scholarly journals Effect of ozone precursors on surface ozone variations in GAW Kototabang and Cibeureum

2021 ◽  
Vol 893 (1) ◽  
pp. 012073
Author(s):  
A I Utami ◽  
R I Nasution ◽  
M Asnia

Abstract Ozone composition is widely distributed in the troposphere. Surface ozone, known as a secondary pollutant, is a by-product of burning fossil fuels. Increasing the concentration of GHG (CO2, CH4, and CO) as precursors can affect the surface ozone concentration. This study aims to determine the type of precursor that affects the concentration of surface ozone and also to determine the impact of surface ozone and its precursors in rural and remote areas. In general, surface ozone concentrations in both Kototabang and Cibereum begin to increase at 08 – 09 WIB, following the increase in solar radiation intensity, and decrease at 18 – 19 WIB. This pattern is because surface ozone is a secondary pollutant formed by photochemical reactions, in which the photochemical reactions are triggered by energy from solar radiation. The correlation of the surface ozone concentration with CO2, CH4, and CO in the Cibeureum was -0.17, 0.31, and 0.40. The correlation values of surface ozone concentration with CO2, CH4, and CO in the Cibeureum area are 0.09, 0.45, and 0.48. The highest correlation is shown by a CO correlation of 0.40. moreover the highest correlation is shown by a CO correlation of 0.48. The results in this study indicate the effect of each precursor on surface ozone concentration and the accompanying processes.

2020 ◽  
Author(s):  
Igor V. Ptashnik ◽  
Boris D. Belan ◽  
Denis E. Savkin ◽  
Gennadii N. Tolmachev ◽  
Tatayana K. Sklyadneva ◽  
...  

<p>In the review compiled by Monks et al. (2015), it is noted that the main variations in the tropospheric ozone are determined by the exchange between the troposphere and the stratosphere, in-situ photochemical production from gaseous precursors depending on their composition and concentration, solar radiation income, and meteorological conditions. The impact of precipitation on the surface ozone concentration is a less well-studied factor.</p><p>The process of ozone interaction with precipitation was studied theoretically (Heicklen, 1982). Two ways of the above process were analyzed: adsorption of gas molecules on the surface of a particle and a chemical reaction with its surface. There are no direct data on the verification of these findings in the literature. At the same time, there is some evidence of a possible link between precipitation and ozone.</p><p>This study is aimed to analyze the presence or absence of changes in the ozone concentration during precipitation. Variations of the surface ozone concentration (SOC) in the presence of precipitation were analyzed using the long-term data obtained at the TOR-station established in 1992 for ozone monitoring in Tomsk. It was revealed that these changes can be both positive (increase in concentration) and negative. The sharp changes in the SOC are observed when frontal precipitation takes place. In the presence of air-mass precipitation, the sign and magnitude of the change is determined by the diurnal variation of ozone concentration.</p><p>The analysis showed a coincidence of the SOC growth during precipitation with its increase in diurnal variation in 59% of cases. The coincidence in the wave of the concentration decline in the diurnal variation with decreasing precipitation rate is even higher and amounts to 85%.</p><p>Airborne sounding carried out in the vicinity of the TOR-station shown that in a number of cases the ozone deposition from the boundary layer is observed upon the transition of thermal stratification during the precipitation to neutral.</p><p> </p><p>Monks P. S, Archibald A. T., Colette A., Cooper O., Coyle M., Derwent R., Fowler D., Granier C., Law K. S., Mills G. E., Stevenson D. S., Tarasova O., Thouret V., von Schneidemesser E., Sommariva R., Wild O., Williams M. L. Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer. Atmos. Chem. Phys., 2015, v.15, N15, p.8889–8973.</p><p>Heicklen J. The Removal of Atmospheric Gases by Particulate Matter. In Heterogeneous Atmospheric Chemistry, ed. D. R. Schryer, Geophysical Monograph 26. American Geophysical Union, Washington, DC, USA, 1982, p. 93-98.</p>


