scholarly journals Ozone production and hydrocarbon reactivity in Hong Kong, Southern China

2006 ◽  
Vol 6 (5) ◽  
pp. 8961-9002 ◽  
Author(s):  
J. Zhang ◽  
T. Wang ◽  
W. L. Chameides ◽  
C. Cardelino ◽  
J. Kwok ◽  
...  
Keyword(s):  
Hong Kong ◽  
Southern China ◽  
Ground Level ◽  
Ozone Production ◽  
Back Trajectories ◽  
Ground Level Ozone ◽  
Abstract Data ◽  
The Pearl River ◽  
Ozone Episodes ◽  
The Relationship

Abstract. Data obtained in Hong Kong during the Hong Kong and the Pearl River Delta (PRD) Pilot Air Monitoring Study in autumn 2002 are analyzed to unravel the relationship between ground-level ozone (O3), pollution precursors, and cross-border transport. Ten ozone episodes, during which the hourly O3 concentration exceeded 100 ppbv in 9 cases and 90 ppbv in one case, are subject to detailed analysis, including one case with hourly O3 of 203 ppbv, which is the highest concentration on record to date in Hong Kong. Combined with high-resolution back trajectories, dCO/dNOy is used to define whether O3 is locally or regionally produced. Five out of the ten Hong Kong O3-episodes studied show a ''pollution signature'' that is indicative of impact from Guangdong Province. Examination of speciated volatile organic compounds (VOCs) shows that the reactivity of VOCs is dominated by anthropogenic VOCs, of which the reactive aromatics dominate, in particular xylenes and toluene. Calculations using a photochemical box model indicate that between 50–100% of the O3 increase observed in Hong Kong during the O3 episodes can be explained by photochemical generation within the Hong Kong area, provided that nitrous acid (HONO) is present at the concentrations derived from this study. An Observation-Based Model (OBM) is used to calculate the sensitivity of the O3 production to changes in the concentrations of the precursor compounds. Generally the production of O3 throughout much of the Hong Kong area is limited by VOCs, while high nitric oxide (NO) concentrations suppress O3 concentration.

scholarly journals Ozone production and hydrocarbon reactivity in Hong Kong, Southern China

2007 ◽  
Vol 7 (2) ◽  
pp. 557-573 ◽  
Author(s):  
J. Zhang ◽  
T. Wang ◽  
W. L. Chameides ◽  
C. Cardelino ◽  
J. Kwok ◽  
...  
Keyword(s):  
Hong Kong ◽  
Southern China ◽  
Ground Level ◽  
Ozone Production ◽  
Back Trajectories ◽  
Ground Level Ozone ◽  
Abstract Data ◽  
The Pearl River ◽  
Ozone Episodes ◽  
The Relationship

Abstract. Data obtained in Hong Kong during the Hong Kong and the Pearl River Delta (PRD) Pilot Air Monitoring Study in autumn 2002 are analyzed to unravel the relationship between ground-level ozone (O3), pollution precursors, and cross-border transport. Ten ozone episodes, during which the hourly O3 concentration exceeded 100 ppbv in 9 cases and 90 ppbv in one case, are subject to detailed analysis, including one case with hourly O3 of 203 ppbv, which is the highest concentration on record to date in Hong Kong. Combined with high-resolution back trajectories, dCO/dNOy (the ratio of enhancement of CO concentration above background to that of NOy) is used to define whether O3 is locally or regionally produced. Five out of the ten Hong Kong O3-episodes studied show a "pollution signature" that is indicative of impact from Guangdong Province. Examination of speciated volatile organic compounds (VOCs) shows that the reactivity of VOCs is dominated by anthropogenic VOCs, of which the reactive aromatics dominate, in particular xylenes and toluene. Calculations using a photochemical box model indicate that between 50–100% of the O3 increase observed in Hong Kong during the O3 episodes can be explained by photochemical generation within the Hong Kong area, provided that nitrous acid (HONO) is present at the concentrations derived from this study. An Observation-Based Model (OBM) is used to calculate the sensitivity of the O3 production to changes in the concentrations of the precursor compounds. Generally the production of O3 throughout much of the Hong Kong area is limited by VOCs, while high nitric oxide (NO) concentrations suppress O3 concentration.

scholarly journals The impacts of precursor reduction and meteorology on ground-level ozone in the Greater Toronto Area

2014 ◽  
Vol 14 (15) ◽  
pp. 8197-8207 ◽  
Author(s):  
S. C. Pugliese ◽  
J. G. Murphy ◽  
J. A. Geddes ◽  
J. M. Wang
Keyword(s):  
Health Hazard ◽  
Ground Level ◽  
Ozone Production ◽  
Ground Level Ozone ◽  
Ozone Concentrations ◽  
Greater Toronto Area ◽  
High Solar Radiation ◽  
Linear Effects ◽  
Human Health Hazard ◽  
Ozone Levels

