AS4.4

Aerosols play an important role in radiation processes in the atmosphere, as well as they have a significant impact on global and regional air quality. The process of the atmospheric nanoparticle formation starts from in situ conversion of condensable vapors. Then, the freshly formed nanometer-size clusters begin to grow due to the condensation of nucleating vapours on them and a self-coagulation as well, thus reaching the optically active size ranges. The relative contribution of the above mechanisms can be estimated by the chemical composition of size-segregated particles. Here, we present preliminary results of the analysis of aerosol samples characterizing the inorganic chemical composition of particles ranging from a few nm to 10 mm. The sampling was performed at Fonovaya Observatory (West Siberia) in October 2021 by means of the Model 125R Nano-MOUDI Impactor.

The analysis showed that in the lowest size range (<10 nm), only five ions were detected: SO₄^2-, Cl^-, K⁺, Na⁺, H⁺. The growth of the nucleation mode particles to the size range of 60-100 nm was accompanied by increasing content of SO₄^2-, Na⁺, H⁺ ions to 50, 37 and 13%, respectively, suggesting the condensation of H₂SO₄ vapours or the coagulation of particles contained mainly Na₂SO₄. A content of ammonium ions (NH₄⁺) appeared to be significant only in the accumulation mode size range (0.1-1.0 mm). Nitrates (NO₃^-) were detected mainly in the Aitken mode particles and then their contribution increases in accumulation and coarse mode ranges.

This work was supported by the RFBR grant No. 19-05-50024 (Microparticles in the atmosphere: formation and transformation in the atmospheric surface layer and in the free troposphere, radiation effects and impact on public health).

How to cite: Belan, B. D., Simonenkov, D., Arshinov, M., Belan, S., Golobokova, L., Davydov, D., Ivlev, G., Kozlov, A., Kozlov, A., Onischuk, N., Sklyadneva, T., Tolmachev, G., Fofonov, A., and Khodzher, T.: Peculiarities of the chemical composition of size-segregated atmospheric aerosols sampled at Fonovaya Observatory, West Siberia, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3537, https://doi.org/10.5194/egusphere-egu22-3537, 2022.

The stratosphere and troposphere are the main layers that define a significant part of the atmospheric processes of our planet. They are demarcated by the tropopause - a layer that has a stable stratification and makes it difficult to exchange air between them. As a consequence, the composition of the air differs slightly in the stratosphere and troposphere. However, the tropopause is not a fully material impermeable surface and therefore the exchange of impurities between both layers occurs. Under the conditions of a changing climate, the composition of the air in the troposphere has also noticeably changed. Therefore, it is important to study the processes of air exchange between the troposphere and stratosphere in a warming climate, especially if we take into account that one of the proposed geoengineering methods assumes to affect climate-forming factors by means of spraying sulphate particles into the stratosphere.

Here, we present the results of airborne measurements of the size distribution and chemical composition of aerosols carried out at the tropopause level and in the upper troposphere and lower stratosphere (UTLS) using the 'Optik' Tu-134 aircraft laboratory as a research platform. For the analysis, we have chosen 14 flight segments when the aircraft crossed the tropopause, which level was determined by the temperature gradient (up to 2°C/ km). All the selected profiles of atmospheric constituents were measured over the Russian Arctic seas or coastal areas, since the tropopause in the northern latitudes is much lower than in the middle ones.

Significant differences in the elemental composition of aerosol particles were revealed in the UTLS. Si was dominated in the composition of stratospheric particles, and Fe or Al in the tropospheric ones. The ionic composition of the LS aerosols was predominantly represented by sulfates (SO₄^2-), while tropospheric ones by a group of different ions.

The particle number size distributions (PNSD) in both UT and LS were dominated by the Aitken mode (20-50 nm). At the same time, there were some differences in PNSD – in the stratosphere, the distribution curve was shifted towards larger sizes that suggests the older age of particles measured there. It is also important to note that the nucleation mode particles (3–20 nm) were also detected during some flights in the lower stratosphere. This indicates that, despite the low humidity and the very low content of ammonia here, the processes of the new particle formation (NPF) in the stratosphere were taking place. Taking into account the dominance of SO₄^2- in the ionic composition, one can be assumed that sulfuric acid played a dominant role in the lower stratospheric NPF.

This work was supported by the grant of the Ministry of Science and Higher Education of the Russian Federation (Agreement No 075-15-2021-934).

