scholarly journals Long-term measurements of ground-level ozone in Windsor, Canada – Part I. temporal variations and trends

2018 ◽  
Author(s):  
Xiaohong Xu ◽  
Tianchu Zhang ◽  
Yushan Su
Keyword(s):  
Ground Level ◽  
Temporal Variations ◽  
Control Measures ◽  
Ground Level Ozone ◽  
Ozone Formation Potential ◽  
Volatile Organic ◽  
Increasing Trend ◽  
Annual Means ◽  
Collaborative Efforts

Abstract. This study investigates temporal variations and long-term (1996–2015) trends of ground-level O3 (ozone) and its precursors, NOx (nitrogen oxides) and volatile organic compounds in Windsor, Ontario, Canada. During the 20-year study period, NOx, non-methane hydrocarbon concentrations and ozone formation potential decreased significantly by 58 %, 61 %, and 73 %, respectively, while O3 concentrations increased by 33 % (20.3 ppb in 1996 vs. 27 ppb in 2015). Our analysis revealed that the increased annual O3 concentrations in Windsor were due to (1) decreased O3 titration (by 50 % between 1996 and 2015) owing to declining nitric oxide concentrations, which is suggested by a slightly decreasing trend of annual mean total O3 concentrations after the titration effect is removed, (2) reduced local photochemical production of O3, because of dwindling precursor emissions, and (3) increased background O3 level that has more impact on the low-to-median concentrations. The net effect of those factors is decreasing peak O3 levels during the smog season from May to September, but an overall increasing trend of annual means. These results indicate that the emission control measures are effective in reducing peak ozone concentrations. However, challenges in lowering annual O3 levels call for long-term collaborative efforts in the region and around the globe.

scholarly journals Temporal variations and trend of ground-level ozone based on long-term measurements in Windsor, Canada

2019 ◽  
Vol 19 (11) ◽  
pp. 7335-7345 ◽  
Author(s):  
Xiaohong Xu ◽  
Tianchu Zhang ◽  
Yushan Su
Keyword(s):  
Ground Level ◽  
Temporal Variations ◽  
Control Measures ◽  
Ground Level Ozone ◽  
Ozone Formation Potential ◽  
Volatile Organic ◽  
Increasing Trend ◽  
Annual Means ◽  
Collaborative Efforts

Abstract. This study investigates temporal variations and long-term (1996–2015) trends of ground-level O3 (ozone) and its precursors, NOx (nitrogen oxides), and volatile organic compounds in Windsor, Ontario, Canada. During the 20-year study period, NOx, non-methane hydrocarbon concentrations, and ozone formation potential decreased significantly by 58 %, 61 %, and 73 %, respectively, while O3 concentrations increased by 33 % (20.3 ppb in 1996 vs. 27 ppb in 2015). Our analysis revealed that the increased annual O3 concentrations in Windsor were due to (1) decreased O3 titration (by 50 % between 1996 and 2015) owing to declining nitric oxide concentrations, which is suggested by a slightly decreasing trend of annual mean total O3 concentrations after the titration effect is removed, (2) reduced local photochemical production of O3 because of dwindling precursor emissions, and (3) an increased background O3 level that has a greater impact on the low-to-median concentrations. The net effect of those factors is decreasing peak O3 levels during the smog season from May to September but an overall increasing trend of annual means. These results indicate that the emission control measures are effective in reducing peak ozone concentrations. However, challenges in lowering annual O3 levels call for long-term collaborative efforts in the region and around the globe.

scholarly journals Contribution of solvents from road marking paints to tropospheric ozone formation

2016 ◽  
Vol 15 (1) ◽  
pp. 007-018 ◽  
Author(s):  
Tomasz Burghardt ◽  
Anton Pashkevich ◽  
Lidia Żakowska
Keyword(s):  
Tropospheric Ozone ◽  
Western Europe ◽  
Ground Level ◽  
Solar Irradiation ◽  
Ozone Formation ◽  
Potential Contribution ◽  
Ground Level Ozone ◽  
Ozone Formation Potential ◽  
Volatile Organic ◽  
Road Marking

