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Shen W, Wang M, Dong X. Enhanced Aging of Black Carbon under Recent Clean Air Actions and Future Carbon Neutrality Scenario in China. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 39026181 DOI: 10.1021/acs.est.4c02030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
China has implemented strict emission control measures, but it is unclear how they affect black carbon (BC) aging and light absorption. Here, we use the Community Atmosphere Model version 6 (CAM6) with the four-mode version of the Modal Aerosol Module coupled with machine learning (MAM4-ML) to simulate BC aging during 2011-2018 and 2050/2100 following a carbon neutrality scenario (SSP1-2.6), respectively. During 2011-2018, the mass ratio of coatings to BC (RBC) widely increased (5.4% yr-1) over the east of China. The increased secondary organic aerosol (SOA) coatings dominate (88%) the increased RBC, while the sulfate coatings decrease. The drivers of BC coating changes come from the different magnitudes of emission reductions in secondary aerosol precursors (i.e., volatile organic compounds (VOCs) and SO2) and BC. During 2011-2018, the increased RBC enhances the BC mass absorption cross section (MAC, 0.7% yr-1). In 2050/2100 for SSP1-2.6, emission control leads to further increased RBC (95/145%) and BC MAC (12/17%). For both 2011-2018 and 2050/2100, the enhanced BC MAC partly offsets the declining direct radiative effect (DRE) of BC due to direct emission reduction. As a result, the full impact of direct emission reductions of BC on BC DRE is only 75% for 2011-2018 and 90/94% for 2050/2100.
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Affiliation(s)
- Wenxiang Shen
- School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China
- Joint International Research Laboratory of Atmospheric and Earth System Sciences and Institute for Climate and Global Change Research, Nanjing University, Nanjing 210023, China
| | - Minghuai Wang
- School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China
- Joint International Research Laboratory of Atmospheric and Earth System Sciences and Institute for Climate and Global Change Research, Nanjing University, Nanjing 210023, China
| | - Xinyi Dong
- School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China
- Joint International Research Laboratory of Atmospheric and Earth System Sciences and Institute for Climate and Global Change Research, Nanjing University, Nanjing 210023, China
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2
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Pipal AS, Kaur P, Singh SP, Rohra H, Taneja A. Morphology, aspect ratio, and surface elemental composition of primary aerosol particles at urban region of India. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024:10.1007/s11356-024-34372-w. [PMID: 39014140 DOI: 10.1007/s11356-024-34372-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Accepted: 07/09/2024] [Indexed: 07/18/2024]
Abstract
The PM2.5 and PM10 particles were characterized in terms of morphology (size and shape) and surface elemental composition at two different (traffic and industrial) locations in urban region of India and further linked to different morphological defining parameters. The overall PM2.5 and PM10 showed significant daily variability indicating higher PM10 as compared to PM2.5. PM2.5/PM10 ratio was found to be 0.58 ± 0.10 indicating the abundance of PM2.5. Soot aggregates, aluminosilicates, and brochosomes particles were classified based on morphology, aspect ratio (AR), and surface elemental composition of single particles. The linear regression analysis indicates the significant correlation between area equivalent (Daeq) and feret diameter (Dfd) (R2 0.86-0.98). Higher aspect ratio (1.48 ± 0.87-1.43 ± 0.50) was noted at traffic site as compared to industrial site (1.33 ± 0.58-1.29 ± 0.30), while circularity showed the opposite trend. Fractal dimension (Df) of soot aggregates estimated by the soot parameters method (SPM) were found to be 1.70, 1.72, and 1.88, mainly attributed to vehicular emissions, biomass, and industrial emission/coal burning, respectively. This further inferred that freshly emitted soot particles exhibited lacey in nature with spherical shape (Df 1.70) at traffic site, while at industrial location, they were different with compact shapes (Df 1.88) due to particle aging processes. This study inferred the synoptic changes in mass, chemical characteristics, and morphology of aerosol particles which provide the new insights into individual atmospheric particle and their dynamic nature.
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Affiliation(s)
- Atar Singh Pipal
- Department of Chemistry, Dr. B R Ambedkar University, Agra, 282002, India
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, 411008, India
| | - Parminder Kaur
- Department of Physics, Tripura University, Suryamaninagar, West Tripura, 799022, India
| | | | - Himanshi Rohra
- Department of Chemistry, Savitribai Phule Pune University, Pune, 411007, India
| | - Ajay Taneja
- Department of Chemistry, Dr. B R Ambedkar University, Agra, 282002, India.
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3
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Chen L, Cui B, Zhang C, Hu X, Wang Y, Li G, Chang L, Liu L. Impacts of Fuel Stage Ratio on the Morphological and Nanostructural Characteristics of Soot Emissions from a Twin Annular Premixing Swirler Combustor. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:10558-10566. [PMID: 38833713 DOI: 10.1021/acs.est.4c03478] [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: 06/06/2024]
Abstract
Soot particles emitted from aircraft engines constitute a major anthropogenic source of pollution in the vicinity of airports and at cruising altitudes. This emission poses a significant threat to human health and may alter the global climate. Understanding the characteristics of soot particles, particularly those generated from Twin Annular Premixing Swirler (TAPS) combustors, a mainstream combustor in civil aviation engines, is crucial for aviation environmental protection. In this study, a comprehensive characterization of soot particles emitted from TAPS combustors was conducted using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. The morphology and nanostructure of soot particles were examined across three distinct fuel stage ratios (FSR), at 10%, 15%, and 20%. The SEM analysis of soot particle morphology revealed that coated particles constitute over 90% of the total particle sample, with coating content increasing proportionally to the fuel stage ratio. The results obtained from HRTEM indicated that average primary particle sizes increase with the fuel stage ratio. The results of HRTEM and Raman spectroscopy suggest that the nanostructure of soot particles becomes more ordered and graphitized with an increasing fuel stage ratio, resulting in lower oxidation activity. Specifically, soot fringe length increased with the fuel stage ratio, while soot fringe tortuosity and separation distance decreased. In addition, there is a prevalent occurrence of defects in the graphitic lattice structure of soot particles, suggesting a high degree of elemental carbon disorder.
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Affiliation(s)
- Longfei Chen
- School of Energy and Power Engineering, Beihang University, Beijing 100191, China
| | - Boxuan Cui
- School of Energy and Power Engineering, Beihang University, Beijing 100191, China
| | - Chenglin Zhang
- Hangzhou International Innovation Institute, Beihang University, 166 Shuanghongqiao Street, Pingyao Town, Yuhang District, Hangzhou 311115, China
| | - Xuehuan Hu
- School of Energy and Power Engineering, Beihang University, Beijing 100191, China
| | - Yingying Wang
- School of Energy and Power Engineering, Beihang University, Beijing 100191, China
| | - Guangze Li
- School of Energy and Power Engineering, Beihang University, Beijing 100191, China
- Hangzhou International Innovation Institute, Beihang University, 166 Shuanghongqiao Street, Pingyao Town, Yuhang District, Hangzhou 311115, China
| | - Liuyong Chang
- School of Energy and Power Engineering, Beihang University, Beijing 100191, China
- Hangzhou International Innovation Institute, Beihang University, 166 Shuanghongqiao Street, Pingyao Town, Yuhang District, Hangzhou 311115, China
| | - Lei Liu
- Hangzhou International Innovation Institute, Beihang University, 166 Shuanghongqiao Street, Pingyao Town, Yuhang District, Hangzhou 311115, China
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4
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Kong Y, Zhi G, Jin W, Zhang Y, Shen Y, Li Z, Sun J, Ren Y. A review of quantification methods for light absorption enhancement of black carbon aerosol. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 924:171539. [PMID: 38462012 DOI: 10.1016/j.scitotenv.2024.171539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 02/28/2024] [Accepted: 03/04/2024] [Indexed: 03/12/2024]
Abstract
Black carbon (BC) is a distinct type of carbonaceous aerosol that has a significant impact on the environment, human health, and climate. A non-BC material coating on BC can alter the mixing state of the BC particles, which considerably enhances the mass absorption efficiency of BC by directing more energy toward the BC cores (lensing effect). A lot of methods have been reported for quantifying the enhancement factor (Eabs), with diverse results. However, to the best of our knowledge, a comprehensive review specific to the quantification methods for Eabs has not been systematically performed, which is unfavorable for the evaluation of obtained results and subsequent radiative forcing. In this review, quantification methods are divided into two broad categories, direct and indirect, depending on whether experimental removal of the coating layer from an aged carbonaceous particle is required. The direct methods described include thermal peeling, solvent dissolution, and optical virtual exfoliation, while the indirect methods include intercept-linear regression fitting, minimum R squared, numerical simulation, and empirical value. We summarized the principles, procedures, virtues, and limitations of the major Eabs quantification methods and analyzed the current problems in the determination of Eabs. We pointed out what breakthroughs are needed to improve or innovate Eabs quantification methods, particularly regarding the need to avoid the influence of brown carbon, develop a broadband Eabs quantification scheme, quantify the Eabs values for the emissions of low-efficiency combustions, measure the Eabs of particles in a high-humidity environment, design a real-time monitor of Eabs by a proper combination of mature techniques, and make more use of artificial intelligence for better Eabs quantification. This review deepens the understanding of Eabs quantification methods and benefits the estimation of the contribution of BC to radiative forcing using climate models.
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Affiliation(s)
- Yao Kong
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Atmospheric Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Guorui Zhi
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Atmospheric Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Wenjing Jin
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Atmospheric Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Yuzhe Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Atmospheric Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Yi Shen
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Atmospheric Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Zhengying Li
- Beijing Municipal Ecological and Environmental Monitoring Center, Beijing 100048, China
| | - Jianzhong Sun
- School of Physical Education, Chizhou University, Chizhou, Anhui 247000, China
| | - Yanjun Ren
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Atmospheric Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
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Yin J, Xie X, Wei X, Zhang H, Ying Q, Hu J. Source-specified atmospheric age distribution of black carbon and its impact on optical properties over the Yangtze River Delta. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171353. [PMID: 38432390 DOI: 10.1016/j.scitotenv.2024.171353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 02/27/2024] [Accepted: 02/27/2024] [Indexed: 03/05/2024]
Abstract
Black carbon (BC) exerts a profound and intricate impact on both air quality and climate due to its high light absorption. However, the uncertainty in representing the absorption enhancement of BC in climate models leads to an increased range in the modeled aerosol climate effects. Changes in BC optical properties could result either from atmospheric aging processes or from variations in its sources. In this study, a source-age model for identifying emission sources and aging states presented by University of California at Davis/California Institute of Technology (UCD/CIT) was used to simulate the atmospheric age distribution of BC from different sources and to quantify its impact on the optical properties of BC-containing particles. The results indicate that regions with greater aged BC concentrations do not correspond to regions with higher BC emissions due to atmospheric transport. High concentrations of aged BC are found in northern Yangtze River Delta (YRD) regions during summer. The chemical compositions of particles from different sources and with different atmospheric ages differ significantly. BC and primary organic aerosols (POA) are dominating in Traffic-dominated source while other components dominate in Industry-dominated source. As the atmospheric age increases, the mass fraction of secondary inorganic aerosols rises. Compared to the original model, the simulated mass absorption cross section of BC particles in the source-age model decreases while the single scattering albedo increases. This compensates for ~11 % of the overestimation of the simulated BC direct radiative forcing. Our study highlights that incorporating atmospheric age and source information into models can greatly improve the estimation of optical properties of BC-containing particles and deepen our understanding of their climate effects.
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Affiliation(s)
- Junjie Yin
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Xiaodong Xie
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
| | - Xiaodong Wei
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Hongliang Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Qi Ying
- Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Jianlin Hu
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science & Technology, Nanjing 210044, China
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Cheng Z, Morgenstern M, Henning S, Zhang B, Roberts GC, Fraund M, Marcus MA, Lata NN, Fialho P, Mazzoleni L, Wehner B, Mazzoleni C, China S. Cloud condensation nuclei activity of internally mixed particle populations at a remote marine free troposphere site in the North Atlantic Ocean. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166865. [PMID: 37690758 DOI: 10.1016/j.scitotenv.2023.166865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/31/2023] [Accepted: 09/01/2023] [Indexed: 09/12/2023]
Abstract
This study reports results from research conducted at the Observatory of Mount Pico (OMP), 2225 m above mean sea level on Pico Island in the Azores archipelago in June and July 2017. We investigated the chemical composition, mixing state, and cloud condensation nuclei (CCN) activities of long-range transported free tropospheric (FT) particles. FLEXible PARTicle Lagrangian particle dispersion model (FLEXPART) simulations reveal that most air masses that arrived at the OMP during the sampling period originated in North America and were highly aged (average plume age > 10 days). We probed size-resolved chemical composition, mixing state, and hygroscopicity parameter (κ) of individual particles using computer-controlled scanning electron microscopy with an energy-dispersive X-ray spectrometer (CCSEM-EDX). Based on the estimated individual particle mass from elemental composition, we calculated the mixing state index, χ. During our study, FT particle populations were internally mixed (χ of samples are between 53 % and 87 %), owing to the long atmospheric aging time. We used data from a miniature Cloud Condensation Nucleus Counter (miniCCNC) to derive the hygroscopicity parameter, κCCNC. Combining κCCNC and FLEXPART, we found that air masses recirculated above the North Atlantic Ocean with lower mean altitude had higher κCCNC due to the higher contribution of sea salt particles. We used CCSEM-EDX and phase state measurements to predict single-particle κ (κCCSEM-EDX) values, which overlap with the lower range of κCCNC measured below 0.15 % SS. Therefore, CCSEM-EDX measurements can be useful in predicting the lower bound of κ, which can be used in climate models to predict CCN activities, especially in remote locations where online CCN measurements are unavailable.