How to cite: Arshinov, M. Yu., Antokhin, P., Arshinova, V., Belan, B., Belan, S., Golobokova, L., Davydov, D., Ivlev, G., Kozlov, A., Kozlov, A., Rasskazchikova, T., Simonenkov, D., Tolmachev, G., and Fofonov, A.: Differences in the upper tropospheric and lower stratospheric aerosol composition, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3737, https://doi.org/10.5194/egusphere-egu22-3737, 2022.

Anomalous or extreme climate conditions in high northern latitudes are likely to become more frequent and intense for the last several years. Based on the eddy covariance flux data from 2013-2017 collected at a boreal forest and peatland in central Siberia, net CO₂ uptake in spring 2015 was the highest compared with the 2013-2017 average because of the anomalous surface warming over the region > 60N. This enhanced spring net CO₂ uptake may be associated with more snowfall amount in winter. However, an increased spring net CO₂ uptake may be compensated with summertime net CO₂ uptake due to the relatively cool summer surface temperature in 2015. Spring 2020 in central Siberia has experienced even more substantial surface warming than in spring 2015, probably associated with excessive spring snowmelt. This suggests that further investigations in the effects of anomalous seasonal climate and snow conditions on net CO₂ uptake, photosynthesis and ecosystem respiration are necessary to better understand annual CO₂ balance. To characterize carbon fluxes and underlying mechanisms related to climate condition and snow characteristics from 2012-2020, we analyzed upscaling carbon flux dataset based on a random forest model by Jing et al. (2021), satellite-based net ecosystem exchange of CO₂ (i.e., Soil Moisture Active Passive (SMAP) L4 data), snow characteristics (e.g. freeze-thaw cycle, snow depth), and reanalysis dataset. We will focus on seasonal CO₂ uptake, photosynthesis and ecosystem respiration under the anomalous temperature and snowfall/snowmelt conditions, then discuss factors regulating annual net CO₂ uptake capacity in boreal forests and peatlands in central Siberia.

How to cite: Park, S.-B. and Park, S. S.: Changes in net CO2 uptake, photosynthesis, and ecosystem respiration and their relationships with climate and snow characteristics in central Siberia, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3425, https://doi.org/10.5194/egusphere-egu22-3425, 2022.

The Arctic is particularly sensitive to global warming and the effects of the increasing temperatures can already be detected in this region by occurring events such as thawing permafrost and decreasing Arctic sea ice area. One of the possible consequences is the risk of enhanced regional greenhouse gas emissions such as methane (CH₄) due to the exposure of large terrestrial carbon pools or subsea permafrost which have previously been shielded by ice and frozen soil.

Various sources, both natural and anthropogenic, are presently emitting methane in the Arctic. Natural sources include wetlands and other freshwater biomes, as well as the ocean and biomass burning. Despite the relatively small population in this region, CH₄ emissions due to human activities are also significant. The main anthropogenic sources are the extraction and distribution of fossil fuels in the Arctic nations and, to a lesser extent, livestock activities and waste management.

However, assessing the amount of CH₄ emissions in the Arctic and their contribution to the global budget still remains challenging due to the difficulties in carrying out accurate measurements in such remote areas. Besides, high variations in the spatial distribution of methane sources and a poor understanding of the effects of ongoing changes in carbon decomposition, vegetation and hydrology also complicate the assessment.

Therefore, the aim of this work is to reduce uncertainties on methane emissions in high northern latitudes. In order to achieve that, an inverse modeling approach has been implemented by using observational data sets of CH₄ concentrations obtained at 42 surface stations located in different Arctic regions for the period from 2008 to 2019, the atmospheric transport model FLEXPART, as well as available bottom-up estimates of methane emissions provided by process-based surface models and CH₄ emission inventories. The results have been analysed with regards to seasonal and inter-annual fluctuations, spatial differences and trends over the period of study.

How to cite: Wittig, S., Berchet, A., Paris, J.-D., Saunois, M., Arshinov, M., Machida, T., Sasakawa, M., Worthy, D., and Pison, I.: Evaluating methane emissions between 2008 and 2019 in high northern latitudes by using inverse modeling, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4297, https://doi.org/10.5194/egusphere-egu22-4297, 2022.

