years (December 2017–November 2019). The temporal variations in BC concentration throughout a year and the location of its main sources are analyzed. The average values for two cold and two warm half-years were 128 and 62 ng/m3, respectively. The BC concentration in near-surface atmosphere was compared with MERRA-2 reanalysis data. On a monthly scale, the anomalous increase in BC concentration during short-term smoke aerosol transport across the observation area is more clearly revealed from the reanalysis data, rather than by values measured at a single point. Daily monitoring allows us to detect the specific dates of such situations.

Data on black carbon (BC) concentrations obtained from the board of research vessels (R/V), “Acad. Mstislav Keldysh”, “Acad. M. A. Lavrentyev” and “Prof. Molchanov” in 2011–2018. They were used to study the quantitative distribution of black carbon in the driving air layer over the seas of the Russian Arctic in the summer-autumn period and to determine its main source regions. Variations in the BC content in the near water layer of the atmosphere at the North Pole, in the Norwegian, Barents, Kara, East Siberian Seas and the Laptev Sea are obtained. As a result of 12 marine expeditions in the summer-autumn period of 2011 - 2018 the BC concentration in the atmospheric drive layer in the Arctic was mainly at the background level and averaged 47 ng/m 3 (9-95 ng/m 3 ). An increase in the BC concentration by several times, as shown by trajectory analysis, occurs occasionally upon receipt of air masses from the mainland, from areas of associated gas combustion. Low BC values were observed when air masses passed over the water surface from the northern regions of the Arctic. The BC concentration above the water surface depends on the state of the atmosphere in the region of soot sources on the mainland.

Size distributions of saltating aleurite and sand particles have been measured in a windsand flux in a desertified area in Astrakhan oblast. The distributions are approximated by a sum of lognormal distributions for the aleurite-sand and aleurite fractions. The threshold wind velocity for the total particle concentration is determined under conditions of nonintermittent saltation. It is found that the threshold velocity depends on the size of saltating particles. Empirical approximations of the total number concentration and differential particle concentration of aleurite and sand particles as functions of wind velocity are obtained.

The paper presents the results of a study of the concentrations of black carbon in the marine boundary layer over the Baltic and North Seas, the North Atlantic, the Norwegian, the Barents, the Kara and the Laptev seas from June 30 to September 29, 2017 in the 68th and 69th voyages of research vessel "Akademik Mstislav Keldysh". Black carbon has a significant impact on climate change and the degree of pollution of the Arctic. Black carbon is formed as a result of incomplete combustion of fossil fuels (primarily coal, oil) and biomass or biofuel. It consists of submicron particles and their aggregates and can be transported a great distance from the source. Samples were taken by pumping air for 46 hours through quartz filters Hahnemule at an altitude of 10 m above sea level in a headwind to prevent smoke of the vessel from entering the filters. Subsequently, the black carbon content was determined in the laboratory by the aetalometric method. The backward trajectories of the air mass transfer and the black carbon particles transported by them to the sampling points were calculated using the HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) model at http://www.arl.noaa.gov/ready.html. The conducted studies show low values of black carbon concentrations (50 ng/m3) along the expedition route when air masses came from the background areas of the North Atlantic and the Arctic. High concentrations of black carbon (100200 ng/m3 and higher) are characteristic for areas with active navigation (the South-Eastern Baltic, the North Sea) and near ports (eg Reykjavik), as well as for incoming air masses from the industrialized regions of Europe to South-Eastern Baltic and from areas of oil and gas fields where associated gas is flared (the North, the Norwegian and the Kara seas).