Assessment of tropospheric ozone at an industrial site of Chennai megacity
22 Aug 2019-Journal of The Air & Waste Management Association (Taylor & Francis)-Vol. 69, Iss: 9, pp 1079-1095
TL;DR: The temporal variation in surface-level ozone (O3) measured at Gummidipoondi near Chennai, Tamilnadu, shows a marked seasonal variation and can be useful for setting up control strategies in such industrial areas.
Abstract: This paper presents the temporal variation in surface-level ozone (O3) measured at Gummidipoondi near Chennai, Tamilnadu. The site chosen for the present study has high potential for ozone ...
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TL;DR: Wang et al. as discussed by the authors used the empirical orthogonal function method to find three main spatial distribution patterns of ozone pollution in Shandong province and found that ozone concentrations were significantly positively correlated with solar radiation.
Abstract: The summer ozone pollution of Shandong province has become a severe problem in the period 2014–2018. Affected by the monsoon climate, the monthly average ozone concentrations in most areas were unimodal, with peaks in June, whereas in coastal areas the concentrations were bimodal, with the highest peak in May and the second highest peak in September. Using the empirical orthogonal function method, three main spatial distribution patterns were found. The most important pattern proved the influences of solar radiation, temperature, and industrial structure on ozone. Spatial clustering analysis of the ozone concentration showed Shandong divided into five units, including Peninsula Coastal area (PC), Lunan inland area (LN), Western Bohai area (WB), Luxi plain area (LX), and Luzhong mountain area (LZ). Influenced by air temperature and local circulation, coastal cities had lower daytime and higher nighttime ozone concentrations than inland. Correlation analysis suggested that ozone concentrations were significantly positively correlated with solar radiation. The VOCs from industries or other sources (e.g., traffic emission, petroleum processing, and chemical industries) had high positive correlations with ozone concentrations, whereas NOx emissions had significantly negatively correlation. This study provides a comprehensive understanding of ozone pollution and theoretical reference for regional management of ozone pollution in Shandong province.
20 citations
TL;DR: Current knowledge of physiological processes of NO production and consumption in roots are summarized and processes invovled in NO homeostasis in root cells with particular emphasis on root growth, development, nutrient acquisition, environmental stresses and organismic interactions are summarized.
Abstract: Nitric oxide (NO) is essential for plant growth and development, as well as interactions with abiotic and biotic environments. Its importance for multiple functions in plants means that tight regulation of NO concentrations is required. This is of particular significance in roots, where NO signalling is involved in processes, such as root growth, lateral root formation, nutrient acquisition, heavy metal homeostasis, symbiotic nitrogen fixation and root-mycorrhizal fungi interactions. The NO signal can also be produced in high levels by microbial processes in the rhizosphere, further impacting root processes. To explore these interesting interactions, in the present review, we firstly summarize current knowledge of physiological processes of NO production and consumption in roots and, thereafter, of processes involved in NO homeostasis in root cells with particular emphasis on root growth, development, nutrient acquisition, environmental stresses and organismic interactions.
16 citations
TL;DR: The results indicate that predominantly ozone is increasing, with a significant trend visible in all crop growing seasons, and with the presence of the dominant tropospheric ozone in the regression model, the temperature's impact on productivity becomes statistically inconsequential.
10 citations
TL;DR: In this paper , the authors investigated selected secondary atmospheric responses to the widely reported emission change attributed to COVID•19 lockdowns in the highly polluted Indo-Gangetic Plain (IGP) using ground-based measurements of trace gases and particulate matter.
Abstract: This study investigates selected secondary atmospheric responses to the widely reported emission change attributed to COVID‐19 lockdowns in the highly polluted Indo‐Gangetic Plain (IGP) using ground‐based measurements of trace gases and particulate matter. We used a chemical box‐model to show that production of nighttime oxidant, NO3, was affected mainly by emission decrease (average nighttime production rates 1.2, 0.8 and 1.5 ppbv hr−1 before, during and relaxation of lockdown restrictions, respectively), while NO3 sinks were sensitive to both emission reduction and seasonal variations. We have also shown that the maximum potential mixing ratio of nitryl chloride, a photolytic chlorine radical source which has not been previously considered in the IGP, is as high as 5.5 ppbv at this inland site, resulting from strong nitrate radical production and a potentially large particulate chloride mass. This analysis suggests that air quality measurement campaigns and modeling explicitly consider heterogeneous nitrogen oxide and halogen chemistry.
