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Han T, Xie C, Yang Y, Zhang Y, Huang Y, Liu Y, Chen K, Sun H, Zhou J, Liu C, Guo J, Wu Z, Li SM. Spatial mapping of greenhouse gases using a UAV monitoring platform over a megacity in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 951:175428. [PMID: 39128527 DOI: 10.1016/j.scitotenv.2024.175428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 07/15/2024] [Accepted: 08/08/2024] [Indexed: 08/13/2024]
Abstract
Urban environments are recognized as main anthropogenic contributors to greenhouse gas (GHG) emissions, characterized by unevenly distributed emission sources over the urban environments. However, spatial GHG distributions in urban regions are typically obtained through monitoring at only a limited number of locations, or through model studies, which can lead to incomplete insights into the heterogeneity in the spatial distribution of GHGs. To address such information gap and to evaluate the spatial representation of a planned GHG monitoring network, a custom-developed atmospheric sampler was deployed on a UAV platform in this study to map the CO2 and CH4 mixing ratios in the atmosphere over Zhengzhou in central China, a megacity of nearly 13 million people. The aerial survey was conducted along the main roads at an altitude of 150 m above ground, covering a total distance of 170 km from the city center to the suburbs. The spatial distributions of CO2 and CH4 mixing ratios in Zhengzhou exhibited distinct heterogeneities, with average mixing ratios of CO2 and CH4 at 439.2 ± 10.8 ppm and 2.12 ± 0.04 ppm, respectively. A spatial autocorrelation analysis was performed on the measured GHG mixing ratios across the city, revealing a spatial correlation range of approximately 2 km for both CO2 and CH4 in the urban area. Such a spatial autocorrelation distance suggests that the urban GHG monitoring network designed for emission inversion purposes need to have a spatial resolution of 4 km to characterize the spatial heterogeneities in the GHGs. This UAV-based measurement approach demonstrates its capability to monitor GHG mixing ratios across urban landscapes, providing valuable insights for GHG monitoring network design.
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Affiliation(s)
- Tianran Han
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Conghui Xie
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Yanrong Yang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Yuheng Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Yufei Huang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Yayong Liu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Keyu Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Haijiong Sun
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Jietao Zhou
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Chang Liu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Junfei Guo
- Beijing Wisdominc Technology Co., Ltd., Beijing 100070, PR China
| | - Zhijun Wu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Shao-Meng Li
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
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2
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Zhang L, Shan Y, Yan Z, Liu Z, Yu Y, He H. Efficient Pt/KFI zeolite catalysts for the selective catalytic reduction of NO x by hydrogen. J Environ Sci (China) 2024; 138:102-111. [PMID: 38135379 DOI: 10.1016/j.jes.2023.03.004] [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: 01/19/2023] [Revised: 03/02/2023] [Accepted: 03/02/2023] [Indexed: 12/24/2023]
Abstract
Aiming at purification of NOx from hydrogen internal combustion engines (HICEs), the hydrogen selective catalytic reduction (H2-SCR) reaction was investigated over a series of Pt/KFI zeolite catalysts. H2 can readily reduce NOx to N2 and N2O while O2 inhibited the deNOx efficiency by consuming the reductant H2. The Pt/KFI zeolite catalysts with Pt loading below 0.1 wt.% are optimized H2-SCR catalysts due to its suitable operation temperature window since high Pt loading favors the H2-O2 reaction which lead to the insufficient of reactants. Compared to metal Pt0 species, Ptδ+ species showed lower activation energy of H2-SCR reaction and thought to be as reasonable active sites. Further, Eley-Rideal (E-R) reaction mechanism was proposed as evidenced by the reaction orders in kinetic studies. Last, the optimized reactor was designed with hybrid Pt/KFI catalysts with various Pt loading which achieve a high NOx conversion in a wide temperature range.
