Представлено описание автоматизированного комплекса, созданного для измерений содержания веществ с разной летучестью в шести диапазонах размеров частиц от 0,3 до 5 мкм при искусственном нагреве от 25 до 200 °С (с промежуточной точкой 100 °С). Концентрация частиц регистрировалась фотоэлектрическим счетчиком. Приборный комплекс был апробирован в отдельных сериях круглосуточных наблюдений в разные сезоны 2021–2023 гг. Проведено сравнение измерений фотоэлектрическим счетчиком и интегральным нефелометром в декабре 2022 г. и марте 2023 г. Показано, что вариации долевого содержания растворимых сернистых соединений по данным счетчика хорошо согласуются с изменчивостью параметра конденсационной активности. Применение метода термического воздействия позволит получить дополнительные сведения о сезонном и суточном ходе состава аэрозоля в среднедисперсном диапазоне размеров частиц. A description of the designed automated complex is presented. The results of measurements of the content of species with different volatility in six particle size ranges from 0.3 to 5 mm with artificial heating from 25 °С to 100 and 200 °С are discussed. The particle concentration was recorded by an optical counter. The instrumentation complex was tested in the period 2021–2023 in separate series of round-the-clock observations in different seasons. It has been shown that variations in the relative content of soluble sulfur compounds according to the counter data are in good agreement with the variability of the values of the parameter of condensation activity. In general, we believe that the use of this method will make it possible to obtain additional information about the seasonal and diurnal variations in aerosol composition in the intermediate range of particle sizes.

The results of describing the spatial distribution of methane concentration in the surface water of Lake Baikal in the spring are presented. The basis was the measurements of CH4 content which were first carried out in the round-the-clock continuous mode along the entire route of the passage of research vessel in the complex expeditions of Limnological Institute, Siberian Branch, Russian Academy of Sciences, in the spring seasons of 2013, 2016, 2017, 2018, 2021, and 2022. Based on the results of six expeditions, a merged data array was compiled; it included 12 100 segments (with a step of 0.005° in latitude and 0.01° in longitude) which covered the total area 4466.7 km2, or 14

Plumes from wildfires are transported over large distances from remote to populated areas and threaten sensitive ecosystems. Dense wildfire plumes are processed by atmospheric oxidants and complex multiphase chemistry, differing from processes at typical ambient concentrations. For studying dense biomass burning plume chemistry in the laboratory, we establish a Photochemical Large Aerosol Chamber (PHOTO-LAC) being the world's largest aerosol chamber with a volume of 1800 m3 and provide its figures of merit. While the photolysis rate of NO2 (jNO2) is comparable to that of other chambers, the PHOTO-LAC and its associated low surface-to-volume ratio lead to exceptionally low losses of particles to the walls. Photochemical ageing of toluene under high-NOx conditions induces substantial formation of secondary organic aerosols (SOAs) and brown carbon (BrC). Several individual nitrophenolic compounds could be detected by high resolution mass spectrometry, demonstrating similar photochemistry to other environmental chambers. Biomass burning aerosols are generated from pine wood and debris under flaming and smouldering combustion conditions and subsequently aged under photochemical and dark ageing conditions, thus resembling day- and night-time atmospheric chemistry. In the unprecedented long ageing with alternating photochemical and dark ageing conditions, the temporal evolution of particulate matter and its chemical composition is shown by ultra-high resolution mass spectrometry. Due to the spacious cavity, the PHOTO-LAC may be used for applications requiring large amounts of particulate matter, such as comprehensive chemical aerosol characterisation or cell exposures under submersed conditions.

The long-term data the aureole scattering phase function are analyzed for angles φ = 1.2° and 20° (I1.2 and I20). They were measured with a closed-type halo photometer at the aerosol station in the V.E. Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, in 2010–2021. The interannual, annual, and daily variations in the parameters are analyzed. The daily averages of I1.2, I20 are calculated from the hourly data, the monthly averages, from the daily averages, and the annual averages, from the monthly averages. A weak but significant (at the p = 0.05 level) time trend is found only for the interannual values of I1.2, 1.14% per year. In the annual behavior of I1.2 (I20), we clearly discern a monotonic increase (decrease) from winter toward summer months. Smokes from distant wildfires in 2012 and 2016, and partly in 2018 and 2019, disturb this pattern with high I20 values from July to September. The annual variations in the daily behavior of the monthly average I1.2, I20, and the ratio I20/I1.2 are characteristic for continental surface aerosol. Smokes from distant wildfires lead to high I20 values at nighttime, morning, and evening; and the decrease in I20 in the daytime is not significant with the 0.95 probability due to large standard deviations.