The SMEAR Estonia is an important step towards understanding how forest ecosystem and the atmosphere affect each other. The station provides long-term continuously measured eddy-covariance CO₂ flux data. Parameters such as wind speed and direction are not controllable by human, but forest management methods are, thus the flux tower helps to assess how human activities affect forest ecosystem-atmosphere relationship as well as to assess natural processes. In this study, the footprint for years 2015–2020 was calculated with Kljun model according to wind speed and direction. Measurements were taken from 30 m and 70 m height. Data was obtained by continuous high frequency (10 Hz) measurements by the eddy-covariance method and averaged over half-hour intervals. Results showed that the footprint area measured from 30 m over six-year period differed only by 5%. From 70 m this difference was only 1.2% over the six-year period. Average area for both 30 m and 70 m FFP was 61,5 ha and 4029,7 ha respectively. The growing stock of the forest was affected by forest management, but in general it grew by 3,2% for 30 m FFP. The main tree species growing in the area of the footprint are Scots pine (Pinus sylvestris), Norway spruce (Picea abies) and Silver birch (Betula pendula) with some small amount of aspen and alder species. The dominant wind directions were ranging from west to south in 2015–2017 and in 2018–2020 from south-west to south-east. The footprint area is affected mainly by wind speed and direction, and by forest management activities like harvesting and clear-cutting. Such measurements help to understand how human activity and natural processes affect formation of the footprint.

How to cite: Kollo, J., Padari, A., Krasnova, A., Kangur, A., and Noe, S.: Linking the measurement data of the substance flows of the SMEAR Estonia measuring station with the place of growth, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4365, https://doi.org/10.5194/egusphere-egu22-4365, 2022.

Rapid changes due to climate warming in the Arctic environment call for action and the implementation of sustainable measures in a scientific data driven policy process.

Assessment of available data on the Arctic and Antarctic regions and their linkage to Essential Variables (EV) and the UN Sustainable Development Goals (SDG) allow the implementation of scientific data driven policies and socio-economic activities mechanisms towards sustainable development. In the iCUPE (Integrative and Comprehensive Understanding on Polar Environments; www.atm.helsinki.fi/icupe) project (Petäjä et al., 2020), multiscale datasets ranging from in-situ small local scale to remotes sensing satellite data operating on global scale were generated and made public.

iCUPE developed further several data pilot applications that included flow of different data sources towards public services. Inclusion of indigenous knowledge and feedback by data users were tested (Noe et al., 2021)

The iCUPE datasets were used to evaluate impacts on social-economical activities in the Arctic and are well-linked to Sustainable Development Goals (SDGs) such as #3, 4, 11, 13, 14, 15, and 17. In particular, DSs (on aerosols, including black carbon, physico-chemical properties and spatio-temporal variability based on ground-based, satellite and unmanned aerial systems observations) show links to atmospheric pollution and climate change. These DSs allow to evaluate impact on environment and population (especially, indigenous people) health for the Arctic States as well as long-range transport/ deposition of pollution to remote populated regions. Hence, the evaluation results will be useful for the climate adaptation and changing social lifestyle and economic activities in Arctic regions. The DSs (on atmospheric mercury observations) show links to atmospheric pollution and deposition on underlying surfaces, and hence, the contamination of seas/lands. This helps to estimate impact on fishery and reindeer herding economical activities, and hence, impact on environment and population health through food chains. The DSs (emerging organic contaminants in water) show a situation on contamination of seas, which is important for evaluating the impacts on fishery industry, and hence, impact on population health and well-being through food chains and prosperity. The DSs (on emerging organic and anthropogenic contaminants in snow) underline contamination of food supply for reindeers, which is valuable for evaluating impact on economic activities and style of the life of indigenous people as well as impact on population health through food chains. The DSs (time series of lake size changes in Northeast Greenland) show changes in water resources availability, which can influence the hydropower plans of the Greenlandic government to foster economic development in Greenland.

Petaja, T., et al. (2020): Overview: Integrative and Comprehensive Understanding on Polar Environments (iCUPE) - concept and initial results. Atmospheric Chemistry and Physics. 20, 14, p. 8551-8592.

Noe S.M. et al. (2021): Arctic observations and Sustainable Development Goals - Contributions and examples from ERA-PLANET iCUPE data. Environmental Science and Policy, Manuscript in Review.

How to cite: Noe, S. M., Mahura, A., Petäjä, T., Tabakova, K., Lappalainen, H. K., and Leaders, D.: Assessing the impact of observation networks and data mobility for their impacts on socio-economical activities in the Arctic – Perspectives by the iCUPE project, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4945, https://doi.org/10.5194/egusphere-egu22-4945, 2022.

