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Zhong H, Zhen L, Yang L, Lin C, Yao Q, Xiao Y, Xu Q, Liu J, Chen B, Ni H, Xu W. Understanding the variability of ground-level ozone and fine particulate matter over the Tibetan plateau with data-driven approach. JOURNAL OF HAZARDOUS MATERIALS 2024; 477:135341. [PMID: 39079303 DOI: 10.1016/j.jhazmat.2024.135341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/12/2024] [Accepted: 07/25/2024] [Indexed: 08/17/2024]
Abstract
The Tibetan Plateau, known as the "Third Pole", is susceptible to ground-level ozone (O3) and fine particulate matter (PM2.5) pollution due to its unique high-altitude environment. This study constructed random forest regression models using multi-source data from ground measurements and meteorological satellites to predict variations in ground-level O3 and PM2.5 concentrations and their influencing factors across seven major cities in the Tibetan Plateau over two-year periods. The models successfully reproduced O3 and PM2.5 levels with satisfactory R-squared values of 0.71 and 0.73, respectively. Results reveal combustion-related carbon monoxide (CO) and nitrogen dioxide (NO2) as the most substantial influences on O3 and PM2.5 concentrations. Solar radiation, geographical factors, and meteorological variables also played crucial roles in driving pollutant variations. Conversely, transport-related and human activity factors exhibited relatively lower significance. High O3 and PM2.5 pollution occurred during pre-monsoon and post-monsoon/winter seasons, driven by solar radiation and emissions, respectively. While CO consistently contributed across cities and seasons, key influencing factors varied locally. This study unveils the key driving forces governing air pollutant variations across the Tibetan Plateau, shedding light on complex atmospheric processes in this unique high-altitude region.
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Affiliation(s)
- Haobin Zhong
- School of Advanced Materials Engineering, Jiaxing Nanhu University, Jiaxing 314001, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Jiaxing key Laboratory of Preparation and Application of Advanced Materials for Energy Conservation and Emission Reduction, Jiaxing 314001, China
| | - Ling Zhen
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lin Yang
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Chunshui Lin
- State Key Laboratory of Loess and Quaternary Geology, Key Laboratory of Aerosol Chemistry and Physics, CAS Center for Excellence in Quaternary Science and Global Change, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Qiufang Yao
- School of Advanced Materials Engineering, Jiaxing Nanhu University, Jiaxing 314001, China
| | - Yanping Xiao
- School of Advanced Materials Engineering, Jiaxing Nanhu University, Jiaxing 314001, China
| | - Qi Xu
- School of Advanced Materials Engineering, Jiaxing Nanhu University, Jiaxing 314001, China
| | - Jinsong Liu
- School of Advanced Materials Engineering, Jiaxing Nanhu University, Jiaxing 314001, China
| | - Baihua Chen
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Haiyan Ni
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Wei Xu
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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2
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Edwards PM, Young CJ. Primary Radical Effectiveness: Do the Different Chemical Reactivities of Hydroxyl and Chlorine Radicals Matter for Tropospheric Oxidation? ACS ES&T AIR 2024; 1:780-788. [PMID: 39144752 PMCID: PMC11320563 DOI: 10.1021/acsestair.3c00108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 05/17/2024] [Accepted: 05/17/2024] [Indexed: 08/16/2024]
Abstract
The atmospheric oxidation of organics occurs primarily via reaction cycles involving gas phase radical species, catalysed by nitric oxide (NO), which result in the production of secondary pollutants such as ozone. For these oxidation cycles to occur, they must be initialized by a primary radical, i.e., a radical formed from non-radical precursors. Once formed, these primary radicals can result in the oxidation of organic compounds to produce peroxy radicals that, providing sufficient NO is present, can re-generate "secondary" radicals which can go on to oxidize further organics. Thus, one primary radical can result in the catalytic oxidation of multiple organics. Although the photolysis of ozone in the presence of water vapor to form two hydroxyl (OH) radicals is accepted as the dominant tropospheric primary radical source, multiple other primary radical sources exist and can dominate in certain environments. The chemical reactivity of different radicals to organic and inorganic compounds can be very different, however, and how these differences in radical chemistry impact atmospheric organic oxidation under different atmospheric conditions has not been previously demonstrated. In this work, we use a series of model simulations to investigate the impact of the chemical reactivity of the primary radical on the effectiveness in initializing organic oxidation and thus the production of the secondary pollutant ozone. We compare the chemistries of the OH and atomic chlorine (Cl) radicals and their effectiveness at initializing organic oxidation under different nitrogen oxide and organic concentrations. The OH radical is the dominant tropospheric radical, with both primary and secondary sources. In contrast, Cl has primary sources that show significant spatial heterogeneity throughout the troposphere but is not typically regenerated in catalytic cycles. Both primary OH and Cl can initiate organic oxidation, but this work shows that the relative effectiveness with which they oxidize organics and produce ozone depends on their balance of propagation vs termination reactions which is in turn determined by the chemical environment in which they are produced. In particular, our work shows that in high NOx radical-limited environments, like those found in many urban areas, Cl will be more efficient at oxidizing organics than OH.
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Affiliation(s)
- Peter M. Edwards
- Wolfson
Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York YO10 5DQ, United Kingdom
- National
Centre for Atmospheric Science, University
of York, York YO10 5DQ, United Kingdom
| | - Cora J. Young
- Department
of Chemistry, York University, Toronto, ON M3J1P3, Canada
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3
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Liu J, Wang S, Zhang Y, Yan Y, Zhu J, Zhang S, Wang T, Tan Y, Zhou B. Investigation of formaldehyde sources and its relative emission intensity in shipping channel environment. J Environ Sci (China) 2024; 142:142-154. [PMID: 38527880 DOI: 10.1016/j.jes.2023.06.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 03/27/2024]
Abstract
Formaldehyde (HCHO) is considered one of the most abundant gas-phase carbonyl compounds in the atmosphere, which can be directly emitted through transportation sources. Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS) was used to observe HCHO in the river channel of Wusong Wharf in Shanghai, China for the whole year of 2019. Due to the impact of ship activity, the annual average HCHO level in the channel is about 2.5 times higher than that in the nearby campus environment. To explain the sources of HCHO under different meteorological conditions, the tracer-pair of CO and Ox (NO2+O3) was used on the clustered air masses. The results of the source appointment show that primary, secondary and background account for 24.14% (3.34 ± 1.19 ppbv), 44.78% (6.20 ± 2.04 ppbv) and 31.09% (4.31 ± 2.33 ppbv) of the HCHO in the channel when the air masses were from the mixed direction of the city and channel, respectively. By performing background station subtraction at times of high primary HCHO values and resolving the plume peaks, directly emitted HCHO/NO2 in the channel environment and plume were determined to be mainly distributed between 0.2 and 0.3. General cargo ships with higher sailing speeds or main engine powers tend to have higher HCHO/NO2 levels. With the knowledge of NO2 (or NOx) emission levels from ships, this study may provide data support for the establishment of HCHO emission factors.
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Affiliation(s)
- Jiaqi Liu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Shanshan Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; Institute of Eco-Chongming (IEC), No. 20 Cuiniao Road, Shanghai 202162, China.
| | - Yan Zhang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; Institute of Eco-Chongming (IEC), No. 20 Cuiniao Road, Shanghai 202162, China; National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Fudan University, Shanghai 200438, China; Institute of Digitalized Sustainable Transformation, Big Data Institute, Fudan University, Shanghai 200433, China
| | - Yuhao Yan
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Jian Zhu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Sanbao Zhang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Tianyu Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Yibing Tan
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Bin Zhou
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; Institute of Eco-Chongming (IEC), No. 20 Cuiniao Road, Shanghai 202162, China; Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China.
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4
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Nie Q, Wang Z, Duan K, Hu M, Du M, Ren W. Sub-ppt level detection of carbon monoxide and nitrous oxide enabled by mid-infrared doubly resonant photoacoustic spectroscopy. OPTICS LETTERS 2024; 49:3648-3651. [PMID: 38950231 DOI: 10.1364/ol.530578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Accepted: 06/04/2024] [Indexed: 07/03/2024]
Abstract
We report highly sensitive detection of carbon monoxide (CO) and nitrous oxide (N2O) using doubly resonant photoacoustic spectroscopy paired with a quantum cascade laser (QCL) at 4.57 μm. The butterfly-packaged QCL is used to exploit the CO absorption line at 2190.02 cm-1 and the N2O absorption line at 2191.42 cm-1 by scanning the injection current. Leveraging the simultaneous acoustic and optical resonances and adopting a lower photoacoustic detection frequency, we achieve a minimum detection limit of 0.85 part-per-trillion (ppt) for CO over the 500 s averaging time, and 0.7 ppt for N2O over the 200 s averaging time. Our approach demonstrates record sensitivity for CO and N2O detection compared to state-of-the-art optical gas sensors.
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5
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Shutter JD, Millet DB, Wells KC, Payne VH, Nowlan CR, Abad GG. Interannual changes in atmospheric oxidation over forests determined from space. SCIENCE ADVANCES 2024; 10:eadn1115. [PMID: 38748807 PMCID: PMC11095458 DOI: 10.1126/sciadv.adn1115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 04/10/2024] [Indexed: 05/19/2024]
Abstract
The hydroxyl radical (OH) is the central oxidant in Earth's troposphere, but its temporal variability is poorly understood. We combine 2012-2020 satellite-based isoprene and formaldehyde measurements to identify coherent OH changes over temperate and tropical forests with attribution to emission trends, biotic stressors, and climate. We identify a multiyear OH decrease over the Southeast United States and show that with increasingly hot/dry summers the regional chemistry could become even less oxidizing depending on competing temperature/drought impacts on isoprene. Furthermore, while global mean OH decreases during El Niño, we show that near-field effects over tropical rainforests can alternate between high/low OH anomalies due to opposing fire and biogenic emission impacts. Results provide insights into how atmospheric oxidation will evolve with changing emissions and climate.
