Impacts of atmospheric vertical structures on transboundary aerosol transport from China to South Korea

Abstract To forecast haze pollution episodes caused by high concentrations of long-range transported pollutants emitted in the areas upstream of South Korea, it is crucial to study and identify their behaviour. We analysed the three-dimensional air quality structure in Seoul using ground observation data and aerosol lidar measurements to identify vertical aerosol intrusion into the Korean Peninsula during the spring of 2016. The intrusions were particularly affected by the development of the atmospheric boundary layer (ABL) in the leeward regions. The nocturnal pollutant intrusion into the Korean peninsula via the Yellow Sea was examined using measured data. The pollutants first reached the area above the nocturnal boundary layer (548 ± 180 m) and approached ground level on the following day due to convective mixing depending on the convective ABL growth (1182 ± 540 m) in daytime. These intrusion mechanisms were mostly attributed to extremely high concentrations (i.e. >100 μg m−3) of fine particulate matter in the leeward regions, accounting for four of the total of six cases for which the warnings and alerts were issued in Seoul Metropolitan Area over a year-long period (2016). The horizontal and vertical pathways of the long-range transported pollutants and the atmospheric vertical structure were identified as key factors affecting the surface air quality concentration in the leeward regions.

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Spatial Analysis (Measurements at Heights of 10 m and 20 m above Ground Level) of the Concentrations of Particulate Matter (PM10, PM2.5, and PM1.0) and Gaseous Pollutants (H2S) on the University Campus: A Case Study

Atmosphere ◽

10.3390/atmos12010062 ◽

2021 ◽

Vol 12 (1) ◽

pp. 62

Author(s):

Robert Cichowicz ◽

Maciej Dobrzański

Keyword(s):

Spatial Distribution ◽

Hydrogen Sulfide ◽

Particulate Matter ◽

Air Quality ◽

Spatial Analysis ◽

Ground Level ◽

Leeward Side ◽

High Concentration ◽

Above Ground Level ◽

High Concentrations

Spatial analysis of the distribution of particulate matter PM10, PM2.5, PM1.0, and hydrogen sulfide (H2S) gas pollution was performed in the area around a university library building. The reasons for the subject matter were reports related to the perceptible odor characteristic of hydrogen sulfide and a general poor assessment of air quality by employees and students. Due to the area of analysis, it was decided to perform measurements at two heights, 10 m and 20 m above ground level, using measuring equipment attached to a DJI Matrice 600 unmanned aerial vehicle (UAV). The aim of the measurements was air quality assessment and investigate the convergence of the theory of air flow around the building with the spatial distribution of air pollutants. Considerable differences of up to 63% were observed in the concentrations of pollutants measured around the building, especially between opposite sides, depending on the direction of the wind. To explain these differences, the theory of aerodynamics was applied to visualize the probable airflow in the direction of the wind. A strong convergence was observed between the aerodynamic model and the spatial distribution of pollutants. This was evidenced by the high concentrations of dust in the areas of strong turbulence at the edges of the building and on the leeward side. The accumulation of pollutants was also clearly noticeable in these locations. A high concentration of H2S was recorded around the library building on the side of the car park. On the other hand, the air turbulence around the building dispersed the gas pollution, causing the concentration of H2S to drop on the leeward side. It was confirmed that in some analyzed areas the permissible concentration of H2S was exceeded.

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Entrainment and Mixing of Transported Ozone Layers: Implications for Surface Air Quality in the Western U.S.

EPJ Web of Conferences ◽

10.1051/epjconf/202023703012 ◽

2020 ◽

Vol 237 ◽

pp. 03012

Author(s):

Christoph Senff ◽

Andrew Langford ◽

Raul Alvarez ◽

Tim Bonin ◽

Alan Brewer ◽

...