A more accurate characterization of the sources and sinks of methane (CH₄) and carbon dioxide (CO₂) in the vulnerable Arctic environment is required to better predict climate change. A large-scale aircraft campaign took place in September 2020 focusing on Siberian coast. CH₄ and CO₂ were measured in situ during the campaign and form the core of the study. Measured ozone (O₃) and carbon monoxide (CO) are used here as tracers. Compared to the reference (i.e., the seasonal value at Mauna Loa, Hawaii, US), median CH₄ mixing ratios are fairly higher (1890-1969 ppb vs 1887 ppb) while CO₂ mixing ratios from all flights are lower (408.09-411.50 ppm vs 411.52 ppm). We also report on 3 case studies. Our analysis suggests that during the campaign the European part of Russia’s Arctic and Western Siberia were subject to long-range transport of polluted air masses, while the East mainly was under the influence of local emission of greenhouse gases. The relative contributions of anthropogenic and natural sources of CH₄ in Siberia are simulated using the Lagrangian model FLEXPART in order to identify dominant sources in the boundary layer and in the free troposphere. In western terrestrial flights, air masses composition is influenced by from wetlands and anthropogenic activities (waste management, the fossil fuel industry and to a lesser extent the agricultural sector), while in the East, emissions are dominated by freshwaters, wetlands, and the oceans, with an ambiguous contribution from likely anthropogenic sources related to fossil fuels. Our results generally highlight the importance of the contribution form freshwater and oceans emissions and, combined with the large uncertainties associated with them, suggest that the emission from these aquatic sources should receive more attention in Siberia.

How to cite: Narbaud, C., Paris, J.-D., Berchet, A., Wittig, S., Saunois, M., Nédelec, P., Belan, B., Arshinov, M., Davydov, D., Fofonov, A., and Kozlov, A.: Measurement report: Disentangling methane and other trace gases sources and transport across the Russian Arctic from aircraft measurements, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8036, https://doi.org/10.5194/egusphere-egu22-8036, 2022.

The presented work evolves the study of the Space Weather state before and during the macrosynoptic processes movements in North Atlantic and Eurasia extratropical latitudes. The atmosphere circulation types – E-type (east transport), W-type (west transport) and C-type (meridional transport) – were investigated by their periods of the conservation:  (5-7) days which corresponds to the Natural Synoptic Period (NSP) in Europe region and the Long Period (LP) which endured more than 10 days.

The investigation time interval: 1.01.2007 – 1.01.2014. That corresponds to: the Solar Activity (SA) 23-d cycle's fall branch, the SA minimum, the rise branch of the 24-th SA cycle, the maximum of 24-th SA cycle.

Space Weather parameters were: global  variations of SA parameters; daily characteristics of the SA flare component in various bands of the electromagnetic spectrum; variations of daily statistics of Interplanetary Space characteristics in the near-Earth space; variations of daily statistics of Geomagnetic Field characteristics.

Results:

1. LP-E-type occurs 56% of all LP when LP-W-type occurs 36% and LP-C-type occurs 8%.

2. The concrete Space Weather parameters which behavior differences the moments of LP-beginnings from the moments of NSP-beginnings for the E-type circulation (here we are presenting only results for the most frequent macrosynoptic type) are follows:

• All daily indexes of SA global variations – the integral solar radioflux on the wavelength of 10.7cm, the solar spot number, the summarized spot area on the solar disk, the number of new Active Regions on the solar disk.
• The daily statistics (maximum, mean, range, standard deviation) of α-particle fluxes with the energy of 4-10 MeV. 
• The daily statistics (maximum, mean, range, standard deviation) of electron fluxes of energy that is greater than 2 MeV. 
• The daily statistics (maximum, mean, range, standard deviation) of the intensity of the whole magnetic field vector in the near-Earth space.
• The daily statistics (maximum, mean, range, standard deviation) of the intensity of the geomagnetic field that was measured at different terrestrial latitudes.

3. The most prominent events we can see in the behavior of the α-particle fluxes and in the behavior of the whole magnetic field vector in the near-Earth space those went on the background of the significant changing of global SA-indexes.

We suppose the complex impact the mentioned above Space Weather characteristics on the terrestrial atmosphere.

Results may be useful for the forecast of atmosphere response to the space impact.

How to cite: Stupishina, O. and Golovina, E.: The Space Weather events those accompany the long-lived macrosynoptic processes, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5714, https://doi.org/10.5194/egusphere-egu22-5714, 2022.

Last year, in Russia there was started a new government long-term initiative, that aims reduction for Russian greenhouse gas emissions by up to 70 percent compared to the 1990 level in less than next 10 years (by 2030).

On the one hand such ambitious goal to includes massive technical and industrial modernization and other hand – supposed to provide valid, verified and globally recognized scientific data on the runoff and emission of greenhouse gases from ecosystems all around Russia. Thus, a large-scale program for the development of carbon stations has started with running of carbon polygons, which should combine both research-methodological and educational functions, and, eventually, contribute to the achievement of the specified state objective. The educational function of the polygons includes training personnel with interdisciplinary competencies to work on "carbon" topics, including the highest qualifications.