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Affiliation(s)
- Joshua D. Shutter
- Department of Soil, Water, and Climate, University of Minnesota, St. Paul, MN 55108, USA
| | - Dylan B. Millet
- Department of Soil, Water, and Climate, University of Minnesota, St. Paul, MN 55108, USA
| | - Kelley C. Wells
- Department of Soil, Water, and Climate, University of Minnesota, St. Paul, MN 55108, USA
| | - Vivienne H. Payne
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91011, USA
| | - Caroline R. Nowlan
- Center for Astrophysics | Harvard & Smithsonian, Cambridge, MA 02138, USA
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6
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Liu M, Song Y, Matsui H, Shang F, Kang L, Cai X, Zhang H, Zhu T. Enhanced atmospheric oxidation toward carbon neutrality reduces methane's climate forcing. Nat Commun 2024; 15:3148. [PMID: 38605008 PMCID: PMC11009326 DOI: 10.1038/s41467-024-47436-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 04/02/2024] [Indexed: 04/13/2024] Open
Abstract
The hydroxyl radical (OH), as the central atmospheric oxidant, controls the removal rates of methane, a powerful greenhouse gas. It is being suggested that OH levels would decrease with reductions of nitrogen oxides and ozone levels by climate polices, but this remains unsettled. Here, we show that driven by the carbon neutrality pledge, the global-mean OH concentration, derived from multiple chemistry-climate model simulations, is projected to be significantly increasing with a trend of 0.071‒0.16% per year during 2015-2100. The leading cause of this OH enhancement is dramatic decreases in carbon monoxide and methane concentrations, which together reduce OH sinks. The OH increase shortens methane's lifetime by 0.19‒1.1 years across models and subsequently diminishes methane's radiative forcing. If following a largely unmitigated scenario, the global OH exhibits a significant decrease that would exacerbate methane's radiative forcing. Thus, we highlight that targeted emission abatement strategies for sustained oxidation capacity can benefit climate change mitigation in the Anthropocene.
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Affiliation(s)
- Mingxu Liu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
- Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan
| | - Yu Song
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Hitoshi Matsui
- Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan.
| | - Fang Shang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Ling Kang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Xuhui Cai
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Hongsheng Zhang
- Laboratory for Atmosphere-Ocean Studies, Department of Atmospheric and Oceanic Science, School of Physics, Peking University, Beijing, 100871, China
| | - Tong Zhu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China.
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7
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Chu W, Li H, Ji Y, Zhang X, Xue L, Gao J, An C. Research on ozone formation sensitivity based on observational methods: Development history, methodology, and application and prospects in China. J Environ Sci (China) 2024; 138:543-560. [PMID: 38135419 DOI: 10.1016/j.jes.2023.02.052] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 02/25/2023] [Accepted: 02/26/2023] [Indexed: 12/24/2023]
Abstract
Observation-based method for O3 formation sensitivity research is an important tool to analyze the causes of ground-level O3 pollution, which has broad application potentials in determining the O3 pollution formation mechanism and developing prevention and control strategies. This paper outlined the development history of research on O3 formation sensitivity based on observational methods, described the principle and applicability of the methodology, summarized the relative application results in China and provided recommendations on the prevention and control of O3 pollution in China based on relevant study results, and finally pointed out the shortcomings and future development prospects in this field in China. The overview study showed that the O3 formation sensitivity in some urban areas in China in recent years presented a gradual shifting tendency from the VOC-limited regime to the transition regime or the NOx-limited regime due to the implementation of the O3 precursors emission reduction policies; O3 pollution control strategies and precursor control countermeasures should be formulated based on local conditions and the dynamic control capability of O3 pollution control measures should be improved. There are still some current deficiencies in the study field in China. Therefore, it is recommended that a stereoscopic monitoring network for atmospheric photochemical components should be further constructed and improved; the atmospheric chemical mechanisms should be vigorously developed, and standardized methods for determining the O3 formation sensitivity should be established in China in the near future.
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Affiliation(s)
- Wanghui Chu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Hong Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Yuanyuan Ji
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Xin Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Likun Xue
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Jian Gao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Cong An
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
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8
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Zhang W, Zhong J, Li R, Li L, Ma X, Ji Y, Li G, Francisco JS, An T. Distinctive Heterogeneous Reaction Mechanism of ClNO 2 on the Air-Water Surface Containing Cl. J Am Chem Soc 2023; 145:22649-22658. [PMID: 37811579 DOI: 10.1021/jacs.3c07843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The heterogeneous reaction of nitryl chloride (ClNO2) on the air-water surface plays a significant role in the chloride lifecycle. The air-water surface is ubiquitous on ice surfaces under supercooled conditions, affecting the uptake and heterogeneous reaction processes of trace gases. Previous studies suggest that ClNO2 is formed on Cl-doped ice surfaces following the N2O5 uptake. Herein, a distinctive heterogeneous reaction mechanism of ClNO2 is suggested on an air-water surface containing Cl under supercooled conditions using combined classic molecular dynamics (MD) and Born-Oppenheimer MD simulations. It is found that N2O5 dissociates into a NO2+ and NO3- ionic pair on the top air-water surface. In the top layer of the surface containing barely any Cl-, NO2+ proceeds through hydrolysis and produces H3O+ and HNO3. Thus, surface acidification appears because of H3O+ yields. With NO2+ diffusion to the deep layer of the surface, NO2+ reacts with Cl- and forms ClNO2. Note that ClNO2 formation competes with NO2+ hydrolysis, and the rate of ClNO2 formation is 27.7[Cl-] larger than that of NO2+ hydrolysis. Afterward, the reaction of ClNO2 with Cl- becomes barrierless with the catalysis by H3O+, which is not feasible on a neutral surface. Cl2 is thus generated and escapes into the atmosphere (low solubility of Cl2), contributing to the Cl radical. The proposed mechanism bolsters the current understanding of ClNO2's fate and its role in Cl chemistry in extremely cold environments like the Arctic and other high-latitude regions in wintertime.
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Affiliation(s)
- Weina Zhang
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Jie Zhong
- School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Ruijing Li
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Liwen Li
- School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Xiaohui Ma
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Yuemeng Ji
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Guiying Li
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Joseph S Francisco
- Department of Earth and Environmental Science and Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6316, United States
| | - Taicheng An
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
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9
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Joshi A, Pathak M, Kuttippurath J, Patel VK. Adoption of cleaner technologies and reduction in fire events in the hotspots lead to global decline in carbon monoxide. CHEMOSPHERE 2023:139259. [PMID: 37343635 DOI: 10.1016/j.chemosphere.2023.139259] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 05/12/2023] [Accepted: 06/16/2023] [Indexed: 06/23/2023]
Abstract
Carbon Monoxide (CO) is not a greenhouse gas (GHG), but has the capacity to change atmospheric chemistry of other GHGs such as methane and ozone, and therefore indirectly affects Earth's radiative forcing of the GHGs and surface temperature. Here, we use the CO mixing ratio at 850 hPa from the Tropospheric Emission Spectrometer (TES) reanalysis and the Measurement of Pollution in the Troposphere (MOPITT) satellite measurements for the period 2005-2019 to examine the spatio-temporal changes in CO across the latitudes. We find a substantial decrease in global CO, about 0.21 ± 0.09 ppb/yr (0.23 ± 0.12%/yr) with the TES data and about 0.36 ± 0.07 ppb/yr (0.45 ± 0.08%/yr) with the MOPITT satellite measurements during the study period. The highest CO decreasing trend is observed in Eastern China (2.7 ± 0.37 ppb/yr) followed by Myanmar (2.142 ± 0.59 ppb/yr) and South America (1.08 ± 0.82 ppb/yr). This negative trend in CO is primarily due to the decrease in biomass burning and stringent environmental regulations in the respective regions and countries. The sources including road transport that account for about 33.6% of CO emissions, followed by industries (18.3%) and agricultural waste burning (8.8%), might also be responsible for the reduction in CO due to adaptation of improved emission control technology and regulations in the past decade from 2005 to 2019. Therefore, the study provides new insights on the current trends of global CO distribution and reasons for recent reduction in global CO emissions, which would be useful for future decision-making process to control air pollution.
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Affiliation(s)
- A Joshi
- Coral, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India
| | - M Pathak
- Coral, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India
| | - J Kuttippurath
- Coral, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India.
| | - V K Patel
- Coral, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India
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Gildersleeve EJ, Vaßen R. Thermally Sprayed Functional Coatings and Multilayers: A Selection of Historical Applications and Potential Pathways for Future Innovation. JOURNAL OF THERMAL SPRAY TECHNOLOGY 2023; 32:778-817. [PMID: 37521528 PMCID: PMC10136405 DOI: 10.1007/s11666-023-01587-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 02/03/2023] [Accepted: 02/15/2023] [Indexed: 08/01/2023]
Abstract
Thermal spray coatings are material systems with unique structures and properties that have enabled the growth and evolution of key modern technologies (i.e., gas turbines, structurally integrated components, etc.). The inherent nature of these sprayed coatings, such as their distinctive thermal and mechanical properties, has been a driving force for maintaining industrial interest. Despite these benefits and proven success in several fields, the adoption of thermal spray technology in new applications (i.e., clean energy conversion, semiconductor thermally sprayed materials, biomedical applications, etc.) at times, however, has been hindered. One possible cause could be the difficulty in concurrently maintaining coating design considerations while overcoming the complexities of the coatings and their fabrication. For instance, a coating designer must consider inherent property anisotropy, in-flight decomposition of molten material (i.e., loss of stoichiometry), and occasionally the formation of amorphous materials during deposition. It is surmisable for these challenges to increase the risk of adoption of thermal spray technology in new fields. Nevertheless, industries other than those already mentioned have benefited from taking on the risk of implementing thermal spray coatings in their infrastructure. Benefits can be quantified, for example, based on reduced manufacturing cost or enhanced component performance. In this overview paper, a historical presentation of the technological development of thermal spray coatings in several of these industries is presented. Additionally, emerging industries that have not yet attained this level of thermal spray maturation will also be discussed. Finally, where applicable, the utility and benefits of multilayer functional thermal spray coating designs will be demonstrated.
