Analysis Of Ozone Concentrations Research Articles

Inversion and Analysis of Ozone Concentration Using Ultraviolet Multi-Wavelength Lidar

Inversion and Analysis of Ozone Concentration Using Ultraviolet Multi-Wavelength Lidar

Analysis of Ozone Concentrations between 2002–2020 in Urban Air in Northern Spain

This paper analyses surface ozone measurements at five stations in an urban area (Valladolid) in the upper Spanish plateau over the period 2002–2020. Temporal evolutions, the relationship between ozone and other pollutants such as nitrogen oxides, and the assessment of the ozone concentration trend during the study period were analysed. Daily evolution of ozone at all the stations showed mean maximum concentrations in the afternoon, 15:00 GMT, with values ranging between 73.8 and 80.9 µg m−3, evidencing the influence of photochemical processes favoured by solar radiation in ozone formation. The lowest levels were recorded at night and in the early morning, 7:00 GMT, and were between 23.4 and 32.3 µg m−3, related with the reduction by NO reactions and deposition processes. A broad spring–summer peak between May and July was seen, with the highest values in the latter, with a mean value of up to 73.8 µg m−3. The variation in the monthly mean ozone concentrations of the different percentiles was analysed using a harmonic model. The empirical equation described the experimental values satisfactorily, with a confidence level of 95% and coefficients of determination above 80%, confirming the major decreasing trend in the ozone peak values over the study period.

Characteristics and Source Apportionment of the Vertical Distribution of Ozone at a Site of the Pearl River Delta Region of China

AbstractOzone pollution adversely affects human health. In recent years, ozone pollution has become an important research topic and a challenge. By combining differential absorption lidar (DIAL), meteorological gradient tower data, the Weather Research and Forecasting (WRF) model, and the backward trajectories model, changes in vertical ozone concentration, the influencing factors on ozone vertical distribution, and ozone sources were analyzed in Shenzhen from September 20 to 30, 2019. Results indicated that from September 25 to 30, there was obvious residual ozone and transport at night. The analysis of ozone concentration and meteorological factors shows that the temperatures of 291.3–301.8 K and the humidity of 19.4%–71.6% were conducive to ozone formation. As height increased from less than 0.1–0.3 km, the average ozone concentration increased, and the average NO2 concentration decreased. The analysis of potential ozone sources showed that ozone was mainly transported from the northeast of China and that the highest concentration of ozone mainly comes from southeast of Jiangxi province in southeastern China.

Analysis of ozone concentration in the Korean Peninsula using nonstationary generalized extreme value distribution

대기오염물질인 오존이 지표면에서 고농도로 발생하면 동물과 식물에 악영향을 미친다. 세계보건기구(World Health Organization. WHO)는 지구의 지표면 오존농도 0.01ppm이 증가할수록 인구 사망률을 0.5%부터 0.8%까지 증가시키는 효과가 있다고 보고하였다. 고농도의 오존은 인간의 기관지를 통해 유입되어 호흡기질환과 피부질환을 유발한다. 본 연구는 고농도 오존의 위험성을 평가하기 위해 2001년부터 2019년까지 총 19년간 한반도의 총 158개의 대기오염물질 측정소에서 측정된 일 최대 시간단위(ppm) 오존농도 자료를 사용하였다. 연 최대값을 추출하여 추세성 분석을 실행하였고, 추세성을 띄는 지역과 추세성을 띄지 않는 지역을 구분하여 일반화극단치분포와 비정상성 일반화극단치분포에 적합시켰다. 본 연구의 표본 수가 크지 않으므로 일반화극단치분포의 모수추정법으로 소표본에 적절한 L-적률추정법이 사용되었다. 또한 Anderson-Darling검정과 Cramér-von Mises검정을 통해 모형의 적합도도 검정하였다. 25년, 50년, 100년의 재현수준을 추정하여 남한의 고농도 오존 위험성을 시각화하여 나타내었다. 결론적으로 남한의 고농도 오존 위험성을 평가한 결과 경기도의 동쪽과 북동쪽, 그리고 전라남도 서쪽 해안지역이 위험성이 높았다.The ozone is an air pollutant which adversely affects the ecosystem. The World Health Organization reported that the earth s surface ozone concentration of 0.01 ppm has the effect of increasing population mortality from 0.5% to 0.8%. It is known that high concentrations of ozone cause respiratory and skin diseases in human beings. For the study, hourly ozone concentrations obtained from 58 air pollutant monitoring sites in South Korea between 2001 and 2019. The trend analysis was performed by identifying stationarity individually. The Generalized extreme value distribution and non-stationary Generalized extreme value distribution were considered. The L-moment estimation method was used to estimate parameters because of the lack of sample size. The Anderson-Darling test and Cramér-von Mises test were employed to the goodness of fit test. The return levels of 25, 50, and 100 years were estimated to be visualized about the risk of high concentration of ozone in South Korea. As a result, the eastern and northeastern parts of Gyeonggi-do and the western coastal areas of Jeollanam-do were exposed to high risk of ozone.

