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The present study aimed to investigate atmospheric optical characteristics over the Gorky and Cheboksary Reservoirs and their multi-scale temporal variations to obtain the background characteristics and to identify events involving the transfer of absorbing aerosol to the studied region in 2022–2023. The region is located at a considerable distance (500 km) from the nearest AERONET station; therefore, previous atmospheric data were not available. As a solution, the in situ self-measured aerosol optical depth (AOD) and Angström exponent, as well as satellite products (MAIAC and CALIPSO) for MODIS data, were used. This allowed us to set background values of an AOD of 0.11 at a wavelength of 500 nm and an Angström exponent of 1.2, against their maximum values of 0.38 and 2.5, respectively. To explain these variations, the registered conditions and the microstructure of the dust aerosol over the studied region are presented. For days with background values, the analysis of the particle size distribution data did not show a predominance of any particle size. The optical properties of a smoke aerosol in an atmospheric column are described, and an analysis of the dynamics of particle size variability is presented. A comparative analysis of the optical characteristics of atmospheric aerosol over the Gorky and Cheboksary Reservoirs using in situ and MODIS products was carried out. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Anomalous absorption of finely dispersed smoke aerosol was recorded in large-scale smoke haze during mass fires in the boreal forests of Alaska in July 2019 in the visible and near-infrared regions of the spectrum (440‒1020 nm) according to the data of monitoring of the spectral dependences in the refractive index imaginary part on the network of AERONET stations. The variations in the spectral dependences of the aerosol optical depths (extinction and absorption), as well as the size distribution function of aerosol particles, are analyzed. During the anomalous absorption, the imaginary part of the refractive index increased by a factor of 1.8‒7.2 with an increasing optical wavelength from 440 to 1020 nm, reaching a value of 0.315 for the wavelength of 1020 nm. A power approximation is proposed for the spectral dependence of the imaginary part of the refractive index with indices of power approximately from 0.7 to 2.3. [ABSTRACT FROM AUTHOR]

Smoke aerosol dispersion and transport have a significant impact on air quality levels and can be examined by environmental monitoring and modelling techniques. The purpose of this study is to determine the characteristics of the smoke aerosols and the level of air quality during November and December 2019 under the influence of extensive bushfires in the Sydney area, New South Wales (NSW), Australia. To achieve this goal, air quality and meteorological data were analysed in combination with remote sensing satellite measurements. Meteorological and air quality data were obtained from the Bureau of Meteorology (BOM) and Environmental Protection Agency monitoring sites in NSW. In Richmond the daily maximum average hourly concentration of particulate matter (PM10) was 848.9 μg/m3 at 07:00 UTC on 26 November 2019 and 785 μg/m3 at 07:00 UTC on 12 December 2019. On 10 December 2019, the highest PM10 recorded in the Sydney region was 961.5 μg/m3 in St Marys at 01:00 UTC, while the highest PM2.5 concentration was 714.6 μg/m3 in Oakdale in southwest Sydney at 18:00 UTC. These values all decreased again to the standard level (<50 μg/m3) in a few days. The potential sources of smoke aerosols originated from bushfires to the northwest of Sydney (Blue Mountains) as well as from southwest and northwest NSW. The smoke plumes were revealed by the combined AOD values from Aqua and Terra sensors on the MODIS satellite. In each case, the smoke travelled towards the east coast of Australia and out over the Pacific Ocean. The NAAPS model displays the existence of smoke at ground level, while the CALIPSO satellite data showed that the plumes extended 14 km up into the stratosphere layer. Backward trajectories obtained from the HYSPLIT model agree well with the movement of smoke plumes observed in the MODIS satellite images. [ABSTRACT FROM AUTHOR]