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Affiliation(s)
- Edward J. Gildersleeve
- Institute of Energy and Climate Research, Materials Synthesis and Processing (IEK-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Robert Vaßen
- Institute of Energy and Climate Research, Materials Synthesis and Processing (IEK-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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11
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Raza T, Shehzad M, Abbas M, Eash NS, Jatav HS, Sillanpaa M, Flynn T. Impact assessment of COVID-19 global pandemic on water, environment, and humans. ENVIRONMENTAL ADVANCES 2023; 11:100328. [PMID: 36532331 PMCID: PMC9741497 DOI: 10.1016/j.envadv.2022.100328] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 11/15/2022] [Accepted: 12/04/2022] [Indexed: 06/17/2023]
Abstract
One of the most significant threats to global health since the Second World War is the COVID-19 pandemic. Due to COVID-19 widespread social, environmental, economic, and health concerns. Other unfavourable factors also emerged, including increased trash brought on by high consumption of packaged foods, takeout meals, packaging from online shopping, and the one-time use of plastic products. Due to labour shortages and residents staying at home during mandatory lockdowns, city municipal administrations' collection and recycling capacities have decreased, frequently damaging the environment (air, water, and soil) and ecological and human systems. The COVID-19 challenges are more pronounced in unofficial settlements of developing nations, particularly for developing nations of the world, as their fundamental necessities, such as air quality, water quality, trash collection, sanitation, and home security, are either non-existent or difficult to obtain. According to reports, during the pandemic's peak days (20 August 2021 (741 K cases), 8 million tonnes of plastic garbage were created globally, and 25 thousand tonnes of this waste found its way into the ocean. This thorough analysis attempts to assess the indirect effects of COVID-19 on the environment, human systems, and water quality that pose dangers to people and potential remedies. Strong national initiatives could facilitate international efforts to attain environmental sustainability goals. Significant policies should be formulated like good quality air, pollution reduction, waste management, better sanitation system, and personal hygiene. This review paper also elaborated that further investigations are needed to investigate the magnitude of impact and other related factors for enhancement of human understanding of ecosystem to manage the water, environment and human encounter problems during epidemics/pandemics in near future.
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Affiliation(s)
- Taqi Raza
- Department of Biosystems Engineering & Soil Science, University of Tennessee, USA
| | | | - Mazahir Abbas
- Department of Bioscience, University of Wah Cantt, Quaid Avenue, Wah Cantt 47040, Pakistan
| | - Neal S Eash
- Department of Biosystems Engineering & Soil Science, University of Tennessee, USA
| | - Hanuman Singh Jatav
- Department of Soil Science and Agricultural Chemistry, Sri Karan Narendra Agriculture University, Rajasthan 303329, India
- Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Mika Sillanpaa
- Department of Chemical Engineering, School of Mining, Metallurgy and Chemical Engineering, University of Johannesburg, P.O. Box 17011, Doornfontein 2028, South Africa
| | - Trevan Flynn
- Department of Horticulture and Natural Resources, University of Bonn, Germany
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12
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Lin Y, Wu Y, Lin JJ. Building an oxidation reactor in Taiwan: From volatile organic compounds to secondary organic aerosols. J CHIN CHEM SOC-TAIP 2022. [DOI: 10.1002/jccs.202200470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yen‐Hsiu Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica Taipei Taiwan
- Department of Chemistry National Taiwan University Taipei Taiwan
| | - Yen‐Ju Wu
- Institute of Atomic and Molecular Sciences, Academia Sinica Taipei Taiwan
- Department of Chemistry National Taiwan University Taipei Taiwan
| | - Jim Jr‐Min Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica Taipei Taiwan
- Department of Chemistry National Taiwan University Taipei Taiwan
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13
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Abstract
The past 60 years have seen large reductions in vehicle emissions of particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons (HCs), sulfur dioxide (SO2), and lead (Pb). Advanced emission after-treatment technologies have been developed for gasoline and diesel vehicles to meet increasingly stringent regulations, yielding absolute emission reductions from the on-road fleet despite increased vehicle miles traveled. As a result of reduced emissions from vehicles and other sources, the air quality in cities across the U.S. and Europe has improved greatly. Turn-over of the on-road fleet, increasingly stringent emission regulations (such as Tier 3 in the U.S., LEV III in California, Euro 6 in Europe, and upcoming rules in these same regions), and the large-scale introduction of electric vehicles will lead to even lower vehicle emissions and further improvements in air quality. We review historical vehicle emissions and air quality trends and discuss the future outlook.
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14
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Ozone Monitoring in the Baikal Region (East Siberia): Spatiotemporal Variability under the Influence of Air Pollutants and Site Conditions. ATMOSPHERE 2022. [DOI: 10.3390/atmos13040519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This article analyses the results of year-round automatic ozone monitoring in seven cities of the Baikal region (southeastern Siberia). We reveal that significant differences in the spatiotemporal variability of the average daily ozone concentrations depend on different anthropogenic loads. In large cities with heavy industry, which are located in the Angara River valley, the ozone concentrations were minimal and changed little during the year: less than 5 µg/m3 in the Angarsk city and 20–30 µg/m3 in the Irkutsk city. In the settlements of a less polluted region, the Selenga River valley, the ozone concentrations were significantly higher, and the annual ozone variability was typical of East Siberia: the maximum in spring (60 to 70 μg/m3) and the minimum in autumn and winter (10 to 30 μg/m3). The maximum ozone concentrations were observed in rural conditions (Listvyanka station), up to 80–100 μg/m3 during the spring maximum. Nitrogen oxides had the main influence on ozone depletion in the surface atmosphere of the cities, especially in winter, the season of maximum burning of fossil fuels (negative correlation can reach −0.9). In cities with heavy industry, the effect of NOx on ozone was weaker. Perhaps other anthropogenic impurities can also affect ozone suppression in these cities, which have not yet been studied.
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CO Fluxes in Western Europe during 2017–2020 Winter Seasons Inverted by WRF-Chem/Data Assimilation Research Testbed with MOPITT Observations. REMOTE SENSING 2022. [DOI: 10.3390/rs14051133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
The study of anthropogenic carbon monoxide (CO) emissions is crucial to investigate anthropogenic activities. Assuming the anthropogenic CO emissions accounted for the super majority of the winter CO fluxes in western Europe, they could be roughly estimated by the inversion approach. The CO fluxes and concentrations of four consecutive winter seasons (i.e., December–February) in western Europe since 2017 were estimated by a regional CO flux inversion system based on the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and the Data Assimilation Research Testbed (DART). The CO retrievals from the Measurements Of Pollution In The Troposphere instrument (MOPITT) version 8 level 2 multi-spectral Thermal InfraRed (TIR)/Near-InfraRed (NIR) CO retrieval data products were assimilated by the inversion system. The analyses of the MOPITT data used by the inversion system indicated that the mean averaging kernel row sums of the surface level was about 0.25, and the difference percentage of the surface-level retrievals relative to a priori CO-mixing ratios was 14.79%, which was similar to that of the other levels. These results suggested the MOPITT’s surface-level observations contained roughly the same amount of information as the other levels. The inverted CO fluxes of the four winter seasons were 6198.15 kilotons, 4939.72 kilotons, 4697.80 kilotons, and 5456.19 kilotons, respectively. Based on the assumption, the United Nations Framework Convention on Climate Change (UNFCCC) inventories were used to evaluate the accuracy of the inverted CO fluxes. The evaluation results indicated that the differences between the inverted CO fluxes and UNFCCC inventories of the three winter seasons of 2017–2019 were 13.36%, −4.59%, and −4.76%, respectively. Detailed surface-CO concentrations and XCO comparative analyses between the experimental results and the external Community Atmosphere Model with Chemistry (CAM-Chem) results and the MOPITT data were conducted. The comparative analysis results indicated that the experimental results of the winter season of 2017 were obviously affected by high boundary conditions. The CO concentrations results of the experiments were also evaluated by the CO observation data from Integrated Carbon Observation System (ICOS), the average Mean Bias Error (MBE), and the Root Mean Square Error (RMSE) between the CO concentrations results of the inversion system, and the ICOS observations were −22.43 ppb and 57.59 ppb, respectively. The MBE and RMSE of the inversion system were 17.53-ppb and 4.17-ppb better than those of the simulation-only parallel experiments, respectively.
