Air pollution in Ukraine: a view from the Sentinel-5P satellite

The study presents analysis of current air pollution state over Ukraine including remote regions and uncontrolled Ukrainian territories; features of NO2, SO2, and CO spatial distribution and seasonality under the influence of local anthropogenic emissions. The research is based on Sentinel-5P satellite data for the period of November 2018 – January 2020. Despite the increasing traffic emissions, the industrial emissions still greatly influence the air pollution in Ukraine. Sentinel-5P coverage allowed detecting a number of cities with huge anthropogenic NO2 and SO2 emissions, where ground-based measurements are absent. Uncontrolled territories on the east part of Ukraine still negatively affect air quality in the region due to the activity of coal-fired thermal power plants. The study indicates significant air quality changes during the heating season in winter and open burning in March – April. There were found differences in NO2 seasonal variability over clean remote regions and industrial zones. The paper analyzes features of shipping emissions during the tourist season for Ukrainian coastline of Black and Azov Seas, showing huge negative impact of chaotic movements of tourists boats near the Dzharylhach National Nature Park

Enviro-HIRLAM model estimates of elevated black carbon pollution over Ukraine resulted from forest fires

Funding Information: The study is part of the Enviro–PEEX on the ECMWF (Pan-Eurasian Experiment (PEEX; https://www.atm.helsinki.fi/peex , last access: last access: 8 December 2022) Modelling Platform research and development of online coupled integrated meteorology–chemistry–aerosols feedback and interactions in weather, climate, and atmospheric composition multi-scale modelling) project (2018–2020). The Enviro-HIRLAM model simulations were performed on the CSC (Center for Science Computing) Sisu HPC (Finland) during the Enviro-HIRLAM and HARMONIE research training course at the Institute for Atmospheric and Earth System Research (INAR) of the University of Helsinki (UHEL). The authors also gratefully acknowledge the computer resources and technical support provided by the Center for Science Computing (CSC) HPC (Finland). This study was carried out within the framework of the State Emergency Service of Ukraine and National Academy of Sciences of Ukraine. The work has been partially supported by Academy of Finland via a Flagship programme for Atmospheric and Climate Competence Center (ACCC, 337549) and Academy of Finland projects (334792, 328616, 345510) and European Commission via a project “Non-CO Forcers and Their Climate, Weather, Air Quality and Health Impacts”, (FOCI) and the project “Research Infrastructures Services Reinforcing air quality monitoring capacities in European URBAN & Industrial areaS” (RI-URBANS), no. 101036245. Funding Information: This research has been supported by a grant within the ENVRIplus project for multi-domain access to RI platforms (H2020-INFRAIA-2014-2015, grant no.: 654182). The work has been partially performed under the Project HPC-EUROPA3 (INFRAIA-2016-1-730897) with the support of the EC Research Innovation Action under the H2020 Programme. Publisher Copyright: © 2022 Copernicus GmbH. All rights reserved.Biomass burning is one of the biggest sources of atmospheric black carbon (BC), which negatively impacts human health and contributes to climate forcing. In this work, we explore the horizontal and vertical variability of BC concentrations over Ukraine during wildfires in August 2010. Using the Enviro-HIRLAM modelling framework, the BC atmospheric transport was modelled for coarse, accumulation, and Aitken mode aerosol particles emitted by the wildfire. Elevated pollution levels were observed within the boundary layer. The influence of the BC emissions from the wildfire was identified up to 550hPa level for the coarse and accumulation modes and at distances of about 2000km from the fire areas. BC was mainly transported in the lowest 3km layer and mainly deposited at night and in the morning hours due to the formation of strong surface temperature inversions. As modelling is the only available source of BC data in Ukraine, our results were compared with ground-level measurements of dust, which showed an increase in concentration of up to 73% during wildfires in comparison to average values. The BC contribution was found to be 10%-20% of the total aerosol mass near the wildfires in the lowest 2km layer. At a distance, BC contribution exceeded 10% only in urban areas. In the areas with a high BC content represented by both accumulation and coarse modes, downwelling surface long-wave radiation increased up to 20Wm-2, and 2m air temperature increased by 1-4°C during the midday hours. The findings of this case study can help to understand the behaviour of BC distribution and possible direct aerosol effects during anticyclonic conditions, which are often observed in mid-latitudes in the summer and lead to wildfire occurrences.Peer reviewe