Smoke aerosol dispersion and transport have a significant impact on air quality levels and can be examined by environmental monitoring and modelling techniques. The purpose of this study is to determine the characteristics of the smoke aerosols and the level of air quality during November and December 2019 under the influence of extensive bushfires in the Sydney area, New South Wales (NSW), Australia. To achieve this goal, air quality and meteorological data were analysed in combination with remote sensing satellite measurements. Meteorological and air quality data were obtained from the Bureau of Meteorology (BOM) and Environmental Protection Agency monitoring sites in NSW. In Richmond the daily maximum average hourly concentration of particulate matter (PM10) was 848.9 μg/m3 at 07:00 UTC on 26 November 2019 and 785 μg/m3 at 07:00 UTC on 12 December 2019. On 10 December 2019, the highest PM10 recorded in the Sydney region was 961.5 μg/m3 in St Marys at 01:00 UTC, while the highest PM2.5 concentration was 714.6 μg/m3 in Oakdale in southwest Sydney at 18:00 UTC. These values all decreased again to the standard level (3) in a few days. The potential sources of smoke aerosols originated from bushfires to the northwest of Sydney (Blue Mountains) as well as from southwest and northwest NSW. The smoke plumes were revealed by the combined AOD values from Aqua and Terra sensors on the MODIS satellite. In each case, the smoke travelled towards the east coast of Australia and out over the Pacific Ocean. The NAAPS model displays the existence of smoke at ground level, while the CALIPSO satellite data showed that the plumes extended 14 km up into the stratosphere layer. Backward trajectories obtained from the HYSPLIT model agree well with the movement of smoke plumes observed in the MODIS satellite images.

Small cumulus clouds over the western United States were measured via airborne instruments during the wildfire season in summer of 2018. Statistics of the sampled clouds are presented and compared to smoke aerosol properties. Cloud droplet concentrations were enhanced in regions impacted by biomass burning smoke, at times exceeding 3,000 cm−3. Images and elemental composition of individual smoke particles and cloud droplet residuals are presented and show that most are dominantly organic, internally mixed with some inorganic elements. Despite their high organic content and relatively low hygroscopicity, on average about half of smoke aerosol particles >80 nm diameter formed cloud droplets. This reduced cloud droplet size in small, smoke‐impacted clouds. A number of complex and competing climatic impacts may result from wide‐spread reductions in cloud droplet size due to wildfires prevalent across the region during summer months. Plain Language Summary: Wildfires over the western United States produce large quantities of smoke during the summer months. The smoke includes airborne particles that can act as nuclei for forming individual droplets in clouds. Particles and clouds in the region were sampled with a research aircraft to measure the properties of smoke particles and how they influenced the properties of small cumulus clouds. Clouds were strongly influenced by smoke across the western U.S. On average, sampled clouds had about 5x as many droplets, and droplets were about 1/2 the size, as in clouds not influenced by smoke. Because of their small droplet sizes, these smoky clouds are expected to reflect more light and produce less rain than clouds in clean air. Other complex effects are possible due to warming impacts of the smoke itself, and due to other potential impacts of smoke aerosols on larger, deeper clouds. Key Points: Western wildfires produce organic particles that readily act as cloud condensation nuclei due to their large size and partial hygroscopicityWildfire smoke strongly impacts the microphysics of small cumulus clouds, which have high droplet concentrations and small droplet sizesDiverse impacts on radiative forcing and precipitation are possible over the western U.S. and downwind due to wildfire smoke [ABSTRACT FROM AUTHOR]

Entry receptor for SARS-CoV-2 is expressed in nasal epithelial cells, and nasal delivery pathway can be a key feature of transmission. Here, a possibility of interaction of SARS-CoV-2 with air pollution particulate matter (PM) was considered. It was shown in our recent studies that water-suspended plastic and wood smoke aerosol PM and carbon-containing nanoparticles from burning organics can interact with the plasma membrane of brain nerve terminals presumably due to their lipid components. COVID-19 patients have neurological symptoms, viral particles were found in the brain, SARS-CoV-2 enters the cells via fusion of lipid viral envelope with the plasma membranes of infected cells, and so viral envelop can contain lipid components of the host neuronal membranes. Therefore, interaction of SARS-CoV-2 envelope with PM is possible in water surrounding. After drying, PM can serve as a carrier for transmission of SARS-CoV-2 immobilized at their surface. Moreover, PM and SARS-CoV-2 per se can enter human organism during nasal inhalation, and they both use the same nose-to-brain delivery pathways moving along axons directly to the brain, influencing the nervous system and exocytosis/endocytosis in nerve cells. Thus, PM can aggravate neurological symptoms of SARS-CoV-2 and vice versa, due to their identical nose-to-brain delivery mechanism and possible interference of neuronal effects. In addition, different types of PM because of their ability to interact with the plasma membranes of nerve cells can facilitate unspecific SARS-CoV-2 entrance to the cells, and can influence envelope features of SARS-CoV-2. Detailed studies are required to analyze interaction of SARS-CoV-2 with PM. [ABSTRACT FROM AUTHOR]