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16
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Theoretical study of mechanisms and kinetics of reactions of the O(3P) atom with alkyl hydroperoxides (ROOH) where (R = CH3 & C2H5). COMPUT THEOR CHEM 2022. [DOI: 10.1016/j.comptc.2021.113547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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17
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Shi G, Song J, Li Z. Theoretical study of the reactions of triplet Oxygen atom with methyl and ethyl hydroperoxides. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1973605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Gai Shi
- State Key Laboratory of Engines, Tianjin University, Tianjin, People’s Republic of China
| | - Jinou Song
- State Key Laboratory of Engines, Tianjin University, Tianjin, People’s Republic of China
| | - Zhijun Li
- State Key Laboratory of Engines, Tianjin University, Tianjin, People’s Republic of China
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18
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Lin S, Peng D, Yang W, Gu FL, Lan Z. Theoretical studies on triplet-state driven dissociation of formaldehyde by quasi-classical molecular dynamics simulation on machine-learning potential energy surface. J Chem Phys 2021; 155:214105. [PMID: 34879677 PMCID: PMC8654486 DOI: 10.1063/5.0067176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 11/09/2021] [Indexed: 11/15/2022] Open
Abstract
The H-atom dissociation of formaldehyde on the lowest triplet state (T1) is studied by quasi-classical molecular dynamic simulations on the high-dimensional machine-learning potential energy surface (PES) model. An atomic-energy based deep-learning neural network (NN) is used to represent the PES function, and the weighted atom-centered symmetry functions are employed as inputs of the NN model to satisfy the translational, rotational, and permutational symmetries, and to capture the geometry features of each atom and its individual chemical environment. Several standard technical tricks are used in the construction of NN-PES, which includes the application of clustering algorithm in the formation of the training dataset, the examination of the reliability of the NN-PES model by different fitted NN models, and the detection of the out-of-confidence region by the confidence interval of the training dataset. The accuracy of the full-dimensional NN-PES model is examined by two benchmark calculations with respect to ab initio data. Both the NN and electronic-structure calculations give a similar H-atom dissociation reaction pathway on the T1 state in the intrinsic reaction coordinate analysis. The small-scaled trial dynamics simulations based on NN-PES and ab initio PES give highly consistent results. After confirming the accuracy of the NN-PES, a large number of trajectories are calculated in the quasi-classical dynamics, which allows us to get a better understanding of the T1-driven H-atom dissociation dynamics efficiently. Particularly, the dynamics simulations from different initial conditions can be easily simulated with a rather low computational cost. The influence of the mode-specific vibrational excitations on the H-atom dissociation dynamics driven by the T1 state is explored. The results show that the vibrational excitations on symmetric C-H stretching, asymmetric C-H stretching, and C=O stretching motions always enhance the H-atom dissociation probability obviously.
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Affiliation(s)
| | | | - Weitao Yang
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - Feng Long Gu
- Authors to whom correspondence should be addressed: and
| | - Zhenggang Lan
- Authors to whom correspondence should be addressed: and
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19
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Murray LT, Fiore AM, Shindell DT, Naik V, Horowitz LW. Large uncertainties in global hydroxyl projections tied to fate of reactive nitrogen and carbon. Proc Natl Acad Sci U S A 2021; 118:e2115204118. [PMID: 34686608 PMCID: PMC8639338 DOI: 10.1073/pnas.2115204118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2021] [Indexed: 11/18/2022] Open
Abstract
The hydroxyl radical (OH) sets the oxidative capacity of the atmosphere and, thus, profoundly affects the removal rate of pollutants and reactive greenhouse gases. While observationally derived constraints exist for global annual mean present-day OH abundances and interannual variability, OH estimates for past and future periods rely primarily on global atmospheric chemistry models. These models disagree ± 30% in mean OH and in its changes from the preindustrial to late 21st century, even when forced with identical anthropogenic emissions. A simple steady-state relationship that accounts for ozone photolysis frequencies, water vapor, and the ratio of reactive nitrogen to carbon emissions explains temporal variability within most models, but not intermodel differences. Here, we show that departure from the expected relationship reflects the treatment of reactive oxidized nitrogen species (NO y ) and the fraction of emitted carbon that reacts within each chemical mechanism, which remain poorly known due to a lack of observational data. Our findings imply a need for additional observational constraints on NO y partitioning and lifetime, especially in the remote free troposphere, as well as the fate of carbon-containing reaction intermediates to test models, thereby reducing uncertainties in projections of OH and, hence, lifetimes of pollutants and greenhouse gases.
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Affiliation(s)
- Lee T Murray
- Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY 14627;
| | - Arlene M Fiore
- Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964
| | - Drew T Shindell
- Nicholas School of the Environment, Duke University, Durham, NC 27708
| | - Vaishali Naik
- Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration, Princeton, NJ 08540
| | - Larry W Horowitz
- Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration, Princeton, NJ 08540
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20
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Shi G, Song J, Tian P, Li Z. Theoretical studies of the reactions of 1,2-Ethanediol with triplet oxygen and hydrogen atoms. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1989069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Gai Shi
- State Key Laboratory of Engines, Tianjin University, Tianjin, People’s Republic of China
| | - Jinou Song
- State Key Laboratory of Engines, Tianjin University, Tianjin, People’s Republic of China
| | - Pengzhen Tian
- College of Mathematics and Information Science, Hebei University, Baoding, People’s Republic of China
| | - Zhijun Li
- State Key Laboratory of Engines, Tianjin University, Tianjin, People’s Republic of China
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21
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Shi G, Song J, Tian P. Theoretical study of the reactions of triplet oxygen atom with 1-propanol and 2-propanol. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138990] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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22
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Shi G, Song J, Tian P, Li Z. Kinetics study on the reactions of dimethyl ether with triplet oxygen and hydrogen atoms. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138855] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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23
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24
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Corral AF, Braun RA, Cairns B, Gorooh VA, Liu H, Ma L, Mardi AH, Painemal D, Stamnes S, van Diedenhoven B, Wang H, Yang Y, Zhang B, Sorooshian A. An Overview of Atmospheric Features Over the Western North Atlantic Ocean and North American East Coast - Part 1: Analysis of Aerosols, Gases, and Wet Deposition Chemistry. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2021; 126:e2020JD032592. [PMID: 34211820 PMCID: PMC8243758 DOI: 10.1029/2020jd032592] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 11/04/2020] [Indexed: 06/13/2023]
Abstract
The Western North Atlantic Ocean (WNAO) and adjoining East Coast of North America are of great importance for atmospheric research and have been extensively studied for several decades. This broad region exhibits complex meteorological features and a wide range of conditions associated with gas and particulate species from many sources regionally and other continents. As Part 1 of a 2-part paper series, this work characterizes quantities associated with atmospheric chemistry, including gases, aerosols, and wet deposition, by analyzing available satellite observations, ground-based data, model simulations, and reanalysis products. Part 2 provides insight into the atmospheric circulation, boundary layer variability, three-dimensional cloud structure, properties, and precipitation over the WNAO domain. Key results include spatial and seasonal differences in composition along the North American East Coast and over the WNAO associated with varying sources of smoke and dust and meteorological drivers such as temperature, moisture, and precipitation. Spatial and seasonal variations of tropospheric carbon monoxide and ozone highlight different pathways toward the accumulation of these species in the troposphere. Spatial distributions of speciated aerosol optical depth and vertical profiles of aerosol mass mixing ratios show a clear seasonal cycle highlighting the influence of different sources in addition to the impact of intercontinental transport. Analysis of long-term climate model simulations of aerosol species and satellite observations of carbon monoxide confirm that there has been a significant decline in recent decades among anthropogenic constituents owing to regulatory activities.
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Affiliation(s)
- Andrea F Corral
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - Rachel A Braun
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - Brian Cairns
- NASA Goddard Institute for Space Studies, New York, NY, USA
| | - Vesta Afzali Gorooh
- Center for Hydrometeorology and Remote Sensing (CHRS), Department of Civil and Environmental Engineering, The Henry Samueli School of Engineering, University of California, Irvine, CA, USA
| | - Hongyu Liu
- National Institute of Aerospace, Hampton, VA, USA
| | - Lin Ma
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - Ali Hossein Mardi
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - David Painemal
- NASA Langley Research Center, Hampton, VA, USA
- Science Systems and Applications, Inc., Hampton, VA, USA
| | | | - Bastiaan van Diedenhoven
- NASA Goddard Institute for Space Studies, New York, NY, USA
- Columbia University Center for Climate System Research, New York, NY, USA
| | - Hailong Wang
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Yang Yang
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Bo Zhang
- National Institute of Aerospace, Hampton, VA, USA
| | - Armin Sorooshian
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
- Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
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25
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Cao F, Shi G, Song J, Tian P, Li Z. Kinetics of the Reactions of Methyl Radical with Hydrogen, Methyl and Ethyl Peroxides. ChemistrySelect 2021. [DOI: 10.1002/slct.202100193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Fei Cao
- State Key Laboratory of Engines Tianjin University Tianjin 300350 P.R. China
| | - Gai Shi
- State Key Laboratory of Engines Tianjin University Tianjin 300350 P.R. China
| | - Jinou Song
- State Key Laboratory of Engines Tianjin University Tianjin 300350 P.R. China
| | - Pengzhen Tian
- College of Mathematics and Information Science Hebei University Baoding Hebei 071002 P.R. China
| | - Zhijun Li
- State Key Laboratory of Engines Tianjin University Tianjin 300350 P.R. China
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26
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Lyu X, Guo H, Yao D, Lu H, Huo Y, Xu W, Kreisberg N, Goldstein AH, Jayne J, Worsnop D, Tan Y, Lee SC, Wang T. In Situ Measurements of Molecular Markers Facilitate Understanding of Dynamic Sources of Atmospheric Organic Aerosols. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:11058-11069. [PMID: 32805105 DOI: 10.1021/acs.est.0c02277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Reducing the amount of organic aerosol (OA) is crucial to mitigation of particulate pollution in China. We present time and air-origin dependent variations of OA markers and source contributions at a regionally urban background site in South China. The continental air contained primary OA markers indicative of source categories, such as levoglucosan, fatty acids, and oleic acid. Secondary OA (SOA) markers derived from isoprene and monoterpenes also exhibited higher concentrations in continental air, due to more emissions of their precursors from terrestrial ecosystems and facilitation of anthropogenic sulfate for monoterpenes SOA. The marine air and continental-marine mixed air had more abundant hydroxyl dicarboxylic acids (OHDCA), with anthropogenic unsaturated organics as potential precursors. However, OHDCA formation in continental air was likely attributable to both biogenic and anthropogenic precursors. The production efficiency of OHDCA was highest in marine air, related to the presence of sulfur dioxide and/or organic precursors in ship emissions. Regional biomass burning (BB) was identified as the largest contributor of OA in continental air, with contributions fluctuating from 8% to 74%. In contrast, anthropogenic SOA accounted for the highest fraction of OA in marine (37 ± 4%) and mixed air (31 ± 3%), overriding the contributions from BB. This study demonstrates the utility of molecular markers for discerning OA pollution sources in the offshore marine atmosphere, where continental and marine air pollutants interact and atmospheric oxidative capacity may be enhanced.