NO2 Seasonal and Interannual Variability in Ukrainian Industrial Cities

The paper aims to define the main features and principles of seasonal and interannual NO2 variations in Ukrainian industrial cities. Using ground-based measurements for 15-year period, it shows weak NO2 seasonal variability that could intensify in case of three regularities. These regularities depend on impact of natural conditions during anthropogenic emissions growth and redistribution between emission sources. Most industrial cities are characterized by positive trends even if stationary industrial emissions fall. NO2 interannual changes forms under variety of fluctuations. However, 6.2- and 9.3-year periods have the biggest impact and might be explained by low-frequent lunar tidal forces through its influence on meteorological conditions

Enviro-HIRLAM model estimates of elevated black carbon pollution over Ukraine resulted from forest fires

Funding Information: The study is part of the Enviro–PEEX on the ECMWF (Pan-Eurasian Experiment (PEEX; https://www.atm.helsinki.fi/peex , last access: last access: 8 December 2022) Modelling Platform research and development of online coupled integrated meteorology–chemistry–aerosols feedback and interactions in weather, climate, and atmospheric composition multi-scale modelling) project (2018–2020). The Enviro-HIRLAM model simulations were performed on the CSC (Center for Science Computing) Sisu HPC (Finland) during the Enviro-HIRLAM and HARMONIE research training course at the Institute for Atmospheric and Earth System Research (INAR) of the University of Helsinki (UHEL). The authors also gratefully acknowledge the computer resources and technical support provided by the Center for Science Computing (CSC) HPC (Finland). This study was carried out within the framework of the State Emergency Service of Ukraine and National Academy of Sciences of Ukraine. The work has been partially supported by Academy of Finland via a Flagship programme for Atmospheric and Climate Competence Center (ACCC, 337549) and Academy of Finland projects (334792, 328616, 345510) and European Commission via a project “Non-CO Forcers and Their Climate, Weather, Air Quality and Health Impacts”, (FOCI) and the project “Research Infrastructures Services Reinforcing air quality monitoring capacities in European URBAN & Industrial areaS” (RI-URBANS), no. 101036245. Funding Information: This research has been supported by a grant within the ENVRIplus project for multi-domain access to RI platforms (H2020-INFRAIA-2014-2015, grant no.: 654182). The work has been partially performed under the Project HPC-EUROPA3 (INFRAIA-2016-1-730897) with the support of the EC Research Innovation Action under the H2020 Programme. Publisher Copyright: © 2022 Copernicus GmbH. All rights reserved.Biomass burning is one of the biggest sources of atmospheric black carbon (BC), which negatively impacts human health and contributes to climate forcing. In this work, we explore the horizontal and vertical variability of BC concentrations over Ukraine during wildfires in August 2010. Using the Enviro-HIRLAM modelling framework, the BC atmospheric transport was modelled for coarse, accumulation, and Aitken mode aerosol particles emitted by the wildfire. Elevated pollution levels were observed within the boundary layer. The influence of the BC emissions from the wildfire was identified up to 550hPa level for the coarse and accumulation modes and at distances of about 2000km from the fire areas. BC was mainly transported in the lowest 3km layer and mainly deposited at night and in the morning hours due to the formation of strong surface temperature inversions. As modelling is the only available source of BC data in Ukraine, our results were compared with ground-level measurements of dust, which showed an increase in concentration of up to 73% during wildfires in comparison to average values. The BC contribution was found to be 10%-20% of the total aerosol mass near the wildfires in the lowest 2km layer. At a distance, BC contribution exceeded 10% only in urban areas. In the areas with a high BC content represented by both accumulation and coarse modes, downwelling surface long-wave radiation increased up to 20Wm-2, and 2m air temperature increased by 1-4°C during the midday hours. The findings of this case study can help to understand the behaviour of BC distribution and possible direct aerosol effects during anticyclonic conditions, which are often observed in mid-latitudes in the summer and lead to wildfire occurrences.Peer reviewe