3 citations
References
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Book•
24 Nov 1999
TL;DR: A detailed overview of the chemistry of Polluted and Remote Atmospheres can be found in this paper, where the OZIPR model is used to simulate the formation of gases and particles in the Troposphere.
Abstract: Overview of the Chemistry of Polluted and Remote Atmospheres. The Atmospheric System. Spectroscopy and Photochemistry: Fundamentals. Photochemistry of Important Atmospheric Species. Kinetics and Atmospheric Chemistry. Rates and Mechanisms of Gas-Phase Reactions in Irradiated Organic-NOx-Air Mixtures. Chemistry of Inorganic Nitrogen Compounds. Acid Deposition: Formation and Fates of Inorganic and Organic Acids in the Troposphere. Particles in the Troposphere. Airborne Polycyclic Aromatic Hydrocarbons and Their Derivatives: Atmospheric Chemistry and Toxicological Implications. Analytical Methods and Typical Atmospheric Concentrations for Gases and Particles. Homogeneous and Heterogeneous Chemistry in the Stratosphere. Scientific Basis for Control of Halogenated Organics. Global Tropospheric Chemistry and Climate Change. Indoor Air Pollution: Sources, Levels, Chemistry, and Fates. Applications of Atmospheric Chemistry: Air Pollution Control Strategies and Risk Assessments for Tropospheric Ozone and Associated Photochemical Oxidants, Acids, Particles, and Hazardous Air Pollutants. Appendix I: Enthalpies of Formation of Some Gaseous Molecules, Atoms, and Free Radicals at 298 K. Appendix II: Bond Dissociation Energies. Appendix III: Running the OZIPR Model. Appendix IV: Some Relevant Web Sites. Appendix V: Pressures and Temperatures for Standard Atmosphere. Appendix VI: Answers to Selected Problems. Subject Index.
2,051 citations
"Assessment of tropospheric ozone at..." refers background in this paper
...The formation of ozone is a complex phenomena, because the ozone production efficiency is “transformed” by favorablemeteorological parameters, especially the temperature and solar radiation (Finlayson-Pitts and Pitts 2000; Jenkin and Clemitshaw 2002)....
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TL;DR: A model for the photochemistry of the global troposphere constrained by observed concentrations of H2O, O3, CO, CH4, NO, NO2, and HNO3 is presented in this paper.
Abstract: A model for the photochemistry of the global troposphere constrained by observed concentrations of H2O, O3, CO, CH4, NO, NO2, and HNO3 is presented. Data for NO and NO2 are insufficient to define the global distribution of these gases but are nonetheless useful in limiting several of the more uncertain parameters of the model. Concentrations of OH, HO2, H2O2, NO, NO2, NO3, N2O5, HNO2, HO2NO2, CH3O2, CH3OOH, CH2O, and CH3CCl3 are calculated as functions of altitude, latitude, and season. Results imply that the source for nitrogen oxides in the remote troposphere is geographically dispersed and surprisingly small, less than 107 tons N yr−1. Global sources for CO and CH4 are 1.5 × 109 tons C yr−1 and 4.5 × 108 tons C yr−1, respectively. Carbon monoxide is derived from combustion of fossil fuel (15%) and oxidation of atmospheric CH4 (25%), with the balance from burning of vegetation and oxidation of biospheric hydrocarbons. Production of CO in the northern hemisphere exceeds that in the southern hemisphere by about a factor of 2. Industrial and agricultural activities provide approximately half the global source of CO. Oxidation of CO and CH4 provides sources of tropospheric O3 similar in magnitude to loss by in situ photochemistry. Observations of CH3CCl3 could offer an important check of the tropospheric model and results shown here suggest that computed concentrations of OH should be reliable within a factor of 2. A more definitive test requires better definition of release rates for CH3CCl3 and improved measurements for its distribution in the atmosphere.
1,762 citations
"Assessment of tropospheric ozone at..." refers background in this paper
...Ozone is a key precursor of hydroxyl radical (OH), which controls the oxidizing power of the atmosphere (Logan et al. 1981; Thompson 1992)....
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TL;DR: Models and the observational network for oxidants are improving, but validation of global models is still at an early stage and positive and negative trends possible for OH and H2O2.