Keyword(s):

Boundary Layer ◽

Air Quality ◽

Mixed Layer ◽

Las Vegas ◽

Surface Ozone ◽

Ground Level ◽

San Joaquin Valley ◽

Fire Emissions ◽

Ozone Transport ◽

The Impact

Recently, two air quality campaigns were conducted in the southwestern United States to study the impact of transported ozone, stratospheric intrusions, and fire emissions on ground-level ozone concentrations. The California Baseline Ozone Transport Study (CABOTS) took place in May – August 2016 covering the central California coast and San Joaquin Valley, and the Fires, Asian, and Stratospheric Transport Las Vegas Ozone Study (FAST-LVOS) was conducted in the greater Las Vegas, Nevada area in May – June 2017. During these studies, nearly 1000 hours of ozone and aerosol profile data were collected with the NOAA TOPAZ lidar. A Doppler wind lidar and a radar wind profiler provided continuous observations of atmospheric turbulence, horizontal winds, and mixed layer height. These measurements allowed us to directly observe the degree to which ozone transport layers aloft were entrained into the boundary layer and to quantify the resulting impact on surface ozone levels. Mixed layer heights in the San Joaquin Valley during CABOTS were generally below 1 km above ground level (AGL), while boundary layer heights in Las Vegas during FAST-LVOS routinely exceeded 3 km AGL and occasionally reached up to 4.5 km AGL. Consequently, boundary layer entrainment was more often observed during FAST-LVOS, while most elevated ozone layers passed untapped over the San Joaquin Valley during CABOTS.

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An Observing System Simulation Experiment Framework for Air Quality Forecasts in Northeast Asia: A Case Study Utilizing Virtual Geostationary Environment Monitoring Spectrometer and Surface Monitored Aerosol Data

Remote Sensing ◽

10.3390/rs14020389 ◽

2022 ◽

Vol 14 (2) ◽

pp. 389

Author(s):

Hyeon-Kook Kim ◽

Seunghee Lee ◽

Kang-Ho Bae ◽

Kwonho Jeon ◽

Myong-In Lee ◽

...

Keyword(s):

Air Quality ◽

South Korea ◽

System Simulation ◽

Northeast Asia ◽

Gobi Desert ◽

Observation Data ◽

Environment Monitoring ◽

Study Results ◽

Current Monitoring

Prior knowledge of the effectiveness of new observation instruments or new data streams for air quality can contribute significantly to shaping the policy and budget planning related to those instruments and data. In view of this, one of the main purposes of the development and application of the Observing System Simulation Experiments (OSSE) is to assess the potential impact of new observations on the quality of the current monitoring or forecasting systems, thereby making this framework valuable. This study introduces the overall OSSE framework established to support air quality forecasting and the details of its individual components. Furthermore, it shows case study results from Northeast Asia and the potential benefits of the new observation data scenarios on the PM2.5 forecasting skills, including the PM data from 200 virtual monitoring sites in the Gobi Desert and North Korean non-forest areas (NEWPM) and the aerosol optical depths (AOD) data from South Korea’s Geostationary Environment Monitoring Spectrometer (GEMS AOD). Performance statistics suggest that the concurrent assimilation of the NEWPM and the PM data from current monitoring sites in China and South Korea can improve the PM2.5 concentration forecasts in South Korea by 66.4% on average for October 2017 and 95.1% on average for February 2018. Assimilating the GEMS AOD improved the performance of the PM2.5 forecasts in South Korea for October 2017 by approximately 68.4% (~78.9% for February 2018). This OSSE framework is expected to be continuously implemented to verify its utilization potential for various air quality observation systems and data scenarios. Hopefully, this kind of application result will aid environmental researchers and decision-makers in performing additional in-depth studies for the improvement of PM air quality forecasts.

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Application of the "SIX SIGMA" method for the analysis of the improvement of the environmental air quality parameters at the municipality of Bucharest, by monitoring the pollutances of NOX pollutants

10.24264/icams-2020.iii.5 ◽

2020 ◽

Author(s):

Ion Durbaca ◽

Nicoleta Sporea ◽

Dana-Claudia Farcas-Flamaropol ◽

Elena Surdu

Keyword(s):