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Affiliation(s)
- Zezhen Cheng
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory (PNNL), Richland, WA 99352, USA
| | - Megan Morgenstern
- Atmospheric Sciences Program, Michigan Technological University, Houghton, MI 49921, USA
| | - Silvia Henning
- Leibniz Institute for Tropospheric Research, Permoserstraße 15, 04318 Leipzig, Germany
| | - Bo Zhang
- National Institute of Aerospace, Hampton, VA 23666, USA
| | - Gregory C Roberts
- Centre National de Recherches Météorologiques, Université de Toulouse, Météo-France, CNRS, Toulouse 31400, France; Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA
| | | | - Matthew A Marcus
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Nurun Nahar Lata
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory (PNNL), Richland, WA 99352, USA
| | - Paulo Fialho
- Institute of Volcanology and Risk Assessment - IVAR, Rua da Mãe de Deus, 9500-321 Ponta Delgada, Portugal
| | - Lynn Mazzoleni
- Atmospheric Sciences Program, Michigan Technological University, Houghton, MI 49921, USA
| | - Birgit Wehner
- Leibniz Institute for Tropospheric Research, Permoserstraße 15, 04318 Leipzig, Germany
| | - Claudio Mazzoleni
- Atmospheric Sciences Program, Michigan Technological University, Houghton, MI 49921, USA
| | - Swarup China
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory (PNNL), Richland, WA 99352, USA.
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7
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Chen X, Ye C, Wang Y, Wu Z, Zhu T, Zhang F, Ding X, Shi Z, Zheng Z, Li W. Quantifying evolution of soot mixing state from transboundary transport of biomass burning emissions. iScience 2023; 26:108125. [PMID: 37876807 PMCID: PMC10590856 DOI: 10.1016/j.isci.2023.108125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 09/14/2023] [Accepted: 09/28/2023] [Indexed: 10/26/2023] Open
Abstract
Incomplete combustion of fossil fuels and biomass burning emit large amounts of soot particles into the troposphere. The condensation process is considered to influence the size (Dp) and mixing state of soot particles, which affects their solar absorption efficiency and lifetimes. However, quantifying aging evolution of soot remains hampered in the real world because of complicated sources and observation technologies. In the Himalayas, we isolated soot sourced from transboundary transport of biomass burning and revealed soot aging mechanisms through microscopic observations. Most of coated soot particles stabilized one soot core under Dp < 400 nm, but 34.8% of them contained multi-soot cores (nsoot ≥ 2) and nsoot increased 3-9 times with increasing Dp. We established the soot mixing models to quantify transformation from condensation- to coagulation-dominant regime at Dp ≈ 400 nm. Studies provide essential references for adopting mixing rules and quantifying the optical absorption of soot in atmospheric models.
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Affiliation(s)
- Xiyao Chen
- Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province, Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
| | - Chunxiang Ye
- College Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Yuanyuan Wang
- Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province, Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
| | - Zhijun Wu
- College Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Tong Zhu
- College Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Fan Zhang
- Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province, Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
| | - Xiaokun Ding
- Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Zongbo Shi
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Zhonghua Zheng
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester M13 9PL, UK
| | - Weijun Li
- Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province, Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
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Mathai S, Veghte D, Kovarik L, Mazzoleni C, Tseng KP, Bucci S, Capek T, Cheng Z, Marinoni A, China S. Optical Properties of Individual Tar Balls in the Free Troposphere. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:16834-16842. [PMID: 37856673 DOI: 10.1021/acs.est.3c03498] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
Tar balls are brown carbonaceous particles that are highly viscous, spherical, amorphous, and light absorbing. They are believed to form in biomass burning smoke plumes during transport in the troposphere. Tar balls are also believed to have a significant impact on the Earth's radiative balance, but due to poorly characterized optical properties, this impact is highly uncertain. Here, we used two nighttime samples to investigate the chemical composition and optical properties of individual tar balls transported in the free troposphere to the Climate Observatory "Ottavio Vittori" on Mt. Cimone, Italy, using multimodal microspectroscopy. In our two samples, tar balls contributed 50% of carbonaceous particles by number. Of those tar balls, 16% were inhomogeneously mixed with other constituents. Using electron energy loss spectroscopy, we retrieved the complex refractive index (RI) for a wavelength range from 200 to 1200 nm for both inhomogeneously and homogeneously mixed tar balls. We found no significant difference in the average RI of inhomogeneously and homogeneously mixed tar balls (1.40-0.03i and 1.36-0.03i at 550 nm, respectively). Furthermore, we estimated the top of the atmosphere radiative forcing using the Santa Barbara DISORT Atmospheric Radiative Transfer model and found that a layer of only tar balls with an optical depth of 0.1 above vegetation would exert a positive radiative forcing ranging from 2.8 W m-2 (on a clear sky day) to 9.5 W m-2 (when clouds are below the aerosol layer). Understanding the optical properties of tar balls can help reduce uncertainties associated with the contribution of biomass-burning aerosol in current climate models.
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Affiliation(s)
- Susan Mathai
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
- Physics Department and Atmospheric Sciences Program, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Daniel Veghte
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
- Center for Electron Microscopy and Analysis, The Ohio State University, Columbus, Ohio 43212, United States
| | - Libor Kovarik
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Claudio Mazzoleni
- Physics Department and Atmospheric Sciences Program, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Kuo-Pin Tseng
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Silvia Bucci
- Institute of Atmospheric Sciences and Climate (ISAC)-National Research Council of Itlay, 40129 Bologna, Italy
- Department of Meteorology and Geophysics, University of Vienna, UZA II, Althanstraße 14, 1090 Vienna, Austria
| | - Tyler Capek
- Physics Department and Atmospheric Sciences Program, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Zezhen Cheng
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Angela Marinoni
- Institute of Atmospheric Sciences and Climate (ISAC)-National Research Council of Itlay, 40129 Bologna, Italy
| | - Swarup China
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
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9
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Peng Y, Cao LM, Wei J, Cheng Y, Yu K, Du K, Huang XF. Key drivers to heterogeneity evolution of black carbon-containing particles in real atmosphere. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 897:166394. [PMID: 37597544 DOI: 10.1016/j.scitotenv.2023.166394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/27/2023] [Accepted: 08/16/2023] [Indexed: 08/21/2023]
Abstract
The evolution of black carbon (BC) particles during atmospheric aging led to the complexity of their environmental and climate effect assessment. This study simultaneously measured the heterogeneous distribution of multi-level microphysical properties of BC-containing particles (i.e., BC mass concentration, coating amounts, and morphology) by a suite of state-of-the-art instruments, and investigated how atmospheric processing influence these heterogeneities. Our field measurements show that the mixing states of atmospheric BC-containing particles exhibit a clear dependence on BC core diameters. The particles with small BC core sizes (80-160 nm) are coated and reshaped more rapidly in real atmosphere, with coating-to-BC mass ratios (MR) and non-spherical fractions of 5.1 ± 1.2 and 61 ± 19 %, respectively. Conversely, the particles with large core sizes (240-320 nm) are thinly coated and fractal, with MR and non-spherical fractions of 4.0 ± 0.3 and 74 ± 15 %, respectively. Furthermore, primary emissions result in low heterogeneity in coating amount but great heterogeneity in morphology between BC-containing particles of different sizes, while photochemical processing would enhance heterogeneity in coating amount but weaken the heterogeneity in morphology. Overall, our field measurement of multi-level microphysical properties highlights that BC core size and atmospheric processing are the key factors that drive the heterogeneity evolution of BC-containing particles in real atmosphere.
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Affiliation(s)
- Yan Peng
- Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Li-Ming Cao
- Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; Environmental Laboratory, PKU-HKUST Shenzhen-Hong Kong Institution, Shenzhen 518057, China
| | - Jing Wei
- Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Yong Cheng
- Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Kuangyou Yu
- Environmental Laboratory, PKU-HKUST Shenzhen-Hong Kong Institution, Shenzhen 518057, China; Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Canada.
| | - Ke Du
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Canada
| | - Xiao-Feng Huang
- Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
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10
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Chakrabarty RK, Shetty NJ, Thind AS, Beeler P, Sumlin BJ, Zhang C, Liu P, Idrobo JC, Adachi K, Wagner NL, Schwarz JP, Ahern A, Sedlacek AJ, Lambe A, Daube C, Lyu M, Liu C, Herndon S, Onasch TB, Mishra R. Shortwave absorption by wildfire smoke dominated by dark brown carbon. NATURE GEOSCIENCE 2023; 16:683-688. [PMID: 37564378 PMCID: PMC10409647 DOI: 10.1038/s41561-023-01237-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 06/26/2023] [Indexed: 08/12/2023]
Abstract
Wildfires emit large amounts of black carbon and light-absorbing organic carbon, known as brown carbon, into the atmosphere. These particles perturb Earth's radiation budget through absorption of incoming shortwave radiation. It is generally thought that brown carbon loses its absorptivity after emission in the atmosphere due to sunlight-driven photochemical bleaching. Consequently, the atmospheric warming effect exerted by brown carbon remains highly variable and poorly represented in climate models compared with that of the relatively nonreactive black carbon. Given that wildfires are predicted to increase globally in the coming decades, it is increasingly important to quantify these radiative impacts. Here we present measurements of ensemble-scale and particle-scale shortwave absorption in smoke plumes from wildfires in the western United States. We find that a type of dark brown carbon contributes three-quarters of the short visible light absorption and half of the long visible light absorption. This strongly absorbing organic aerosol species is water insoluble, resists daytime photobleaching and increases in absorptivity with night-time atmospheric processing. Our findings suggest that parameterizations of brown carbon in climate models need to be revised to improve the estimation of smoke aerosol radiative forcing and associated warming.