Ferula ovina Boiss. (Apiaceae) is a perennial rangeland medicinal plant found in the mountainous area of Iran. Due to overexploitation, climate changes in the area, and seed dormancy at time of maturity, the population of this species is being reduced. Accordingly, in the present study the effects of smoke treatments (aerosol smoke and two methods of smoke extract preparation) were investigated on seed germination characteristics of this plant after varying periods of cold stratification including 0, 7, 15, and 30 days. Findings suggested that cold stratification changed significantly the level of seed dormancy and increased the rate and percentage of seed germination. Furthermore, aerosol smoke applied after cold stratification increased the rate and percentage of seed germination. The greatest increase in germination percentage compared to control (20%) was observed in seeds that had been cold-stratified for 7 days and were exposed to aerosol smoke for two minutes. Smoke extracts with concentrations (0.001 - 0.01 v/v) prepared by the two methods also increased the germination of cold stratified seeds so that the maximum percentage of germination (80%) was obtained for seeds cold stratified for 30 days and treated with 0.001 dilution of charred straw solution. However, undiluted smoke water decreased the percentage of seed germination after 0 and 30 days of cold stratification and led to abnormal seedling development. In general, the results of this study demonstrated that smoke treatments improve seed germination percentage and speed of cold stratified Ferula ovina seeds.

Fires in southeastern Australia produced at least 18 pyrocumulonimbus (pyroCb) between 29 December 2019 and 4 January 2020. The largest plumes from this event exhibited several previously undocumented phenomena in the stratosphere. These include (i) the generation of potential vorticity and anticyclonic circulations from absorptive aerosol heating, (ii) the formation of a vertical temperature anomaly dipole, (iii) the rapid ascent from the lowermost stratosphere (15–16 km) to altitudes above 31 km in less than 2 months, (iv) an unprecedented abundance of H2O and CO in the stratosphere, and (v) the displacement of background O3 and N2O from rapid ascent of air from the troposphere and lower stratosphere. Each of these phenomena is traced back to a 5‐day‐old stratospheric plume composed of a massive amount of aerosol and biomass burning gases from a pyroCb outbreak. Until now, there has been no documented evidence that pyroCb plumes can affect stratospheric winds. Plain Language Summary: The 2019–2020 bushfire season in Australia has been referred to as the Black Summer by the Australian government due to the extreme amount of destruction it caused. One particularly intense period during this season was between 29 December 2019 and 4 January 2020, when an outbreak of huge thunderstorms fueled by very intense bushfires in southeast Australia emitted unprecedented amounts of smoke to heights 16 km above the surface. Multiple smoke plumes traveled around the Southern Hemisphere over the next few months. One plume (about 1,000 km across and 5 km thick) with very high smoke concentration traveled east from Australia to South America by late January, then reversed course, and completely circled the globe westward over the next few weeks. This plume showed several unusual characteristics, such as excessive lofting from 15 to 30 km due to smoke‐induced heating, low ozone, and high nitrous oxide concentrations typical of air at much lower altitudes and winds rotating around the plume at about 15 m s−1. Some of the smaller smoke plumes also showed significant rising and rotation. This is the first evidence of smoke causing changes to winds in the stratosphere and opens up a whole new vein of scientific research. Key Points: Pyrocumulonimbus plumes diabatically heated the local stratosphere, driving rapid ascent from the tropopause to heights above 31 kmA global model shows that these aerosol perturbations generated potential vorticity and anticyclonic circulations, lasting for 2 monthsH2O, CO, O3, and N2O concentrations suggest that the injected plumes experienced slow mixing and little chemical changes over this time [ABSTRACT FROM AUTHOR]

The content and evolution of brown carbon (BrC) in smokes from Siberian forest fires were analyzed using measurements of the aerosol absorption optical depth (AAOD) at three Russian AERONET stations located in Tomsk, Zvenigorod, and Yekaterinburg. Estimates are obtained of the relative contribution of BrC in fine aerosol particles to the absorption of solar radiation at a wavelength of 440 nm (ηBrC) and, in particular, for an anomalous episode of long-range transport of smokes from Siberia to the European part of Russia in summer 2016. A considerable BrC content is found in smokes in Tomsk and Zvenigorod (where ηBrC is estimated to be 15 and 18% on average). It is noteworthy that no significant ηBrC values were revealed during passage of smokes from Siberian fires over Yekaterinburg. The ηBrC values were found to decrease with aerosol aging under sunlit conditions on the characteristic timescale of about 30 h. At the same time, the measurements in Zvenigorod indicate that the absorption properties of the organic component of smoke aerosol increase during a much longer evolution. [ABSTRACT FROM AUTHOR]