Local temperature near native vascular plants in the Argentine Islands–Kyiv Peninsula region, Antarctic Peninsula: annual variability and approximation using standard meteorological measurements

We describe the main features of LT variability that influence native vascular plants in the Antarctic and examine the relationship between the temperature regime at the micro-level and meteorological conditions at the macro-level. We used a period of over a year, during which 37 specialized mini-loggers recorded LT near vascular plants in the Argentine Islands–Kyiv Peninsula region of the Antarctic Peninsula. Rather than measuring standard air or soil temperature, these loggers detect the temperature near the ground, in the microhabitats that harbour vascular plants. On a daily scale, LT correlates with standard (2-m) air temperature, with the values higher at rock slopes than at rock terraces and ledges. A moderate correlation was found with wind and radiation parameters. Seasonality accounted for 75–93% of total LT variability, with better results on open rock terraces compared to protected areas and clefts. LT day-to-day variability during the cold season is mostly responsible for differences in R2 of the annual cycle. We estimated daily mean LT using regression dependencies from 2-m air temperature and wind speed measured at a nearby meteorological station. R2 for these statistical models varies from 0.46 to 0.68. However, they underestimate the observed LT. LT measured on rock slopes showed better modelling results with air temperature, whereas wind speed was a better predictor on rock ledges. This study contributes to our understanding of the micro-scale temperature regime that influences native vascular plants and provides a method for its rough approximation using standard meteorological parameters

Two-decade variability of climatic factors and its effect on the link between photosynthesis and meteorological parameters : example of Finland's boreal forest

Climate and forests are linked to each other via sophisticated feedback mechanisms. Recognizing the complexity of atmosphere-biosphere interactions, here we use a simplified approach aiming to establish connections between the parameters characterizing the boreal forest as a carbon sink and meteorological parameters using a two-decade data set (1996-2017) from the Station for Measuring Ecosystem - Atmosphere Relations (SMEAR II), Finland. First, we quantify climate changes in Finland using growing season length and climatic indices. Then we apply the indices to determine unusually cold, warm, wet, or dry years as compared with the typical conditions at SMEAR II. Further, we analyze the relationships between air temperature, precipitation, absorbed photosynthetically active radiation (PAR) and atmospheric CO2 concentration. Our results suggest increased photosynthesis in the Finnish boreal forest with warming and emphasize the importance of long-term measurements for integrated atmosphere-biosphere studies.Peer reviewe

Seamless Modeling of Direct and Indirect Aerosol Effects during April 2020 Wildfire Episode in Ukraine

Wildfires frequently occur in Ukraine during agricultural open-burning seasons in spring and autumn. High aerosol concentrations from fire emissions can significantly affect meteorological processes via direct and indirect aerosol effects. To study these impacts, we selected a severe wildfire episode from April 2020 in the Chornobyl Exclusion Zone (CEZ) and its surrounding area as a case study. We employed the Enviro-HIRLAM modeling system to simulate reference (REF) meteorological conditions, along with direct (DAE), indirect (IDAE), and combined (COMB) aerosol effects. In our simulations, black carbon (BC) and organic carbon (OC) comprised 70–80% of all aerosol mass in the region, represented in two layers of higher concentrations: one near the surface and the other 3–4 km above the surface. Our simulations showed that the inclusion of aerosol effects into the modeling framework led to colder (up to −3 °C) and drier (relative humidity drop up to −20%) conditions near the surface. We also observed localized changes in cloudiness, precipitation (mainly redistribution), and wind speed (up to ±4 m/s), particularly during the movement of atmospheric cold fronts. Larger uncertainties were observed in coarser model simulations when direct aerosol effects were considered. Quantifying the aerosol effects is crucial for predicting and promptly detecting changes that could exacerbate unfavorable weather conditions and wildfires. Such knowledge is essential for improving the effectiveness of emergency response measures