scholarly journals Air Quality Analyses for Photochemical Smog Associated with Atmospheric Aerosol Particles and Ozone Precursors Using CMAQ and CAMx Modeling Systems

Author(s):  
Muhammad Ibrahim

Pollution due to air quality deterioration is directly or indirectly connected to the phenomenon of biogeochemistry (i.e the scientific discipline that involves the study of the chemical, physical, geological, and biological processes and reactions that influence the composition of the natural environment) which in turn links to the human health. Human health and well-being, along with the well-being of animals, plants, and agricultural products, are solely dependent upon the quality of air we inhale. In response to the emission control threshold levels, prediction of how changes in emission levels could affect ambient air quality has been documented. The use of photochemical air quality models is becoming widely acceptable by various global regulatory agencies for the purpose of regulatory analyses and for the attainment exhibition by evaluating and assessing the effectiveness of control strategies. This review work tries to figure out the two most important and uncommon models namely; Comprehensive Air Quality Model with Extensions (CAMx) and Community Multiscale Air Quality (CMAQ) Modeling System. These modeling systems are used to predict, characterize, determine and simulate the photochemical air quality conditions. This paper gives a substantial detailed information of findings from related multidimensional studies carried out long ago and recently on photochemical smog analyses. Photochemical smog; causes and impacts on both the environment and living-being health were succinctly spelt out. Ozone formation and its different precursors; atmospheric aerosols; emission of biogenics as well as Ozone modeling phases were also discussed. The researcher still talks about the model formulations such as Zhang Model formulation; application and history of CMAQ and CAMx models respectively.

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Kuo-Cheng Lo ◽  
Chung-Hsuang Hung

Due to the distinct geographical and meteorological conditions of Taiwan, air pollutants concentrations in the ambient air of it may vary with seasons. Accordingly, this study aimed to investigate the formation of high O3concentration in the ambient air of Southern Taiwan during summers. A high O3concentration case occurring between June 28 and July 2, 2013, was modeled and analyzed with WRF-Chem meteorological and air quality model. During the investigated period, a typical western Pacific subtropical high (WPSH) covered most East Asia, including Taiwan and its surrounding areas. The observations showed strong correlations between WPSH invasion and forming high O3concentrations. The dispersion of air pollutants in the ambient air is not sufficient to dilute their concentrations. In the afternoon of June 30, more than 60% of the air quality monitoring stations found O3concentrations exceeding 100 ppb, which were 2~3 times higher than their normal concentrations. Model simulation results verified that the presence of the WPSH hindered the dilution and transportation of air pollutants in ambient air. In addition, the air quality would be getting worse due to the leeward sides caused by the counter clockwise vertex formed in Southwestern Taiwan.


2013 ◽  
Vol 726-731 ◽  
pp. 2324-2332
Author(s):  
Wen Yong Wang ◽  
Xiao Juan Ma

Based on the detailed survey on the source and volume of NOx emission over Chengdu Economic Circle, the third-generation air quality model CMAQ is adopted for simulating the density of NOx in the air over Chengdu Economic Circle. The result shows that the hourly concentration, daily mean concentration and annual mean concentration of NOx in air exceed the standard data, and the affected areas respectively account for 0.2%, 0.18% and 0.12% of the total area of the economic circle. Meanwhile, in accordance with the simulation calculation, The NOX emission of the vehicle exhaust, the thermal power plant and the cement plant are the major NOX concentration contribution sources in air, contribution rate is amounting to 39.13%, 21.41% and 15.34% respectively. Thus, three main measures to reduce the emission of NOx of Chengdu Economic Circle are proposed as follows: firstly, strengthen the management of vehicle and reduce the emission of NOx by the vehicle; secondly, manage the NOx of the industrial enterprise; flue gas denitrification equipment must be constructed in the thermal power plant and cement manufacturing enterprise, and the comprehensive denitration efficiency of the thermal power plant should be not less than 70% and the comprehensive denitration efficiency of the cement plant should not be less than 60%; thirdly, joint prevention and control measures should be implemented between the cities, so as to reduce the transport of NOx. With the application of the above measures, the emission reductions of NOx can be reduced to 55% of the existing volume, and the concentration of NOx in the air can meet with the Class II of national ambient air quality Standard.