The technique for constructing the spatial distribution of maximum aerosol optical depth (MAOD) has been used to estimate the optically dense haze expansion scales from July 15 to 31, 2016 (over an area of 20 million km2), including the record-scale Siberian smoke haze (SSH) with an area of around 16 million km2, smog over the Northern China Plain (around 2 million km2) and the adjacent offshore zones, a dust haze in the Taklamakan Desert (around 0.8 million km2), and hazes in India and Pakistan (almost 1 million km2). The empirical distribution function (EDF) of the MAOD is approximated by a linear function of the MAOD logarithm. The spatial distribution of aerosol optical depth (AOD) at a wavelength of 550 nm in the SSH has been analyzed. The total mass of smoke aerosol in the SSH has been estimated to be 3.2 million t, including around 2 million t over the territory of Siberia (50–70° N, 60–120° E) during the peak haze from July 22 to July 26, 2016. The qualitative composition of smoke aerosol in the SSH during its transport is illustrated through spatial and temporal variations in the aerosol index (AI). It is shown that AI variations are correlated with AOD variations. Aerosol radiative forcings (ARFs) at the upper and lower atmospheric boundaries over Siberia from July 22 to 26, 2016, have been estimated (with an average ARF of –68 and –98 W/m2). The EDFs of AOD and ARF at the upper atmospheric boundary have been approximated by exponential and power function of AOD, respectively. [ABSTRACT FROM AUTHOR]

Abstract: The smoke haze over the European part of Russia (EPR) and Belorus in July 2016 has been studied with the use of aerosol optical thickness (AOT) data measured by MODIS satellite spectrometers. The AOT maximum on the territory limited by coordinates 45°-70° N and 20°-60° E reached 2.95 on July 24, 2016 with an average regional value of 0.48. The total mass of smoke aerosol without the area covered by clouds was 0.73 million tons. Analysis of the wind fields and five-day back trajectories of air mass movement showed that the smoke was transported by the northeast winds to the EPR and Belorus from western Siberia, including the Yamalo-Nenets Autonomous District, which was characterized by large forest fires from July 17 to 23. Simulation of the radiation regime of the smoky atmosphere indicated that the average radiative forcings of smoke aerosol at upper and lower boundaries of the atmosphere for the above-mentioned territory are -29 and -54 W/m2, respectively (the extreme values are -124 and -154 W/m2, respectively). A comparative analysis of the smoke haze characteristics over the EPR in July 2016 and in summer 2010 has been conducted. According to ground-based measurement data, the mass concentration of PM10 during the smoke period from July 24 to 27 in the Moscow region reached 0.25 mg/m3. [ABSTRACT FROM AUTHOR]