Solventborne road marking paints are meaningful sources of Volatile Organic Compounds (VOCs), which under solar irradiation affect formation of tropospheric ozone, a signif cant pulmonary irritant and a key pollutant responsible for smog formation. Influence of particular VOCs on ground-level ozone formation potential, quantified in Maximum Incremental Reactivities (MIR), were used to calculate potential contribution of solvents from road marking paints used in Poland to tropospheric ozone formation. Based on 2014 data, limited only to roads administered by General Directorate for National Roads and Motorways (GDDKiA), emissions of VOCs from road marking paints in Poland were about 494 838 kg, which could lead to production of up to 1 003 187 kg of ropospheric ozone. If aromatic-free solventborne paints based on ester solvents, such as are commonly used in Western Europe, were utilised, VOC emissions would not be lowered, but potentially formed ground-level ozone could be limited by 50-70%. Much better choice from the perspective of environmental protection would be the use of waterborne road marking paints like those mandated in Scandinavia – elimination of up to 82% of the emitted VOCs and up to 95% of the potentially formed tropospheric ozone could be achieved.

scholarly journals Trends in PM2.5 Concentration in Nagoya, Japan, from 2003 to 2018 and Impacts of PM2.5 Countermeasures

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 590
Author(s):  
Makiko Yamagami ◽  
Fumikazu Ikemori ◽  
Hironori Nakashima ◽  
Kunihiro Hisatsune ◽  
Kayo Ueda ◽  
...  
Keyword(s):  
Fine Particulate Matter ◽  
Control Measures ◽  
Source Control ◽  
Atmospheric Concentration ◽  
Construction Machinery ◽  
Emission Regulations ◽  
Volatile Organic ◽  
Stationary Sources ◽  
Pm2.5 Concentration

In Japan, various countermeasures have been undertaken to reduce the atmospheric concentration of fine particulate matter (PM2.5). We evaluated the extent to which these countermeasures were effective in reducing PM2.5 concentrations by analyzing the long-term concentration trends of the major components of PM2.5 and their emissions in Nagoya City. PM2.5 concentrations decreased by 53% over the 16-year period from fiscal years 2003 to 2018 in Nagoya City. Elemental carbon (EC) was the component of PM2.5 with the greatest decrease in concentration over the 16 years, decreasing by 4.3 μg/m3, followed by SO42− (3.0 μg/m3), organic carbon (OC) (2.0 μg/m3), NH4+ (1.6 μg/m3), and NO3− (1.3 μg/m3). The decrease in EC concentration was found to be caused largely by the effect of diesel emission control. OC concentrations decreased because of the effects of volatile organic compound (VOC) emission regulations for stationary sources and reductions in VOCs emitted by vehicles and construction machinery. NO3− concentrations decreased alongside decreased contributions from vehicles, construction machinery, and stationary sources, in descending order of the magnitude of decrease. Although these findings identify some source control measures that have been effective in reducing PM2.5, they also reveal the ineffectiveness of some recent countermeasures for various components, such as those targeting OC concentrations.

scholarly journals Impact of VOCs on the formation of ozone in a central China city during severe pollution periods

2018 ◽  
Author(s):  
Bowei Li ◽  
Steven Sai Hang Ho ◽  
Sunling Gong ◽  
Jingwei Ni ◽  
Huairui Li ◽  
...  
Keyword(s):  
Temporal Variations ◽  
Central China ◽  
Compressed Natural Gas ◽  
Pmf Model ◽  
Sampling Campaign ◽  
Time Period ◽  
Ozone Formation Potential ◽  
Range Transport ◽  
Volatile Organic ◽  
First Time

Abstract. In this work, a five-month sampling campaign was conducted for volatile organic compounds (VOCs) for the first time in Zhengzhou City, Henan province, China, where ozone (O3) pollution has shown an increasing trend in recent years. Fifty-seven VOCs defined by the Photochemical Assessment Monitoring Stations (PAMS) were sampled using canister method. Meanwhile, other O3 precursor gases were monitored online at four different sites between the time period of May–September, 2017. The results indicated that the average mixing ratio of ΣPAMS (31.57 ± 23.35 ppbv) in Zhengzhou was lower than the other megacities in China, while alkyne was in a significantly higher proportion. The abundances, compositions and ratios of PAMS showed strong spatial and temporal variations. Alkenes were the largest contributors to the ozone formation potential (OFP). On clear days, higher O3 levels were often accompanied with high ΣPAMS/NOx ratio at each site, demonstrating that the VOCs were more sensitive during the O3 formation period in Zhengzhou. Furthermore, source apportionmemt was conducted with Positive Matrix Factorization (PMF) model, and it was found that the use of compressed natural gas (CNG), the evaporation of gasoline and the exhaust from vehicles were the important sources for ambient VOCs at all four sites. Besides, the meterological conditions and long-range transport from other surrounding provinces also had an impact on the air quality determined using the cluster analysis. It is worth mentioning that the reduction in VOCs' emissions is necessary to suppress the O3 pollution.