Modelling and analysis of ozone concentration by artificial intelligent techniques for estimating air quality

High ozone concentration is an important cause of air pollution mainly due to its role in the greenhouse gas emission. Ozone is produced by photochemical processes which contain nitrogen oxides and volatile organic compounds in the lower atmospheric level. Therefore, monitoring and controlling the quality of air in the urban environment is very important due to the public health care. However, air quality prediction is a highly complex and non-linear process; usually several attributes have to be considered. Artificial intelligent (AI) techniques can be employed to monitor and evaluate the ozone concentration level.The aim of this study is to develop an Adaptive Neuro-Fuzzy inference approach (ANFIS) to determine the influence of peripheral factors on air quality and pollution which is an arising problem due to ozone level in Jeddah city. The concentration of ozone level was considered as a factor to predict the Air Quality (AQ) under the atmospheric conditions. Using Air Quality Standards of Saudi Arabia, ozone concentration level was modelled by employing certain factors such as; nitrogen oxide (NOx), atmospheric pressure, temperature, and relative humidity. Hence, an ANFIS model was developed to observe the ozone concentration level and the model performance was assessed by testing data obtained from the monitoring stations established by the General Authority of Meteorology and Environment Protection of Kingdom of Saudi Arabia. The outcomes of ANFIS model were re-assessed by fuzzy quality charts using quality specification and control limits based on US-EPA air quality standards. The results of present study show that the ANFIS model is a comprehensive approach for the estimation and assessment of ozone level and is a reliable approach to produce more genuine outcomes.

Analysis of Ozone Concentration by TD and Q-mass Method

In order to get oxidizing power enough for growth of a superconductive thin film with oxide gas, concentrated ozone was used. As a method for concentrating ozone, a method for concentrating ozone by adsorbing ozone selectively into silica-gel beads is adopted, and this concentration is analyzed by the ultraviolet absorption method, the thermal decomposition method and the Q-mass analyzing method. Thermal decomposition method is most effective for measurement of a high concentration of ozone. Ozone as concentrated by the adsorption method got to have a concentration of 97 mol % at the maximum, and it was identified that the concentration of the ozone gas was stable for the time while a thin film was formed.

Analysis of ozone concentration for superconductor thin film

Abstract Ozone is usually generated from oxygen gas using a silent discharge apparatus and its concentration is less then 10 mol%. Ozone is condensed by the adsorption method, which is widely used for the growth of oxidation thin films such as superconductor. Highly condensed ozone is analyzed by three methods; ultraviolet absorption, thermal decomposition and Q-mass analyzing methods. Thermal decomposition method is most effective in the highly condensed ozone region and its method is superior to Q-mass analyzer for determining ozone concentration because of the simplicity of the method. The decomposition of condensed ozone takes place mainly on the inner surface of the vessel. Ozone concentration decreased to less then 50 mol% over a 8 h period.

A composite space/time approach to studying ozone distribution over eastern united states

This work is concerned with the composite space/time analysis of ozone concentrations over Eastern U.S. A novel method is used, which introduces a mode of reasoning that is a fundamental combination of inductive and deductive processes. The method is based on a spatiotemporal random field that organizes information concerning ozone distribution by reference to a space/time continuum. Randomness manifests itself as an ensemble of realizations (possibilities, potentialities) regarding the ozone distribution. Random field representations can take several forms which can embody physical characteristics of the ozone distribution or transform the data into a form that has certain desirable features. Numerical applications of the composite space/time method show that it generates ozone estimates that are more accurate than the estimates obtained from purely spatial mapping methods; and it also leads to a technique of space/time ozone trend determination that performs better than mean filtering. Composite space/time ozone maps offer a means of gaining understanding and insight into the variation of ozone concentrations over the Eastern U.S. and are important tools in ascertaining compliance with ambient air quality standards. Theses maps are also the necessary inputs to ozone reliability studies and to ozone exposure-health damage analysis.

Results from the UN/ECE ICP-Crops indicate the extent of exceedance of the critical levels of ozone in Europe

The experiments of the United Nations/Economic Commission for Europe (UN/ECE) International Cooperative Programme on effects of air pollution and other stresses on crops and non-wood plants (ICP-Crops) are designed to investigate the effects of ambient ozone pollution on crops and non-wood plants. Each year, participants from approximately 17 European countries conduct a series of coordinated experiments to determine which species develop visible injury following ozone episodes and whether the biomass or yield of sensitive species is reduced. In 1993, ozone injury was only seen at two thirds of sites but in 1994 injury was detected at almost all sites. This coincides with generally higher ozone concentrations measured in that year. Injury was seen on crops including subterranean clover (Trifolium subterraneum L.), white clover (Trifolium repens L.), bean (Phaseolus vulgaris L.), tomato (Lycopersicon esculentum), soybean (Glycine max), watermelon (Citrullus lanatus) and tobacco (Nicotiana tabacum L.) at experimental sites and in some cases, in commercial fields. The application of ethylenediurea (EDU) to some crop species reduced the level of visible injury. At some sites, the yield of EDU-treated bean plants was greater than that of untreated plants where the critical level of ozone for yield reduction was exceeded. Preliminary analysis of ozone concentrations in the days preceding injury indicated a sequential ozone concentration effect. The results are discussed in relation to Level I and Level II mapping of exceedance of the short- and long-term critical levels for ozone.

Analysis of Ozone Concentration and its Influence on the Archives of the Kingdom of Aragon, Barcelona

Analysis of Ozone Concentration and its Influence on the Archives of the Kingdom of Aragon, Barcelona