scholarly journals Ozone production in the megacities of Tianjin and Shanghai, China: a comparative study

2012 ◽  
Vol 12 (4) ◽  
pp. 9161-9194 ◽  
Author(s):  
L. Ran ◽  
C. S. Zhao ◽  
W. Y. Xu ◽  
M. Han ◽  
X. Q. Lu ◽  
...  
Keyword(s):  
Comparative Study ◽  
Surface Ozone ◽  
Regional Scale ◽  
Yangtze River Delta ◽  
Scientific Basis ◽  
Ozone Production ◽  
Ozone Pollution ◽  
Light Alkenes ◽  
Highly Nonlinear ◽  
Ozone Precursor

Abstract. Rapid economic growth has given rise to a significant increase in ozone precursor emissions in many regions of China, especially in the densely populated North China Plain (NCP) and Yangtze River Delta (YRD). Improved understanding of ozone formation in response to different precursor emissions is imperative to address the highly nonlinear ozone problem and to provide a solid scientific basis for efficient ozone abatement in these regions. A comparative study on ozone photochemical production in summer has thus been carried out in the megacities of Tianjin (NCP) and Shanghai (YRD). Two intensive field campaigns were carried out respectively at an urban and a suburban site of Tianjin, in addition to routine monitoring of trace gases in Shanghai, providing data sets of surface ozone and its precursors including nitrogen oxides (NOx) and various volatile organic compounds (VOCs). Ozone pollution was found to be more severe in Tianjin than in Shanghai during the summer, either based on the frequency or the duration of high ozone events. Such differences might be attributed to the large amount of highly reactive VOC mixture in the Tianjin region. It is found that industry related species like light alkenes were of particular importance in both urban and suburban Tianjin, while in Shanghai aromatics dominate. In general, the ozone problem in Shanghai is on an urban scale. Stringent control policies on local emissions would help reduce the occurrence of high ozone concentrations. By contrast, ozone pollution in Tianjin is a regional problem. Combined efforts to reduce ozone precursor emissions on a regional scale must be undertaken to bring the ozone problem under control.

scholarly journals Ozone production in summer in the megacities of Tianjin and Shanghai, China: a comparative study

2012 ◽  
Vol 12 (16) ◽  
pp. 7531-7542 ◽  
Author(s):  
L. Ran ◽  
C. S. Zhao ◽  
W. Y. Xu ◽  
M. Han ◽  
X. Q. Lu ◽  
...  
Keyword(s):  
Comparative Study ◽  
Surface Ozone ◽  
Regional Scale ◽  
Yangtze River Delta ◽  
Scientific Basis ◽  
Ozone Production ◽  
Ozone Pollution ◽  
Light Alkenes ◽  
Highly Nonlinear ◽  
Ozone Precursor

Abstract. Rapid economic growth has given rise to a significant increase in ozone precursor emissions in many regions of China, especially in the densely populated North China Plain (NCP) and Yangtze River Delta (YRD). Improved understanding of ozone formation in response to different precursor emissions is imperative to address the highly nonlinear ozone problem and to provide a solid scientific basis for efficient ozone abatement in these regions. A comparative study on ozone photochemical production in summer has thus been carried out in the megacities of Tianjin (NCP) and Shanghai (YRD). Two intensive field campaigns were carried out respectively at an urban and a suburban site of Tianjin, in addition to routine monitoring of trace gases in Shanghai, providing data sets of surface ozone and its precursors including nitrogen oxides (NOx) and various non-methane hydrocarbons (NMHCs). Ozone pollution in summer was found to be more severe in the Tianjin region than in the Shanghai region, based on either the frequency or the duration of high ozone events. Such differences might be attributed to the large amount of highly reactive NMHCs in Tianjin. Industry related species like light alkenes were of particular importance in both urban and suburban Tianjin, while in Shanghai aromatics dominated. In general, the ozone problem in Shanghai is on an urban scale. Stringent control policies on local emissions would help reduce the occurrence of high ozone concentrations. By contrast, ozone pollution in Tianjin is probably a regional problem. Combined efforts to reduce ozone precursor emissions on a regional scale must be undertaken to bring the ozone problem under control.

scholarly journals The influence of European pollution on ozone in the Near East and northern Africa