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Affiliation(s)
- Ligang Zhang
- School of Rare Earths, University of Science and Technology of China, Hefei 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China
| | - Yulong Shan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Zidi Yan
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China
| | - Zhongqi Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yunbo Yu
- School of Rare Earths, University of Science and Technology of China, Hefei 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Hong He
- School of Rare Earths, University of Science and Technology of China, Hefei 230026, China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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3
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Vogel F, Ars S, Wunch D, Lavoie J, Gillespie L, Maazallahi H, Röckmann T, Nęcki J, Bartyzel J, Jagoda P, Lowry D, France J, Fernandez J, Bakkaloglu S, Fisher R, Lanoiselle M, Chen H, Oudshoorn M, Yver-Kwok C, Defratyka S, Morgui JA, Estruch C, Curcoll R, Grossi C, Chen J, Dietrich F, Forstmaier A, Denier van der Gon HAC, Dellaert SNC, Salo J, Corbu M, Iancu SS, Tudor AS, Scarlat AI, Calcan A. Ground-Based Mobile Measurements to Track Urban Methane Emissions from Natural Gas in 12 Cities across Eight Countries. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:2271-2281. [PMID: 38270974 PMCID: PMC10851421 DOI: 10.1021/acs.est.3c03160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 01/02/2024] [Accepted: 01/03/2024] [Indexed: 01/26/2024]
Abstract
To mitigate methane emission from urban natural gas distribution systems, it is crucial to understand local leak rates and occurrence rates. To explore urban methane emissions in cities outside the U.S., where significant emissions were found previously, mobile measurements were performed in 12 cities across eight countries. The surveyed cities range from medium size, like Groningen, NL, to large size, like Toronto, CA, and London, UK. Furthermore, this survey spanned across European regions from Barcelona, ES, to Bucharest, RO. The joint analysis of all data allows us to focus on general emission behavior for cities with different infrastructure and environmental conditions. We find that all cities have a spectrum of small, medium, and large methane sources in their domain. The emission rates found follow a heavy-tailed distribution, and the top 10% of emitters account for 60-80% of total emissions, which implies that strategic repair planning could help reduce emissions quickly. Furthermore, we compare our findings with inventory estimates for urban natural gas-related methane emissions from this sector in Europe. While cities with larger reported emissions were found to generally also have larger observed emissions, we find clear discrepancies between observation-based and inventory-based emission estimates for our 12 cities.
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Affiliation(s)
- F. Vogel
- Climate
Research Division, Environment and Climate
Change Canada, Toronto M3H 5T4, Canada
| | - S. Ars
- Climate
Research Division, Environment and Climate
Change Canada, Toronto M3H 5T4, Canada
| | - D. Wunch
- Department
of Physics, University of Toronto, Toronto M5S 1A7, Canada
| | - J. Lavoie
- Department
of Physics, University of Toronto, Toronto M5S 1A7, Canada
| | - L. Gillespie
- Climate
Research Division, Environment and Climate
Change Canada, Toronto M3H 5T4, Canada
- Department
of Physics, University of Toronto, Toronto M5S 1A7, Canada
| | - H. Maazallahi
- Institute
for Marine and Atmospheric Research Utrecht, Utrecht University, Utrecht 3584 CC, The Netherlands
| | - T. Röckmann
- Institute
for Marine and Atmospheric Research Utrecht, Utrecht University, Utrecht 3584 CC, The Netherlands
| | - J. Nęcki
- AGH, University of Kraków, Kraków 30-059, Poland
| | - J. Bartyzel
- AGH, University of Kraków, Kraków 30-059, Poland
| | - P. Jagoda
- AGH, University of Kraków, Kraków 30-059, Poland
| | - D. Lowry
- Department
of Earth Sciences, Royal Holloway University
of London, Egham, Surrey TW20 0EX, U.K.
| | - J. France
- Department
of Earth Sciences, Royal Holloway University
of London, Egham, Surrey TW20 0EX, U.K.
| | - J. Fernandez
- Department
of Earth Sciences, Royal Holloway University
of London, Egham, Surrey TW20 0EX, U.K.
| | - S. Bakkaloglu
- Department
of Earth Sciences, Royal Holloway University
of London, Egham, Surrey TW20 0EX, U.K.
| | - R. Fisher
- Department
of Earth Sciences, Royal Holloway University
of London, Egham, Surrey TW20 0EX, U.K.
| | - M. Lanoiselle
- Department
of Earth Sciences, Royal Holloway University
of London, Egham, Surrey TW20 0EX, U.K.