Air Quality ◽

Six Sigma ◽

Harmful Effect ◽

Ground Level ◽

Ambient Air ◽

Quality Parameters ◽

Maximum Efficiency ◽

Ambient Air Quality ◽

High Concentrations ◽

Environmental Air

This paper analyzes the improvement of ambient air quality indicators by monitoring the NOx concentration in one of the most polluted areas of Bucharest, using the statistical method "SIX SIGMA" (6σ). By applying the methodology of this statistical approach, the aim is to reduce non-conformities within the specified limits (according to the standards and legislative norms in force) and respectively, to ensure maximum efficiency (99,99%), equivalent to a yield of 3.4 defects per million opportunities (DPMO). As high concentrations of air pollutants have a major impact on human health, the most harmful effect has been found to be caused by nitrogen dioxide (NO2), mainly from ground-level ozone. Using the "6σ" method, the optimal solutions for eliminating non-conformities and implicitly for reducing the NO2 concentration and ensuring the improvement of the ambient air quality can be identified.

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Diurnal cycle of coastal anthropogenic pollutant transport over southern West Africa during the DACCIWA campaign

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-473-2019 ◽

2019 ◽

Vol 19 (1) ◽

pp. 473-497 ◽

Cited By ~ 13

Author(s):

Adrien Deroubaix ◽

Laurent Menut ◽

Cyrille Flamant ◽

Joel Brito ◽

Cyrielle Denjean ◽

...

Keyword(s):

Boundary Layer ◽

Air Quality ◽

West Africa ◽

Biomass Burning ◽

Diurnal Cycle ◽

Ground Level ◽

Transport Pathways ◽

Anthropogenic Pollutants ◽

Coastal Cities ◽

Anthropogenic Pollutant

Abstract. During the monsoon season, pollutants emitted by large coastal cities and biomass burning plumes originating from central Africa have complex transport pathways over southern West Africa (SWA). The Dynamics–Aerosol–Chemistry–Cloud Interactions in West Africa (DACCIWA) field campaign has provided numerous dynamical and chemical measurements in and around the super-site of Savè in Benin (≈185 km away from the coast), which allows quantification of the relative contribution of advected pollutants. Through the combination of in situ ground measurements with aircraft, radio-sounding, satellite, and high-resolution chemistry-transport modeling with the CHIMERE model, the source attribution and transport pathways of pollutants inland (here, NOx and CO) are carefully analyzed for the 1–7 July 2016 period. The relative contributions of different sources (i.e., emissions from several large coastal cities) to the air quality in Savè are characterized. It is shown that a systematic diurnal cycle exists with high surface concentrations of pollutants from 18:00 to 22:00 UTC. This evening peak is attributed to pollution transport from the coastal city of Cotonou (Benin). Numerical model experiments indicate that the anthropogenic pollutants are accumulated during the day close to the coast and transported northward as soon as the daytime convection in the atmospheric boundary layer ceases after 16:00 UTC, reaching 8∘ N at 21:00 UTC. When significant biomass burning pollutants are transported into continental SWA, they are mixed with anthropogenic pollutants along the coast during the day, and this mixture is then transported northward. At night, most of the coastal anthropogenic plumes are transported within the planetary boundary layer (below about 500 m above ground level), whereas the biomass burning pollutants are mostly transported above it, thus generally not impacting ground level air quality.

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Distribution Characteristics and Impact Factors of the Haze Weather in Changsha Area

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1010-1012.478 ◽

2014 ◽

Vol 1010-1012 ◽

pp. 478-483

Author(s):

Xiao Hong Zhang ◽

Lian Ye Liu ◽

Xi Hong Chen

Keyword(s):

Air Quality ◽

Ambient Air ◽

Impact Factors ◽

Observation Data ◽

Distribution Characteristics ◽

Meteorological Observation ◽

Ambient Air Quality ◽

Haze Pollution ◽

Autumn And Winter ◽

Environmental Monitoring Data

Based on meteorological observation data and environmental monitoring data of Changsha in the period from 1970 to 2012, this paper analyzes the distribution characteristics and import factors of the haze weather in Changsha. The results show that in the recent forty-three years, haze in Changsha is on the rise as a whole, and the haze weather mainly concentrates in autumn and winter. During the occurrence of the haze weather, the annual sunshine durations and the annual mean temperature are positively correlated with the haze weather, the annual precipitation is negatively correlated with the haze weather, and the concentration of PM2.5is significantly positively correlated with the occurrence of the haze weather, with the correlation coefficient of 0.893, indicating that PM2.5is the primary factor for the haze weather. Therefore, the control of PM2.5will be the key in reducing the haze pollution and improving the ambient air quality.