2008 ◽  
Vol 8 (1) ◽  
pp. 1913-1950 ◽  
Author(s):  
B. N. Duncan ◽  
J. J. West ◽  
Y. Yoshida ◽  
A. M. Fiore ◽  
J. R. Ziemke
Keyword(s):  
Boundary Layer ◽  
Air Quality ◽  
Near East ◽  
Surface Ozone ◽  
Northern Africa ◽  
Ozone Production ◽  
Ozone Pollution ◽  
East European ◽  
European Health ◽  
Ozone Precursor

Abstract. We present a modeling study of the long-range transport of pollution from Europe, showing that European emissions regularly elevate surface ozone by as much as 20 ppbv in summer in northern Africa and the Near East. European emissions cause 50–150 additional violations per year (i.e., above those that would occur without European pollution) of the European health standard for ozone (8-h average >120 μg/m3 or ~60 ppbv) in northern Africa and the Near East. We estimate that 19 000 additional mortalities occur annually in these regions from exposure to European ozone pollution and 50 000 additional deaths globally; the majority of the additional deaths occurs outside of Europe. Much of the pollution from Europe is exported southward at low altitudes in summer to the Mediterranean Sea, northern Africa and the Near East, regions with favorable photochemical environments for ozone production. Our results suggest that assessments of the human health benefits of reducing ozone precursor emissions in Europe should include effects outside of Europe, and that comprehensive planning to improve air quality in northern Africa and the Near East likely needs to address European emissions. We also show that the tropospheric ozone column data product derived from the OMI and MLS instruments is currently of limited value for air quality applications as the portion of the column above the boundary layer and below the tropopause is large and variable, effectively obscuring the boundary layer signal.

scholarly journals The influence of European pollution on ozone in the Near East and northern Africa

2008 ◽  
Vol 8 (8) ◽  
pp. 2267-2283 ◽  
Author(s):  
B. N. Duncan ◽  
J. J. West ◽  
Y. Yoshida ◽  
A. M. Fiore ◽  
J. R. Ziemke
Keyword(s):  
Near East ◽  
Surface Ozone ◽  
Northern Africa ◽  
Ozone Production ◽  
Ozone Pollution ◽  
Comprehensive Planning ◽  
East European ◽  
Range Transport ◽  
European Health ◽  
Ozone Precursor

Abstract. We present a modeling study of the long-range transport of pollution from Europe, showing that European emissions regularly elevate surface ozone by as much as 20 ppbv in summer in northern Africa and the Near East. European emissions cause 50–150 additional violations per year (i.e. above those that would occur without European pollution) of the European health standard for ozone (8-h average >120 μg/m3 or ~60 ppbv) in northern Africa and the Near East. We estimate that European ozone pollution is responsible for 50 000 premature mortalities globally each year, of which the majority occurs outside of Europe itself, including 37% (19 000) in northern Africa and the Near East. Much of the pollution from Europe is exported southward at low altitudes in summer to the Mediterranean Sea, northern Africa and the Near East, regions with favorable photochemical environments for ozone production. Our results suggest that assessments of the human health benefits of reducing ozone precursor emissions in Europe should include effects outside of Europe, and that comprehensive planning to improve air quality in northern Africa and the Near East likely needs to address European emissions.

scholarly journals Measurements of ozone and its precursors in Beijing during summertime: impact of urban plumes on ozone pollution in downwind rural areas

2011 ◽  
Vol 11 (6) ◽  
pp. 17337-17373 ◽  
Author(s):  
J. Xu ◽  
J. Z. Ma ◽  
X. L. Zhang ◽  
X. B. Xu ◽  
X. F. Xu ◽  
...  
Keyword(s):  
Rural Areas ◽  
Surface Ozone ◽  
Regional Scale ◽  
Rural Site ◽  
Traffic Density ◽  
Prevailing Wind ◽  
Ozone Pollution ◽  
Rural Sites ◽  
Urban And Rural Areas ◽  
Urban Plumes