Alternative finding of toxic pollutant materials in proper utilization is a great challenge. Toxic and pollutant cigarette smoke having different π-conjugated organic components may work well as a precursor for carbon dots (CDs). In this work, cigarette smoke aerosol has been used for the synthesis of CDs and CDs have been further used for the fabrication of supercapacitor electrode. This methodology could be able to mitigate the two major problems-energy crisis and environment pollution. The smart combination of EDLC-type CDs deposited boron nitride (BN) and pseudocapacitive type Zn-doped MoS 2 was able to enhance the supercapacitive performances. Heteroatom doping into MoS 2 enhances the capacitive performances through the effective Faradic reactions. CDs and CDs deposited BN (CDs@BN) have been characterized using different characterization techniques. Zn-doped MoS 2 has been uniformly grown on the CDs decorated BN (Zn–MoS 2 /CDs@BN) resulting in the stabilization of the electrode system. Zn–MoS 2 /CDs@BN nanohybrid delivered a specific capacitance (Sp.C) of 397 F/g in three-electrode system. Further, the asymmetric supercapacitor (ASC) device using Zn–MoS 2 /CDs@BN as cathode demonstrated wide potential range (up to 1.8 V) with a volumetric energy density of 3.42 mW h/cm3 and retaining a capacitance of ∼89% after 10,000 charging-discharging processes. Moreover, a flexible ASC device was made-up using viscous ionic electrolyte and it was able to glow a red LED, while it was bended in different angles. The methods described here will give a straightforward approach for using toxic-pollutant cigarette smoke to fabricate supercapacitor electrodes in order to compensate the upcoming energy crisis in a sustainable way. Cigarette smoke aerosol derived carbon dots decorated boron nitride supported Zn-doped MoS 2 for high performance flexible asymmetric supercapacitor device in low-cost viable ionic electrolyte. [Display omitted] • For waste to wealth perspective, synthesis of CDs using toxic pollutant cigarette smoke aerosol for flexible asymmetric supercapacitor device. • Synthesis of CDs induced BN supported Zn-doped MoS 2 using a facile hydrothermal method for the enhancement of electrochemical efficiency. • Zn–MoS 2 /CDs@BN, as positive electrode for the asymmetric supercapacitor achieved an enhanced energy density of 119 W h/kg with ∼91% retention of specific capacitance. • ASC device revealed decent volumetric energy density of 3.42 mW h/cm3. • Fabrication of flexible asymmetric supercapacitor in low-cost viable ionic electrolyte. [ABSTRACT FROM AUTHOR]

Serious forest fires were observed over Siberia, particularly in the vast area between Lake Baikal and the Gulf of Ob, during the period of 18–27 July 2016 using Moderate Resolution Imaging Spectroradiometer (MODIS) data. The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite simultaneously detected a multitude of smoke aerosols surrounding the same area. Combing a Lagrangian Flexible Particle dispersion model (FLEXPART) executed using the Weather Research and Forecasting (WRF) model output, the transport of smoke aerosols and the quantification of impact of Russian forest fires on the Asia were investigated. From model simulations, two transport paths were determined for the smoke plumes from the Russian forest fires. The first path was directed southwestward from Russia to Central Asia and eventually Xinjiang Province of China, furthermore, the second path was directed southeastward through Mongolia to Northeast China. The FLEXPART-WRF model simulations also revealed that the smoke aerosol concentrations entering the Central Asia, Mongolia and Northern China were approximately 60–300 μg m −3 , 40–250 μg m −3 and 5–140 μg m −3 , respectively. Meanwhile, the aerosol particles from these forest fires have an impact on the air quality in Asia. With the arrival of smoke aerosols from the Russian forest fires, the near-surface PM10 concentrations over Altay, Hulunbuir and Harbin increased to 61, 146 and 42 μg m −3 , respectively. In conclusion, smoke aerosols from Russian forest fires can variably influence the air quality over Central Asia, Mongolia and Northern China. [ABSTRACT FROM AUTHOR]

Results of measurements of the soot and fine aerosol mass concentration in the center of Moscow and at two points of the Zvenigorod Scientific Site (ZSS) in the spring-autumn periods of 2014-2016 are presented. The results are compared with data of complex measurements made during 1989-2013. Events where the increase in atmospheric air pollution by smokes from burning peat bogs in Bryansk oblast and smoke from burning trees infested by bark beetles in forests in Moscow region, as well as by forest fire smoke coming from Siberia, have been identified. The considerable increase in vehicle density during past 25 years near the ZSS measurement point located 150 m from a highway led to an increase in the level of air contamination by aerosol components by two or three times. At the second point, 1 km from the highway, the soot contamination level is comparable with data obtained in the 1990s and is approximately a third as high as in Moscow. [ABSTRACT FROM AUTHOR]

We have characterized the large-scale smoke pollution of the European territory of Russia (ETR) and adjoining areas in July 2017, caused by long-range transport from forest-fire areas in Siberia, confirmed by calculations of ten-day back trajectories of air mass motion to the ETR urban area, spanning Archangelsk to Rostov-on-Don. The smoke-laden ETR area with an AOD > 0.3 (average value being 0.43 and maximal value being 2.5) on July 25, 2016, covered 5 million km2, and the total smoke mass was ~1.2 million tons. It is shown that the daily average mass concentration of aerosol with particle sizes less than 2.5 μm exceeded the corresponding maximum permissible concentration in the Moscow region during the period from July 24 to 27, 2016. The influence of local sources on aerosol and gas pollution of atmospheric air was estimated. The smoke haze in 2016 was found to be deficient in carbon monoxide as compared to smoke pollution in 2010. It is shown that the thermal and wind stratification in the atmospheric boundary layer markedly influenced the pollution level in the smoke-laden urban atmosphere. Smoke aerosol radiative effect was estimated. The average aerosol radiative forcings at the top and bottom of the atmosphere over ETR on July 25, 2016, were-29 and-53 W/m2, and extreme forcings reached-112 and-215 W/m2, respectively. [ABSTRACT FROM AUTHOR]