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Affiliation(s)
- Xiaopu Lyu
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong
| | - Hai Guo
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong
| | - Dawen Yao
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong
| | - Haoxian Lu
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong
| | - Yunxi Huo
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong
| | - Wen Xu
- Center for Aerosol and Cloud Chemistry, Aerodyne Research Incorporated, Billerica, Massachusetts 01821, United States
| | - Nathan Kreisberg
- Aerosol Dynamics Incorporated, Berkeley, California 94710, United States
| | - Allen H Goldstein
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94720, United States
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - John Jayne
- Center for Aerosol and Cloud Chemistry, Aerodyne Research Incorporated, Billerica, Massachusetts 01821, United States
| | - Douglas Worsnop
- Center for Aerosol and Cloud Chemistry, Aerodyne Research Incorporated, Billerica, Massachusetts 01821, United States
| | - Yan Tan
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong
| | - Shun-Cheng Lee
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong
| | - Tao Wang
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong
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27
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Kwon YS, Kang HW, Polimene L, Rhee TS. A marine carbon monoxide (CO) model with a new parameterization of microbial oxidation. Ecol Modell 2020. [DOI: 10.1016/j.ecolmodel.2020.109203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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28
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Ni L, Xin X, Wang Y, Wang D. Quantum dynamics study of isotope effects of the OD/OH + CH 3 reactions. Mol Phys 2020. [DOI: 10.1080/00268976.2019.1710610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Liyan Ni
- College of Physics and Electronics, Shandong Normal University, Jinan, People’s Republic of China
| | - Xin Xin
- College of Physics and Electronics, Shandong Normal University, Jinan, People’s Republic of China
| | - Yuping Wang
- College of Physics and Electronics, Shandong Normal University, Jinan, People’s Republic of China
| | - Dunyou Wang
- College of Physics and Electronics, Shandong Normal University, Jinan, People’s Republic of China
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29
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Kim SU, Kim KY. Physical and chemical mechanisms of the daily-to-seasonal variation of PM 10 in Korea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 712:136429. [PMID: 31931224 DOI: 10.1016/j.scitotenv.2019.136429] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/18/2019] [Accepted: 12/29/2019] [Indexed: 06/10/2023]
Abstract
In this study, the CSEOF technique is used to investigate the physical and chemical mechanisms associated with the weekly PM10 variation in South Korea. For this end, 9 years of hourly measurements of PM10 in South Korea is used together with other gaseous contaminants (NO2, SO2, CO and O3) and traffic counts at the toll gates. The diurnal variation of PM10 concentrations indicates a significant correlation with human activities; higher concentrations in densely populated areas with a large volume of traffics and vice versa. In particular, the diurnal cycles of PM10, NO2 and CO show bimodal structures with maxima corresponding to the morning and evening rush hours. While NO2 and CO maxima are observed at ~9 AM, with some delay from the traffic maximum, PM10 peak is observed ~11 AM, indicating roughly 2 h of conversion process from gaseous pollutants to particulate matter. After the sunset, gas-to-particle conversion efficiency is significantly reduced and PM10 concentration begins to increase slowly. SO2 exhibits a slightly different feature, showing diurnal variation with a single peak at 11 AM and relatively minor contribution to the diurnal variation of PM10. O3 participates in the photochemical reactions of the gaseous pollutants, providing OH radical as an oxidant. Physical factors (e.g. boundary layer height, 10 m wind gust, wind convergence) affecting horizontal and vertical mixing of polluted air are responsible for dispersion of accumulated PM10 in the afternoon. As a result, strong morning-evening asymmetry is seen in the diurnal variation of PM10 concentrations. Also, notable seasonal dependency is observed in the concentrations of PM10 and the gaseous contaminants due to the seasonal variation of emission and the physical factors.
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Affiliation(s)
- Seung-Uk Kim
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Kwang-Yul Kim
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea.
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30
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Satellite-Observed Variations and Trends in Carbon Monoxide over Asia and Their Sensitivities to Biomass Burning. REMOTE SENSING 2020. [DOI: 10.3390/rs12050830] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
As the carbon monoxide (CO) total column over Asia is among the highest in the world, it is important to characterize its variations in space and time. Using Measurements of Pollution in the Troposphere (MOPITT) and Atmospheric InfraRed Sounder (AIRS) satellite data, the variations and trends in CO total column over Asia and its seven subregions during 2003–2017 are investigated in this study. The CO total column in Asia is higher in spring and winter than in summer and autumn. The seasonal maximum and minimum are in spring and summer respectively in the regional mean over Asia, varying between land and oceans, as well as among the subregions. The CO total column in Asia shows strong interannual variation, with a regional mean coefficient of variation of 5.8% in MOPITT data. From 2003 to 2017, the annual mean of CO total column over Asia decreased significantly at a rate of (0.58 ± 0.15)% per year (or −(0.11 ± 0.03) × 1017 molecules cm−2 per year) in MOPITT data, resulting from significant CO decreases in winter, summer, and spring. In most of the subregions, significant decreasing trends in CO total column are also observed, more obviously over areas with high CO total column, including eastern regions of China and the Sichuan Basin. The regional decreasing trends in these areas are over 1% per year. Over the entire Asia, and in fire-prone subregions including South Siberia, Indo-China Peninsula, and Indonesia, we found significant correlations between the MOPITT CO total column and the fire counts from the Moderate Resolution Imaging Spectroradiometer (MODIS). The variations in MODIS fire counts may explain 58%, 60%, 36%, and 71% of the interannual variation in CO total column in Asia and these three subregions, respectively. Over different land cover types, the variations in biomass burning may explain 62%, 52%, and 31% of the interannual variation in CO total column, respectively, over the forest, grassland, and shrubland in Asia. Extremes in CO total column in Asia can be largely explained by the extreme fire events, such as the fires over Siberia in 2003 and 2012 and over Indonesia in 2006 and 2015. The significant decreasing trends in MODIS fire counts inside and outside Asia suggest that global biomass burning may be a driver for the decreasing trend in CO total column in Asia, especially in spring. In general, the variations and trends in CO total column over Asia detected by AIRS are similar to but smaller than those by MOPITT. The two datasets show similar spatial and temporal variations in CO total column over Asia, with correlation coefficients of 0.86–0.98 in the annual means. This study shows that the interannual variation in atmospheric CO in Asia is sensitive to biomass burning, while the decreasing trend in atmospheric CO over Asia coincides with the decreasing trend in MODIS fire counts from 2003 to 2017.
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Abstract
The atmosphere is composed of nitrogen, oxygen and argon, a variety of trace gases, and particles or aerosols from a variety of sources. Reactive, trace gases have short mean residence time in the atmosphere and large spatial and temporal variations in concentration. Many trace gases are removed by reaction with hydroxyl radical and deposition in rainfall or dryfall at the Earth's surface. The upper atmosphere, the stratosphere, contains ozone that screens ultraviolet light from the Earth's surface. Chlorofluorocarbons released by humans lead to the loss of stratospheric ozone, which might eventually render the Earth's land surface uninhabitable. Changes in the composition of the atmosphere, especially rising concentrations of CO2, CH4, and N2O, will lead to climatic changes over much of the Earth's surface.
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Liu S, Fang S, Liang M, Ma Q, Feng Z. Study on CO data filtering approaches based on observations at two background stations in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 691:675-684. [PMID: 31325866 DOI: 10.1016/j.scitotenv.2019.07.162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 07/07/2019] [Accepted: 07/11/2019] [Indexed: 06/10/2023]
Abstract
The identification of regional representative carbon monoxide (CO) measurements that are minimally influenced by local sources/sinks is essential to understand the characteristics of atmospheric CO over a certain region. In this study, three commonly used data filtering approaches were applied to atmospheric CO data obtained from 2010/2011 to 2017 at two World Meteorological Administration/Global Atmospheric Programme (WMO/GAW) regional stations (Lin'an, LAN and Shangdianzi, SDZ) in China, to study their applicability for individual stations. The three methods used were the meteorological conditions (MET), statistical approaches (robust extraction of baseline signal, REBS), and the time scale of the CO variations (standard deviations of the running mean, SDM). The results from the three methods displayed almost the same seasonal cycles at LAN but different variations at SDZ. They each extracted similar yearly CO growth rates at LAN, but there was a large difference at SDZ, with values of -10.6 ± 0.5, -2.2 ± 0.1, and - 23.5 ± 0.3 ppb yr-1 for MET, REBS, and SDM, respectively. The slight decrease observed using REBS at SDZ was mainly due to the biased distribution of CO records, which was a purely statistical method that did not consider topography or meteorological conditions. Thus, the REBS method should be applied cautiously to CO observations at stations like SDZ. The SDM method may overestimate multi-year trends. Among the three approaches, MET may be the most suitable for filtering CO observation records, especially at stations like SDZ with special geographical and meteorological conditions in economically-developed regions.