Abstract. Sea-land and mount-valley circulations are the dominant mesoscale synoptic systems affecting the Beijing area during summertime. Under the influence of these two circulations, the prevailing wind is southwesterly from afternoon to midnight, and then changes to northeasterly till forenoon. In this study, surface ozone (O3), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO2), nitrogen oxide (NOx) and non-methane hydrocarbons (NMHCs) were measured at four sites located along the route of prevailing wind, including two upwind urban sites (Fengtai (FT) and Baolian (BL)), an upwind suburban site (Shunyi (SY)) and a downwind rural site (Shangdianzi (SDZ)) during 20 June–16 September 2007. The purpose is to improve our understanding of ozone photochemistry in urban and rural areas of Beijing and the influence of urban plumes on ozone pollution in downwind rural areas. It is found that ozone pollution was synchronism in the urban and rural areas of Beijing, coinciding with the regional-scale synoptic processes. Due to the high traffic density and local emissions, the average levels of reactive gases NOx and NMHCs at the non-rural sites were much higher than those at SDZ. The level of long-lived gas CO at SDZ was comparable to and slightly lower than it was at other sites. The daily-averaged ozone concentration at SDZ was much higher than at other sites due to weak titration. Ranking by OH loss rate coefficient (LOH), alkenes played a dominant role in total NMHCs reactivity at both urban and rural sites during the experiment, accounting for 48.6 % and 52.1 % of total LOH, respectively. The NMHCs data were also used to estimate the ozone potential formation (OFP) in Beijing. The leading contributors to ozone formation were aromatics at both urban and rural sites during the experiment, which accounts for 55.5 % and 49.4 % of total OFP, respectively. The ozone peak values are found to lag behind one site after another along the route of prevailing wind from SW to NE. Intersection analyses of trace gases reveal that polluted air masses arriving at SDZ were more aged with both higher O3 and Ox concentrations than those at BL. The results indicate that urban plume can transport not only O3 but its precursors, the latter leading more photochemical O3 production when being mixed with background atmosphere in the downwind rural area.

scholarly journals Observed changes in the temperature dependence response of surface ozone under NO<sub><i>x</i></sub> reductions

2020 ◽  
Author(s):  
Noelia Otero ◽  
Henning W. Rust ◽  
Tim Butler
Keyword(s):  
Temperature Dependence ◽  
Surface Ozone ◽  
Additive Models ◽  
Ozone Production ◽  
Temperature Relationship ◽  
Strong Temperature Dependence ◽  
Ozone Pollution ◽  
Production Rates ◽  
Penalty Factor ◽  
Second Period

Abstract. Due to the strong temperature dependence of surface ozone concentrations (O3), future warmer conditions may worsen ozone pollution levels despite continued efforts on emission controls of ozone precursors. Using long-term measurements of hourly O3 concentrations co-located with NOx concentrations in stations distributed throughout Germany, we assess changes in the climate penalty, defined as the slope of ozone-temperature relationship during the period 1999–2018. We find a stronger temperature sensitivity in the urban stations over the southwestern regions, especially in the first period of the study (1999–2008).We show a decrease in the climate penalty in most of stations during the second period of the study (2009–2018), with some exceptions (e.g. Berlin) where the climate penalty did not show significant changes. To examine the impacts of NOx reductions on the O3 sensitivity to temperature, we propose a statistical approach based on generalized additive models (GAMs) to describe ozone production rates, inferred from hourly observations, as a function of NOx and temperature, among other variables relevant during the O3 production. We find lower O3 production rates during the second period (2009–2018) at most stations and a decreasing sensitivity to temperature, pointing out that lowering NOx concentrations resulted in decreasing O3 production rates. However, we also observe changes in the shape of the function representing the O3-temperature relationship, which indicate that NOx reductions alone can not explain the changes in the temperature dependence of O3. Our analysis would suggest that decreasing NOx concentrations are not the only factor causing the observed changes in the climate penalty factor.

Impacts of Stratospheric Intrusion on Surface Ozone over Eastern China

2020 ◽  
Author(s):  
Wuke Wang
Keyword(s):  
Yangtze River ◽  
Surface Ozone ◽  
Eastern China ◽  
Yangtze River Delta ◽  
River Delta ◽  
Anthropogenic Sources ◽  
The Yangtze River ◽  
Ozone Pollution ◽  
Stratospheric Intrusion ◽  
The Yangtze River Delta