scholarly journals Ozone formation sensitivity study using machine learning coupled with reactivity of VOC species

2021 ◽  
Author(s):  
Junlei Zhan ◽  
Yongchun Liu ◽  
Wei Ma ◽  
Xin Zhang ◽  
Xuezhong Wang ◽  
...  
Keyword(s):  
Positive Response ◽  
Meteorological Factors ◽  
Ground Level ◽  
Sensitivity Study ◽  
Computationally Efficient ◽  
Timely Manner ◽  
Ground Level Ozone ◽  
Volatile Organic ◽  
Response To Temperature ◽  
Better Than

Abstract. The formation of ground-level ozone (O3) is dependent on both atmospheric chemical processes and meteorological factors. Traditional models have difficulty assessing O3 formation sensitivity in a timely manner due to the limitations of flexibility and computational efficiency. In this study, a random forest (RF) model coupled with the reactivity of volatile organic compound (VOC) species was used to investigate the O3 formation sensitivity in Beijing from 2014 to 2016, and evaluate the relative importance (RI) of chemical and meteorological factors to O3 formation. The results showed that the O3 prediction performance using initial concentrations of VOC species (R2 = 0.87) was better than that using total VOCs (TVOCs) concentrations (R2 = 0.77). Meanwhile, the RIs of VOC species correlated well with their O3 formation potentials (OFPs). O3 formation presented a negative response to NOx, PM2.5 and relative humidity, and a positive response to temperature, solar radiation and VOCs. The O3 isopleth curves calculated by the RF model were generally comparable with those calculated by the box model. O3 formation shifted from a VOC-limited regime to a transition regime from 2014 to 2016. This study demonstrates that the RF model coupled with the initial concentrations of VOC species could provide an accurate, flexible, and computationally efficient approach for O3 sensitivity analysis.

scholarly journals AIR QUALITY MONITORING AND DATA MANAGEMENT IN GERMANY – STATUS QUO AND SUGGESTIONS FOR IMPROVEMENT

2020 ◽  
Vol XLIV-4/W2-2020 ◽  
pp. 37-43
Author(s):  
L. Petry ◽  
H. Herold ◽  
G. Meinel ◽  
T. Meiers ◽  
I. Müller ◽  
...  
Keyword(s):  
Decision Making ◽  
Air Quality ◽  
Management Practices ◽  
System Development ◽  
Ground Level ◽  
Ground Level Ozone ◽  
Novel Approach ◽  
Depth Analysis ◽  
New Generation

Abstract. This paper proposes a novel approach to facilitate air quality aware decision making and to support planning actors to take effective measures for improving the air quality in cities and regions. Despite many improvements over the past decades, air pollutants such as particulate matter (PM), nitrogen dioxide (NO2) and ground-level ozone (O3) pose still one of the major risks to human health and the environment. Based on both a general analysis of the air quality situation and regulations in the EU and Germany as well as an in-depth analysis of local management practices requirements for better decision making are identified. The requirements are used to outline a system architecture following a co-design approach, i.e., besides scientific and industry partners, local experts and administrative actors are actively involved in the system development. Additionally, the outlined system incorporates two novel methodological strands: (1) it employs a deep neural network (DNN) based data analytics approach and (2) makes use of a new generation of satellite data, namely Sentinel-5 Precursor (Sentinel-5P). Hence, the system allows for providing areal and high-resolution (e.g., street-level) real-time and forecast (up to 48 hours) data to inform decision makers for taking appropriate short-term measures, and secondly, to simulate air quality under different planning options and long-term actions such as modified traffic flows and various urban layouts.

A Neglected Long-Term Series of Ground-Level Ozone

1985 ◽  
pp. 788-790 ◽  
Author(s):  
E. G. Mariolopoulos ◽  
C. C. Repapis ◽  
C. S. Zerefos ◽  
C. Varotsos ◽  
I. Ziomas ◽  
...  
Keyword(s):  
Ground Level ◽  
Ground Level Ozone
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