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Modeling regional aerosol and aerosol precursor variability over California and its sensitivity to emissions and long-range transport during the 2010 CalNex and CARES campaigns

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-10013-2014 ◽

2014 ◽

Vol 14 (18) ◽

pp. 10013-10060 ◽

Cited By ~ 43

Author(s):

J. D. Fast ◽

J. Allan ◽

R. Bahreini ◽

J. Craven ◽

L. Emmons ◽

...

Keyword(s):

Boundary Layer ◽

Air Quality ◽

Aerosol Optical Depth ◽

Long Range ◽

Optical Depth ◽

Trace Gases ◽

Organic Aerosol ◽

Long Range Transport ◽

Range Transport ◽

Aerosol Radiative

Abstract. The performance of the Weather Research and Forecasting regional model with chemistry (WRF-Chem) in simulating the spatial and temporal variations in aerosol mass, composition, and size over California is quantified using the extensive meteorological, trace gas, and aerosol measurements collected during the California Nexus of Air Quality and Climate Experiment (CalNex) and the Carbonaceous Aerosol and Radiative Effects Study (CARES) conducted during May and June of 2010. The overall objective of the field campaigns was to obtain data needed to better understand processes that affect both climate and air quality, including emission assessments, transport and chemical aging of aerosols, aerosol radiative effects. Simulations were performed that examined the sensitivity of aerosol concentrations to anthropogenic emissions and to long-range transport of aerosols into the domain obtained from a global model. The configuration of WRF-Chem used in this study is shown to reproduce the overall synoptic conditions, thermally driven circulations, and boundary layer structure observed in region that controls the transport and mixing of trace gases and aerosols. Reducing the default emissions inventory by 50% led to an overall improvement in many simulated trace gases and black carbon aerosol at most sites and along most aircraft flight paths; however, simulated organic aerosol was closer to observed when there were no adjustments to the primary organic aerosol emissions. We found that sulfate was better simulated over northern California whereas nitrate was better simulated over southern California. While the overall spatial and temporal variability of aerosols and their precursors were simulated reasonably well, we show cases where the local transport of some aerosol plumes were either too slow or too fast, which adversely affects the statistics quantifying the differences between observed and simulated quantities. Comparisons with lidar and in situ measurements indicate that long-range transport of aerosols from the global model was likely too high in the free troposphere even though their concentrations were relatively low. This bias led to an over-prediction in aerosol optical depth by as much as a factor of 2 that offset the under-predictions of boundary-layer extinction resulting primarily from local emissions. Lowering the boundary conditions of aerosol concentrations by 50% greatly reduced the bias in simulated aerosol optical depth for all regions of California. This study shows that quantifying regional-scale variations in aerosol radiative forcing and determining the relative role of emissions from local and distant sources is challenging during `clean' conditions and that a wide array of measurements are needed to ensure model predictions are correct for the right reasons. In this regard, the combined CalNex and CARES data sets are an ideal test bed that can be used to evaluate aerosol models in great detail and develop improved treatments for aerosol processes.

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Investigation of factors controlling PM2.5 variability across the South Korean Peninsula during KORUS-AQ

Elem Sci Anth ◽

10.1525/elementa.424 ◽

2020 ◽

Vol 8 ◽

Cited By ~ 4

Author(s):

Carolyn E. Jordan ◽

James H. Crawford ◽

Andreas J. Beyersdorf ◽

Thomas F. Eck ◽

Hannah S. Halliday ◽

...