The gross and net primary production is estimated for the most characteristic seasonal life cycles of Baikal plankton based on long-term measurement series of carbon dioxide concentrations in the near-water atmosphere and surface and bottom water and “water–air” carbon dioxide fluxes. The calculations are carried out according to the scheme similar to the diel technique. With regard to the conditions of the coastal zone, the methodological issues are analyzed, neglect of which can lead to a significant uncertainty in these characteristics. We show that it is impossible to correctly estimate the net primary production only from CO2 concentration measurements in this technique. For periods of open water, the net primary production is calculated from the daily average CO2 flux. The estimates of the productivity for individual series of measurements in different periods quite adequately show the main features and are consistent with long-term observations.

A 25-year long series of observations of the parameter of aerosol condensation activity in the near-ground layer of the suburb atmosphere of Tomsk is analyzed. The regularities of inter-annual variations of its average monthly values are determined, as well as the dates of the spring maximum of condensation activity.

An approach of a technique for estimation of the content of aerosol matter with different volatility in individual fractions of atmospheric aerosol is discussed. The estimated are performed on the basis of the results of measurements of the number density of particles in 6 size ranges from 0.3 to 5 μm at artificial heating of the atmospheric air under analysis from 25 to 200°C. The number density of particles was recorded by AZ-10 optical counter at temperatures of 25, 100 and 200°C.

The aerosol optical characteristics in the wavelength range of 0.46-0.87 μm were calculated on the basis of an empirical model of the aerosol optical characteristics in the summer background haze of Western Siberia. The Monte Carlo method was used to estimate the sensitivity of the model to uncertainties in measuring the input parameters: angular light scattering coefficient at a wavelength of 0.53 μm at an angle of 45°, mass concentration of the absorbing substance, and parameters of its lognormal size distribution, relative humidity of air. The relative errors in the reconstructed scattering, extinction, and absorption coefficients, single-scattering albedo, asymmetry factor, and lidar ratio are analyzed.

When studying the condensation growth of atmospheric aerosol, many researchers note the dependence of hygroscopic properties on the particle size. In this work we consider the relationship between the parameter of condensation activity and the parameters of particle size distribution in the nanometer range on the example of test measurements. Due to the small amount of data, the results are preliminary.

Проанализированы многолетние ряды наблюдений потоков углекислого газа и метана в системе «вода-атмосфера» в прибрежной зоне озера Байкал. По результатам многолетних измерений показано, что суммарный сток углекислого газа из атмосферы на водную поверхность составляет 5,9 гСО2 м-2 год-1, а выход метана из воды оценивается в 100мгСН4 м-2 год-1. Для сравнительной оценки радиационного эффекта предположим, что молекула метана поглощает ИК излучение в 20 раз эффективней по сравнению с молекулой СО2. Показано, что суммарный сток углекислого газа из атмосферы в течение года достоверно снижает радиационный эффект, обусловленный выходом метана.

На основе анализа наблюдений 24-летнего ряда параметра конденсационной активности аэрозоля в приземном слое атмосферы г. Томска выявлено, что наиболее значимые его изменения наблюдаются в годовом ходе. Также обнаружены более медленные колебания с периодом 6-7 лет.

We analyze the long-term variations in the microstructural characteristics of aerosol in the surface air layer measured in the monitoring mode at the Aerosol Station of V.E. Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, in 2000–2020. Estimates are carried out based on the following characteristics: the concentrations of submicron Nf and coarse Nc particles and their ratio Nf /Nc. Two datasets are considered: “total” and separately for the “background” type of the “aerosol weather.” The variability range of the annual average values of the total concentration of particles N(r > 0.2 μm) is found to be 8–50 cm−3, and the aerosol concentrations for the background situations is 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 dataset showed the presence of a significant (with the 0.95 probability) time period of about a year for Nf /Nc and Nf and its absence for Nc.