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Affiliation(s)
- Shuo Liu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuangxi Fang
- Meteorological Observation Centre (MOC), China Meteorological Administration (CMA), Beijing 100081, China.
| | - Miao Liang
- Meteorological Observation Centre (MOC), China Meteorological Administration (CMA), Beijing 100081, China
| | - Qianli Ma
- Lin'an Regional Background Station, China Meteorological Administration, Zhejiang 314016, China
| | - Zhaozhong Feng
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
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Chutia L, Ojha N, Girach IA, Sahu LK, Alvarado LMA, Burrows JP, Pathak B, Bhuyan PK. Distribution of volatile organic compounds over Indian subcontinent during winter: WRF-chem simulation versus observations. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 252:256-269. [PMID: 31153030 DOI: 10.1016/j.envpol.2019.05.097] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 05/06/2019] [Accepted: 05/19/2019] [Indexed: 06/09/2023]
Abstract
We investigate the distribution of volatile organic compounds (VOCs) over Indian subcontinent during a winter month of January 2011 combining the regional model WRF-Chem (Weather Research and Forecasting model coupled with Chemistry) with ground- and space-based observations and chemical reanalysis. WRF-Chem simulated VOCs are found to be comparable with ground-based observations over contrasting environments of the Indian subcontinent. WRF-Chem results reveal the elevated levels of VOCs (e. g. propane) over the Indo-Gangetic Plain (16 ppbv), followed by the Northeast region (9.1 ppbv) in comparison with other parts of the Indian subcontinent (1.3-8.2 ppbv). Higher relative abundances of propane (27-31%) and ethane (13-17%) are simulated across the Indian subcontinent. WRF-Chem simulated formaldehyde and glyoxal show the western coast, Eastern India and the Indo-Gangetic Plain as the regional hotspots, in a qualitative agreement with the MACC (Monitoring Atmospheric Composition and Climate) reanalysis and satellite-based observations. Lower values of RGF (ratio of glyoxal to formaldehyde <0.04) suggest dominant influences of the anthropogenic emissions on the distribution of VOCs over Indian subcontinent, except the northeastern region where higher RGF (∼0.06) indicates the role of biogenic emissions, in addition to anthropogenic emissions. Analysis of HCHO/NO2 ratio shows a NOx-limited ozone production over India, with a NOx-to-VOC transition regime over central India and IGP. The study highlights a need to initiate in situ observations of VOCs over regional hotspots (Northeast, Central India, and the western coast) based on WRF-Chem results, where different satellite-based observations differ significantly.
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Affiliation(s)
- Lakhima Chutia
- Centre for Atmospheric Studies, Dibrugarh University, Dibrugarh, India
| | - Narendra Ojha
- Space and Atmospheric Sciences Division, Physical Research Laboratory, Ahmedabad, India.
| | - Imran A Girach
- Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, India
| | - Lokesh K Sahu
- Space and Atmospheric Sciences Division, Physical Research Laboratory, Ahmedabad, India
| | | | - John P Burrows
- Institute of Environmental Physics (IUP), University of Bremen, Bremen, Germany
| | - Binita Pathak
- Centre for Atmospheric Studies, Dibrugarh University, Dibrugarh, India; Department of Physics, Dibrugarh University, Dibrugarh, India
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Mohan S, Saranya P. Assessment of tropospheric ozone at an industrial site of Chennai megacity. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2019; 69:1079-1095. [PMID: 30973317 DOI: 10.1080/10962247.2019.1604451] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/08/2019] [Accepted: 03/30/2019] [Indexed: 06/09/2023]
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 generation sources, such as vehicular traffic and industrial activities. The site is also located near a hazardous waste management facility. The key sources of nitrogen oxides (NOx), which are considered to be an important precursor of O3, include hazardous waste incineration, trucks bringing the hazardous wastes, and vehicles plying on the nearby National Highway 16 (NH 16). The measurements clearly showed diurnal variation, with maximum values observed during the noon hours and minimum values observed when solar radiation was less. The data showed a marked seasonal variation in O3, with the highest hourly average O3 concentration (497.2 µg/m3) in the summer season. Consequently, in order to identify the long-range transport sources adding to the increased O3 levels, backward trajectories were computed using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model. It was found that the polluted air mass originated from the Southeast Asian region and the Indo-Gangetic Plain. The polluted air mass, which advected large amounts of carbon monoxide (CO) plumes, was analyzed using the Measurement of Pollution in the Troposphere (MOPITT) retrievals. The correlations of O3 with temperature (r = 0.746; P < 0.01) and solar radiation (r = 0.751; P < 0.01) were strongly positive, and that with NOx was found to be negative. Stronger correlation of O3 with NOx was observed during pre-monsoon months (r = 0.627; P < 0.01) and following hours of photochemical reactions. There were substantial differences in concentrations between weekdays and weekends, with higher nitric oxide (NO) and nitrogen dioxide (NO2), but lower O3, concentrations on weekdays. A substantial weekday-weekend difference in O3, which was higher on weekends, appears to be attributable to lower daytime traffic activity and hence reduced emissions of NOx to a "NOx-saturated" atmosphere. Implications: The assessment of ground-level ozone in an industrial area with hazardous waste management facility is very important, as there is high possibility for more generation of tropospheric ozone. Since the location of the study area is coastal, wind plays a major role in O3 transportation; hence, the effects of wind speed and wind direction have been studied in different seasons. When compared with the other studies carried out in different places across India, the present study area has recorded much greater O3 mixing ratio. This study can be useful for setting up control strategies in such industrial areas.
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Affiliation(s)
- S Mohan
- Environmental and Water Resources Engineering Division, Department of Civil Engineering, Indian Institute of Technology Madras , Chennai , Tamil Nadu , India
| | - Packiam Saranya
- Environmental and Water Resources Engineering Division, Department of Civil Engineering, Indian Institute of Technology Madras , Chennai , Tamil Nadu , India
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McCaslin LM, Johnson MA, Gerber RB. Mechanisms and competition of halide substitution and hydrolysis in reactions of N 2O 5 with seawater. SCIENCE ADVANCES 2019; 5:eaav6503. [PMID: 31183400 PMCID: PMC6551187 DOI: 10.1126/sciadv.aav6503] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 05/02/2019] [Indexed: 06/09/2023]
Abstract
SN2-type halide substitution and hydrolysis are two of the most ubiquitous reactions in chemistry. The interplay between these processes is fundamental in atmospheric chemistry through reactions of N2O5 and seawater. N2O5 plays a major role in regulating levels of O3, OH, NO x , and CH4. While the reactions of N2O5 and seawater are of central importance, little is known about their mechanisms. Of interest is the activation of Cl in seawater by the formation of gaseous ClNO2, which occurs despite the fact that hydrolysis (to HNO3) is energetically more favorable. We determine key features of the reaction landscape that account for this behavior in a theoretical study of the cluster N2O5/Cl-/H2O. This was carried out using ab initio molecular dynamics to determine reaction pathways, structures, and time scales. While hydrolysis of N2O5 occurs in the absence of Cl-, results here reveal that a low-lying pathway featuring halide substitution intermediates enhances hydrolysis.
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Affiliation(s)
- Laura M. McCaslin
- Institute of Chemistry and the Fritz Haber Center for Molecular Dynamics, The Hebrew University, Jerusalem 9190401, Israel
| | - Mark A. Johnson
- Department of Chemistry, Yale University, New Haven, CT 06525, USA
| | - R. Benny Gerber
- Institute of Chemistry and the Fritz Haber Center for Molecular Dynamics, The Hebrew University, Jerusalem 9190401, Israel
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697, USA
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Li S, Dong L, Wu H, Sampaolo A, Patimisco P, Spagnolo V, Tittel FK. Ppb-Level Quartz-Enhanced Photoacoustic Detection of Carbon Monoxide Exploiting a Surface Grooved Tuning Fork. Anal Chem 2019; 91:5834-5840. [DOI: 10.1021/acs.analchem.9b00182] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shangzhi Li
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, P. R. China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, P. R. China
| | - Lei Dong
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, P. R. China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, P. R. China
| | - Hongpeng Wu
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, P. R. China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, P. R. China
| | - Angelo Sampaolo
- PolySense Lab—Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, Bari, Italy
| | - Pietro Patimisco
- PolySense Lab—Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, Bari, Italy
| | - Vincenzo Spagnolo
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, P. R. China
- PolySense Lab—Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, Bari, Italy
| | - Frank K. Tittel
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
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Abstract
Abstract
Remarkable progress has occurred over the last 100 years in our understanding of atmospheric chemical composition, stratospheric and tropospheric chemistry, urban air pollution, acid rain, and the formation of airborne particles from gas-phase chemistry. Much of this progress was associated with the developing understanding of the formation and role of ozone and of the oxides of nitrogen, NO and NO2, in the stratosphere and troposphere. The chemistry of the stratosphere, emerging from the pioneering work of Chapman in 1931, was followed by the discovery of catalytic ozone cycles, ozone destruction by chlorofluorocarbons, and the polar ozone holes, work honored by the 1995 Nobel Prize in Chemistry awarded to Crutzen, Rowland, and Molina. Foundations for the modern understanding of tropospheric chemistry were laid in the 1950s and 1960s, stimulated by the eye-stinging smog in Los Angeles. The importance of the hydroxyl (OH) radical and its relationship to the oxides of nitrogen (NO and NO2) emerged. The chemical processes leading to acid rain were elucidated. The atmosphere contains an immense number of gas-phase organic compounds, a result of emissions from plants and animals, natural and anthropogenic combustion processes, emissions from oceans, and from the atmospheric oxidation of organics emitted into the atmosphere. Organic atmospheric particulate matter arises largely as gas-phase organic compounds undergo oxidation to yield low-volatility products that condense into the particle phase. A hundred years ago, quantitative theories of chemical reaction rates were nonexistent. Today, comprehensive computer codes are available for performing detailed calculations of chemical reaction rates and mechanisms for atmospheric reactions. Understanding the future role of atmospheric chemistry in climate change and, in turn, the impact of climate change on atmospheric chemistry, will be critical to developing effective policies to protect the planet.