We have investigated the variability of smoke aerosol absorbing ability with variations in the content of brown carbon (BrC) and black carbon (BC). Using monitoring data on radiative characteristics of smoke aerosol at AERONET stations and the spatial distribution of aerosol optical depth (AOD) obtained by the MODIS spectrometer (Terra satellite), we have detected large-scale smokes during boreal forest fires in Russia and Canada (1995-2012). The spatial distribution (50°-70° N, 95°-125° W) and temporal variability (at AERONET station Fort McMurray) of AOD during the smoking of a part of Canada in July 2012 have been analyzed. AOD probability distributions for July 14-18, 2012, and an estimate of aerosol radiative forcing of smoke aerosol at the upper boundary of the atmosphere have been obtained. We have proposed a technique for the diagnostics of BrC and BC in smoke aerosol particles from the spectral dependence of the imaginary part of the refractive index. At a wavelength of 440 nm, the contributions of BrC and BC to the smokeaerosol absorbing abitity can be comparable in magnitude. In many cases, the absorption spectra of smoke aerosol can be adequately approximated by either power or exponential functions. The presence of BrC in smoke-aerosol particles highly extends the variety of observed absorption spectra in a smoky atmosphere and spectral dependences of single scattering albedo. In the spectral range of 440-1020 nm, the radiative characteristics of smoke aerosol are largely contributed by its fine mode. [ABSTRACT FROM AUTHOR]

The mechanism of smoke haze formation over the European part of Russia (EPR) in the summer of 2016 is analyzed using satellite measurements, ground-based observations, reanalysis data, and trajectory modeling. The analysis reveals that smoke in the atmosphere over EPR with the aerosol optical depth increase up to 3 was caused by the long-range transport of combustion products from Siberian wildfires. The increase in the concentration of smoke aerosol in the atmosphere over EPR was accompanied by the increase in the concentration of carbon monoxide in the air. The long-range atmospheric transport of the products of pyrogenic emission from east to west for a distance up to 5000 km with the speed of 5-6 m/s predominantly occurred in the lower troposphere. The peculiarities of tropospheric circutation over Northern Eurasia in July 2016 are identified which were responsible for the transport of combustion products in the troposphere for thousands of kilometers in the direction opposite to the westerlies that prevail in the mid-latitudes. [ABSTRACT FROM AUTHOR]

Different microphysical, optical and radiative properties of aerosol were analyzed according to the 10 years of measurements (2001–2010) at the Meteorological Observatory of Moscow State University within the framework of international AERONET program. Volume aerosol size distribution was shown to have a bimodal character with dominating the fine mode aerosol particles at effective radius of reff-fine=0.15 µm. In smoke conditions reff-fine was shown to increase to 0.25 µm at extremely large aerosol optical thickness (AOT). Real and imaginary parts of refractive index are characterized by REFR=1.45, REFI=0.01 respectively, changing to REFR=1.49, REFI=0.006 for smoke aerosol. AOT seasonal changes are characterized by the increase towards warm period with a local minimum in June. The joint analysis of aerosol characteristics with the NOAA_NCEP_CPC_CAMS_OPI climatology shows the nature of these changes. For typical conditions aerosol single scattering albedo (SSA) is about 0.9 at 675 nm and is characterized by a distinct decrease with wavelength while in forest fires conditions it is significantly higher (SSA=0.95). The interaction between volume aerosol concentration of different aerosol fractions was obtained with a distinct decrease of variation towards large aerosol content.