По данным измерений в 2000-2019 гг методом активной спектронефелометрии проанализирована взяимосвязь гигроскопических свойств аэрозоля с объемной долей веществ, испаряющихся из частиц в разных диапазонах температуры при их искусственном нагреве. В течение всего года наблюдается стабильная отрицательная корреляция параметра конденсационной активности и объемной доли веществ, улетучивающихся в диапазоне 200-250°С. Стабильная положительная корреляция наблюдается в диапазоне температур от 25-75 до 160-200°С, границы интервала варьируют в зависимости от сезона.

The optical and microphysical characteristics of smog phenomena in the Akademgorodok of Tomsk in the winter period of 1997-2022 were studied. It was found that since 2011 the number and intensity of such situations has increased. On the example of smog on January 13-14, 2022 it is shown that a significant increase in the concentrations of atmospheric aerosol and equivalent of black carbon develops with temperature inversion and with a wind regime close to calm. There is an increase in both the submicron and coarse particle fractions, but more intense in the range of the submicron fraction. The formation of smog is accompanied by a decrease in the ability of aerosol particles to absorb moisture.

The paper presents a complex refractive index in the model of the aerosol optical characteristics in the lower 5-km atmospheric layer of Western Siberia. The model is based on the data of long-term airborne sounding of the vertical profiles of angular scattering coefficients, atmospheric aerosol disperse composition, content of absorbing substance, and condensation activity of aerosol particles. Various algorithms for taking into account the absorbing substance and the aerosol condensation activity are considered.

The relationship between the aerosol hygroscopic properties and the volume fraction of substances evaporating from particles in different temperature ranges during their artificial heating was analyzed by the method of active spectral nephelometry based on the measurement data obtained in 2000-2019. Throughout the year, there is a stable negative correlation between the parameter of condensation activity and the volume fraction of substances volatilizing in the range of 200-250°C. A stable positive correlation is observed in the temperature range from 25-75 to 160-200°C, the boundaries of the interval vary depending on the season.

A large-scale comprehensive study of the composition of the troposphere over the Russian sector of the Arctic was carried out in September 2020 onboard the Tu-134 Optik aircraft laboratory. We studied the spatiotemporal variations in aerosol and black carbon (BC) concentrations. The sensing data were used to analyze the general and particular features of the spatial variations in the vertical profiles of aerosol and BC concentrations. The columnar BC concentrations at the Arctic and subarctic latitudes were obtained.

Исследованы оптико-микрофизические характеристики смоговых явлений в Академгородке г.Томска в зимний период 1997-2022гг. Выявлено, что с 2011г. количество и интенсивность таких ситуаций увеличились. На примере смога 13-14 января 2022г. показано, что значительный рост концентраций атмосферного аэрозоля и эквивалента черного углерода развивается при температурной инверсии и с ветровым режимом, близким к штилю. Происходит увеличение как субмикронной, так и крупнодисперсной фракции частиц, но более интенсивное – в области субмикронной фракции. Формирование смога сопровождается уменьшением способности частиц аэрозоля впитывать влагу.

A series of simultaneous measurements of the spectral aerosol extinction coefficients at wavelengths of 0.45-3.9 μm, angular scattering and absorption in the wavelength range of 0.46-0.63 μm in pine combustion smokes was carried out in the Big Aerosol Chamber of IAO (BAC) in 2019-2021. Relationships between the aerosol optical characteristics at the initial stage of smoke formation are considered depending on: a) the value of the mass mixing parameter for open flame combustion (generation of black carbon microparticles) and smoldering combustion (brown carbon particles); b) the total mass of the combusted material. The spectral dependences of the aerosol scattering and absorption coefficients of pyrolysis (12 realizations) and mixed (28 realizations) smokes in the wavelength range from 0.45 to 3.9 μm were estimated.

To study the parameters of the condensation activity of individual fractions of atmospheric aerosol with an artificial change in the relative humidity of the air, a prototype was designed in which small particle counters are used as a number concentration analyzer. The advantage of such meters is their small size and low cost. The prototype uses Alphasense OPC-N3 counters. Preliminary results of the evaluation of the studied parameters are presented.