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Viciani S, Montori A, Chiarugi A, D'Amato F. A Portable Quantum Cascade Laser Spectrometer for Atmospheric Measurements of Carbon Monoxide. SENSORS 2018; 18:s18072380. [PMID: 30037111 PMCID: PMC6068545 DOI: 10.3390/s18072380] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 07/17/2018] [Accepted: 07/18/2018] [Indexed: 11/30/2022]
Abstract
Trace gas concentration measurements in the stratosphere and troposphere are critically required as inputs to constrain climate models. For this purpose, measurement campaigns on stratospheric aircraft and balloons are being carried out all over the world, each one involving sensors which are tailored for the specific gas and environmental conditions. This paper describes an automated, portable, mid-infrared quantum cascade laser spectrometer, for in situ carbon monoxide mixing ratio measurements in the stratosphere and troposphere. The instrument was designed to be versatile, suitable for easy installation on different platforms and capable of operating completely unattended, without the presence of an operator, not only during one flight but for the whole period of a campaign. The spectrometer features a small size (80 × 25 × 41 cm3), light weight (23 kg) and low power consumption (85 W typical), without being pressurized and without the need of calibration on the ground or during in-flight operation. The device was tested in the laboratory and in-field during a research campaign carried out in Nepal in summer 2017, onboard the stratospheric aircraft M55 Geophysica. The instrument worked extremely well, without external maintenance during all flights, proving an in-flight sensitivity of 1–2 ppbV with a time resolution of 1 s.
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Affiliation(s)
- Silvia Viciani
- National Research Council-National Institute of Optics (CNR-INO), Largo E. Fermi 6, 50125 Firenze, Italy.
| | - Alessio Montori
- National Research Council-National Institute of Optics (CNR-INO), Via N. Carrara 1, 50019 Sesto Fiorentino, Italy.
| | - Antonio Chiarugi
- National Institute of Geophysics and Vulcanology (INGV), Sez. di Pisa, Via della Faggiola 32, 56126 Pisa, Italy.
| | - Francesco D'Amato
- National Research Council-National Institute of Optics (CNR-INO), Largo E. Fermi 6, 50125 Firenze, Italy.
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Labuschagne C, Kuyper B, Brunke EG, Mokolo T, van der Spuy D, Martin L, Mbambalala E, Parker B, Khan MAH, Davies-Coleman MT, Shallcross DE, Joubert W. A review of four decades of atmospheric trace gas measurements at Cape Point, South Africa. ACTA ACUST UNITED AC 2018. [DOI: 10.1080/0035919x.2018.1477854] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Casper Labuschagne
- Global Atmospheric Watch, South African Weather Service, Stellenbosch, South Africa
| | - Brett Kuyper
- Department of Chemistry, University of the Western Cape, Cape Town, South Africa
| | - Ernst-Günther Brunke
- Global Atmospheric Watch, South African Weather Service, Stellenbosch, South Africa
| | - Thumeka Mokolo
- Global Atmospheric Watch, South African Weather Service, Stellenbosch, South Africa
| | - Danie van der Spuy
- Global Atmospheric Watch, South African Weather Service, Stellenbosch, South Africa
| | - Lynwill Martin
- Global Atmospheric Watch, South African Weather Service, Stellenbosch, South Africa
| | - Ernst Mbambalala
- Global Atmospheric Watch, South African Weather Service, Stellenbosch, South Africa
| | - Bhawoodien Parker
- Global Atmospheric Watch, South African Weather Service, Stellenbosch, South Africa
- Department of Environmental Affairs and Development Planning, Western Cape Government, South Africa
| | - M. Anwar H. Khan
- Atmospheric Chemistry Research Group, School of Chemistry, University of Bristol, United Kingdom
| | | | - Dudley E. Shallcross
- Department of Chemistry, University of the Western Cape, Cape Town, South Africa
- Atmospheric Chemistry Research Group, School of Chemistry, University of Bristol, United Kingdom
| | - Warren Joubert
- Global Atmospheric Watch, South African Weather Service, Stellenbosch, South Africa
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Esquivel-Elizondo S, Maldonado J, Krajmalnik-Brown R. Anaerobic carbon monoxide metabolism by Pleomorphomonas carboxyditropha sp. nov., a new mesophilic hydrogenogenic carboxydotroph. FEMS Microbiol Ecol 2018; 94:4980905. [DOI: 10.1093/femsec/fiy056] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 03/22/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Sofia Esquivel-Elizondo
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875701, Tempe, AZ 85287- 5701, USA
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-5701, USA
| | - Juan Maldonado
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875701, Tempe, AZ 85287- 5701, USA
- Center for Fundamental and Applied Microbiomics, The Biodesign Institute, Arizona State University, Tempe, AZ 85287–6101, USA
| | - Rosa Krajmalnik-Brown
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875701, Tempe, AZ 85287- 5701, USA
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-5701, USA
- Center for Fundamental and Applied Microbiomics, The Biodesign Institute, Arizona State University, Tempe, AZ 85287–6101, USA
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Murtaza R, Khokhar MF, Noreen A, Atif S, Hakeem KR. Multi-sensor temporal assessment of tropospheric nitrogen dioxide column densities over Pakistan. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:9647-9660. [PMID: 29363034 DOI: 10.1007/s11356-017-1176-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 12/27/2017] [Indexed: 06/07/2023]
Abstract
Spatial and temporal distributions of tropospheric NO2 vertical column densities over Pakistan during the period 2002-2014 are discussed. Data products from three satellite instruments SCIAMACHY, OMI, and GOME-2 are used to prepare a database of tropospheric NO2 column densities over Pakistan and temporal evolution is also determined. Plausible NO2 sources in Pakistan are also discussed. The results show a large NO2 growth over all provinces and the major cities of Pakistan except the megacity of Karachi. Decline in industrial activities due to energy crises, worsening law and order situation, terrorist attacks, and political instability was explored as the main factor for lower NO2 VCDs over Karachi City. The overall increase can be attributed to the anthropogenic emissions over the areas with high population, traffic density, and industrial activities. Source identification revealed that use of fossil fuels by various sectors including power generation, vehicles, and residential sectors along with agriculture fires are among significant sources of NO2 emissions in Pakistan. Existing emission inventories such as EDGARv4.2 and MACCity largely underestimate the true anthropogenic NOx emissions in Pakistan. This study may provide vital information to policy makers and regulatory authorities in developing countries, including Pakistan, in order to devise effective air pollution abatement policies.
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Affiliation(s)
- Rabbia Murtaza
- Institute of Environmental Sciences and Engineering, National University of Sciences and Technology, H-12, Islamabad, 44000, Pakistan
| | - Muhammad Fahim Khokhar
- Institute of Environmental Sciences and Engineering, National University of Sciences and Technology, H-12, Islamabad, 44000, Pakistan.
| | - Asma Noreen
- Institute of Environmental Sciences and Engineering, National University of Sciences and Technology, H-12, Islamabad, 44000, Pakistan
| | - Salman Atif
- Institute of Geographical Information System, National University of Sciences and Technology, H-12, Islamabad, 44000, Pakistan
| | - Khalid Rehman Hakeem
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.
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Effects of Climate Change and Ozone Concentration on the Net Primary Productivity of Forests in South Korea. FORESTS 2018. [DOI: 10.3390/f9030112] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Delre A, Mønster J, Scheutz C. Greenhouse gas emission quantification from wastewater treatment plants, using a tracer gas dispersion method. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 605-606:258-268. [PMID: 28667853 DOI: 10.1016/j.scitotenv.2017.06.177] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 06/21/2017] [Accepted: 06/21/2017] [Indexed: 06/07/2023]
Abstract
Plant-integrated methane (CH4) and nitrous oxide (N2O) emission quantifications were performed at five Scandinavian wastewater treatment plants, using a ground-based remote sensing approach that combines a controlled release of tracer gas from the plant with downwind concentration measurements. CH4 emission factors were between 1 and 21% of CH4 production, and between 0.2 and 3.2% of COD influent. The main CH4 emitting sources at the five plants were sludge treatment and energy production units. The lowest CH4 emission factors were obtained at plants with enclosed sludge treatment and storage units. N2O emission factors ranged from <0.1 to 5.2% of TN influent, and from <0.1 to 5.9% of TN removed. In general, measurement-based, site-specific CH4 and N2O emission factors for the five studied plants were in the upper range of the literature values and default emission factors applied in international guidelines. This study showed that measured CH4 and N2O emission rates from wastewater treatment plants were plant-specific and that emission rates estimated using models in current guidelines, mainly meant for reporting emissions on the country scale, were unsuitable for Scandinavian plant-specific emission reporting.
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Affiliation(s)
- Antonio Delre
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet, Bygning 115, 2800 Kgs. Lyngby, Denmark.
| | - Jacob Mønster
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet, Bygning 115, 2800 Kgs. Lyngby, Denmark.
| | - Charlotte Scheutz
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet, Bygning 115, 2800 Kgs. Lyngby, Denmark.