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Affiliation(s)
- Rajan K. Chakrabarty
- Center for Aerosol Science and Engineering, Department of Energy, Environmental, and Chemical Engineering, Washington University in St Louis, St Louis, MO USA
| | - Nishit J. Shetty
- Center for Aerosol Science and Engineering, Department of Energy, Environmental, and Chemical Engineering, Washington University in St Louis, St Louis, MO USA
| | - Arashdeep S. Thind
- Institute of Materials Science and Engineering, Washington University in St Louis, St Louis, MO USA
| | - Payton Beeler
- Center for Aerosol Science and Engineering, Department of Energy, Environmental, and Chemical Engineering, Washington University in St Louis, St Louis, MO USA
| | - Benjamin J. Sumlin
- Center for Aerosol Science and Engineering, Department of Energy, Environmental, and Chemical Engineering, Washington University in St Louis, St Louis, MO USA
| | - Chenchong Zhang
- Center for Aerosol Science and Engineering, Department of Energy, Environmental, and Chemical Engineering, Washington University in St Louis, St Louis, MO USA
| | - Pai Liu
- Center for Aerosol Science and Engineering, Department of Energy, Environmental, and Chemical Engineering, Washington University in St Louis, St Louis, MO USA
- Present Address: Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Juan C. Idrobo
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Present Address: Department of Materials Science and Engineering, University of Washington, Seattle, WA USA
| | - Kouji Adachi
- Department of Atmosphere, Ocean and Earth System Modeling Research, Meteorological Research Institute, Tsukuba, Japan
| | - Nicholas L. Wagner
- Chemical Sciences Laboratory, NOAA Earth System Research Laboratories, Boulder, CO USA
- Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO USA
- Present Address: Ball Aerospace, Broomfield, CO USA
| | - Joshua P. Schwarz
- Chemical Sciences Laboratory, NOAA Earth System Research Laboratories, Boulder, CO USA
| | - Adam Ahern
- Chemical Sciences Laboratory, NOAA Earth System Research Laboratories, Boulder, CO USA
- Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO USA
| | - Arthur J. Sedlacek
- Environmental and Climate Sciences, Brookhaven National Laboratory, Upton, NY USA
| | | | | | - Ming Lyu
- Department of Chemistry, University of Alberta, Edmonton, Alberta Canada
| | - Chao Liu
- China Meteorological Administration Aerosol–Cloud–Precipitation Key Laboratory, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing, China
| | | | | | - Rohan Mishra
- Institute of Materials Science and Engineering, Washington University in St Louis, St Louis, MO USA
- Department of Mechanical Engineering and Materials Science, Washington University in St Louis, St Louis, MO USA
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11
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Wei J, Huang XF, Peng Y, Lin XY, Lei ZH, Cao LM, Zhu WF, Guo S, He LY. Evolution characteristic of atmospheric black carbon particles at a coastal site in the Pearl River Delta, China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 324:121380. [PMID: 36863439 DOI: 10.1016/j.envpol.2023.121380] [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: 11/29/2022] [Revised: 02/26/2023] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
The mixing of black carbon (BC) with secondary materials is a major uncertainty source in assessing its radiative forcing. However, current understanding of the formation and evolution of various BC components is limited, particularly in the Pearl River Delta, China. This study measured submicron BC-associated nonrefractory materials and the total submicron nonrefractory materials using a soot particle aerosol mass spectrometer and a high-resolution time-of-flight aerosol mass spectrometer, respectively, at a coastal site in Shenzhen, China. Two distinct atmospheric conditions were also identified to further explore the distinctive evolution of BC-associated components: polluted period (PP) and clean period (CP). Comparing the components of two particles, we found that more-oxidized organic factor (MO-OOA) prefers to form on BC during PP rather CP. The formation of MO-OOA on BC (MO-OOABC) was affected by both enhanced photochemical processes and nocturnal heterogeneous processes. Enhanced photo-reactivity of BC, photochemistry during the daytime, and heterogeneous reaction at nighttime were potential pathways for MO-OOABC formation during PP. The fresh BC surface was favorable for the formation of MO-OOABC. Our study shows the evolution of BC-associated components under different atmospheric conditions, which should be considered in regional climate models to improve the assessment of the climate effects of BC.
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Affiliation(s)
- Jing Wei
- Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Xiao-Feng Huang
- Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.
| | - Yan Peng
- Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Xiao-Yu Lin
- Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Zhen-Hua Lei
- Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Li-Ming Cao
- Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Wen-Fei Zhu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, International Joint Laboratory for Regional Pollution Control, Ministry of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Song Guo
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, International Joint Laboratory for Regional Pollution Control, Ministry of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Ling-Yan He
- Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
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12
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Benavides RAS, Leiro-Vidal JM, Rodriguez-Gonzalez JA, Ares-Pena FJ, López-Martín E. The HL-60 human promyelocytic cell line constitutes an effective in vitro model for evaluating toxicity, oxidative stress and necrosis/apoptosis after exposure to black carbon particles and 2.45 GHz radio frequency. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 867:161475. [PMID: 36632900 DOI: 10.1016/j.scitotenv.2023.161475] [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: 05/12/2022] [Revised: 12/21/2022] [Accepted: 01/04/2023] [Indexed: 06/17/2023]
Abstract
The cellular and molecular mechanisms by which atmospheric pollution from particulate matter and/or electromagnetic fields (EMFs) may prove harmful to human health have not been extensively researched. We analyzed whether the combined action of EMFs and black carbon (BC) particles induced cell damage and a pro-apoptotic response in the HL-60 promyelocytic cell line when exposed to 2.45 GHz radio frequency (RF) radiation in a gigahertz transverse electromagnetic (GTEM) chamber at sub-thermal specific absorption rate (SAR) levels. RF and BC induced moderately significant levels of cell damage in the first 8 or 24 h for all exposure times/doses and much greater damage after 48 h irradiation and the higher dose of BC. We observed a clear antiproliferative effect that increased with RF exposure time and BC dose. Oxidative stress or ROS production increased with time (24 or 48 h of radiation), BC dose and the combination of both. Significant differences between the proportion of damaged and healthy cells were observed in all groups. Both radiation and BC participated separately and jointly in triggering necrosis and apoptosis in a programmed way. Oxidative-antioxidant action activated mitochondrial anti-apoptotic BCL2a gene expression after 24 h irradiation and exposure to BC. After irradiation of the cells for 48 h, expression of FASR cell death receptors was activated, precipitating the onset of pro-apoptotic phenomena and expression and intracellular activity of caspase-3 in the mitochondrial pathways, all of which can lead to cell death. Our results indicate that the interaction between BC and RF modifies the immune response in the human promyelocytic cell line and that these cells had two fates mediated by different pathways: necrosis and mitochondria-caspase dependent apoptosis. The findings may be important in regard to antimicrobial, inflammatory and autoimmune responses in humans.
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Affiliation(s)
- Rosa Ana Sueiro Benavides
- Institute of Research in Biological and Chemical Analysis, IAQBUS, University of Santiago de Compostela, Santiago de Compostela, Spain.
| | - José Manuel Leiro-Vidal
- Institute of Research in Biological and Chemical Analysis, IAQBUS, University of Santiago de Compostela, Santiago de Compostela, Spain.
| | - J Antonio Rodriguez-Gonzalez
- Department of Applied Physics, Santiago de Compostela School of Physics, University of Santiago de Compostela, Santiago de Compostela, Spain.
| | - Francisco J Ares-Pena
- Department of Applied Physics, Santiago de Compostela School of Physics, University of Santiago de Compostela, Santiago de Compostela, Spain.
| | - Elena López-Martín
- Department of Morphological Sciences, Santiago de Compostela School of Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain.
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13
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Werden B, Giordano MR, Mahata K, Islam MR, Goetz JD, Puppala SP, Saikawa E, Panday AK, Yokelson RJ, Stone EA, DeCarlo PF. Submicron Aerosol Composition and Source Contribution across the Kathmandu Valley, Nepal, in Winter. ACS EARTH & SPACE CHEMISTRY 2023; 7:49-68. [PMID: 36704179 PMCID: PMC9869769 DOI: 10.1021/acsearthspacechem.2c00226] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 11/23/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
The Kathmandu valley experiences an average wintertime PM1 concentration of ∼100 μg m-3 and daily peaks over 200 μg m-3. We present ambient nonrefractory PM1 chemical composition, and concentration measured by a mini aerosol mass spectrometer (mAMS) sequentially at Dhulikhel (on the valley exterior), then urban Ratnapark, and finally suburban Lalitpur in winter 2018. At all sites, organic aerosol (OA) was the largest contributor to combined PM1 (C-PM1) (49%) and black carbon (BC) was the second largest contributor (21%). The average background C-PM1 at Dhulikhel was 48 μg m-3; the urban enhancement was 120% (58 μg m-3). BC had an average of 6.1 μg m-3 at Dhulikhel, an urban enhancement of 17.4 μg m-3. Sulfate (SO4) was 3.6 μg m-3 at Dhulikhel, then 7.5 μg m-3 at Ratnapark, and 12.0 μg m-3 at Lalitpur in the brick kiln region. Chloride (Chl) increased by 330 and 250% from Dhulikhel to Ratnapark and Lalitpur on average. Positive matrix factorization (PMF) identified seven OA sources, four primary OA sources, hydrocarbon-like (HOA), biomass burning (BBOA), trash burning (TBOA), a sulfate-containing local OA source (sLOA), and three secondary oxygenated organic aerosols (OOA). OOA was the largest fraction of OA, over 50% outside the valley and 36% within. HOA (traffic) was the most prominent primary source, contributing 21% of all OA and 44% of BC. Brick kilns were the second largest contributor to C-PM1, 12% of OA, 33% of BC, and a primary emitter of aerosol sulfate. These results, though successive, indicate the importance of multisite measurements to understand ambient particulate matter concentration heterogeneity across urban regions.
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Affiliation(s)
- Benjamin
S. Werden
- Department
of Civil, Architectural, and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania19104, United States
| | - Michael R. Giordano
- Department
of Civil, Architectural, and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania19104, United States
| | - Khadak Mahata
- International
Centre for Integrated Mountain Development, Khumaltar, Lalitpur, 44700Kathmandu, Nepal
| | - Md. Robiul Islam
- Department
of Chemistry, University of Iowa, 230 North Madison Street, Iowa City, Iowa52242-1294, United States
| | - J. Douglas Goetz
- Department
of Civil, Architectural, and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania19104, United States
| | - Siva Praveen Puppala
- International
Centre for Integrated Mountain Development, Khumaltar, Lalitpur, 44700Kathmandu, Nepal
| | - Eri Saikawa
- Department
of Environmental Sciences, Emory University, 400 Dowman Drive, Atlanta, Georgia30322, United States
| | - Arnico K. Panday
- International
Centre for Integrated Mountain Development, Khumaltar, Lalitpur, 44700Kathmandu, Nepal
| | - Robert J. Yokelson
- Department
of Chemistry, University of Montana, 32 Campus Drive, Missoula, Montana59812, United States
| | - Elizabeth A. Stone
- Department
of Chemistry, University of Iowa, 230 North Madison Street, Iowa City, Iowa52242-1294, United States
| | - Peter F. DeCarlo
- Department
of Civil, Architectural, and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania19104, United States
- Department
of Environmental Health and Engineering, John Hopkins University, 3400 North Charles Street, Baltimore, Maryland21218, United States
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14
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Fatima S, Mishra SK, Ahlawat A, Dimri AP. Physico-Chemical Properties and Deposition Potential of PM 2.5 during Severe Smog Event in Delhi, India. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:15387. [PMID: 36430104 PMCID: PMC9690713 DOI: 10.3390/ijerph192215387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/12/2022] [Accepted: 11/13/2022] [Indexed: 06/16/2023]
Abstract
The present work studies a severe smog event that occurred in Delhi (India) in 2017, targeting the characterization of PM2.5 and its deposition potential in human respiratory tract of different population groups in which the PM2.5 levels raised from 124.0 µg/m3 (pre-smog period) to 717.2 µg/m3 (during smog period). Higher concentration of elements such as C, N, O, Na, Mg, Al, Si, S, Fe, Cl, Ca, Ti, Cr, Pb, Fe, K, Cu, Cl, P, and F were observed during the smog along with dominant organic functional groups (aldehyde, ketones, alkyl halides (R-F; R-Br; R-Cl), ether, etc.), which supported potential contribution from transboundary biomass-burning activities along with local pollution sources and favorable meteorological conditions. The morphology of individual particles were found mostly as non-spherical, including carbon fractals, aggregates, sharp-edged, rod-shaped, and flaky structures. A multiple path particle dosimetry (MPPD) model showed significant deposition potential of PM2.5 in terms of deposition fraction, mass rate, and mass flux during smog conditions in all age groups. The highest PM2.5 deposition fraction and mass rate were found for the head region followed by the alveolar region of the human respiratory tract. The highest mass flux was reported for 21-month-old (4.7 × 102 µg/min/m2), followed by 3-month-old (49.2 µg/min/m2) children, whereas it was lowest for 21-year-old adults (6.8 µg/min/m2), indicating babies and children were more vulnerable to PM2.5 pollution than adults during smog. Deposition doses of toxic elements such as Cr, Fe, Zn, Pb, Cu, Mn, and Ni were also found to be higher (up to 1 × 10-7 µg/kg/day) for children than adults.
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Affiliation(s)
- Sadaf Fatima
- CSIR-National Physical Laboratory, New Delhi 110012, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sumit Kumar Mishra
- CSIR-National Physical Laboratory, New Delhi 110012, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Ajit Ahlawat
- Atmospheric Chemistry Department, Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße, 04318 Leipzig, Germany
| | - Ashok Priyadarshan Dimri
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India
- Indian Institute of Geomagnetism, Navi Mumbai 410206, India
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15
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Qin Z, Zhang Q, Luo J, Zhang Y. Optical properties of soot aggregates with different monomer shapes. ENVIRONMENTAL RESEARCH 2022; 214:113895. [PMID: 35863444 DOI: 10.1016/j.envres.2022.113895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 06/26/2022] [Accepted: 07/10/2022] [Indexed: 06/15/2023]
Abstract
The monomer of soot fractal aggregate is usually considered to be sphere, but the monomer shapes are cube and hexagon by some transmission electron microscope (TEM) and scanning electron microscope (SEM) observation. In this paper, the fractal soot models of different monomer shapes (sphere, cube, ellipsoid, hexagonal prism) were established. And the optical properties of models are calculated by discrete dipole approximation (DDA). After systematically comparing the Muller matrix and optical cross section properties between the models, we find that monomer deviation from sphericity does not necessarily lead to further decline of F22(π)/F11(π) even at shorter wavelengths. In other words, the non-sphericity of monomers does not necessarily affect the non-sphericity of whole soot particle. This can provide some implication for lidar remote sensing observation. However, other light scattering matrix elements can keep good consistency. The maximum deviation of extinction cross section of hexagonal prism model is 11.2%. The more the monomer shape deviates from the sphere, the more the optical integral properties of the non-spherical monomer model deviates from the optical integral properties of sphere monomer model. Hence, the difference in optical properties caused by different monomer shapes cannot be neglected when the monomer deviates significantly from a spherical shape. This work is helpful to evaluate the optical properties of soot aggregates more precisely.