2007 ◽  
Vol 7 (5) ◽  
pp. 1193-1212 ◽  
Author(s):  
A. M. Aghedo ◽  
M. G. Schultz ◽  
S. Rast

Abstract. We investigate the influence of African biomass burning, biogenic, lightning and anthropogenic emissions on the tropospheric ozone over Africa and globally using a coupled global chemistry climate model. Our model studies indicate that surface ozone concentration may rise by up to 50 ppbv in the burning region during the biomass burning seasons. Biogenic emissions yield between 5–30 ppbv increase in the near surface ozone concentration over tropical Africa. The impact of lightning on surface ozone is negligible, while anthropogenic emissions yield a maximum of 7 ppbv increase in the annual-mean surface ozone concentration over Nigeria, South Africa and Egypt. Our results show that biogenic emissions are the most important African emission source affecting total tropospheric ozone. The influence of each of the African emissions on the global tropospheric ozone burden (TOB) of 384 Tg yields about 9.5 Tg, 19.6 Tg, 9.0 Tg and 4.7 Tg for biomass burning, biogenic, lightning and anthropogenic emissions emitted in Africa respectively. The impact of each of these emission categories on African TOB of 33 Tg is 2.5 Tg, 4.1 Tg, 1.75 Tg and 0.89 Tg respectively, which together represents about 28% of the total TOB calculated over Africa. Our model calculations also suggest that more than 70% of the tropospheric ozone produced by each of the African emissions is found outside the continent, thus exerting a noticeable influence on a large part of the tropical troposphere. Apart from the Atlantic and Indian Ocean, Latin America experiences the largest impact of African emissions, followed by Oceania, the Middle East, Southeast and south-central Asia, northern North America (i.e. the United States and Canada), Europe and north-central Asia, for all the emission categories.


2021 ◽  
Vol 8 (65) ◽  
pp. 15164-15172
Author(s):  
S. Pratap ◽  
Aziz Fatima

In present scenario of COVID-19, the effect of pandemic on Digital Marketing is visible not only in urban areas but also in rural areas. Customers are searching for various products and services through Google by which they can purchase wide range of products and services to fill their needs and desires at relatively low price. The freedom to select numerous products is available by browsing various websites. Hence this study focuses on Impact of digital marketing particularly in the selected rural areas of Telangana state. This state been formed recently but in the IT sector it is receiving much attention throughout the globe, as many MNC’s are establishing their operations in this state. Therefore, an attempt has been made in this study to find out how the Impact of digital marketing is trickling down in the rural and remote areas of newly formed Telangana state. Hence this study focuses the impact of digital marketing in the selected areas of Telangana state.


2010 ◽  
Vol 98 (1) ◽  
pp. 125-139 ◽  
Author(s):  
B. Suresh Kumar Reddy ◽  
K. Raghavendra Kumar ◽  
G. Balakrishnaiah ◽  
K. Rama Gopal ◽  
R.R. Reddy ◽  
...  

2010 ◽  
Vol 49 (4) ◽  
pp. 748-759 ◽  
Author(s):  
J. A. Adame ◽  
E. Serrano ◽  
J. P. Bolívar ◽  
B. A. de la Morena

Abstract It is well established that surface ozone levels are greatly affected by orography, solar radiation intensity, meteorological conditions, and the levels of their precursors. In this work, the authors study the sea–land breeze circulation in its relation with the behavior of ozone in a coastal area, located in southwestern Europe, with high levels of solar radiation and an important industrial complex emitting air pollutants. Hourly mean data over a 7-yr period (1999–2005) have been used in the study. Two patterns of sea–land breeze have been identified after analyzing 2298 days of measurements: a “pure” breeze (179 cases) and another one, called a “nonpure” breeze (284 cases), which is the resulting flow of the former and northwesterlies synoptic forcing. Among other results, the highest levels of surface ozone were observed under pure sea–land breeze, with hourly values up to 100 μg m−3 in the mean daily evolution. In contrast, for a nonpure breeze, the 24-h average daily value was lower than the corresponding one under a pure breeze by a factor of 1.16 and could reach 1.60 in representative real cases. These findings give evidence that the formation and accumulation of ozone are favored by the conditions under a pure sea–land breeze: that is, perpendicular wind directions toward the coastline, effective recirculation of air masses, and formation of ozone residual layers above the sea. Because these atmospheric conditions occur in other coastal regions in the world, the conclusions of this study could be extended to them.