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Liang Q, Chipperfield MP, Fleming EL, Abraham NL, Braesicke P, Burkholder JB, Daniel JS, Dhomse S, Fraser PJ, Hardiman SC, Jackman CH, Kinnison DE, Krummel PB, Montzka SA, Morgenstern O, McCulloch A, Mühle J, Newman PA, Orkin VL, Pitari G, Prinn RG, Rigby M, Rozanov E, Stenke A, Tummon F, Velders GJM, Visioni D, Weiss RF. Deriving Global OH Abundance and Atmospheric Lifetimes for Long-Lived Gases: A Search for CH 3CCl 3 Alternatives. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2017; 122:11914-11933. [PMID: 38515436 PMCID: PMC10956888 DOI: 10.1002/2017jd026926] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
An accurate estimate of global hydroxyl radical (OH) abundance is important for projections of air quality, climate, and stratospheric ozone recovery. As the atmospheric mixing ratios of methyl chloroform (CH3CCl3) (MCF), the commonly used OH reference gas, approaches zero, it is important to find alternative approaches to infer atmospheric OH abundance and variability. The lack of global bottom-up emission inventories is the primary obstacle in choosing a MCF alternative. We illustrate that global emissions of long-lived trace gases can be inferred from their observed mixing ratio differences between the Northern Hemisphere (NH) and Southern Hemisphere (SH), given realistic estimates of their NH-SH exchange time, the emission partitioning between the two hemispheres, and the NH versus SH OH abundance ratio. Using the observed long-term trend and emissions derived from the measured hemispheric gradient, the combination of HFC-32 (CH2F2), HFC-134a (CH2FCF3, HFC-152a (CH3CHF2), and HCFC-22 (CHClF2), instead of a single gas, will be useful as a MCF alternative to infer global and hemispheric OH abundance and trace gas lifetimes. The primary assumption on which this multispecies approach relies is that the OH lifetimes can be estimated by scaling the thermal reaction rates of a reference gas at 272 K on global and hemispheric scales. Thus, the derived hemispheric and global OH estimates are forced to reconcile the observed trends and gradient for all four compounds simultaneously. However, currently, observations of these gases from the surface networks do not provide more accurate OH abundance estimate than that from MCF.
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Affiliation(s)
- Qing Liang
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
- Universities Space Research Association, GESTAR, Columbia, Maryland, USA
| | - Martyn P Chipperfield
- National Centre for Earth Observation, School of Earth and Environment, University of Leeds, Leeds, UK
| | - Eric L Fleming
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
- Science Systems and Applications, Inc, Lanham, Maryland, USA
| | - N Luke Abraham
- National Centre for Atmospheric Science, Leeds, UK
- Department of Chemistry, University of Cambridge, Cambridge, UK
| | | | - James B Burkholder
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
| | - John S Daniel
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
| | - Sandip Dhomse
- National Centre for Earth Observation, School of Earth and Environment, University of Leeds, Leeds, UK
| | - Paul J Fraser
- Climate Science Centre, CSIRO Oceans and Atmosphere, Aspendale, Vic, Australia
| | | | - Charles H Jackman
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | | | - Paul B Krummel
- Climate Science Centre, CSIRO Oceans and Atmosphere, Aspendale, Vic, Australia
| | - Stephen A Montzka
- Global Monitoring Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
| | - Olaf Morgenstern
- National Institute of Water and Atmospheric Research, Wellington, New Zealand
| | | | - Jens Mühle
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA
| | - Paul A Newman
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - Vladimir L Orkin
- National Institute of Standards and Technology, Gaithersburg, Maryland, USA
| | - Giovanni Pitari
- Department of Physical and Chemical Sciences, Università dell'Aquila, L'Aquila, Italy
| | - Ronald G Prinn
- Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Matthew Rigby
- School of Chemistry, University of Bristol, Bristol, UK
| | - Eugene Rozanov
- Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
- Physikalisch-Meteorologisches Observatorium Davos World Radiation Centre, Davos Dorf, Switzerland
| | - Andrea Stenke
- Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
| | - Fiona Tummon
- Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
| | - Guus J M Velders
- National Institute for Public Health and the Environment, Bilthoven, Netherlands
- Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, Netherlands
| | - Daniele Visioni
- Department of Physical and Chemical Sciences, Università dell'Aquila, L'Aquila, Italy
| | - Ray F Weiss
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA
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Variations of Carbon Monoxide Concentrations in the Megacity of São Paulo from 2000 to 2015 in Different Time Scales. ATMOSPHERE 2017. [DOI: 10.3390/atmos8050081] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Crosley DR, Araps CJ, Doyle-Eisele M, McDonald JD. Gas-phase photolytic production of hydroxyl radicals in an ultraviolet purifier for air and surfaces. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2017; 67:231-240. [PMID: 27629801 DOI: 10.1080/10962247.2016.1229236] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 07/14/2016] [Accepted: 08/08/2016] [Indexed: 06/06/2023]
Abstract
UNLABELLED We have measured the concentration of hydroxyl radicals (OH) produced in the gas phase by a commercially available purifier for air and surfaces, using the time rate of decay of n-heptane added to an environmental chamber. The hydroxyl generator, an Odorox® BOSS™ model, produces the OH through 185-nm photolysis of ambient water vapor. The steady-state concentration of OH produced in the 120 m3 chamber is, with 2σ error bars, (3.25 ± 0.80) × 106 cm-3. The properties of the hydroxyl generator, in particular the output of the ultraviolet lamps and the air throughput, together with an estimation of the water concentration, were used to predict the amount of OH produced by the device, with no fitted parameters. To relate this calculation to a steady-state concentration, we must estimate the OH loss rate within the chamber owing to reaction with the n-heptane and the 7 ppb of background hydrocarbons that are present. The result is a predicted steady-state concentration in excellent agreement with the measured value. This shows we understand well the processes occurring in the gas phase during operation of this hydroxyl radical purifier. IMPLICATIONS Hydroxyl radical air purifiers are used for cleaning both gaseous contaminants, such as volatile organic compounds (VOCs) or hazardous gases, and biological pathogens, both airborne and on surfaces. This is the first chemical kinetic study of such a purifier that creates gas-phase OH by ultraviolet light photolysis of H2O. It shows that the amount of hydroxyls produced agrees well with nonparameterized calculations using the purifier lamp output and device airflow. These results can be used for designing appropriate remediation strategies.
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Affiliation(s)
- David R Crosley
- a Private consultant to HGI Industries (Boynton Beach, Florida) , Palo Alto , CA , USA
| | | | | | - Jacob D McDonald
- c Lovelace Respiratory Research Institute , Albuquerque , NM , USA
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Müller JF, Liu Z, Nguyen VS, Stavrakou T, Harvey JN, Peeters J. The reaction of methyl peroxy and hydroxyl radicals as a major source of atmospheric methanol. Nat Commun 2016; 7:13213. [PMID: 27748363 PMCID: PMC5071643 DOI: 10.1038/ncomms13213] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 09/13/2016] [Indexed: 11/25/2022] Open
Abstract
Methyl peroxy, a key radical in tropospheric chemistry, was recently shown to react with the hydroxyl radical at an unexpectedly high rate. Here, the molecular reaction mechanisms are elucidated using high-level quantum chemical methodologies and statistical rate theory. Formation of activated methylhydrotrioxide, followed by dissociation into methoxy and hydroperoxy radicals, is found to be the main reaction pathway, whereas methylhydrotrioxide stabilization and methanol formation (from activated and stabilized methylhydrotrioxide) are viable minor channels. Criegee intermediate formation is found to be negligible. Given the theoretical uncertainties, useful constraints on the yields are provided by atmospheric methanol measurements. Using a global chemistry-transport model, we show that the only explanation for the high observed methanol abundances over remote oceans is the title reaction with an overall methanol yield of ∼30%, consistent with the theoretical estimates given their uncertainties. This makes the title reaction a major methanol source (115 Tg per year), comparable to global terrestrial emissions.
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Affiliation(s)
- Jean-François Müller
- Atmospheric Composition Department, Royal Belgian Institute for Space Aeronomy, Avenue Circulaire 3, B-1180 Brussels, Belgium
| | - Zhen Liu
- Department of Chemistry, University of Leuven, B-3001 Heverlee, Belgium
- State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Meilong Road 130, Shanghai 200237, China
| | - Vinh Son Nguyen
- Department of Chemistry, University of Leuven, B-3001 Heverlee, Belgium
| | - Trissevgeni Stavrakou
- Atmospheric Composition Department, Royal Belgian Institute for Space Aeronomy, Avenue Circulaire 3, B-1180 Brussels, Belgium
| | - Jeremy N. Harvey
- Department of Chemistry, University of Leuven, B-3001 Heverlee, Belgium
| | - Jozef Peeters
- Department of Chemistry, University of Leuven, B-3001 Heverlee, Belgium
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48
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Yang L, Zhang J. The potential energy surface of OH anion reaction with CH3OOH: Theoretical investigations. COMPUT THEOR CHEM 2016. [DOI: 10.1016/j.comptc.2016.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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49
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Yang L, Zhang J. The non-IRC mechanism of OH anion reaction with CH3OOH revealed by direct dynamics simulations. COMPUT THEOR CHEM 2016. [DOI: 10.1016/j.comptc.2016.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Li Y, Wang N, Wang C, Wang X, Zhang J, Wang L. Theoretical study on the unimolecular decomposition of 2-chlorinated ethyl hydroperoxide. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2016. [DOI: 10.1142/s0219633616500085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Chlorine-containing organic compounds have been of major interest since such compounds would serve as temporary reservoirs for HOX, ROX and ClOX radicals. Moreover, it would transport chlorine species to the atmosphere and stratosphere. However, limited studies have been performed on the 2-chlorinated ethyl hydroperoxide. In this work, the mechanism of unimolecular dissociation of 2-chlorinated ethyl hydroperoxide is theoretically studied. The equilibrium structures are optimized at the Boese–Martin for kinetics (BMK) level. And the energies are further refined at the Balanced multi-coefficient correlation-coupled cluster theory with single and double excitations (BMC-CCSD) level on the basis of the optimized geometries. Fifteen reaction channels are finally confirmed including the direct C–O, O–O, O–H, and C–C bond cleavage or the H2-, H2O-, H2O2-, and CH3Cl-elimination.
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Affiliation(s)
- Ya Li
- Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
| | - Na Wang
- Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
| | - Chunzhang Wang
- Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
| | - Xin Wang
- Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
| | - Jinglai Zhang
- Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
| | - Li Wang
- Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
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