| | - H. Chen
- Centre for
Isotope Research, Energy and Sustainability Research Institute, University of Groningen, Groningen 9747 AG, Netherlands
| | - M. Oudshoorn
- Centre for
Isotope Research, Energy and Sustainability Research Institute, University of Groningen, Groningen 9747 AG, Netherlands
| | - C. Yver-Kwok
- LSCE,
CEA-CNRS-UVSQ, University Paris-Saclay, Gif-sur-Yvette 91191, France
| | - S. Defratyka
- LSCE,
CEA-CNRS-UVSQ, University Paris-Saclay, Gif-sur-Yvette 91191, France
| | - J. A. Morgui
- ICTA, Autonomous University of Barcelona, Barcelona 08193, Spain
| | - C. Estruch
- Eurecat, Centre
Tecnològic de Catalunya, Barcelona 08290, Spain
| | - R. Curcoll
- ICTA, Autonomous University of Barcelona, Barcelona 08193, Spain
- INTE, Universitat
Politècnica de Catalunya, Barcelona 08028, Spain
| | - C. Grossi
- INTE, Universitat
Politècnica de Catalunya, Barcelona 08028, Spain
| | - J. Chen
- Environmental Sensing and Modelling, Technical
University of Munich, Munich 80333, Germany
| | - F. Dietrich
- Environmental Sensing and Modelling, Technical
University of Munich, Munich 80333, Germany
| | - A. Forstmaier
- Environmental Sensing and Modelling, Technical
University of Munich, Munich 80333, Germany
| | | | - S. N. C. Dellaert
- Netherlands Organisation for Applied Scientific Research—TNO, Utrecht 3584CB, The Netherlands
| | - J. Salo
- Geography and
GIS, University of Northern
Colorado, Greeley, Colorado 80639, United States
| | - M. Corbu
- Faculty
of Physics, University of Bucharest, Bucharest 050663, Romania
- INCAS, National Institute for Aerospace
Research “Elie Carafoli”, Bucharest 061126, Romania
| | - S. S. Iancu
- Faculty
of Physics, University of Bucharest, Bucharest 050663, Romania
- INCAS, National Institute for Aerospace
Research “Elie Carafoli”, Bucharest 061126, Romania
| | - A. S. Tudor
- Faculty
of Physics, University of Bucharest, Bucharest 050663, Romania
- INCAS, National Institute for Aerospace
Research “Elie Carafoli”, Bucharest 061126, Romania
| | - A. I. Scarlat
- Faculty
of Physics, University of Bucharest, Bucharest 050663, Romania
- INCAS, National Institute for Aerospace
Research “Elie Carafoli”, Bucharest 061126, Romania
| | - A. Calcan
- INCAS, National Institute for Aerospace
Research “Elie Carafoli”, Bucharest 061126, Romania
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4
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Fung PL, Al-Jaghbeer O, Pirjola L, Aaltonen H, Järvi L. Exploring the discrepancy between top-down and bottom-up approaches of fine spatio-temporal vehicular CO 2 emission in an urban road network. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 901:165827. [PMID: 37517739 DOI: 10.1016/j.scitotenv.2023.165827] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 07/23/2023] [Accepted: 07/25/2023] [Indexed: 08/01/2023]
Abstract
Road transport emissions of high spatial and temporal resolution are useful for greenhouse gas emission assessment in local action plans. However, estimating these high-resolution emissions is not straightforward, and different indirect approaches exist. The main aim of this study is to examine the differences in CO2 emissions obtained with different methods within a street canyon network in Helsinki, Finland, where a mobile laboratory campaign to quantify traffic emissions has been conducted. We compared three aerodynamic resistance based top-down methods (MOST1, MOST2 and BHT) and three activity based bottom-up microscopic emission models (NGM, HBEFAv4.2 and PHEMlight). The resulted CO2 fluxes using different methods could vary a few orders of magnitude. The combination of MOST1 and NGM model leads to the smallest discrepancy (sMAPE = 16.90 %) and the highest correlation coefficient (r = 0.78) among the rest. We evaluated the discrepancies in terms of different spatial (microenvrionments, local climate zones LCZs and grid sizes) and temporal features (seasons and periods of day). Measurements taken in LCZs of open high-rise regions and microenvironments of main road tend to have larger discrepancies between the two approaches. Using a coarser grid would lead to a relatively small discrepancy and high correlation in the wintertime, yet a loss in distinctive spatial variation. The discrepancies were also elevated on winter evenings. Among all explanatory variables, relative humidity shows the strongest relative importance for the discrepancy of the two approaches, followed by LCZs. Therefore, we stress the importance of choosing a suitable model for vehicular CO2 emission calculation based on meteorological conditions and LCZs. Such model comparison made on a local scale directly supports environmental organisations and cities' climate action plans where detailed information of CO2 emissions are needed.