2007 ◽  
Vol 41 (7) ◽  
pp. 1521-1538 ◽  
Author(s):  
Qi Ying ◽  
Matthew P. Fraser ◽  
Robert J. Griffin ◽  
Jianjun Chen ◽  
Michael J. Kleeman

Author(s):  
Dung Minh Ho ◽  
Bang Quoc Ho ◽  
Thang Viet Le

Livestock is one of the main activities of the agricultural sector in Tan Thanh district, Ba Ria – Vung Tau province. Beside of pollution sources such as waste water, solid waste, livestock activity in Tan Thanh district, Ba Ria - Vung Tau province in recent years has caused air pollution in the livestock area and surrounding area. This research was carried out to evaluate the process of air pollution dispersion from livestock activities based on applying the TAPM meteorological model and AERMOD air quality model. The results showed that the maximum concentrations of air pollutants from livestock area such as NH3, H2S and CH3SH exceeded the National Technical Regulation on Ambient Air Quality (average hour) in the centre of Tan Thanh district, such as Toc Tien commune, part of Tan Phuoc and Phuoc Hoa communes, is 505 μg/m3; 57.4 μg/m3 and 111 μg/m3, respectively. Phu My district and other suburban communes (Hac Dich, Song Xoai, Chau Pha, Tan Hoa, Tan Hai, My Xuan, etc.) have distribution of lower concentrations of air pollutants. Base on the present results of modeling, the authors have proposed livestock development scenarios to control air pollution from this activity, contributing to environmental protection for Tan Thanh district.


2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Chung-Hsuang Hung ◽  
Kuo-Cheng Lo

This study aimed to use a newly developed weather and air quality model, WRF-Chem, to simulate and analyze formation of high-concentrated ozone (O3) in the ambient air of southwestern Taiwan before the invasion of tropical typhoons. Two typical typhoons, Nanmadol and Usagi that occurred in 2011 and 2013, respectively, were simulated in this study. The O3concentration variation patterns in the ambient air of both offshore and inland parts of southwestern Taiwan were collected and analyzed. The results indicated that the high O3concentration observed in southwestern Taiwan before typhoon arrived was mainly caused by the western Pacific subtropical high (WPSH) shrouding it. On the other hand, the latter increase in ambient O3concentration about 1 to 2 days before issuing sea warning was mainly due to both contributions of weakening WPSH and intensifying leeward side effects. For both cases, atmospheric subsidence occurred to result in low ambient air quality. The invasion of typhoons made ambient O3concentration enhanced up to 2-3-fold compared to its normal concentration in summer. Based on the simulated O3concentration variation results in this study, it is demonstrated that the space-fading patterns of O3before typhoon arrives also can be used as references for predicting typhoon moving tracks 1.0 to 2.0 days before landfall of typhoons.


2021 ◽  
Author(s):  
Aoxing Zhang ◽  
Yongqiang Liu ◽  
Scott Goodrick ◽  
Marcus Williams

Abstract. Wildfires can significantly impact air quality and human health. However, little is known about how duff and peat burning contributes to these impacts. This study investigates the air quality impacts of duff consumption during the four largest wildfire events this century in southeastern United States, with a focus on the different impacts on fine particulate matter less than 2.5 μm in size (PM2.5) and ozone (O3). The emissions of duff burning were estimated based on a field measurement. The emissions from the burning of other fuels were obtained from the Fire INventory from NCAR (FINN). The air quality impacts were simulated using a 3-D regional air quality model. The results show the duff burning emitted PM2.5 comparable to the burning of the above-ground fuels. The simulated surface PM2.5 concentrations due to duff burning increased by 61.3 % locally over a region approximately 300 km within the fire site and by 21.3 % and 29.7 % in the remote metro Atlanta and Charlotte during the 2016 southern Appalachian fires, and by 131.9 % locally and by 17.7 % and 24.8 % in the remote metro Orlando and Miami during the 2007 Okefenokee fire. However, the simulated ozone impacts from the duff burning were negligible due to the small duff emission factors of ozone precursors such as NOx. This study suggests the need to improve the modeling of PM2.5 and the air quality, human health, and climate impacts of wildfires in moist ecosystems by including duff burning in global fire emission inventories.