Starting to design and equip the first running polygon in the Tyumen region (by University of Tyumen), we initially stated concept of creating an ecological and climatic transect across the whole of Russia from north to south. The general idea is connect the new carbon polygon near Tyumen with carbon monitor infrastructure in proposed polygons and stations in Tobolsk and Ishim, Khanty-Mansiysk (Mukhrino) and Yamalo-Nenets (Labytnangi)Autonomous Disctricts. With potential sites in partners, that University of Tyumen has in Central Asian republics, there are prospect to continue this meridional transect further to the south. And in this case, we have the prospect of getting a global-scale monitoring system in the center of Eurasia across all natural zones from north to south, that provide massive raw data set for global observation system.

How to cite: Smirnov, P. and Tolstikov, A.: West-Siberian meridional carbon transect: the concept, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6436, https://doi.org/10.5194/egusphere-egu22-6436, 2022.

Cities are prone to air pollution caused by emissions associated with population activities such as road transport, industry, heating, and residential sector. The concentration and chemical composition of particulate matter (PM) is of particular importance as the parameter of air quality measurements. Concerning impact on urban air quality and hazardous health effects accompanied by the capacity for long-range atmospheric transport, polyromantic hydrocarbons (PAHs) are numbered among priority pollutants in the national and international regulatory activities. Seasonal dynamics and toxicity of PM-bound PAHs in a northern context attract the particular attention.

Sampling and PM₁₀-bound PAHs characterization were carried out in urban background of Moscow megacity, the largest as well as the northernmost megacity in Europe. Composition of 16 PAHs which are numbered in the EPA list of ‘Priority Pollutants’, were considered for three periods: spring (from mid-April to the end of May, when a positive average daily temperature is set in Moscow), autumn (from the end of September to the end of November), and winter (from early December to mid-January, when the average daily temperature reliably drops below zero). The sum of 16 PAHs had ranged over the observation period from 0.4 to 10 ng/m³, with increase of the median concentration from spring and autumn to winter due to the maximum anticyclonic atmospheric circulation and emissions from thermal power plants in winter as well as the transition of PAH from PM to the gas phase with an increase of the temperature in spring. Average PAH toxic equivalent (TEQs) were higher in winter and autumn than those in summer and spring. Increased concentrations for BaA, BaP,BgP, Cry, BbF due to high wind speeds indicate a distant source and a long-range transfer of pollutants. While the presence of maxima of concentrations at medium or low wind speeds can serve as an indication of the proximity of sources, as well as the weakening of atmospheric circulation, which leads to accumulation of pollutants (ANT, PYR, BbF, DiBaA, BLU, PHE, BkF) in the measurement area.

Based on the statistical processing, high (> 0.75) positive correlations for all individual PAHs were obtained in autumn and winter. This indicates the high stability and the absence of significant transformation of PAH due to physical and photochemical reactions. At higher temperature in spring compared to autumn-winter, low correlations for phenanthrene was observed due to evaporation of the lowest molecular weight PAHs could proceed more intensively on the aerosol surface.

This work is supported by the Russian Government, through its grant number 14.W03.31.0002.

How to cite: Chichaeva, M., Zavgorodnyaya, Y., Popovicheva, O., Semenova, A., and Kasimov, N.: Seasonal dynamics and toxicity of PM-bound PAHs in northernmost European megacity., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6967, https://doi.org/10.5194/egusphere-egu22-6967, 2022.

Siberian wildfires inject into the atmosphere huge amounts of aerosol particles, part of which are transported into the Arctic. Once in the Arctic, biomass burning (BB) aerosol can contribute to the radiative balance and affect the climate processes in different ways, including the absorption and scattering of the solar radiation, changes in the albedo of the ice/snow surface cover, modification of the optical properties of clouds. However, quantitative knowledge of the role of Siberian BB aerosol in the Arctic is deficient, reflecting major uncertainties in available model representations of its emissions, chemical composition, and optical properties.

In this study, the CHIMERE v2020 chemistry transport model (https://www.lmd.polytechnique.fr/chimere/) coupled with the WRF meteorological model was used to examine the effects of aerosol-radiation interactions (the direct aerosol radiative effect and the associated semi-direct effects) due to the transport of BB plumes from Siberia into the Eastern Arctic. The analysis features the use of satellite and in situ observations to constrain the BB aerosol sources and optical properties. Furthermore, the simulations brought together new model representations of the optical properties and aging of the organic component of Siberian BB aerosol [1,2], which were also constrained by satellite and ground-based observations, and recent findings from aerosol chamber experiments [3]. The study focuses on the radiative effects associated with the strong fires that occurred in Siberia in July 2016.