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Affiliation(s)
- Pak Lun Fung
- Institute for Atmospheric and Earth System Research (INAR)/Physics, Faculty of Science, University of Helsinki, P.O. Box 64, Helsinki 00014, Finland; Helsinki Institute of Sustainability Science (HELSUS), Finland.
| | - Omar Al-Jaghbeer
- Institute for Atmospheric and Earth System Research (INAR)/Physics, Faculty of Science, University of Helsinki, P.O. Box 64, Helsinki 00014, Finland
| | - Liisa Pirjola
- Institute for Atmospheric and Earth System Research (INAR)/Physics, Faculty of Science, University of Helsinki, P.O. Box 64, Helsinki 00014, Finland; Department of Automotive and Mechanical Engineering, Metropolia Applied University, P.O. Box 4071, Vantaa 01600, Finland
| | - Hermanni Aaltonen
- Finnish Meteorological Institute, P.O. Box 503, Helsinki 00101, Finland
| | - Leena Järvi
- Institute for Atmospheric and Earth System Research (INAR)/Physics, Faculty of Science, University of Helsinki, P.O. Box 64, Helsinki 00014, Finland; Helsinki Institute of Sustainability Science (HELSUS), Finland
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5
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Jiang H, Han Y, Zalhaf AS, Yang P, Wang C. Low-cost urban carbon monitoring network and implications for china: a comprehensive review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:105012-105029. [PMID: 37726626 DOI: 10.1007/s11356-023-29836-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 09/07/2023] [Indexed: 09/21/2023]
Abstract
The development and renewal of gas sensor technology have enabled more and more low-cost gas sensors to form a carbon monitoring network to meet the requirements of the city. In the context of China's commitment to achieving the "double carbon" target by 2060, this paper reviews the principles of four standard gas sensors and the application of several low-cost sensors in urban carbon monitoring networks, with the aim of providing a practical reference for the future deployment of carbon monitoring networks in Chinese cities. Moreover, the types, prices, and deployment of the sensors used in each project are summarized. Based on this review, non-dispersive infrared sensors have the best performance among the sensors and are commonly used in many cities. Lots of urban climate networks in cities were summarized by many reviews in the literature, but only a few sensors were studied, and they did not consider carbon dioxide (CO2) sensors. This review focuses on the dense CO2 urban monitoring network, and some case studies are also discussed, such as Seoul and San Francisco. To address the issue of how to better ensure the balance between cost and accuracy in the deployment of sensor networks, this paper proposes a method of simultaneously deploying medium-precision and high-precision fixed sensors and mobile sensors to form an urban carbon monitoring network. Finally, the prospects and recommendations, such as different ways to mitigate CO2 and develop an entire carbon monitoring system for future urban carbon monitoring in China, are also presented.
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Affiliation(s)
- Hongzhi Jiang
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
| | - Yang Han
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China.