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Affiliation(s)
- Zhenhai Qin
- State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Qixing Zhang
- State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui, 230026, China.
| | - Jie Luo
- State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui, 230026, China; State Environment Protection Key Laboratory of Satellite Remote Sensing, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yongming Zhang
- State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui, 230026, China
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16
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Kaur K, Mohammadpour R, Ghandehari H, Reilly CA, Paine R, Kelly KE. Effect of combustion particle morphology on biological responses in a Co-culture of human lung and macrophage cells. ATMOSPHERIC ENVIRONMENT (OXFORD, ENGLAND : 1994) 2022; 284:119194. [PMID: 35937043 PMCID: PMC9348743 DOI: 10.1016/j.atmosenv.2022.119194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Atmospheric aging of combustion particles alters their chemical composition and morphology. Previous studies have reported differences in toxicological responses after exposure to fresh versus aged particles, with chemical composition being the prime suspect behind the differences. However, less is known about the contribution of morphological differences in atmospherically aged particles to toxicological responses, possibly due to the difficulty in resolving the two properties (composition and morphology) that change simultaneously. This study altered the shape of lab-generated combustion particles, without affecting the chemical composition, from fractal-like to a more compact spherical shape, using a water condensation-evaporation method. The two shapes were exposed to a co-culture of human airway epithelial (A549) and differentiated human monocyte (THP-1) cells at air-liquid interface (ALI) conditions. The particles with different shapes were deposited using an electrostatic field-based ALI chamber. For the same mass dose, both shapes were internalized by cells, induced a pro-inflammatory response (IL-8 and TNFα), and enhanced CYP1A1 gene expression compared to air controls. The more compact spherical particles (representative of atmospherically aged particles) induced more early apoptosis and release of TNFα compared to the more fractal-like particles. These results suggest a contribution of morphology to the increased toxicity of aged combustion-derived particles.
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Affiliation(s)
- Kamaljeet Kaur
- Department of Chemical Engineering, University of Utah, United States
| | - Raziye Mohammadpour
- Utah Center for Nanomedicine, University of Utah, United States
- Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, United States
- mRNA Center of Excellence, Sanofi, Waltham, MA, USA
| | - Hamidreza Ghandehari
- Utah Center for Nanomedicine, University of Utah, United States
- Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, United States
- Department of Biomedical Engineering, University of Utah, United States
| | - Christopher A. Reilly
- Utah Center for Nanomedicine, University of Utah, United States
- Department of Pharmacology and Toxicology, Center for Human Toxicology, University of Utah, United States
| | - Robert Paine
- Division of Pulmonary and Critical Care Medicine, University of Utah, United States
| | - Kerry E. Kelly
- Department of Chemical Engineering, University of Utah, United States
- Utah Center for Nanomedicine, University of Utah, United States
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17
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Optical Properties of Black Carbon Aerosols with Different Coating Models. PHOTONICS 2022. [DOI: 10.3390/photonics9050359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Research on the optical properties of black carbon (BC) aerosols is highly important for investigating global climate change. A general inhomogeneous particle superposition model is developed. Inhomogeneous particles with arbitrary shapes can be constructed by this model. BC aerosols with core-shell, spherical, ellipsoid, and irregular coating models are established to explore the impact of coating shape on their optical properties. The optical properties are studied employing the discrete dipole approximation method (DDA). The influences of the morphology of BC aerosols, the coating volume fractions, and the shape of coatings on the optical properties are analyzed. The irregular coating shape causes a higher forward scattering intensity and a lower extinction cross-section. The forward scattering intensity of the core-shell model is lower than other models. The effect of the coating shape on forward scattering intensity becomes smaller as coating volume and fractal dimension increase. Consequently, assuming irregular coating as spherical coating models considered in most studies leads to inaccuracy in the optical properties of BC aerosols. It is necessary to comprehensively consider the effects of aerosol morphology and coating volume for investigating the optical properties of black carbon aerosols.
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18
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Characteristics and Aging of Traffic-Emitted Particles with Sulfate and Organic Compound Formation in Urban Air. ATMOSPHERE 2022. [DOI: 10.3390/atmos13040608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Traffic is a major source of anthropogenic aerosol in urban atmosphere. In this study, aerosol particles were measured with a TEM-EDX system at the roadside of a main road in the northwestern part of Beijing, China, under clear and hazy conditions. Soot, organic, sulfur-rich (S-rich), mineral, and metal particles, as well as the mixtures, were frequently encountered in aerosols. Under hazy conditions, S-rich particles coated with organic matter (S-OM particles) accounted for most of the total particles (15% to 24%), followed by soot particles (18% to 21%), organic particles (17% to 21%), non-mixed S-rich particles (10% to 18%), and S-rich particles with soot-, mineral-, or metal-inclusions (here referred to as S-inclusion particles) (11% to 15%). Under clear conditions, non-mixed S-rich and organic particles were dominant components, while mineral and soot particles were secondary components, among which, ~14% of the total particles had a sulfate core or OM coating; inclusions of mixture particles were often mixed with sulfate cores. In the sulfate core–OM shell structure particles, the ratio of core diameter to the whole particle diameter was ~0.52 under hazy conditions and ~0.60 under clear conditions, indicating a substantial sulfate and organic formation on the particles. Soot particles accounted for 18% to 21% of the total particles. The relative growth of aged soot particles was higher under hazy conditions than under clear conditions. In sum, particles from traffic emissions on a main urban road aged with the formation of sulfate and organic matter.
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19
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McGrory MR, Shepherd RH, King MD, Davidson N, Pope FD, Watson IM, Grainger RG, Jones AC, Ward AD. Mie scattering from optically levitated mixed sulfuric acid-silica core-shell aerosols: observation of core-shell morphology for atmospheric science. Phys Chem Chem Phys 2022; 24:5813-5822. [PMID: 35226003 DOI: 10.1039/d1cp04068e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sulfuric acid is shown to form a core-shell particle on a micron-sized, optically-trapped spherical silica bead. The refractive indices of the silica and sulfuric acid, along with the shell thickness and bead radius were determined by reproducing Mie scattered optical white light as a function of wavelength in Mie spectroscopy. Micron-sized silica aerosols (silica beads were used as a proxy for atmospheric silica minerals) were levitated in a mist of sulfuric acid particles; continuous collection of Mie spectra throughout the collision of sulfuric acid aerosols with the optically trapped silica aerosol demonstrated that the resulting aerosol particle had a core-shell morphology. Contrastingly, the collision of aqueous sulfuric acid aerosols with optically trapped polystyrene aerosol resulted in a partially coated system. The light scattering from the optically levitated aerosols was successfully modelled to determine the diameter of the core aerosol (±0.003 μm), the shell thickness (±0.0003 μm) and the refractive index (±0.007). The experiment demonstrated that the presence of a thin film rapidly changed the light scattering of the original aerosol. When a 1.964 μm diameter silica aerosol was covered with a film of sulfuric acid 0.287 μm thick, the wavelength dependent Mie peak positions resembled sulfuric acid. Thus mineral aerosol advected into the stratosphere would likely be coated with sulfuric acid, with a core-shell morphology, and its light scattering properties would be effectively indistinguishable from a homogenous sulfuric acid aerosol if the film thickness was greater than a few 100 s of nm for UV-visible wavelengths.
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Affiliation(s)
- Megan R McGrory
- Central Laser Facility, Research Complex, STFC Rutherford Appleton Laboratory, Oxford, OX11 0FA, UK. .,Department of Earth Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK
| | - Rosalie H Shepherd
- Central Laser Facility, Research Complex, STFC Rutherford Appleton Laboratory, Oxford, OX11 0FA, UK. .,Department of Earth Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK
| | - Martin D King
- Department of Earth Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK
| | - Nicholas Davidson
- School of Geography, Earth & Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Francis D Pope
- School of Geography, Earth & Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - I Matthew Watson
- School of Earth Science, University of Bristol, Wills Memorial Building, Bristol, BS8 1RJ, UK
| | - Roy G Grainger
- National Centre for Earth Observation, Atmospheric, Oceanic and Planetary Physics, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - Anthony C Jones
- Met Office, Fitzroy Road, Exeter, EX1 3PB, UK.,College of Engineering Maths and Physical Sciences, University of Exeter, Exeter, EX4 4PY, UK
| | - Andrew D Ward
- Central Laser Facility, Research Complex, STFC Rutherford Appleton Laboratory, Oxford, OX11 0FA, UK.
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20
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Zhai J, Yang X, Li L, Bai B, Liu P, Huang Y, Fu TM, Zhu L, Zeng Z, Tao S, Lu X, Ye X, Wang X, Wang L, Chen J. Absorption Enhancement of Black Carbon Aerosols Constrained by Mixing-State Heterogeneity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:1586-1593. [PMID: 35038862 DOI: 10.1021/acs.est.1c06180] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Atmospheric black carbon (BC) has a large yet highly uncertain contribution to global warming. When mixed with non-BC/coating material during atmospheric aging, the BC light absorption can be enhanced through the lensing effect. Laboratory and modeling studies have consistently found strong BC absorption enhancement, while the results in ambient measurements are conflicting, with some reporting weak absorption enhancement even for particles with large bulk coating amounts. Here, from our direct field observations, we report both large and minor absorption enhancement factors for different BC-containing particle populations with large bulk non-BC-to-BC mass ratios. By gaining insights into the measured coating material distribution across each particle population, we find that the level of absorption enhancement is strongly dependent on the particle-resolved mixing state. Our study shows that the greater mixing-state heterogeneity results in the larger difference between observed and predicted absorption enhancement. We demonstrate that by considering the variability in coating material thickness in the optical model, the previously observed model measurement discrepancy of absorption enhancement can be reconciled. The observations and improved optical models reported here highlight the importance of mixing-state heterogeneity on BC's radiative forcing, which should be better resolved in large-scale models to increase confidence when estimating the aerosol radiation effect.
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Affiliation(s)
- Jinghao Zhai
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xin Yang
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Ling Li
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Bin Bai
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Pengfei Liu
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Yuanlong Huang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, United States
| | - Tzung-May Fu
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Lei Zhu
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhenzhong Zeng
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Shu Tao
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Laboratory for Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Xiaohui Lu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Xingnan Ye
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Xiaofei Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Lin Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Jianmin Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
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21
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Wilczyńska-Michalik W, Różańska A, Bulanda M, Chmielarczyk A, Pietras B, Michalik M. Physicochemical and microbiological characteristics of urban aerosols in Krakow (Poland) and their potential health impact. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2021; 43:4601-4626. [PMID: 33913083 PMCID: PMC8528768 DOI: 10.1007/s10653-021-00950-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 04/19/2021] [Indexed: 06/12/2023]
Abstract
Eight aerosol samples were collected in Krakow using a low-volume sampler in February and March 2019 during variable meteorological conditions and times of the day, to study their single particles' properties (size, morphology and chemical composition analyzed using a scanning electron microscope fitted with an energy-dispersive spectrometer) and microbiological characteristics. The content of particles of different chemical compositions larger than 2.5 μm was low. Considering the number of the particles, submicron particles strongly dominated with a high content of ultrafine particles (nanoparticles). Tar ball-type particles were relatively common in the studied samples, while soot was the dominant component. Soot was present as small agglomerates composed of few particles, but also as bigger agglomerates. Metal-containing particles of various chemical characteristics were abundant, with transition metals commonly occurring in these particles. The physicochemical characteristics of aerosols indicate that despite a relatively low mass concentration, their adverse health impact could be very strong because of the high content of nanoparticles, the abundance of soot and other fuel combustion-related particles, and the high incidence of transition metal-rich particles. Microbiological analysis was based on cultures on both solid and liquid agar. The MALDI-TOF method was used for species identification-for bacteria and fungi. Twelve different species of bacteria were isolated from the collected samples of aerosols. The most frequently isolated species was Gram-positive sporulating Bacillus licheniformis. The isolated mold fungi were of the genus Aspergillus.