It is found that weakly-absorbing Siberian BB aerosol exerted a strong cooling effect in the near-surface layer of the atmosphere and at the top of the atmosphere over large areas on land in the Eastern Arctic. However, the aerosol radiative effects over the ocean were found to be of a mixed character, which is partly due to semi-direct effects triggered by the aerosol absorbing components (black carbon and brown carbon). Overall, our study results indicate that direct and semi-direct radiative effects caused by Siberian BB aerosol constitute a significant part of the evolving natural baseline of the Arctic radiative budget and need to be taken into accounts in analyses and predictions of the Arctic amplification of climate change.    

The study was supported by the Russian Science Foundation under grant agreement No. 19-77-20109 (modeling light-absorbing aerosol components), RFBR and CNRS according to the research project № 21-55-15009 (modeling light-scattering aerosol components).

References:

• Konovalov, I.B., Golovushkin, N.A., Beekmann, M., and Andreae, M.O.: Insights into the aging of biomass burning aerosol from satellite observations and 3D atmospheric modeling: evolution of the aerosol optical properties in Siberian wildfire plumes, Atmos. Chem. Phys., https://doi.org/10.5194/acp-21-357-2021, 2021.
• Konovalov, I.B., Golovushkin, N.A., Beekmann, M. Panchenko, M.V.; Andreae, M.O.: Inferring the absorption properties of organic aerosol in biomass burning plumes from remote optical observations, Atmos. Meas. Tech., https://doi.org/10.5194/amt-14-6647-2021, 2021.
• Kozlov, V.S., Konovalov I.B., Panchenko, M.V., Uzhegov, V.N., et al.: Dynamics of aerosol absorption characteristics in smoke combustion of forest biomass burning at the Large Aerosol Chamber at the stages of generation and aging in time. Proc. SPIE, https://doi.org/10.1117/12.2603496, 2021.

How to cite: Konovalov, I. B., Golovushkin, N. A., Beekmann, M., Siour, G., Zhuravleva, T. B., Nasrtdinov, I. M., Uzhegov, V. N., Kuznetsova, I. N., Nakhaev, M. I., Turquety, S., and Couvidat, F.: Elucidating the impact of Siberian biomass burning aerosol on the radiative balance in the Arctic: model analysis constrained by observations, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7090, https://doi.org/10.5194/egusphere-egu22-7090, 2022.

Alteration of the Earth's radiation balance due to the rise of the content of the main anthropogenic greenhouse gas СО2 in the atmosphere leads to the changes of the planet's climate. It is known that megacities contribute approximately 70% to the total anthropogenic CO2 emissions playing a critical role in the climate changes. Several methods of emission estimation are being developed to control commitments undertaken by different countries on reducing greenhouse gas emissions. One of such methods - inverse modelling - combines accurate observations of the increase of gas` content, a priori anthropogenic emissions and numerical modelling of atmospheric transport to define gas` sources and correct emission data used in the simulation. Several studies demonstrated that the inverse modelling of CO₂ anthropogenic emissions highly depends on the modelling of CO₂ transport in the atmosphere. Therefore a careful validation of such models must be carried out before CO₂ emissions estimation by the inverse modelling. In the current research we studied capabilities of numerical weather prediction and chemistry dynamic model WRF-Chem to simulate CO₂ transport on the territory of Saint-Petersburg (Russia) using observations of near-ground and total CO₂ content. 

How to cite: Nerobelov, G., Timofeyev, Y., Foka, S., Hatakka, J., Virolainen, Y., and Smyshlyaev, S.: Validation and adaptation of WRF-Chem numerical model to simulate CO2 transport in Saint-Petersburg, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9011, https://doi.org/10.5194/egusphere-egu22-9011, 2022.

Needs in obtaining independent and high-quality information on anthropogenic emissions of important for climate and ecology gases led to the development of spectroscopic (ground-based and satellite) methods of the emission determination. This challenge can be reduced to two sequential inverse problems - the inverse problem of atmospheric optics and atmospheric transport. Here we studied the merits and disadvantages of differential IR methods for the emissions estimation. Also we investigated the main factors determining their errors such as:

• Quality and number of the observations of spatio-temporal distribution of gases studied
• Capabilities of the numerical models to simulate atmospheric transport
• Spatial and temporal resolutions of emissions estimated
• etc.

In the current study integral anthropogenic CO₂ emissions of Saint-Petersburg were determined using observation data of the city`s anthropogenic contribution to the gas content. In addition we implemented a new approach of inverse problem solution which was based on a priori CO<sub>2</sub> emission data and scale coefficients applied only to the city`s areas covered by the observations. Integral anthropogenic CO₂ emissions obtained were in a range from approximately 52 to 72 Mt/year. These emissions are significantly higher than inventory-based estimates which constitute ⁓30 Mt/year. Nevertheless, the minimal value of the range (~52 Mt/year) is lower by ~21% than emissions which we calculated earlier also using observations (~65 Mt/year).