| | - Amr S Zalhaf
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
- Electrical Power and Machines Engineering Department, Faculty of Engineering, Tanta University, Tanta, 31511, Egypt
| | - Ping Yang
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
| | - Congling Wang
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
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6
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Park C, Jeong S, Kim C, Shin J, Joo J. Machine learning based estimation of urban on-road CO 2 concentration in Seoul. ENVIRONMENTAL RESEARCH 2023; 231:116256. [PMID: 37245580 DOI: 10.1016/j.envres.2023.116256] [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: 03/26/2023] [Revised: 05/15/2023] [Accepted: 05/26/2023] [Indexed: 05/30/2023]
Abstract
The urban on-road CO2 emissions will continue to increase, it is therefore essential to manage urban on-road CO2 concentrations for effective urban CO2 mitigation. However, limited observations of on-road CO2 concentrations prevents a full understanding of its variation. Therefore, in this study, a machine learning-based model that predicts on-road CO2 concentration (CO2traffic) was developed for Seoul, South Korea. This model predicts hourly CO2traffic with high precision (R2 = 0.8 and RMSE = 22.9 ppm) by utilizing CO2 observations, traffic volume, traffic speed, and wind speed as the main factors. High spatiotemporal inhomogeneity of hourly CO2traffic over Seoul, with 14.3 ppm by time-of-day and 345.1 ppm by road, was apparent in the CO2traffic data predicted by the model. The large spatiotemporal variability of CO2traffic was related to different road types (major arterial roads, minor arterial roads, and urban highways) and land-use types (residential, commercial, bare ground, and urban vegetation). The cause of the increase in CO2traffic differed by road type, and the diurnal variation of CO2traffic differed according to land-use type. Our results demonstrate that high spatiotemporal on-road CO2 monitoring is required to manage urban on-road CO2 concentrations with high variability. In addition, this study demonstrated that a model using machine learning techniques can be an alternative for monitoring CO2 concentrations on all roads without conducting observations. Applying the machine learning techniques developed in this study to cities around the world with limited observation infrastructure will enable effective urban on-road CO2 emissions management.
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Affiliation(s)
- Chaerin Park
- Department of Environmental Planning, Graduate School of Environmental Studies, Seoul National University, Seoul, South Korea
| | - Sujong Jeong
- Department of Environmental Planning, Graduate School of Environmental Studies, Seoul National University, Seoul, South Korea; Environmental Planning Institute, Seoul National University, Seoul, South Korea.
| | - Chongmin Kim
- Department of Environmental Planning, Graduate School of Environmental Studies, Seoul National University, Seoul, South Korea
| | - Jaewon Shin
- Environmental Planning Institute, Seoul National University, Seoul, South Korea
| | - Jaewon Joo
- Environmental Planning Institute, Seoul National University, Seoul, South Korea
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7
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Liu X, Huang J, Wang L, Lian X, Li C, Ding L, Wei Y, Chen S, Wang Y, Li S, Shi J. "Urban Respiration" Revealed by Atmospheric O 2 Measurements in an Industrial Metropolis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:2286-2296. [PMID: 36657022 DOI: 10.1021/acs.est.2c07583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Urban regions, which "inhale" O2 from the air and "exhale" CO2 and atmospheric pollutants, including harmful gases and fine particles, are the largest sinks of atmospheric O2, yet long-term O2 measurements in urban regions are currently lacking. In this study, we report continuous measurements of atmospheric O2 in downtown Lanzhou, an industrial metropolis in northwestern China. We found declines in atmospheric O2 associated with deteriorated air quality and robust anticorrelations between O2 and gaseous oxides. By combining O2 and pollutants measurements with a Lagrangian atmospheric transport model, we quantitatively break down "urban respiration" (ΔO2URB) into human respiration (ΔO2RES) and fossil fuel combustion (ΔO2FF). We found increased ΔO2FF contribution (from 66.92% to 72.50%) and decreased ΔO2RES contribution (from 33.08 to 27.50%) as O2 declines and pollutants accumulate. Further attribution of ΔO2FF reveals intracity transport of atmospheric pollutants from industrial sectors and suggests transportation sectors as the major O2 sink in downtown Lanzhou. The varying relationships between O2 and pollutants under different conditions unfold the dynamics of urban respiration and provide insights into the O2 and energy consumption, pollutant emission, and intracity atmospheric transport processes.