2015 ◽  
Vol 07 (04) ◽  
pp. 171-178 ◽  
Author(s):  
Amaury de Souza ◽  
Flavio Aristone ◽  
Ismail Sabbah

2021 ◽  
Vol 21 (2) ◽  
pp. 915-926
Author(s):  
Yuying Wang ◽  
Zhanqing Li ◽  
Qiuyan Wang ◽  
Xiaoai Jin ◽  
Peng Yan ◽  
...  

Abstract. A comprehensive field experiment measuring aerosol chemical and physical properties at a suburban site in Beijing around the 2019 Spring Festival was carried out to investigate the impact of reduced anthropogenic emissions on aerosol formation. Sharply reduced sulfur dioxide (SO2) and nitrogen dioxide (NO2) concentrations during the festival holiday resulted in an unexpected increase in the surface ozone (O3) concentration caused by the strong O3-titration phenomenon. Simultaneously, the reduced anthropogenic emissions resulted in massive decreases in particle number concentration at all sizes and the mass concentrations of organics and black carbon. However, the mass concentrations of inorganics (especially sulfate) decreased weakly. Detailed analyses of the sulfur oxidation ratio and the nitrogen oxidation ratio suggest that sulfate formation during the holiday could be promoted by enhanced nocturnal aqueous-phase chemical reactions between SO2 and O3 under moderate relative humidity (RH) conditions (40 % < RH < 80 %). Daytime photochemical reactions in winter in Beijing mainly controlled nitrate formation, which was enhanced a little during the holiday. A regional analysis of air pollution patterns shows that the enhanced formation of secondary aerosols occurred throughout the entire Beijing–Tianjin–Hebei (BTH) region during the holiday, partly offsetting the decrease in particle matter with an aerodynamic diameter less than 2.5 µm. Our results highlight the necessary control of O3 formation to reduce secondary pollution in winter under current emission conditions.


Author(s):  
Tan Van Nguyen ◽  
Thuy Thanh Ly ◽  
Tu Ngoc Nguyen

Background. The Clinical Frailty Scale (CFS) is gaining increasing acceptance due to its simplicity and applicability. Aims. This pilot study aims to examine the role of CFS in identifying the prevalence of frailty, frailty transition, and the impact of frailty on readmission after discharge in older hospitalized patients. Methods. Patients aged ≥60 admitted to the geriatric ward of a hospital in Vietnam were recruited from 9/2018–3/2019 and followed for three months. Frailty was assessed before discharge and after three months, using the CFS (robust: score 1–2, pre-frail: 3–4, and frail: ≥5). Multivariate logistic regression was applied to investigate the associated factors of frailty transition and the impact of frailty on readmission. Results. There were 364 participants, mean age 74.9, 58.2% female. At discharge, 4 were robust, 160 pre-frail, 200 frail. Among the 160 pre-frail participants at discharge, 124 (77.5%) remained pre-frail, and 36 (22.5%) became frail after 3 months. Age (adjusted OR1.09, 95% CI 1.03–1.16), number of chronic diseases (adjusted OR 1.37, 95% CI 1.03–1.82), and polypharmacy at discharge (adjusted OR 3.68, 95% CI 1.15–11.76) were significant predictors for frailty after 3 months. A frailty status at discharge was significantly associated with increased risk of readmission (adjusted OR2.87, 95% CI 1.71–4.82). Conclusions. Frailty was present in half of the participants and associated with increased risk of readmission. This study suggests further studies to explore the use of the CFS via phone calls for monitoring patients’ frailty status after discharge, which may be helpful for older patients living in rural and remote areas.


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