&lt;p&gt;&lt;span&gt;Ozone pollution is currently a serious environmental issue in China. Most of studies have attributed the surface ozone pollution over China to the strong photochemical production from anthropogenic sources. As another important source of tropospheric ozone, the stratospheric intrusion (SI), however, has been less concerned. This study investigates the SI events over the Yangtze River Delta in eastern China using the newest ERA5 (the fifth generation of ECMWF atmospheric reanalysis) meteorological and ozone data, the In-service Aircraft for a Global Observing System (IAGOS) ozone profiles and the station-based ground-level ozone measurements. Results indicate that SI plays important roles in spring and summer ozone pollution episodes over the Yangtze River Delta, eastern China. Based on CAM-Chem (the Community Atmosphere Model with Chemistry) and LPDM (Lagrangian Particle Dispersion Modeling) model simulations, we found that deep SIs contribute ~15 ppbv in spring and ~10 ppbv in summer to surface ozone variations in eastern China. A deep SI event occurred in 2018 spring associated with a strong horizontal-trough, which brought ozone-rich air from the stratosphere to the troposphere and resulted in severe surface ozone pollution over the Yangtze River Delta. From 7-year statistics, we found that strong SI events during summer are associated with a cyclonic valley between the South Asian High and the Subtropical High, accompanied by downward fast transport of ozone from the stratosphere to the troposphere. Our results provide important information for surface ozone prediction and control in eastern China.&lt;/span&gt;&lt;/p&gt;

scholarly journals Trends and Variability of Ozone Pollution over the Mountain-Basin Areas in Sichuan Province during 2013–2020: Synoptic Impacts and Formation Regimes

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1557
Author(s):  
Youfan Chen ◽  
Han Han ◽  
Murong Zhang ◽  
Yuanhong Zhao ◽  
Yipeng Huang ◽  
...  
Keyword(s):  
High Pressure ◽  
Surface Ozone ◽  
Emission Control ◽  
Warm Season ◽  
Sichuan Province ◽  
Ozone Production ◽  
Daily Maximum ◽  
Ozone Pollution ◽  
Reanalysis Dataset ◽  
Ozone Levels

Sichuan Province, the most industrialized and populated region in southwestern China, has been experiencing severe ozone pollution in the boreal warm season (April–September). With a surface ozone monitoring network and reanalysis dataset, we find that nearly all cities in Sichuan Province showed positive increasing trends in the warm-season ozone levels. The warm-season daily maximum 8-h average (MDA8) ozone levels increased by 2.0 ppb (4.8%) year−1 as a whole, with slightly larger trends in some sites such as a site in Zigong (5.2 ppb year−1). Seasonally, the monthly ozone level in Sichuan peaks from May to August (varies with year). The predominant warm-season synoptic patterns were objectively identified based on concurrent hourly meteorological fields from ERA5. High-pressure systems promote ozone production and result in high ozone concentrations, due to strong solar radiation as well as hot and dry atmospheric conditions. The increased occurrence of high-pressure patterns probably drives the ozone increase in Sichuan. When ozone pollution is relatively weak (with MDA8 ozone around 170 μg m−3), the air quality standard could be achieved in the short term by a 25% reduction of NOx and VOCs emissions. Strengthened emission control is needed when ozone pollution is more severe. Our study provides implications for effective emission control of ozone pollution in Sichuan.

scholarly journals Winter Ozone Pollution in Utah’s Uinta Basin is Attenuating

Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 4
Author(s):  
Marc L. Mansfield ◽  
Seth N. Lyman
Keyword(s):  
Ground Level ◽  
Ambient Air ◽  
Quality Standard ◽  
Ozone Pollution ◽  
Uinta Basin ◽  
Concentration Data ◽  
Previous Decade ◽  
High Concentrations ◽  
Ambient Air Quality Standard ◽  
Ozone Precursor

High concentrations of ground-level ozone have been observed during wintertime in the Uinta Basin of western Utah, USA, beginning in 2010. We analyze existing ozone and ozone precursor concentration data from 38 sites over 11 winter seasons and conclude that there has been a statistically significant (p < 0.02) decline in ozone concentration over the previous decade. Daily exceedances of the National Ambient Air Quality Standard for ozone (70 ppb) have been trending downward at the rate of nearly four per year. Ozone and NOx concentrations have been trending downward at the rates of about 3 and 0.3 ppb per year, respectively. Concentrations of organics in 2018 were at about 30% of their values in 2012 or 2013. Several markers, annual ozone exceedance counts and median ozone and NOx concentrations, were at their largest values in the period 2010 to 2013 and have never recovered since then. We attribute the decline to (1) weakening global demand for oil and natural gas and (2) more stringent pollution regulations and controls, both of which have occurred over the previous decade. We also see evidence of ozone titration when snow cover is absent.