Abstract: A number of critical atmospheric chemical problems depend on the earth's oxidizing capacity, which is essentially the global burden of oxidants in the lower atmosphere. There is limited direct evidence for changes in the earth's oxidizing capacity since recent preindustrial times when, because of industrial and poulation growth, increasing amounts of O3 precursor trace gases (carbon monoxide, nitrogen oxides, and hydrocarbons) have been released into the atmosphere. The concentrations of O3 and possibly H2O2 have increased over large regions. Models predict that tropospheric O3 will increase about 0.3-1.0 percent per year over the next 50 years with both positive and negative trends possible for OH and H2O2. Models and the observational network for oxidants are improving, but validation of global models is still at an early stage.
764 citations
"Assessment of tropospheric ozone at..." refers background in this paper
...Ozone is a key precursor of hydroxyl radical (OH), which controls the oxidizing power of the atmosphere (Logan et al. 1981; Thompson 1992)....
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TL;DR: The aim of this rostrum is to review the relevant publications that provide the appropriate context for assessing the risks of air pollution relative to other more modifiable environmental factors in patients with allergic airways disease.
Abstract: The general public, especially patients with upper or lower respiratory symptoms, is aware from media reports that adverse respiratory effects can occur from air pollution. It is important for the allergist to have a current knowledge of the potential health effects of air pollution and how they might affect their patients to advise them accordingly. Specifically, the allergist–clinical immunologist should be keenly aware that both gaseous and particulate outdoor pollutants might aggravate or enhance the underlying pathophysiology of both the upper and lower airways. Epidemiologic and laboratory exposure research studies investigating the health effects of outdoor air pollution each have advantages and disadvantages. Epidemiologic studies can show statistical associations between levels of individual or combined air pollutants and outcomes, such as rates of asthma, emergency visits for asthma, or hospital admissions, but cannot prove a causative role. Human exposure studies, animal models, and tissue or cellular studies provide further information on mechanisms of response but also have inherent limitations. The aim of this rostrum is to review the relevant publications that provide the appropriate context for assessing the risks of air pollution relative to other more modifiable environmental factors in patients with allergic airways disease.
721 citations
"Assessment of tropospheric ozone at..." refers background or methods in this paper
...Monthly plot (Jan–Dec) of carbon monoxide at 900 hPa obtained from MOPITT. increased when emissions of NOx decreased (Bernstein et al. 2004; Heuss, Kahlbaum, and Wolff 2003; Roberts-Semple, Song, and Gao 2012; Sadanaga et al. 2008)....
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...increased when emissions of NOx decreased (Bernstein et al. 2004; Heuss, Kahlbaum, and Wolff 2003; Roberts-Semple, Song, and Gao 2012; Sadanaga et al. 2008)....
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TL;DR: This review attempts to assemble published information on the impact of combined drought and pathogen stresses on crop productivity, and highlights some agriculturally important morpho-physiological traits that can be utilized to identify genotypes with combined stress tolerance.
Abstract: Global warming leads to the concurrence of a number of abiotic and biotic stresses, thus affecting agricultural productivity. Occurrence of abiotic stresses can alter plant-pest interactions by enhancing host plant susceptibility to pathogenic organisms, insects, and by reducing competitive ability with weeds. On the contrary, some pests may alter plant response to abiotic stress factors. Therefore, systematic studies are pivotal to understand the effect of concurrent abiotic and biotic stress conditions on crop productivity. However, to date, a collective database on the occurrence of various stress combinations in agriculturally-prominent areas is not available. This review attempts to assemble published information on this topic, with a particular focus on the impact of combined drought and pathogen stresses on crop productivity. In doing so, this review highlights some agriculturally important morpho-physiological traits that can be utilized to identify genotypes with combined stress tolerance. In addition, this review outlines potential role of recent genomic tools in deciphering combined stress tolerance in plants. This review will, therefore, be helpful for agronomists and field pathologists in assessing the impact of the interactions between drought and plant-pathogens on crop performance. Further, the review will be helpful for physiologists and molecular biologists to design agronomically relevant strategies for the development of broad spectrum stress tolerant crops.
575 citations
"Assessment of tropospheric ozone at..." refers background in this paper
...High concentration of ground-level ozone causing potential damage to biotic and abiotic factors has been reported in the literature (Pandey et al. 2017)....
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