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Affiliation(s)
| | - Anna Różańska
- Chair of Microbiology, Faculty of Medicine, Jagiellonian University Medical College, ul. Czysta 18, 31-121 Kraków, Poland
| | - Małgorzata Bulanda
- Chair of Microbiology, Faculty of Medicine, Jagiellonian University Medical College, ul. Czysta 18, 31-121 Kraków, Poland
| | - Agnieszka Chmielarczyk
- Chair of Microbiology, Faculty of Medicine, Jagiellonian University Medical College, ul. Czysta 18, 31-121 Kraków, Poland
| | - Bartłomiej Pietras
- Institute of Geography, Pedagogical University in Kraków, ul. Podchorążych 2, Kraków, Poland
| | - Marek Michalik
- Institute of Geological Sciences, Jagiellonian University, Ul. Gronostajowa 3a, 30-387 Kraków, Poland
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22
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Significance of Absorbing Fraction of Coating on Absorption Enhancement of Partially Coated Black Carbon Aerosols. ATMOSPHERE 2021. [DOI: 10.3390/atmos12111422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Black carbon (BC), particularly internally mixed and aged BC, exerts a significant influence on the environment and climate. Black carbon coated by non-absorbing materials shows an enhancement of BC absorption, whereas absorptive coatings on BC can reduce the BC absorption enhancement. In this paper we use the multiple-sphere T-matrix method to accurately model the influence of the absorbing volume fraction of absorbing coatings on the reduction of the absorption enhancement of partially coated BC. The reduction of the absorption enhancement due to the absorbing coating exhibited a strong sensitivity to the absorbing volume fraction of the coating, and no reduction of BC absorption enhancement was seen for BC particles with non-absorbing coatings. We found that coatings with higher absorbing volume fraction, greater coated volume fraction of BC, higher shell/core ratio, and larger coated BC particle size caused stronger reductions of the BC absorption enhancement, whereas the impact of the BC’s fractal dimension was negligible. Moreover, the sensitivity of the reduction of absorption enhancement resulting from the ratio of the absorbing coating shell to the BC core increased for coatings with higher absorbing volume fractions, higher coated volume fractions of BC, or larger particle sizes, although this effect was weaker than the sensitivities to size distribution, absorbing volume fraction of coating, and coated volume fraction of BC. Reductions in the absorption enhancements resulting from the absorbing coating for partially coated BC with various size distributions typically varied in the range of 0.0–0.24 for thin coatings with shell/core ratio of 1.5 and between 0.0 and 0.43 for thick coatings with shell/core ratio of 2.7. In addition, we propose an empirical formula relating the reduction of BC absorption enhancement to the absorbing volume fraction of the coating, which could inform a quantitative understanding and further applications. Our study indicates the significance of the absorbing volume fraction of coatings on the absorption properties of BC.
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23
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Liu Y, Meng X, Wu Z, Huang D, Wang H, Chen J, Chen J, Zong T, Fang X, Tan T, Zhao G, Chen S, Zeng L, Guo S, Huang X, He L, Zeng L, Hu M. The particle phase state during the biomass burning events. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 792:148035. [PMID: 34153758 DOI: 10.1016/j.scitotenv.2021.148035] [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: 11/30/2020] [Revised: 05/14/2021] [Accepted: 05/21/2021] [Indexed: 06/13/2023]
Abstract
The phase state of biomass burning aerosols (BBA) remains largely unclear, impeding our understanding of their effects on air quality, climate and human health, due to its profound roles in mass transfer between gaseous and particulate phase. In this study, the phase state of BBA was investigated by measuring the particle rebound fraction ƒ combining field observations and laboratory experiments. We found that both ambient and laboratory-generated BBA had unexpectedly lower rebound fraction ƒ (<0.6) under the dry conditions (RH = 20-50%), indicating that BBA were in non-solid state at such low RH. This was obviously different from the secondary organic aerosols (SOA) derived from the oxidation of both anthropogenic and biogenic volatile organic compounds, typically with a rebound fraction ƒ larger than 0.8 at RH below 50%. Therefore, we proposed that the diffusion coefficient of gaseous molecular in the bulk of BBA might be much higher than SOA under the dry conditions.
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Affiliation(s)
- Yuechen Liu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xiangxinyue Meng
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Zhijun Wu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science and Technology, Nanjing 210044, China.
| | - Dandan Huang
- State Environmental Protection Key Laboratory of Formation and Prevention of the Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China
| | - Hongli Wang
- State Environmental Protection Key Laboratory of Formation and Prevention of the Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China
| | - Jie Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Jingchuan Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Taomou Zong
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xin Fang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Tianyi Tan
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Gang Zhao
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Shiyi Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Liwu Zeng
- State Environmental Protection Key Laboratory of Formation and Prevention of the Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China
| | - Song Guo
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xiaofeng Huang
- Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Lingyan He
- Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Limin Zeng
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Min Hu
- 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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24
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Ott EJE, Kucinski TM, Dawson JN, Freedman MA. Use of Transmission Electron Microscopy for Analysis of Aerosol Particles and Strategies for Imaging Fragile Particles. Anal Chem 2021; 93:11347-11356. [PMID: 34370455 DOI: 10.1021/acs.analchem.0c05225] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
For over 25 years, transmission electron microscopy (TEM) has provided a method for the study of aerosol particles with sizes from below the optical diffraction limit to several microns, resolving the particles as well as smaller features. The wide use of this technique to study aerosol particles has contributed important insights about environmental aerosol particle samples and model atmospheric systems. TEM produces an image that is a 2D projection of aerosol particles that have been impacted onto grids and, through associated techniques and spectroscopies, can contribute additional information such as the determination of elemental composition, crystal structure, and 3D particle structures. Soot, mineral dust, and organic/inorganic particles have all been analyzed using TEM and spectroscopic techniques. TEM, however, has limitations that are important to understand when interpreting data including the ability of the electron beam to damage and thereby change the structure and shape of particles, especially in the case of particles composed of organic compounds and salts. In this paper, we concentrate on the breadth of studies that have used TEM as the primary analysis technique. Another focus is on common issues with TEM and cryogenic-TEM. Insights for new users on best practices for fragile particles, that is, particles that are easily susceptible to damage from the electron beam, with this technique are discussed. Tips for readers on interpreting and evaluating the quality and accuracy of TEM data in the literature are also provided and explained.
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Affiliation(s)
- Emily-Jean E Ott
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Theresa M Kucinski
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Joseph Nelson Dawson
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Miriam Arak Freedman
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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25
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Hou K, Deng B, Liu A, Ran J. Measurement of harmful nanoparticle distribution among filters, smokers' respiratory systems, and surrounding air during cigarette smoking. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2021; 56:1058-1068. [PMID: 34353208 DOI: 10.1080/10934529.2021.1962158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 07/22/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
This study was undertaken to investigate the filtration effect of filter on nanoparticle and the deposition behavior of nanoparticle in the human respiratory system from the aspect of nanoparticle number during cigarette smoking. For that, two kinds of experiments were designed. One is machine experiment, a well-controlled simulated respiratory system was designed to measure the raw emission and filter effect. Another is human experiment, volunteers were asked to inhale smoke into the oral cavity only and lungs, respectively, to distinguish smoke path. Results revealed that effective inhaled nanoparticle amount of a Taishan and a Hongtaishan cigarette were 5.8E + 9 (#) and 9.4E + 7 (#), respectively. The filter's integrated reduction rate was 41.65% for nanoparticle. For Taishan cigarette, 35.4% and 41.7% of raw emitted nanoparticles were deposited in the oral cavity and lungs, respectively, the rest of 22.9% was exhaled to surrounding air. The corresponding values were 25.6%, 41.5% and 32.9%, respectively, for Hongtaishan. The current findings are expected to provide basic assessments of filter effect and harm to human and to be a warning for smokers.
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Affiliation(s)
- Kaihong Hou
- College of Mechatronics and Control Engineering, Shenzhen University, Shenzhen, China
| | - Banglin Deng
- College of Mechatronics and Control Engineering, Shenzhen University, Shenzhen, China
| | - Aodong Liu
- College of Mechatronics and Control Engineering, Shenzhen University, Shenzhen, China
| | - Jiaqi Ran
- College of Mechatronics and Control Engineering, Shenzhen University, Shenzhen, China
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26
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Enekwizu OY, Hasani A, Khalizov AF. Vapor Condensation and Coating Evaporation Are Both Responsible for Soot Aggregate Restructuring. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8622-8630. [PMID: 34128645 DOI: 10.1021/acs.est.1c02391] [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
Fresh soot is made of fractal aggregates, which often appear collapsed in atmospheric samples. A body of work has concluded that the collapse is caused by liquid shells when they form by vapor condensation around soot aggregates. However, some recent studies argue that soot remains fractal even when engulfed by the shells, collapsing only when the shells evaporate. To reconcile this disagreement, we investigated soot restructuring under conditions ranging from capillary condensation to full encapsulation, also including condensate evaporation. In these experiments, airborne fractal aggregates were exposed to vapors of wetting liquids, and particle size was measured before and after coating loss, allowing us to isolate the contribution from condensation toward restructuring. We show the existence of three distinct regions along the path connecting the initial fractal and final collapsed aggregates, where minor restructuring occurs already at zero vapor supersaturation due to capillary condensation. Increasing supersaturation increases the amount of condensate, producing a more notable aggregate shrinkage. At even higher supersaturations, the aggregates become encapsulated, and subsequent condensate evaporation leaves behind fully compacted aggregates. Hence, for wetting liquids, minor restructuring begins already during capillary condensation and significant restructuring occurs as the coating volume increases. However, at this time, we cannot precisely quantify the contribution of condensate evaporation to the full aggregate compaction.
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Affiliation(s)
- Ogochukwu Y Enekwizu
- Department of Chemical and Materials Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Ali Hasani
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Alexei F Khalizov
- Department of Chemical and Materials Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
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27
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Fu Y, Peng X, Guo Z, Peng L, Lin Q, Li L, Li M, Chen D, Zhang G, Bi X, Wang X, Sheng G. Filter-based absorption enhancement measurement for internally mixed black carbon particles over southern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 762:144194. [PMID: 33373755 DOI: 10.1016/j.scitotenv.2020.144194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/29/2020] [Accepted: 12/02/2020] [Indexed: 06/12/2023]
Abstract
The effect of the mixing state of black carbon (BC) on light absorption is of enduring interest due to its close connection to regional/global climate. Herein, we present concurrent measurements of both BC absorption enhancement (Eabs) and the chemical mixing state in southern China. Eabs was obtained by simultaneous measuring the light absorption coefficient using an aethalometer before and after being heated. The observed Eabs was categorized into non- (Eabs ≤ 1.0), slight (1.0 < Eabs ≤ 1.2), and higher (Eabs > 1.2) enhancement groups, and it was compared to the mixing state of elemental carbon (EC) particles detected by a single particle aerosol mass spectrometer (SPAMS). The individual EC-containing particles were classified into four types, including EC with sodium and potassium ion peaks (NaK-EC), long EC cluster ions (Cn+/-, n ≥ 6) with sulfate (EC-Sul1), short EC cluster ions (Cn+/-, n < 6) with sulfate (EC-Sul2), and EC with OC and sulfate (ECOC-Sul). NaK-EC and EC-Sul2 are the dominant EC types. Slight enhancement group is mainly explained by the photochemical production of ammonium sulfate and organics on EC-Sul2 during afternoon hours. In contrast, the higher Eabs is primarily attributed to the enhanced mixing of ammonium chloride with NaK-EC during morning hours, without photochemistry. The characterization of source emissions indicates that NaK-EC is likely from coal combustion and is associated with a relatively higher amount of ammonium chloride. To our knowledge, this is the first report to state that EC particles associated with ammonium chloride have a relatively higher Eabs.