Abstract. Tropospheric ozone (O3) is a major component of photochemical smog and is a known human health hazard, as well as a damaging factor for vegetation. Its precursor compounds, nitrogen oxides (NOx) and volatile organic compounds (VOCs), have a variety of anthropogenic and biogenic sources and exhibit non-linear effects on ozone production. As an update to previous studies on ground-level ozone in the Greater Toronto Area (GTA), we present an analysis of NO2, VOC and O3 data from federal and provincial governmental monitoring sites in the GTA from 2000 to 2012. We show that, over the study period, summertime 24 h VOC reactivity and NO2 midday (11:00–15:00) concentrations at all sites decreased significantly; since 2000, all sites experienced a decrease in NO2 of 28–62% and in measured VOC reactivity of at least 53–71%. Comparing 2002–2003 to 2011–2012, the summed reactivity of OH towards NO2 and a suite of measured VOCs decreased from 8.6 to 4.6 s−1. Ratios of reactive VOC pairs indicate that the effective OH concentration experienced by primary pollutants in the GTA has increased significantly over the study period. Despite the continuous decrease in precursor levels, ozone concentrations are not following the same pattern at all stations; it was found that the Canada-wide Standard for ozone continues to be exceeded at all monitoring stations. Additionally, while the years 2008–2011 had consistently lower ozone levels than previous years, 2012 experienced one of the highest recorded summertime ozone concentrations and a large number of smog episodes. We demonstrate that these high ozone observations in 2012 may be a result of the number of days with high solar radiation, the number of stagnant periods and the transport of high ozone levels from upwind regions.

Ground-level ozone in the Pearl River Delta and the roles of VOC and NOx in its production

2009 ◽  
Vol 90 (1) ◽  
pp. 512-518 ◽  
Author(s):  
Min Shao ◽  
Yuanhang Zhang ◽  
Limin Zeng ◽  
Xiaoyan Tang ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Pearl River Delta ◽  
Ground Level ◽  
River Delta ◽  
Pearl River ◽  
Ground Level Ozone ◽  
The Pearl River Delta ◽  
The Pearl River

The relationship between typhoons' peripheral circulation and ground-level ozone concentrations in central Taiwan

2013 ◽  
Vol 186 (2) ◽  
pp. 791-804 ◽  
Author(s):  
Wan-Li Cheng ◽  
Li-Wei Lai ◽  
Walter Den ◽  
Meng-Ting Wu ◽  
Chao-An Hsueh ◽  
...  
Keyword(s):  
Ground Level ◽  
Peripheral Circulation ◽  
Ground Level Ozone ◽  
Ozone Concentrations ◽  
Central Taiwan ◽  
The Relationship

scholarly journals Dust storms come to Central and Southwestern China, too: implications from a major dust event in Chongqing

2010 ◽  
Vol 10 (6) ◽  
pp. 2615-2630 ◽  
Author(s):  
Q. Zhao ◽  
K. He ◽  
K. A. Rahn ◽  
Y. Ma ◽  
Y. Jia ◽  
...  
Keyword(s):  
Southern China ◽  
Ground Level ◽  
Cold Season ◽  
Asian Dust ◽  
Dust Storms ◽  
Southwestern China ◽  
Gobi Desert ◽  
Dust Event ◽  
Back Trajectories ◽  
Desert Dust

Abstract. Dust storms from major Asian sources are usually carried by northwesterly or westerly winds over Northern and Southeastern China to the Pacific Ocean. These pathways leave Central and Southwestern China nearly free of incursions. But a strong dust event on 5–6 May 2005 was captured in a 15-month series of weekly filter samples of PM2.5 at three sites in Chongqing. It illustrated that desert dust can be transported to this region, and sometimes strongly. Annual PM2.5 and dust were similar at the three sites, but higher than in simultaneous samples in Beijing. High correlations of dust concentrations were found between the cities during spring, indicating that Asian dust affects a broader swath of China than is often realized. During the event, the concentrations of mineral dust were high at all sites (20–30 μg m−3; 15%–20% of PM2.5 in Chongqing, and 15 μg m−3; 20%–30% of PM2.5 in Beijing), and were part of a broader spring maximum. The proportions of crustal elements and pollution-derived components such as Pb, SO42−, and organic carbon indicated that the sources for this dust differed from Beijing. The dust was considerably enriched in Ca and Mg, characteristic of western deserts, whereas Beijing's dust had the lower Ca and Mg of eastern deserts. This observation agrees with synoptic patterns and back-trajectories. Driven by a cold air outbreak from the northwest, dust from the western Gobi Desert was transported at lower altitudes (<2 km above ground level), while dust from the Takla Makan Desert was transported to Chongqing at higher altitudes. Desert dust can also be important to wide areas of China during the cold season, since almost all the weekly dust peaks in the two cities coincided with extensive dust emissions in source regions. These findings collectively suggest that the amount Asian-dust in China has been underestimated both spatially and temporally, and that transported alkaline dust can even be mitigating the effects of acidic deposition in Southern China.