scholarly journals Modelling the impact of megacities on local, regional and global tropospheric ozone and the deposition of nitrogen species

2013 ◽  
Vol 13 (24) ◽  
pp. 12215-12231 ◽  
Author(s):  
Z. S. Stock ◽  
M. R. Russo ◽  
T. M. Butler ◽  
A. T. Archibald ◽  
M. G. Lawrence ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Climate Model ◽  
Surface Ozone ◽  
Global Scale ◽  
Chemical Environment ◽  
Ozone Production ◽  
The Uk ◽  
The Impact ◽  
Local Emissions

Abstract. We examine the effects of ozone precursor emissions from megacities on present-day air quality using the global chemistry–climate model UM-UKCA (UK Met Office Unified Model coupled to the UK Chemistry and Aerosols model). The sensitivity of megacity and regional ozone to local emissions, both from within the megacity and from surrounding regions, is important for determining air quality across many scales, which in turn is key for reducing human exposure to high levels of pollutants. We use two methods, perturbation and tagging, to quantify the impact of megacity emissions on global ozone. We also completely redistribute the anthropogenic emissions from megacities, to compare changes in local air quality going from centralised, densely populated megacities to decentralised, lower density urban areas. Focus is placed not only on how changes to megacity emissions affect regional and global NOx and O3, but also on changes to NOy deposition and to local chemical environments which are perturbed by the emission changes. The perturbation and tagging methods show broadly similar megacity impacts on total ozone, with the perturbation method underestimating the contribution partially because it perturbs the background chemical environment. The total redistribution of megacity emissions locally shifts the chemical environment towards more NOx-limited conditions in the megacities, which is more conducive to ozone production, and monthly mean surface ozone is found to increase up to 30% in megacities, depending on latitude and season. However, the displacement of emissions has little effect on the global annual ozone burden (0.12% change). Globally, megacity emissions are shown to contribute ~3% of total NOy deposition. The changes in O3, NOx and NOy deposition described here are useful for quantifying megacity impacts and for understanding the sensitivity of megacity regions to local emissions. The small global effects of the 100% redistribution carried out in this study suggest that the distribution of emissions on the local scale is unlikely to have large implications for chemistry–climate processes on the global scale.

Investigating the occurrence, likelihood and regional variability of extreme ozone pollution episodes across the UK

2021 ◽  
Author(s):  
Lily Gouldsbrough ◽  
Ryan Hossaini ◽  
Emma Eastoe ◽  
Paul J. Young
Keyword(s):  
Surface Ozone ◽  
Extreme Value Analysis ◽  
Daily Maximum ◽  
Monitoring Site ◽  
Ozone Pollution ◽  
Threshold Method ◽  
Regional Variability ◽  
Value Analysis ◽  
The Uk ◽  
Pollution Episodes

&lt;p&gt;Warm summer temperatures provide ideal conditions for the occurrence of extreme ground level ozone pollution episodes. Given the well-established negative impacts of ozone on human and plant health, understanding and attributing these extreme events is of importance to the scientific and wider community, particularly as heatwaves may become more frequent due to climate change. Extreme Value Analysis provides a powerful and flexible framework in which to statistically model unusually large observed values of ozone extracted from historical data. Here, a temperature dependent Peaks-Over-Threshold method based upon the Generalised Pareto Distribution is used to carry out a regional comparison of extreme ozone pollution episodes within the UK. Our analysis uses surface ozone observations from the UK&amp;#8217;s extensive Automatic Urban and Rural Network. The statistical model was used to quantify the frequency and magnitude of extreme ozone events, including a probabilistic assessment of exceeding UK public health thresholds, conditional on temperature. Return levels are provided for each monitoring site demonstrating the expected future projections of extreme ozone pollution events across the UK. We find that across UK rural background sites, return periods for a daily maximum 8-hr ozone level of 100 ug/m3 (a 'moderate' level of air pollution in the UK's Air Quality Index) range from 32-147 days, based on analysis of the data in the decade 2010-2019. Similarly, for urban background sites the range is 36-869 days. An analysis of the spatio temporal variability in UK ozone extremes, along with their temperature dependence, will be presented.&lt;/p&gt;

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