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Affiliation(s)
- Yuzhen Fu
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xiaocong Peng
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Ziyong Guo
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Long Peng
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, PR China
| | - Qinhao Lin
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, PR China
| | - Lei Li
- Institute of Mass Spectrometer and Atmospheric Environment, Jinan University, Guangzhou 510632, PR China
| | - Mei Li
- Institute of Mass Spectrometer and Atmospheric Environment, Jinan University, Guangzhou 510632, PR China
| | - Duohong Chen
- State Environmental Protection Key Laboratory of Regional Air Quality Monitoring, Guangdong Environmental Monitoring Center, Guangzhou 510308, PR China
| | - Guohua Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510640, PR China.
| | - Xinhui Bi
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510640, PR China
| | - Xinming Wang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou 510640, PR China
| | - Guoying Sheng
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China
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28
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Bai Z, Zhang L, Cheng Y, Zhang W, Mao J, Chen H, Li L, Wang L, Chen J. Water/Methanol-Insoluble Brown Carbon Can Dominate Aerosol-Enhanced Light Absorption in Port Cities. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14889-14898. [PMID: 32790286 DOI: 10.1021/acs.est.0c03844] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Light absorption enhancement (Eabs) of black carbon (BC) is a key factor in global climate models and is impacted by brown carbon (BrC) and the lensing effect of coatings. We conducted an in-depth field study on Eabs for ambient aerosols at a monitoring point in Shanghai, China, by real-time aerosol optical property monitoring and high-performance liquid chromatography/diode array detector/quadrupole-time-of-flight mass spectrometry (HPLC/DAD/Q-ToF-MS) analysis. The results showed Eabs at λ = 530 nm caused by the lensing effect was about 1.39 ± 027, accounting for 18.84% of the total light absorption. In this study, BrC is classified as soluble BrC (soluble in both water and methanol) or insoluble BrC (insoluble in both water and methanol). Soluble BrC accounted for 13.68 ± 11.15% of the total aerosol light absorption. For the first time, we concluded that insoluble BrC can contribute more than 60 and 97% of total aerosol and BrC light absorption in port cities, respectively. The molecular analysis of soluble BrC identified N-containing aromatic compounds (4-nitrophenol, 4-nitrocatechol, methyl nitrophenol, methyl nitrocatechols, and nitro-1-naphthol) commonly observed in biomass burning emissions or biomass burning-impacted atmospheres. A series of components (C16H26O3S, C17H28O3S, C18H30O3S, and C19H32O3S) were determined to be emissions from nearby cargo ships filled with heavy fuel oil (HFO), which further confirmed that insoluble BrC emitted from cargo ships could be the largest contributor to Eabs. This study confirms the global significance of evaluating HFO used in port cities in climate models. The control measures of cargo ship emission should be considered for the related environmental and health issues in port cities.
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Affiliation(s)
- Zhe Bai
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Linyuan Zhang
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Yi Cheng
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Wei Zhang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Junfang Mao
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Hui Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Ling Li
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Lina Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Jianmin Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
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29
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The Ångström Exponent and Single-Scattering Albedo of Black Carbon: Effects of Different Coating Materials. ATMOSPHERE 2020. [DOI: 10.3390/atmos11101103] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
In this work, the absorption Ångström exponent (AAE), extinction Ångström exponent (EAE), and single-scattering albedo (SSA) of black carbon (BC) with different coating materials are numerically investigated. BC with different coating materials can provide explanations for the small AAE, small EAE, and large AAE observed in the atmosphere, which is difficult to be explained by bare BC aggregate models. The addition of organic carbon (OC) does not necessarily increase AAE due to the transformation of BC morphologies and the existence of non-absorbing OC. The addition of coating materials does also not necessarily decrease EAE. While the addition of coating materials can increase the total size of BC-containing particles, the effective refractive index can be modified by introducing the coating materials, so increases the EAE. We found that it is not possible to differentiate between thinly- and heavily-coated BC based on EAE or AAE alone. On the other hand, SSA is much less sensitive to the size and can provide much more information for distinguishing heavily-coated BC from thinly-coated BC. For BC with different coating materials and mixing states, AAE, EAE, and SSA show rather different sensitivities to particle size and composition ratios, and their spectral-dependences also exhibit distinct differences. Different AAE and EAE trends with BC/OC ratio were also found for BC with different coating materials and mixing states. Furthermore, we also found empirical fittings for AAE, EAE, SSA, and optical cross-sections, which may be useful for retrieving the size information based on the optical measurements.
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30
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Wu Y, Cheng T, Pan X, Zheng L, Shi S, Liu H. The role of biomass burning states in light absorption enhancement of carbonaceous aerosols. Sci Rep 2020; 10:12829. [PMID: 32733027 PMCID: PMC7393073 DOI: 10.1038/s41598-020-69611-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 07/06/2020] [Indexed: 12/03/2022] Open
Abstract
Carbonaceous aerosols, which are emitted from biomass burning, significantly contribute to the Earth's radiation balance. Radiative forcing caused by biomass burning has been poorly qualified, which is largely attributed to uncertain absorption enhancement values (Eabs) of black carbon (BC) aerosols. Laboratory measurements and theoretical modelling indicate a significant value of Eabs; but this enhancement is observed to be negligible in the ambient environment, implying that models may overestimate global warming due to BC. Here, we present an aggregate model integrating BC aerosol ensembles with different morphologies and mixing states and report a quantitative analysis of the BC Eabs from different combustion states during biomass burning. We show that the BC Eabs produced by flaming combustion may be up to two times more than those produced by smouldering combustion, suggesting that the particle morphology and mixing state of freshly emitted BC aerosols is an important source of the contrasting values of Eabs. The particle morphology of freshly emitted BC aerosols is widely assumed to be bare in models, which is rare in the ambient environment and leads to small estimates of Eabs by field observations. We conclude that the exact description of freshly emitted carbonaceous aerosols plays an important role in constraining aerosol radiative forcing.
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Affiliation(s)
- Yu Wu
- State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, No.9 Dengzhuangnan Road, Haidian District, Beijing, 100094, China
| | - Tianhai Cheng
- State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, No.9 Dengzhuangnan Road, Haidian District, Beijing, 100094, China.
| | - Xiaole Pan
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, No.40 Huayanli, Chaoyang District, Beijing, 100029, China
| | - Lijuan Zheng
- Land Satellite Remote Sensing Application Center, Ministry of Natural Resources of China, No.1 Baishengcun, Haidian District, Beijing, 100048, China
| | - Shuaiyi Shi
- State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, No.9 Dengzhuangnan Road, Haidian District, Beijing, 100094, China
| | - Hang Liu
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, No.40 Huayanli, Chaoyang District, Beijing, 100029, China
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31
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Liu L, Mishchenko MI. Spectrally dependent linear depolarization and lidar ratios for nonspherical smoke aerosols. JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER 2020; 248:106953. [PMID: 33362295 PMCID: PMC7756960 DOI: 10.1016/j.jqsrt.2020.106953] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We use the numerically exact T-matrix method to model light scattering and absorption by aged smoke aerosols at lidar wavelengths ranging from 355 to 1064 nm assuming the aerosols to be smooth spheroids or Chebyshev particles. We show that the unique spectral dependence of the linear depolarization ratio (LDR) and extinction-to-backscatter ratio (or lidar ratio, LR) measured recently for stratospheric Canadian wildfire smoke can be reproduced by a range of model morphologies, a range of spectrally dependent particle refractive indices, and a range of particle sizes. For these particles, the imaginary part of the refractive index is always less than (or close to) 0.035, and the corresponding real part always falls in the range [1.35, 1.65]. The measured spectral LDRs and LRs could be produced by nearly-spherical oblate spheroids or Chebyshev particles whose shapes resemble those of oblate spheroids. Their volume-equivalent effective radii should be large enough (r eff = 0.3 μm or greater) to produce the observed enhanced LDRs. Our study demonstrates the usefulness of triple-wavelength LDR measurements as providing additional size information for a more definitive characterization of the particle morphology and composition. Non-zero LDR values indicate the presence of nonspherical aerosols and are highly sensitive to particle shapes and sizes. On the other hand, the LR is a strong function of absorption and is very responsive to changes in the particle refractive index.
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Affiliation(s)
- Li Liu
- NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, USA
- Columbia University, 2880 Broadway, New York, NY 10025, USA
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32
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Radiative absorption enhancements by black carbon controlled by particle-to-particle heterogeneity in composition. Proc Natl Acad Sci U S A 2020; 117:5196-5203. [PMID: 32098848 PMCID: PMC7071900 DOI: 10.1073/pnas.1919723117] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Absorption by black carbon strongly affects regional and global climate. Yet, large discrepancies between standard model predictions and regionally specific observations—often with observed absorption lower than expected—raise questions about current understanding of black carbon absorption and its atmospheric impacts. Through a combination of measurement and modeling, our analysis resolves the discrepancy by showing that particular laboratory designs or atmospheric conditions engender distinct compositional heterogeneity among particles containing black carbon. Lower-than-expected absorption results largely from increased heterogeneity, although slightly lowered absorption occurs even in a purely homogeneous system. This work provides a framework that explains globally disparate observations and that can be used to improve estimates of black carbon’s global impact. Black carbon (BC) absorbs solar radiation, leading to a strong but uncertain warming effect on climate. A key challenge in modeling and quantifying BC’s radiative effect on climate is predicting enhancements in light absorption that result from internal mixing between BC and other aerosol components. Modeling and laboratory studies show that BC, when mixed with other aerosol components, absorbs more strongly than pure, uncoated BC; however, some ambient observations suggest more variable and weaker absorption enhancement. We show that the lower-than-expected enhancements in ambient measurements result from a combination of two factors. First, the often used spherical, concentric core-shell approximation generally overestimates the absorption by BC. Second, and more importantly, inadequate consideration of heterogeneity in particle-to-particle composition engenders substantial overestimation in absorption by the total particle population, with greater heterogeneity associated with larger model–measurement differences. We show that accounting for these two effects—variability in per-particle composition and deviations from the core-shell approximation—reconciles absorption enhancement predictions with laboratory and field observations and resolves the apparent discrepancy. Furthermore, our consistent model framework provides a path forward for improving predictions of BC’s radiative effect on climate.
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33
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Sutcu E, Doner N, Liu F, Ercetin U, Sen F, Yon J, Morán J, Fuentes A. Morphological and radiative characteristics of soot aggregates: Experimental and numerical research. Sci Rep 2020; 10:411. [PMID: 31941934 PMCID: PMC6962357 DOI: 10.1038/s41598-019-57045-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 12/20/2019] [Indexed: 11/09/2022] Open
Abstract
The study is aimed at investigating the radiative properties of soot aggregates at determined morphological features using both experimental and numerical methods. Soot aggregates collected from air monitoring stations in different locations were examined. The locations were divided into three groups. The first group (Case 1) included the coastal and industrial zone; the second group (Case 2) consisted of small and large cities; and the third group (Case 3) included areas in the neighbourhood of thermal power plants. The absorbance measurements of the soot aggregates were conducted in the visible and near-infrared spectra, and in the wavelength range of 2 μm-20 μm. The samples were characterised by scanning electron microscopy (SEM), and their radiative properties were assessed using the discrete dipole approximation (DDA) for numerically generated fractal aggregates with two popular refractive indices of m = 1.60 + 0.60i and m = 1.90 + 0.75i. Calculations were conducted for primary particles in point-contact, with 20% overlapping and with a coating (50% and 80%) in the wavelength range of 0.4–1.064 μm. The largest measured absorbance values in both the winter and summer seasons were found in the cities in Case 1, and the x-ray diffraction (XRD) phases of the samples were also presented. The radiative properties of the aggregates, i.e., Df = 1.78 and kf = 2.0 representing Case 3, were close to those of aggregates with Df = 2.1 and kf = 2.35 representing Case 1 in the investigated wavelength range. The calculated radiative properties and the experimental absorbance measurements for point-contact and overlapping situations showed the same trend in the examined wavelengths. The absorbance properties of the samples of coastal and industrial zones were distinctively higher than others in the wavelength range of 2 μm-20 μm which could be attributed to the PAH effects.
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Affiliation(s)
- Ezgi Sutcu
- Dumlupinar University, Engineering Faculty, Mechanical Engineering Department, 43270, Kutahya, Turkey
| | - Nimeti Doner
- Gazi University, Engineering Faculty, Mechanical Engineering Department, 06570, Ankara, Turkey.
| | - Fengshan Liu
- Black Carbon Metrology, Measurement Science and Standards, National Research Council, Ottawa, Ontario, K1A 0R6, Canada
| | - Umran Ercetin
- Dumlupinar University, Engineering Faculty, Mechanical Engineering Department, 43270, Kutahya, Turkey
| | - Fatih Sen
- Sen Research Group, Biochemistry Department, Dumlupinar University, 43270, Kutahya, Turkey.
| | - Jérôme Yon
- Normandie Univ, INSA Rouen, UNIROUEN, CNRS, CORIA, 76000, Rouen, France
| | - Jose Morán
- Normandie Univ, INSA Rouen, UNIROUEN, CNRS, CORIA, 76000, Rouen, France.,Departamento de Industrias, Universidad Técnica Federico Santa María, Av. España 1680, Casilla, 110-V, Valparaíso, Chile
| | - Andrés Fuentes
- Departamento de Industrias, Universidad Técnica Federico Santa María, Av. España 1680, Casilla, 110-V, Valparaíso, Chile
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Kanngiesser F, Kahnert M. Coating material-dependent differences in modelled lidar-measurable quantities for heavily coated soot particles. OPTICS EXPRESS 2019; 27:36368-36387. [PMID: 31873418 DOI: 10.1364/oe.27.036368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 11/17/2019] [Indexed: 06/10/2023]
Abstract
The optical properties of thickly coated soot particles are sensitive to the chemical composition, thus to the refractive index of the coating material. For 58 differently sized coated soot aggregates the extinction-to-backscatter ratio (lidar ratio) and the depolarisation ratio are computed at a wavelength of 355 nm, 532 nm and 1064 nm for two different coating materials: a toluene-based coating and a sulphate coating. Additionally the Ångström exponents between 355 nm and 532 nm as well as between 532 nm and 1064 nm are calculated. The extinction-to-backscatter ratio is found to allow a distinction between the coating materials at all three wavelengths, and the depolarisation ratio allows for a distinction at 355 and 532 nm.