How to cite: Timofeyev, Y., Nerobelov, G., and Poberovskiy, A.: Analysis of Saint-Petersburg`s CO2 anthropogenic emissions estimation by differential spectroscopy method, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9018, https://doi.org/10.5194/egusphere-egu22-9018, 2022.

Long-range transport to the Arctic carries tracers of anthropogenic activities and wildfires, among other aerosol constituents. Black carbon (BC) shows a contribution of fossil fuels combustion and natural biomass burning (BB) to the Arctic atmosphere chemistry and aerosol pollution.  Fossil sources mostly prevail during winter-spring season while BB sources dominate during low BC concentration periods in summer. Spectral dependence of the light absorption described by the absorption Ångström exponent (AAE) is used to differentiate between different aerosol types (BC, BrC) and indicate the impact of BB.

Long-term airborne observations of BC in Northern Siberia have revealed a strong impact of forest fires in summer (Kozlov et al., 2016; Paris et al., 2009;Popovicheva et al., 2020). Particulate brown carbon (BrC) has been reported to be emitted by intense wildfires and measured in plumes transported over two days  (Forrister et al., 2015). Due to the mixing with background aerosol and ageing processes, the air masses influenced by BB events is expected to have increased AAE as compared to the BC produced by fossil fuel.

Yamalo-Nenets Autonomous Okrug (YNAO) is located in the Far North of Western Siberia, more than 50% of its area takes place beyond the Polar Circle. On August 4 of 2021, strong smoke enveloped Salehard, Noyabrsk, Tarko-Sale and other municipalities of the district. The air mass transportation from the southeastern directions brought smoke from forest fires located on the territory of the Republic of Sakha (Yakutia). According to the operational data of “Avialesokhrana”, 105 wildfires were active over an area of ​​about 1.2 million hectares there.

A dense haze covered a city Nadym, located around 100 km to the south the Polar Circle, as well. Smoke sampling performed from 5 to 12 August 2021 was correlated with the haze day duration and showed the variation of AAE up to 2.5, the feature of strong BB impact. Unprecedented high BC is observed on Bely island taking place in the Kara sea, above Yamal Peninsula. Unprecedented high pollution for the Siberian Arctic was recorded by research polar aerosol station “Island Bely”. An extreme increase of BC concentration was observed on August 5, reaching 4000 ng per m³. The Arctic summer background was exceeded 40 times!  It was found 8 times higher than the highest arctic haze concentrations observed in December 2019. AAE approached 1.4, very high value for area such remoted from wildfires (more than 1000 km). It indicated the long-range transportation from Yakutia of aged air masses influenced by BB events. Basic research in the Siberian Arctic is supported by Russia Geographical Society №17-2021И.

How to cite: Popovicheva, O., Kobelev, V., Chichaeva, M., and Kasimov, N.: Unprecedented wildfire smoke in the Siberian Arctic in August 2021, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9775, https://doi.org/10.5194/egusphere-egu22-9775, 2022.

In 2001, the mercury analyzer was installed at Amderma (69.45⁰ N, 61.39⁰ E, 49 m above sea level; Yugor Peninsula) in the Nenets Autonomous Okrug (Russia) to carry out continuous measurements of gaseous elemental mercury vapor concentration in the atmospheric surface layer. The data analysis demonstrated that the atmospheric mercury depletion evens (AMDEs, concentration < 1 ng m^-3) are observed on a rather limited territory, i.e. along the coast of the Arctic seas. During observational period (2001-2015), the analyzer was placed at three locations at different distances (8.9 km – 2001-2004, 2.5 km – 2005-2010, and 200 m - 2010-2015) from the Kara Sea coast.

For the AMDEs cases, during winters of 2001-2004 the air temperature was in range from -15⁰С to -31⁰С and relative humidity – 68-84%. The dominated atmospheric transport for these cases was mainly observed from the N-N-W direction. The number AMDEs relative to all measurements was about 0.2%. For 2005-2010, the temperature ranged from -1⁰С to -37⁰С and relative humidity – 74-83%. The atmospheric transport – from the E-E-N direction. The number AMDEs relative to all measurements was 2.7%. For 2010-2013, the temperature varied from -22⁰С to -27⁰С and relative humidity – 75-87%. The atmospheric transport – mainly from the S-S-W direction. The number AMDEs relative to all measurements was 26.9%, showing substantial 10-fold increase of AMDEs compared with the previous period. As a result, all cases correspond to range of air temperatures from -1⁰C to -37⁰C and relative humidity of 68-87% for entire monitoring period considered.