Exploring the relationship between nitrogen dioxide and ground-level ozone by applying the joint multifractal analysis

2009 ◽  
Vol 167 (1-4) ◽  
pp. 675-684 ◽  
Author(s):  
Francisco J. Jiménez-Hornero ◽  
Jorge E. Jiménez-Hornero ◽  
Eduardo Gutiérrez de Ravé ◽  
Pablo Pavón-Domínguez
Keyword(s):  
Nitrogen Dioxide ◽  
Multifractal Analysis ◽  
Ground Level ◽  
Ground Level Ozone ◽  
Joint Multifractal Analysis ◽  
The Relationship

scholarly journals Examining the Relationship between Ozone and other Air Pollutants in Al-Hilla City

2018 ◽  
Vol 26 (2) ◽  
pp. 88-96
Author(s):  
Ala'a Hamed Emran Al-Husseini
Keyword(s):  
Carbon Dioxide ◽  
Sulfur Dioxide ◽  
Ozone Concentration ◽  
Air Pollutants ◽  
Ground Level ◽  
Photochemical Activity ◽  
The Other ◽  
Ground Level Ozone ◽  
Carbon Dioxide Co2 ◽  
The Relationship

Air pollution must take more attention because its effects on human health. One of the most important air pollutants is ground-level ozone O3, which plays an important role in air quality and climate change on the earth. Ozone affected by the other air pollutants, so this paper attempt to study the relationship between hourly, daily and monthly ground-level ozone concentration and hourly, daily and monthly air pollutant concentrations and its effect on ground-level ozone concentration. The other air pollutants are: sulfur dioxide SO2, nitrogen oxides NOx, nitrogen monoxide NO, nitrogen dioxide NO2 and carbon dioxide CO2. The monitoring station is in Babylon University in the south of Al-Hilla city, Iraq for the period 2015-2016. By using statistical analysis, correlation coefficient and some statistics for all air pollutants are computed. Results are: the maximum average ozone concentration is in the summer months June, July and August 39.30 ppb, 45.05 ppb and 36.63 ppb respectively and along the day the peak average ozone concentration is in the afternoon because of high temperature and high solar radiation intensity which is increasing the photochemical activity of ozone. There is no significant correlation between ozone and sulfur dioxide SO2, carbon dioxide CO2 (ρ > 0.05). High significant correlation is appeared between ozone and nitrogen oxides forms (ρ < 0.01). To express the complex relation between ozone and nitrogen oxide forms, proportions such as NO/NO2 and (NOx-NO)/NO is determined which explain the ozone photochemical activity. Ozone concentration decreases with increasing of NO/NO2 and increases with (NOx-NO)/NOx increasing.

scholarly journals Caliope: an operational air quality forecasting system for the Iberian Peninsula, Balearic Islands and Canary Islands – first annual evaluation and ongoing developments

2008 ◽  
Vol 2 (1) ◽  
pp. 89-98 ◽  
Author(s):  
J. M. Baldasano ◽  
P. Jiménez-Guerrero ◽  
O. Jorba ◽  
C. Pérez ◽  
E. López ◽  
...  
Keyword(s):  
Air Quality ◽  
Iberian Peninsula ◽  
Ground Level ◽  
Present Contribution ◽  
Ground Level Ozone ◽  
Gross Error ◽  
Quantitative Verification ◽  
Forecasting System ◽  
Ozone Episodes ◽  
Air Quality Forecasting

Abstract. The Caliope project funded by the Spanish Ministry of the Environment establishes an air quality forecasting system for Spain to increase the knowledge on transport and dynamics of pollutants in Spain, to assure the accomplishment of legislation and to inform the population about the levels of pollutants, topics in which the European Commission has shown a great concern. The present contribution describes the first quantitative verification study performed so far with two chemistry transport models (CMAQ and CHIMERE) for a reference year (2004) at medium spatial resolution (around 20×20 km for the Iberian Peninsula). Both models perform similarly in the case of ground-level ozone. The mean normalised gross error MNGE remains below 15–20% during summertime, when ozone episodes occur, outlining the good skills of the system concerning the forecasting of air quality in Spain. Furthermore, the ongoing developments of the system towards high resolution modelling (4×4 km for Spain, 12×12 km for Europe, 1 h temporal resolution) and the integration with observations within the Caliope umbrella are described.

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