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A Scale-up of Energy-Cycle Analysis on Processing Non-Woven Flax/PLA Tape and Triaxial Glass Fibre Fabric for Composites. JOURNAL OF MANUFACTURING AND MATERIALS PROCESSING 2019. [DOI: 10.3390/jmmp3040092] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In the drive towards a sustainable bio-economy, a growing interest exists in the development of composite materials using renewable natural resources. This paper explores the life cycle assessment of processing of Flax fibre reinforced polylactic acid (PLA), with a comparison of glass fibre triaxial fabric in the production process. The use of hydrocarbon fossil resources and synthetic fibres, such as glass and carbon, have caused severe environmental impacts in their entire life cycles. Whereas, Flax/PLA is one of the cornerstones for the sustainable economic growth of natural fibre composites. In this study, the manufacturing processes for the production of Flax/PLA tape and triaxial glass fibre were evaluated through a gate-to-gate life cycle assessment (LCA). The assessment was based on an input-output model to estimate energy demand and environmental impacts. The quality of the natural hybrid composite produced and cost-effectiveness of their LCA was dependent on their roving processing speeds and temperature applied to both the Flax/PLA tape and triaxial glass fabrics during processing. The optimum processing condition was found to be at a maximum of 4 m/min at a constant temperature of 170 °C. In contrast, the optimum for normal triaxial glass fibre production was at a slower speed of 1 m/min using a roving glass fibre laminating machine. The results showed that when the Flax and PLA were combined to produce new composite material in the form of a flax/PLA tape, energy consumption was 0.25 MJ/kg, which is lower than the 0.8 MJ/kg used for glass fibre fabric process. Flax/PLA tape and glass fibre fabric composites have a carbon footprint equivalent to 0.036 kg CO2 and 0.11 kg CO2, respectively, under the same manufacturing conditions. These are within the technical requirements in the composites industry. The manufacturing process adopted to transform Flax/PLA into a similar tape composite was considerably quicker than that of woven glass fibre fabric for composite tape. This work elucidated the relationship of the energy consumptions of the two materials processes by using a standard LCA analytical methodology. The outcomes supported an alternative option for replacement of some conventional composite materials for the automotive industry. Most importantly, the natural fibre composite production is shown to result in an economic benefit and reduced environmental impact.
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36
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Ding S, Liu D, Zhao D, Hu K, Tian P, Zhou W, Huang M, Yang Y, Wang F, Sheng J, Liu Q, Kong S, Cui P, Huang Y, He H, Coe H, Ding D. Size-Related Physical Properties of Black Carbon in the Lower Atmosphere over Beijing and Europe. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:11112-11121. [PMID: 31423774 DOI: 10.1021/acs.est.9b03722] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The size-resolved properties of atmospheric black carbon (BC) importantly determine its absorption capacity and cloud condensation nuclei (CCN) ability. This study reports comprehensive vertical profiles of BC size-related properties over the Beijing area (BJ) and Continental Europe (CE). BC mass loadings over CE were in the range of clean background over BJ. For both planetary boundary layer (PBL) and lower free troposphere, the BC mass median core diameter over BJ during the cold season was 0.21 ± 0.02 μm, larger than the warm season over BJ and CE (0.18 ± 0.01 μm), which may reflect seasonal differences in emissions. The BC coatings were positively correlated with the pollution level, with background BC having a smaller coated count median diameter (0.19 ± 0.01 μm). The modeled absorption enhancement (Eabs) due to coatings was 1.23 ± 0.14 for the background but in the PBL following a linear expression (Eabs = 0.13 × MassBC,surface + 1.26). The CCN ability of BC was significantly enhanced in the polluted PBL, due to both enlarged size and increased hygroscopicity. In polluted BJ at predicted supersaturations, ∼0.08% half of the BC number could be activated, whereas the cleaner environment needs ∼0.14%. The results here suggest that the highly coated and absorbing BC can be efficiently incorporated into clouds and can exert important indirect radiative impacts over the polluted East Asia region.
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Affiliation(s)
- Shuo Ding
- Department of Atmospheric Sciences, School of Earth Sciences , Zhejiang University , Hangzhou 310058 , China
| | - Dantong Liu
- Department of Atmospheric Sciences, School of Earth Sciences , Zhejiang University , Hangzhou 310058 , China
| | - Delong Zhao
- Beijing Weather Modification Office , Beijing 100089 , China
- Beijing Key Laboratory of Cloud, Precipitation and Atmospheric Water Resources , Beijing 100089 , China
- Field Experiment Base of Cloud and Precipitation Research in North China, China Meteorological Administration , Beijing 100089 , China
- Nanjing University , Nanjing 210008 , China
| | - Kang Hu
- Department of Atmospheric Sciences, School of Earth Sciences , Zhejiang University , Hangzhou 310058 , China
| | - Ping Tian
- Beijing Weather Modification Office , Beijing 100089 , China
| | - Wei Zhou
- Beijing Weather Modification Office , Beijing 100089 , China
| | - Mengyu Huang
- Beijing Weather Modification Office , Beijing 100089 , China
| | - Yan Yang
- Beijing Weather Modification Office , Beijing 100089 , China
| | - Fei Wang
- Beijing Weather Modification Office , Beijing 100089 , China
| | - Jiujiang Sheng
- Beijing Weather Modification Office , Beijing 100089 , China
| | - Quan Liu
- Beijing Weather Modification Office , Beijing 100089 , China
| | - Shaofei Kong
- Department of Atmospheric Sciences, School of Environmental Studies , China University of Geosciences (Wuhan) , Wuhan 430074 , China
| | - Pengyi Cui
- School of Environment and Architecture , University of Shanghai for Science and Technology , Shanghai 200093 , China
| | - Yuandong Huang
- School of Environment and Architecture , University of Shanghai for Science and Technology , Shanghai 200093 , China
| | - Hui He
- Beijing Weather Modification Office , Beijing 100089 , China
| | - Hugh Coe
- Centre for Atmospheric Sciences, School of Earth and Environmental Sciences , University of Manchester , Manchester M13 9PL , U.K
| | - Deping Ding
- Beijing Weather Modification Office , Beijing 100089 , China
- Beijing Key Laboratory of Cloud, Precipitation and Atmospheric Water Resources , Beijing 100089 , China
- Field Experiment Base of Cloud and Precipitation Research in North China, China Meteorological Administration , Beijing 100089 , China
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37
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Adachi K, Sedlacek AJ, Kleinman L, Springston SR, Wang J, Chand D, Hubbe JM, Shilling JE, Onasch TB, Kinase T, Sakata K, Takahashi Y, Buseck PR. Spherical tarball particles form through rapid chemical and physical changes of organic matter in biomass-burning smoke. Proc Natl Acad Sci U S A 2019; 116:19336-19341. [PMID: 31488715 PMCID: PMC6765284 DOI: 10.1073/pnas.1900129116] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Biomass burning (BB) emits enormous amounts of aerosol particles and gases into the atmosphere and thereby significantly influences regional air quality and global climate. A dominant particle type from BB is spherical organic aerosol particles commonly referred to as tarballs. Currently, tarballs can only be identified, using microscopy, from their uniquely spherical shapes following impaction onto a grid. Despite their abundance and potential significance for climate, many unanswered questions related to their formation, emission inventory, removal processes, and optical properties still remain. Here, we report analysis that supports tarball formation in which primary organic particles undergo chemical and physical processing within ∼3 h of emission. Transmission electron microscopy analysis reveals that the number fractions of tarballs and the ratios of N and O relative to K, the latter a conserved tracer, increase with particle age and that the more-spherical particles on the substrates had higher ratios of N and O relative to K. Scanning transmission X-ray spectrometry and electron energy loss spectrometry analyses show that these chemical changes are accompanied by the formation of organic compounds that contain nitrogen and carboxylic acid. The results imply that the chemical changes increase the particle sphericity on the substrates, which correlates with particle surface tension and viscosity, and contribute to tarball formation during aging in BB smoke. These findings will enable models to better partition tarball contributions to BB radiative forcing and, in so doing, better help constrain radiative forcing models of BB events.
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Affiliation(s)
- Kouji Adachi
- Department of Atmosphere, Ocean and Earth System Modeling Research, Meteorological Research Institute, 3050052 Tsukuba, Japan;
| | - Arthur J Sedlacek
- Environmental and Climate Sciences, Brookhaven National Laboratory, Upton, NY 11973
| | - Lawrence Kleinman
- Environmental and Climate Sciences, Brookhaven National Laboratory, Upton, NY 11973
| | - Stephen R Springston
- Environmental and Climate Sciences, Brookhaven National Laboratory, Upton, NY 11973
| | - Jian Wang
- Environmental and Climate Sciences, Brookhaven National Laboratory, Upton, NY 11973
- Center for Aerosol Science and Engineering, Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130
| | - Duli Chand
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA 99352
| | - John M Hubbe
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA 99352
| | - John E Shilling
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Timothy B Onasch
- Center for Sensor Systems and Technology, Aerodyne Research Inc., Billerica, MA 01821
| | - Takeshi Kinase
- Department of Atmosphere, Ocean and Earth System Modeling Research, Meteorological Research Institute, 3050052 Tsukuba, Japan
| | - Kohei Sakata
- Center for Global Environmental Research, National Institute for Environmental Studies, 3058506 Tsukuba, Japan
| | - Yoshio Takahashi
- Graduate School of Science, The University of Tokyo, 1130033 Tokyo, Japan
| | - Peter R Buseck
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287
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38
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Lee AKY, Rivellini LH, Chen CL, Liu J, Price DJ, Betha R, Russell LM, Zhang X, Cappa CD. Influences of Primary Emission and Secondary Coating Formation on the Particle Diversity and Mixing State of Black Carbon Particles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:9429-9438. [PMID: 31348654 DOI: 10.1021/acs.est.9b03064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The mixing state of black carbon (BC) affects its environmental fate and impacts. This work investigates particle diversity and mixing state for refractory BC (rBC) containing particles in an urban environment. The chemical compositions of individual rBC-containing particles were measured, from which a mixing state index and particle diversity were determined. The mixing state index (χ) varied between 26% and 69% with the average of 48% in this study and was slightly enhanced with the photochemical age of air masses, indicating that most of the rBC-containing particles cannot be simply explained by fully externally and internally mixed model. Clustering of single particle measurements was used to investigate the potential effects of different primary emissions and atmospheric processes on rBC-containing particle diversity and mixing state. The average particle species diversity and the bulk population species diversity both increased with primary traffic emissions and elevated nitrate concentrations in the morning but gradually decreased with secondary organic aerosol (SOA) formation in the afternoon. The single particle clustering results illustrate that primary traffic emissions and entrainment of nitrate-containing rBC particles from the residual layer to the surface could lead to more heterogeneous aerosol compositions, whereas substantial fresh SOA formation near vehicular emissions made the rBC-containing particles more homogeneous. This work highlights the importance of considering particle diversity and mixing state for investigating the chemical evolution of rBC-containing particles and the potential effects of coating on BC absorption enhancement.