Keyword(s):

Boundary Layer ◽

Air Quality ◽

South Korea ◽

Water Uptake ◽

Vertical Mixing ◽

Future Research ◽

Aerosol Composition ◽

Mixing Depth ◽

South Korean ◽

Transboundary Transport

The Korea – United States Air Quality Study (May – June 2016) deployed instrumented aircraft and ground-based measurements to elucidate causes of poor air quality related to high ozone and aerosol concentrations in South Korea. This work synthesizes data pertaining to aerosols (specifically, particulate matter with aerodynamic diameters <2.5 micrometers, PM2.5) and conditions leading to violations of South Korean air quality standards (24-hr mean PM2.5 < 35 µg m–3). PM2.5 variability from AirKorea monitors across South Korea is evaluated. Detailed data from the Seoul vicinity are used to interpret factors that contribute to elevated PM2.5. The interplay between meteorology and surface aerosols, contrasting synoptic-scale behavior vs. local influences, is presented. Transboundary transport from upwind sources, vertical mixing and containment of aerosols, and local production of secondary aerosols are discussed. Two meteorological periods are probed for drivers of elevated PM2.5. Clear, dry conditions, with limited transport (Stagnant period), promoted photochemical production of secondary organic aerosol from locally emitted precursors. Cloudy humid conditions fostered rapid heterogeneous secondary inorganic aerosol production from local and transported emissions (Transport/Haze period), likely driven by a positive feedback mechanism where water uptake by aerosols increased gas-to-particle partitioning that increased water uptake. Further, clouds reduced solar insolation, suppressing mixing, exacerbating PM2.5 accumulation in a shallow boundary layer. The combination of factors contributing to enhanced PM2.5 is challenging to model, complicating quantification of contributions to PM2.5 from local versus upwind precursors and production. We recommend co-locating additional continuous measurements at a few AirKorea sites across South Korea to help resolve this and other outstanding questions: carbon monoxide/carbon dioxide (transboundary transport tracer), boundary layer height (surface PM2.5 mixing depth), and aerosol composition with aerosol liquid water (meteorologically-dependent secondary production). These data would aid future research to refine emissions targets to further improve South Korean PM2.5 air quality.

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Meteorology, Air Quality, and Health in London: The ClearfLo Project

Bulletin of the American Meteorological Society ◽

10.1175/bams-d-12-00245.1 ◽

2015 ◽

Vol 96 (5) ◽

pp. 779-804 ◽

Cited By ~ 74

Author(s):

S. I. Bohnenstengel ◽

S. E. Belcher ◽

A. Aiken ◽

J. D. Allan ◽

G. Allen ◽

...

Keyword(s):

Boundary Layer ◽

Particulate Matter ◽

Air Quality ◽

Nitrogen Dioxide ◽

Urban Areas ◽

Elevated Temperatures ◽

Interdisciplinary Approach ◽

Urban Boundary Layer ◽

Ozone Production ◽

High Concentrations

Abstract Air quality and heat are strong health drivers, and their accurate assessment and forecast are important in densely populated urban areas. However, the sources and processes leading to high concentrations of main pollutants, such as ozone, nitrogen dioxide, and fine and coarse particulate matter, in complex urban areas are not fully understood, limiting our ability to forecast air quality accurately. This paper introduces the Clean Air for London (ClearfLo; www.clearflo.ac.uk) project’s interdisciplinary approach to investigate the processes leading to poor air quality and elevated temperatures. Within ClearfLo, a large multi-institutional project funded by the U.K. Natural Environment Research Council (NERC), integrated measurements of meteorology and gaseous, and particulate composition/loading within the atmosphere of London, United Kingdom, were undertaken to understand the processes underlying poor air quality. Long-term measurement infrastructure installed at multiple levels (street and elevated), and at urban background, curbside, and rural locations were complemented with high-resolution numerical atmospheric simulations. Combining these (measurement–modeling) enhances understanding of seasonal variations in meteorology and composition together with the controlling processes. Two intensive observation periods (winter 2012 and the Summer Olympics of 2012) focus upon the vertical structure and evolution of the urban boundary layer; chemical controls on nitrogen dioxide and ozone production—in particular, the role of volatile organic compounds; and processes controlling the evolution, size, distribution, and composition of particulate matter. The paper shows that mixing heights are deeper over London than in the rural surroundings and that the seasonality of the urban boundary layer evolution controls when concentrations peak. The composition also reflects the seasonality of sources such as domestic burning and biogenic emissions.

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