For selected considered episode (29-30 Mar 2002), the air temperature varied from -26⁰C to -31⁰C, and when it decreased to the minimum, the effect of mercury depletion was detected with the lowest concentration (0.39 ng m^-3). For episode (29 Feb - 1 Mar 2007), the temperature was also decreasing from -16⁰C to -37⁰C, and at reaching the minimum, the mercury concentration was also the lowest (0.12 ng m^-3). Moreover, in Dec 2006, for the first time, a significant number of AMDEs cases (23 events) was recorded during the polar night. In Feb 2010 the longer duration (up to 40 hours) AMDEs episodes were observed compared with Jan (up to 15 hours).

Note that all AMDEs are generally observed at lower air temperatures and relative humidity values with respect to the average values.

How to cite: Pankratov, F., Mahura, A., Masloboev, V., and Popov, V.: Atmospheric Mercury Depletion Events: Assessment Impact of Meteorological Parameters in the Arctic Winter, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10368, https://doi.org/10.5194/egusphere-egu22-10368, 2022.

Urban aerosol pollution has a significant effect on solar irradiance and meteorological characteristics. Using the two online integrated meteorology – atmospheric composition modelling systems  -  COSMO-Ru2-ART (Consortium for Small-scale Modeling – Aerosols and Reactive Trace gases) and Enviro-HIRLAM (Environment – High Resolution Limited Area Model) ) taking into account urbanization effects, we studied the effects of aerosol pollution and its impact on radiative and meteorological characteristics of the atmosphere with focus on the Moscow megacity region (Russia). For the models’ runs, the initial and boundary conditions from the ICON-COSMO-Ru7 and ERA-5  as well as the CAMS redistributed inventory emissions were utilized.

In order to account for the absorbing aerosol properties of the Moscow urban atmosphere black carbon (BC) emissions were applied according to the ECLIPSE emission inventory, which demonstrated a satisfactory agreement in BC/PM10 ratio with experimental data in Moscow.  A series of models’ simulations over an area of 300x300 km  was performed with a 2 km horizontal grid step with the effects of urban areas (building effects/ BEP, anthropogenic heat fluxes/ AHF in Enviro-HIRLAM and TERRA_URB scheme in COSMO-Ru2-ART), and without their consideration. The estimates of urban aerosol content were made for typical conditions in April-May 2019 and during spring of 2020, when lowered anthropogenic emissions were observed in the Moscow region due to strict lockdown conditions of COVID-19 pandemic.

In this study, we accounted for the changes in emissions for the lockdown situation according to the recommendations (Le Quéré et al., 2020), which were mainly in agreement with the official statements.  The estimates of aerosol urban properties were tested against the difference between the AERONET measurements obtained in the Moscow megacity and in a relatively clean region at Zvenigorod Scientific Station of the Institute of Atmospheric Physics, Russian Academy of Sciences.  The quality of surface aerosol estimation was verified using the MosEcoMonitoring Agency dataset. The variability of concentration of different aerosol species at ground level and changes in aerosol optical depth and its absorbing properties in the total atmospheric column are discussed.  The various aerosol radiative effects - direct, semidirect and indirect - and the influence of aerosol on selected meteorological characteristics (such as temperature, humidity, cloud cover, etc.) are analyzed. The features of spatio-temporal changes in urban aerosol fields and their effects on meteorology in conditions of elevated and lower emissions of pollutants in typical and lockdown conditions are investigated. 

This study is partially supported by the Ministry of Education and Science of the Russian Federation (grant number 075-15-2021-574) and the Finnish Flagship “Atmosphere and Climate Competence Center” (Academy of Finland grant 337549).  This research was performed according to the Development Programme of the Interdisciplinary Scientific and Educational School of MSU “Future Planet and Global Environmental Change”. The CSC - IT Center for Science Computing (Finland), is acknowledged for computational resources.

References:

Le Quéré C. et all (2020): Temporary reduction in daily global CO₂ emissions during the COVID-19 forced confinement, Nat. Clim. Change, 10, 647–653.

How to cite: Chubarova, N., Mahura, A., Androsova, E., Kirsanov, A., Varentsov, M., Poliukhov, A., Paasonen, P., and Rivin, G.: Aerosol pollution in the Moscow megacity environment and its impact on radiative and meteorological properties of the atmosphere, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3947, https://doi.org/10.5194/egusphere-egu22-3947, 2022.