Author(s):  
Hossein Shahbazi ◽  
Vahid Hosseini ◽  
Sara Torbatian ◽  
Masoud Hamedi

In recent years, the city of Tehran has frequently experienced severe air pollution episodes, and the increase in the use of vehicles has exacerbated this critical situation. It is unclear to what extent each vehicle category contributes to the production of pollution during a pollution event. For this purpose, a combination of the weather research and forecasting (WRF) and the Comprehensive Air Quality Model with Extensions (CAMx) modeling systems was used to simulate the distributions of pollutant concentrations over Tehran in a pollution episode from December 3 to 23, 2017. First, the performance of the modeling system was evaluated with respect to the simulation outputs against observations. Results showed satisfactory performance by the models in predicting meteorological parameters and pollutant concentrations. There were some discrepancies between measured and simulated pollutant levels that might have several causes, including, for example, not considering dust emissions in the system. The second step focused on the assessment of different emission scenarios to quantify the impact of each vehicle fleet in producing pollution during such severe episodes. For this reason, eight different scenarios were considered in which the emissions of each vehicle category were entirely eliminated from the corresponding scenario. The results show that the removal of passenger cars and motorcycles could have the most significant impact on PM2.5 reduction, with a maximum drop of 32% and 30%, respectively. In addition, the NO2 concentrations could be reduced by about 20% and 10% as a result of the removal of passenger cars and motorcycles, respectively. Finally, two traffic schemes with a main focus on the role of motorcycles on the degradation of Tehran’s air quality were also examined for the same episode.


2019 ◽  
Vol 116 (22) ◽  
pp. 10711-10716 ◽  
Author(s):  
Sourangsu Chowdhury ◽  
Sagnik Dey ◽  
Sarath Guttikunda ◽  
Ajay Pillarisetti ◽  
Kirk R. Smith ◽  
...  

Exposures to ambient and household fine-particulate matter (PM2.5) together are among the largest single causes of premature mortality in India according to the Global Burden of Disease Studies (GBD). Several recent investigations have estimated that household emissions are the largest contributor to ambient PM2.5 exposure in the country. Using satellite-derived district-level PM2.5 exposure and an Eulerian photochemical dispersion model CAMx (Comprehensive Air Quality Model with Extensions), we estimate the benefit in terms of population exposure of mitigating household sources––biomass for cooking, space- and water-heating, and kerosene for lighting. Complete mitigation of emissions from only these household sources would reduce India-wide, population-weighted average annual ambient PM2.5 exposure by 17.5, 11.9, and 1.3%, respectively. Using GBD methods, this translates into reductions in Indian premature mortality of 6.6, 5.5, and 0.6%. If PM2.5 emissions from all household sources are completely mitigated, 103 (of 597) additional districts (187 million people) would meet the Indian annual air-quality standard (40 μg m−3) compared with baseline (2015) when 246 districts (398 million people) met the standard. At 38 μg m−3, after complete mitigation of household sources, compared with 55.1 μg m−3 at baseline, the mean annual national population-based concentration would meet the standard, although highly polluted areas, such as Delhi, would remain out of attainment. Our results support expansion of programs designed to promote clean household fuels and rural electrification to achieve improved air quality at regional scales, which also has substantial additional health benefits from directly reducing household air pollution exposures.


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