Variations in the aerosol mass concentration in the smoky atmosphere of the Moscow region in autumn 2014 have been analyzed. The soot mass fraction and ratio between the PM2.5 and PM10 mass concentrations were typical of the fires in boreal forests. The smoke event in the Moscow region was due to the long-range transfer of the smoke aerosol, which was confirmed by a joint analysis of aerospace monitoring data and inverse trajectories of air mass transfer, and local fires in the Moscow region. As a result, statistical parameters of variations in the smoke aerosol mass concentrations were atypical, including empirical distribution functions and power spectra. [ABSTRACT FROM AUTHOR]

Abstract: The CALIPSO satellite mission consistently measures volume (including molecule and particulate) light depolarization ratio of ∼2% for smoke, compared to ∼1% for marine aerosols and ∼15% for dust. The observed ∼2% smoke depolarization ratio comes primarily from the nonspherical habits of particles in the smoke at certain particle sizes. In this study, the depolarization of linearly polarized light by small sphere aggregates and irregular Gaussian-shaped particles is studied, to reveal the physics between the depolarization of linearly polarized light and smoke aerosol shape and size. It is found that the depolarization ratio curves of Gaussian-deformed spheres are very similar to sphere aggregates in terms of scattering-angle dependence and particle size parameters when particle size parameter is smaller than 1.0π. This demonstrates that small randomly oriented nonspherical particles have some common depolarization properties as functions of scattering angle and size parameter. This may be very useful information for characterization and active remote sensing of smoke particles using polarized light. We also show that the depolarization ratio from the CALIPSO measurements could be used to derive smoke aerosol particle size. From the calculation results for light depolarization ratio by Gaussian-shaped smoke particles and the CALIPSO-measured light depolarization ratio of ∼2% for smoke, the mean particle size of South-African smoke is estimated to be about half of the 532nm wavelength of the CALIPSO lidar. [Copyright &y& Elsevier]

The shortwave radiative forcings of smoke aerosol in the cloudless atmosphere during the summer fires of 2010 in European Russia were quantitatively estimated for the land surface and the atmospheric upper boundary from measurement data obtained at the Zvenigorod Scientific Station of the Obukhov Institute of Atmospheric Physics (OIAP ZSS), Russian Academy of Sciences. Variations in the temperature of the surface air layer due to the smoke-induced attenuation of incoming solar radiation were estimated. The most intensive smoke generation in the atmosphere was observed on August 7-9, 2010, when the maximum aerosol optical thickness amounted to more than 4.0 at a wavelength of 550 nm. In this case, the albedo of single aerosol scattering amounted to ∼0.95-0.96 and the asymmetry factor amounted to ∼0.69-0.70. The maximum shortwave radiative forcing of aerosol amounted to about −360 W/m for the land surface and almost −150 W/m for the atmospheric upper boundary. During the period of intensive smoke generation, the cooling of the atmospheric surface layer over daylight hours (12 h) amounted, on average, to ∼6°C. The power character of the dependence of the shortwave radiative forcing of aerosol for the land surface on aerosol optical thickness up to its values exceeding 4.0, which was revealed earlier on the basis of data on aerosol optical thickness (up to 1.5) obtained at the OIAP ZSS during the summer forest and peatbog fires of 2002 in the region of Moscow, was supported. [ABSTRACT FROM AUTHOR]

Abstract: This study investigates the chemical characteristics of particles that were collected from the open burning of wax apple agricultural waste, and evaluates the impact of such burning on regional air quality. The water-soluble ions, elemental carbon (EC), and organic carbon (OC) in fine (D p ≤ 2.5 μm) and coarse (2.5 < D p ≤ 10 μm) particles were collected using a micro-orifice uniform deposition impactor (MOUDI) and two Dichot samplers. The average PM2.5/PM10 ratio during open burning (0.90) was higher than those both before and after burning (0.57 and 0.55, respectively). The particle distributions before and during burning were bi-modal and uni-modal, respectively. During the open burning, the OC or K+ content markedly increased; however, that of secondary aerosol decreased. The Na+/Cl− molar ratios of fine particles before, after, and during the open burning 0.40, 0.18, and 0.24, respectively; however, the corresponding (Na+ + K+)/Cl− molar ratios were 0.74, 0.99, and 0.39, respectively. OC, K+ and Cl− were quite abundant in the open burning of agricultural waste (wax apple), and the OC/Na+, K+/Na+, and Cl−/Na+ (mass) ratios in fine particles (318, 10.2, and 10.5, respectively) may be used as reference indexes associated with the open burning of wax apple waste. [Copyright &y& Elsevier]