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Affiliation(s)
- Xiaoyue Liu
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou730000, China
| | - Jianping Huang
- Collaborative Innovation Center for Western Ecological Safety, Lanzhou University, Lanzhou730000, China
- Land-atmosphere Interaction and Its Climatic Effects Group, State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, CAS, Beijing100101, China
| | - Li Wang
- Collaborative Innovation Center for Western Ecological Safety, Lanzhou University, Lanzhou730000, China
| | - Xinbo Lian
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou730000, China
| | - Changyu Li
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou730000, China
| | - Lei Ding
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou730000, China
| | - Yun Wei
- Department of Atmospheric Science, School of Environmental Studies, China University of Geosciences, Wuhan430074, China
| | - Siyu Chen
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou730000, China
| | - Yongqi Wang
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou730000, China
| | - Shixue Li
- Graduate School of Environmental Science, Hokkaido University, Sapporo060-0810, Japan
| | - Jinsen Shi
- Collaborative Innovation Center for Western Ecological Safety, Lanzhou University, Lanzhou730000, China
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Flame-Made La 2O 3-Based Nanocomposite CO 2 Sensors as Perspective Part of GHG Monitoring System. SENSORS 2021; 21:s21217297. [PMID: 34770604 PMCID: PMC8587462 DOI: 10.3390/s21217297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 10/28/2021] [Accepted: 10/30/2021] [Indexed: 12/17/2022]
Abstract
Continuous monitoring of greenhouse gases with high spatio-temporal resolution has lately become an urgent task because of tightening environmental restrictions. It may be addressed with an economically efficient solution, based on semiconductor metal oxide gas sensors. In the present work, CO2 detection in the relevant concentration range and ambient conditions was successfully effectuated by fine-particulate La2O3-based materials. Flame spray pyrolysis technique was used for the synthesis of sensitive materials, which were studied with X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) and low temperature nitrogen adsorption coupled with Brunauer–Emmett–Teller (BET) effective surface area calculation methodology. The obtained materials represent a composite of lanthanum oxide, hydroxide and carbonate phases. The positive correlation has been established between the carbonate content in the as prepared materials and their sensor response towards CO2. Small dimensional planar MEMS micro-hotplates with low energy consumption were used for gas sensor fabrication through inkjet printing. The sensors showed highly selective CO2 detection in the range of 200–6667 ppm in humid air compared with pollutant gases (H2 50 ppm, CH4 100 ppm, NO2 1 ppm, NO 1 ppm, NH3 20 ppm, H2S 1 ppm, SO2 1 ppm), typical for the atmospheric air of urbanized and industrial area.
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Herrera SA, Diskin GS, Harward C, Sachse G, De Wekker SFJ, Yang M, Choi Y, Wisthaler A, Mallia DV, Pusede SE. Wintertime Nitrous Oxide Emissions in the San Joaquin Valley of California Estimated from Aircraft Observations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:4462-4473. [PMID: 33759511 DOI: 10.1021/acs.est.0c08418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Nitrous oxide (N2O) is a long-lived greenhouse gas that also destroys stratospheric ozone. N2O emissions are uncertain and characterized by high spatiotemporal variability, making individual observations difficult to upscale, especially in mixed land use source regions like the San Joaquin Valley (SJV) of California. Here, we calculate spatially integrated N2O emission rates using nocturnal and convective boundary-layer budgeting methods. We utilize vertical profile measurements from the NASA DISCOVER-AQ (Deriving Information on Surface Conditions from COlumn and VERtically Resolved Observations Relevant to Air Quality) campaign, which took place January-February, 2013. For empirical constraints on N2O source identity, we analyze N2O enhancement ratios with methane, ammonia, carbon dioxide, and carbon monoxide separately in the nocturnal boundary layer, nocturnal residual layer, and convective boundary layer. We find that an established inventory (EDGAR v4.3.2) underestimates N2O emissions by at least a factor of 2.5, that wintertime emissions from animal agriculture are important to annual totals, and that there is evidence for higher N2O emissions during the daytime than at night.
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Affiliation(s)
- Solianna A Herrera
- Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Glenn S Diskin
- NASA Langley Research Center, Hampton, Virginia 23681, United States
| | - Charles Harward
- NASA Langley Research Center, Hampton, Virginia 23681, United States
| | - Glen Sachse
- NASA Langley Research Center, Hampton, Virginia 23681, United States
| | - Stephan F J De Wekker
- Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Melissa Yang
- National Suborbital Research Center, Grand Forks, North Dakota 58202, United States
| | - Yonghoon Choi
- NASA Langley Research Center, Hampton, Virginia 23681, United States
| | - Armin Wisthaler
- Institute for Ion Physics and Applied Physics, University of Innsbruck, Innsbruck 6020, Austria
- Department of Chemistry, University of Oslo, Oslo 0315, Norway
| | - Derek V Mallia
- Department of Atmospheric Sciences, University of Utah, Salt Lake City, Utah 84054, United States
| | - Sally E Pusede
- Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia 22904, United States
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