Role of upwind precipitation in transboundary pollution and secondary aerosol formation: A case study during the KORUS-AQ field campaign

Clouds and precipitation play critical roles in wet removal of aerosols and soluble gases in the atmosphere, and hence their accurate prediction largely influences accurate prediction of air pollutants. In this study, the impacts of clouds and precipitation on wet scavenging and long-range transboundary transport of pollutants are examined during the 2016 Korea-United States Air Quality (KORUS-AQ) field campaign using the Weather Research and Forecasting model coupled with chemistry. Two simulations in which atmospheric moisture is constrained vs. it is not are performed and evaluated against surface and airborne observations. The simulation with moisture constraints is found to better reproduce precipitation as well as surface PM2.5, whereas the areal extent and amount of precipitation are overpredicted in the simulation without moisture constraints. As a results of overpredicted clouds and precipitation and consequently overpredicted wet scavenging, PM2.5 concentration is generally underpredicted across the model domain in the simulation without moisture constraints. The effects are significant not only in the precipitating region (upwind region, southern China in this study) but also in the downwind region (South Korea) where no precipitation is observed. The difference in upwind precipitation by 77% on average between the two simulations leads to the difference in PM2.5 by ∼39% both in the upwind and downwind regions. The transboundary transport of aerosol precursors, especially nitric acid, has a considerable impact on ammonium-nitrate aerosol formation in the ammonia-rich downwind region. This study highlights that skillful prediction of atmospheric moisture can have ultimate potential to skillful prediction of aerosols across regions.

Analysis of air pollution in Primorsky Krai in 2019-2020 according to GMAO/NASA satellite monitoring

The results of modeling variations in atmospheric pollutants over Primorsky Krai in 2019 and 2020 based on GMAO/NASA satellite monitoring data are analyzed. It is shown that average annual concentrations of pollutants in 2020 decreased as compared to 2019: by 20–35% for sulfur dioxide; by 5–20% for sulfates; by 8–20% for carbon monoxide; by 25–40 % for particulate matter PM (1, 2.5, and 10 μm). One of the reasons for the air pollution decline in Primorsky Krai in 2020 is the reduction of anthropogenic load in the context of a decrease in industrial activity and traffic flows both in Primorye and in the adjacent areas of China. Episodes of high pollution in 2019 were formed under influence of the transboundary transport of polluted air masses. Keywords: air pollution, aerosol and chemical elements, transboundary transport, satellite monitoring, Primorsky Krai

The synoptic conditions of air pollution in Temirtau

The article examines the state of air pollution in Temirtau, Karaganda region, and the dynamics of the air pollution index (API). The API is calculated based on the 5 main pollutants in the city, namely suspended particles, nitrogen dioxide, carbon monoxide, phenol and ammonia. The article describes the synoptic conditions of atmospheric air pollution in Temirtau, that is, the influence of baric structures, such as cyclones and anticyclones, troughs and ridges, on the maximum permissible concentration of harmful substances and their time in the city air. The meteorological quantity such as the wind contributing to the transport of pollutants is also considered, and a frequency diagram of the wind direction is presented in order to consider the transboundary transport of harmful substances from other regions. The materials of the article used maps of a certain period of time, such as baric topographic maps and terrestrial synoptic maps, and their analysis was carried out. Based on the results of the analysis of maps of a certain period, the article describes the conditions for the occurrence of synoptic processes favorable for the accumulation of large concentrations of harmful substances in the city. The topic under consideration will be interesting to specialists in the field of natural science, politicians and public figures who pay attention to the ecology of our country, in particular to the ecological system of cities with a large industrial complex, such as Temirtau, and to urgent global environmental problems affecting to the state of atmospheric air quality.

Comparative Numerical Study of PM2.5 in Exit-and-Entrance Areas Associated with Transboundary Transport over China, Japan, and Korea

We report the results of year-long PM2.5 (particulate matter less than 2.5 µm in diameter) simulations over Northeast Asia for the base year of 2013 under the framework of the Long-range Transboundary Air Pollutants in Northeast Asia (LTP) project. LTP is a tripartite project launched by China, Japan, and Korea for cooperative monitoring and modeling of the long-range transport (LRT) of air pollutants. In the modeling aspect in the LTP project, each country’s modeling group employs its own original air quality model and options. The three regional air quality models employed by the modeling groups are WRF-CAMx, NHM-RAQM2, and WRF-CMAQ. PM2.5 concentrations were simulated in remote exit-and-entrance areas associated with the LRT process over China, Japan, and Korea. The results showed apparent bias that remains unexplored due to a series of uncertainties from emission estimates and inherent model limitations. The simulated PM10 levels at seven remote exit-and-entrance sites were underestimated with the normalized mean bias of 0.4 ± 0.2. Among the four chemical components of PM2.5 (SO42−, NO3−, organic carbon (OC), and elemental carbon (EC)), the largest inter-model variability was in OC, with the second largest discrepancy in NO3−. Our simulation results also indicated that under considerable SO42− levels, favorable environments for ammonium nitrate formation were found in exit-and-entrance areas between China and Korea, and gas-aerosol partitioning for semi-volatile species of ammonium nitrate could be fully achieved prior to arrival at the entrance areas. Other chemical characteristics, including NO3−/SO42− and OC/EC ratios, are discussed to diagnose the LRT characteristics of PM2.5 in exit-and-entrance areas associated with transboundary transport over China, Japan, and Korea.

The Transformation of Social and Cultural Space in the Context of the Development of Transport Corridors

This article discusses the methodology of analysis and forecasting of complex spatial systems, taking into account a lot of economic, social and cultural relationships that determine the specifics of the individual territories’ development. Particular attention is paid to the formation of specific zones on the basis of urban settlements along the path of transport corridors. In this regard, the authors introduce the concept of ”urban renewal centers” and give a definition. For its disclosure, the methodological part provides a list of related concepts, defines their boundaries and relationships, and also reveals the essence of the definitions of ‘transport corridor’ and ‘zone of transport corridor’. The authors proposed the use of vector estimates for the analysis of heterogeneous spatial systems of extended information volumes with the inclusion of sociological data and problem-oriented adaptation of visualization and processing of graphic data. As a result of a new, more detailed statement of the problem, we can go on to assess the prospects for the development of space for the complex and heterogeneous macro-regional and transboundary transport corridor Ural — Northern Kazakhstan. The study has fixed that development of urban renewal centers acts as a driver for the development of social and cultural spheres, as well as general economic conditions. The social and cultural transformation of urban settlements over time begins to determine their economic development potential. Such settlements are becoming centers of gravity in the labor market with many far-reaching development scenarios. Keywords: regional development, urban settlements, urban renewal, transport corridor, visualization