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Affiliation(s)
- Alex K Y Lee
- Department of Civil and Environmental Engineering , National University of Singapore , 117576 , Singapore
- NUS Environmental Research Institute , National University of Singapore , 117411 , Singapore
| | - Laura-Hélèna Rivellini
- NUS Environmental Research Institute , National University of Singapore , 117411 , Singapore
| | - Chia-Li Chen
- Scripps Institution of Oceanography , University of California, San Diego , La Jolla , California 92093 , United States
| | - Jun Liu
- Scripps Institution of Oceanography , University of California, San Diego , La Jolla , California 92093 , United States
| | - Derek J Price
- Scripps Institution of Oceanography , University of California, San Diego , La Jolla , California 92093 , United States
| | - Raghu Betha
- Scripps Institution of Oceanography , University of California, San Diego , La Jolla , California 92093 , United States
| | - Lynn M Russell
- Scripps Institution of Oceanography , University of California, San Diego , La Jolla , California 92093 , United States
| | - Xiaolu Zhang
- Department of Civil and Environmental Engineering , University of California , Davis , California 95616 , United States
| | - Christopher D Cappa
- Department of Civil and Environmental Engineering , University of California , Davis , California 95616 , United States
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39
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Bhandari J, China S, Chandrakar KK, Kinney G, Cantrell W, Shaw RA, Mazzoleni LR, Girotto G, Sharma N, Gorkowski K, Gilardoni S, Decesari S, Facchini MC, Zanca N, Pavese G, Esposito F, Dubey MK, Aiken AC, Chakrabarty RK, Moosmüller H, Onasch TB, Zaveri RA, Scarnato BV, Fialho P, Mazzoleni C. Extensive Soot Compaction by Cloud Processing from Laboratory and Field Observations. Sci Rep 2019; 9:11824. [PMID: 31413342 PMCID: PMC6694138 DOI: 10.1038/s41598-019-48143-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 07/29/2019] [Indexed: 11/09/2022] Open
Abstract
Soot particles form during combustion of carbonaceous materials and impact climate and air quality. When freshly emitted, they are typically fractal-like aggregates. After atmospheric aging, they can act as cloud condensation nuclei, and water condensation or evaporation restructure them to more compact aggregates, affecting their optical, aerodynamic, and surface properties. Here we survey the morphology of ambient soot particles from various locations and different environmental and aging conditions. We used electron microscopy and show extensive soot compaction after cloud processing. We further performed laboratory experiments to simulate atmospheric cloud processing under controlled conditions. We find that soot particles sampled after evaporating the cloud droplets, are significantly more compact than freshly emitted and interstitial soot, confirming that cloud processing, not just exposure to high humidity, compacts soot. Our findings have implications for how the radiative, surface, and aerodynamic properties, and the fate of soot particles are represented in numerical models.
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Affiliation(s)
- Janarjan Bhandari
- Atmospheric Sciences Program and Department of Physics, Michigan Technological University, Houghton, MI, USA.
| | - Swarup China
- Atmospheric Sciences Program and Department of Physics, Michigan Technological University, Houghton, MI, USA
- Pacific Northwest National Laboratory, Richland, WA, USA
| | - Kamal Kant Chandrakar
- Atmospheric Sciences Program and Department of Physics, Michigan Technological University, Houghton, MI, USA
| | - Greg Kinney
- Atmospheric Sciences Program and Department of Physics, Michigan Technological University, Houghton, MI, USA
| | - Will Cantrell
- Atmospheric Sciences Program and Department of Physics, Michigan Technological University, Houghton, MI, USA
| | - Raymond A Shaw
- Atmospheric Sciences Program and Department of Physics, Michigan Technological University, Houghton, MI, USA
| | - Lynn R Mazzoleni
- Atmospheric Sciences Program and Department of Chemistry, Michigan Technological University, Houghton, MI, USA
| | - Giulia Girotto
- Atmospheric Sciences Program and Department of Physics, Michigan Technological University, Houghton, MI, USA
| | - Noopur Sharma
- Atmospheric Sciences Program and Department of Physics, Michigan Technological University, Houghton, MI, USA
- Pacific Northwest National Laboratory, Richland, WA, USA
| | - Kyle Gorkowski
- Atmospheric Sciences Program and Department of Physics, Michigan Technological University, Houghton, MI, USA
- Atmospheric and Oceanic Sciences, McGill University, Montreal, Canada
- Earth & Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | | | - Stefano Decesari
- Institute of Atmospheric Sciences and Climate (CNR-ISAC), Rome, Italy
| | | | - Nicola Zanca
- Institute of Atmospheric Sciences and Climate (CNR-ISAC), Rome, Italy
- Department of Chemistry and Institute for Atmospheric and Earth System Research (INAR), University of Helsinki, Helsinki, Finland
| | - Giulia Pavese
- Institute of Methodologies for Environmental Analysis (CNR-IMAA), Rome, Italy
| | | | - Manvendra K Dubey
- Earth & Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Allison C Aiken
- Earth & Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Rajan K Chakrabarty
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | | | | | - Rahul A Zaveri
- Pacific Northwest National Laboratory, Richland, WA, USA
| | | | - Paulo Fialho
- Instituto de Investigação em Vulcanologia e Avaliação de Riscos - IVAR, University of Azores, Azores, Portugal
| | - Claudio Mazzoleni
- Atmospheric Sciences Program and Department of Physics, Michigan Technological University, Houghton, MI, USA.
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40
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Characteristics of Spherical Organic Particles Emitted from Fixed-Bed Residential Coal Combustion. ATMOSPHERE 2019. [DOI: 10.3390/atmos10080441] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Residential coal combustion is one of the most significant sources of carbonaceous aerosols in the Highveld region of South Africa, significantly affecting the local and regional climate. This study investigated single coal-burning particles emitted when using different fire-ignition techniques (top-lit up-draft versus bottom-lit up-draft) and air ventilation rates (defined by the number of air holes above and below the fire grate) in selected informal braziers. Aerosol samples were collected on nucleopore filters at the Sustainable Energy Technology and Research Centre Laboratory, University of Johannesburg. The individual particles (~700) were investigated using a scanning electron microscope equipped with energy-dispersive X-ray spectroscopy (EDX). Two distinct forms of spherical organic particles (SOPs) were identified, one less oxidized than the other. The particles were further classified into electronically dark and bright. The EDX analysis showed that 70% of the dark spherical organic particles had higher (~60%) relative oxygen content than in the bright SOPs. The morphology of spherical organic particles were quantified and classified into four categories: ~50% were bare single particles; ~35% particles were aggregated and formed diffusion accretion chains; 10% had inclusions, and 5% were deformed due to impaction on filter material during sampling. This study concludes that there are two distinct kinds of coal burning spherical organic particles and that dark SOPs are less volatile than bright SOPs. The authors also show that these spherical organic particles are similar in nature and characteristics to tar balls observed in biomass combustion and that they have the potential to absorb sunlight thereby affecting the earth’s radiative budget and climate. This study provides insights into the mixing states, morphology, and possible formation mechanisms of these organic particles from residential coal combustion in informal stoves.
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Yuan Q, Xu J, Wang Y, Zhang X, Pang Y, Liu L, Bi L, Kang S, Li W. Mixing State and Fractal Dimension of Soot Particles at a Remote Site in the Southeastern Tibetan Plateau. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:8227-8234. [PMID: 31251592 DOI: 10.1021/acs.est.9b01917] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The mixing state and fractal dimension (Df) of soot particles are two major factors affecting their absorption capacity and their climate effects. Here we investigated these factors of soot particles found in a typical valley of the southeastern Tibetan Plateau where wood burning in local villages was one major source of soot particles. Our motivation revealed Df and the aging property of soot particles in remote air and discussed their regional climatic implications. We found that 64% of total analyzed particles by number were soot-bearing particles and most of them aged with sulfate or organic coating. The Df sequence is bare-like soot (1.75 ± 0.08) < partly coated soot (1.82 ± 0.05) < embedded soot (1.88 ± 0.05). The aging process enlarged the overall size of the soot-bearing particles and increased the compactness of soot. Soot aging critically depended on high relative humidity (RH) during nighttime. Besides emission sources and coating processes, the coating aerosol phase under different RHs is another important factor affecting the soot Df.
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Affiliation(s)
- Qi Yuan
- Department of Atmospheric Sciences, School of Earth Sciences , Zhejiang University , Hangzhou 310027 , Zhejiang , China
| | - Jianzhong Xu
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources , Chinese Academy of Sciences (CAS) , Lanzhou 730000 , Gansu , China
| | - Yuanyuan Wang
- Department of Atmospheric Sciences, School of Earth Sciences , Zhejiang University , Hangzhou 310027 , Zhejiang , China
| | - Xinghua Zhang
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources , Chinese Academy of Sciences (CAS) , Lanzhou 730000 , Gansu , China
| | - Yuner Pang
- Department of Atmospheric Sciences, School of Earth Sciences , Zhejiang University , Hangzhou 310027 , Zhejiang , China
| | - Lei Liu
- Department of Atmospheric Sciences, School of Earth Sciences , Zhejiang University , Hangzhou 310027 , Zhejiang , China
| | - Lei Bi
- Department of Atmospheric Sciences, School of Earth Sciences , Zhejiang University , Hangzhou 310027 , Zhejiang , China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources , Chinese Academy of Sciences (CAS) , Lanzhou 730000 , Gansu , China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences , Beijing 100101 , China
| | - Weijun Li
- Department of Atmospheric Sciences, School of Earth Sciences , Zhejiang University , Hangzhou 310027 , Zhejiang , China
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Ervik TK, Benker N, Weinbruch S, Thomassen Y, Ellingsen DG, Berlinger B. Size distribution and single particle characterization of airborne particulate matter collected in a silicon carbide plant. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2019; 21:564-574. [PMID: 30723847 DOI: 10.1039/c8em00518d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The global SiC market is projected to grow in the coming years, and research on potential health effects as well as epidemiological studies is therefore of importance. A detailed characterization in terms of the phase composition, morphology and mixing state of airborne PM is still missing, though highly necessary to identify sources and to understand the risk factors in this industry. Particles in the size range of 10 nm to 10 µm were collected with a 13-stage NanoMOUDI impactor in the Acheson Furnace Hall as well as in processing departments during two sampling campaigns. Particle mass concentrations, including the fraction of ultrafine particles (UFPs), were lower in the processing departments in comparison to those in the Acheson Furnace Hall. The particle number size distribution measured with a scanning mobility particle sizer confirmed the low amount of UFPs in the processing departments compared to the furnace hall. Significant differences in the particle mass concentration and distribution were observed in the Acheson Furnace Hall during the two sampling campaigns. The PM size distribution depends upon the sampling location, on the cycle of the nearby furnaces and on special incidents occurring during a furnace run. Scanning and transmission electron microscopy (SEM and TEM) showed that the size range of 0.32-10 µm (aerodynamic diameter) is dominated by carbon (C)-rich particles, which were identified as petroleum coke, graphite, soot and amorphous spherical C-rich particles. Soot was further classified into three types based on the primary particle size, morphology and composition. Diesel-powered vehicles, pyrolysis of petroleum coke and incomplete combustion of volatile components from this pyrolysis are suggested as sources of different soot particle types. Amorphous spherical C-rich particles were also sub-classified based on their morphology and composition as tar balls (TBs) and C-spherical type 2. The amount of SiC fibers and crystalline SiO2 was found to be low. In the size fraction below 0.32 µm (aerodynamic diameter), sulphur (S)-rich particles dominate. This knowledge of the particle size distribution, and chemical and physical properties of the PM occurring in the SiC production is fundamental for an appropriate risk assessment, and these findings should have implications for future epidemiological studies and for the mitigation of worker exposure.
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Affiliation(s)
- Torunn Kringlen Ervik
- Department of Chemical and Biological Work Environment, National Institute of Occupational Health, P.O.Box 5330 Majorstuen, NO-0304 Oslo, Norway.
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Yang Y, Xu X, Zhang Y, Zheng S, Wang L, Liu D, Gustave W, Jiang L, Hua Y, Du S, Tang L. Seasonal size distribution and mixing state of black carbon aerosols in a polluted urban environment of the Yangtze River Delta region, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 654:300-310. [PMID: 30445330 DOI: 10.1016/j.scitotenv.2018.11.087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 11/01/2018] [Accepted: 11/07/2018] [Indexed: 06/09/2023]
Abstract
The optical properties of black carbon aerosols (BC) are determined by the particles size and the associated non-BC materials, which may be source-related or modified during secondary processing. The one-year long monitoring of BC was first conducted using a Single Particle Soot Photometer (SP2) from December 2013 to November 2014 in Nanjing, a megacity in the Yangtze River Delta region of China. The seasonal variation in the BC size distribution and mixing state were investigated. There was no apparent systematic variation in the mean BC core mass median diameter between seasons, as these values were 226 ± 12 nm, 217 ± 13 nm, 211 ± 15 nm and 221 ± 12 nm for winter, spring, summer and autumn respectively. The mixing state of BC was quantified as the bulk relative coating thickness (defined as particle size Dp over core size Dc, Dp/Dc), which ranged from 1.05 to 2.65. The BC was found to be significantly more coated in the winter (Dp/Dc = 1.50 ± 0.30) than in other seasons (Dp/Dc = 1.27 ± 0.09, 1.28 ± 0.10, 1.27 ± 0.11 in spring, summer and autumn respectively). Higher levels of coating during the winter may due to the contributions of the primary source (with the highest BC mass loadings between seasons) or secondary processes such as low temperature that facilitated the condensation. It was found that the photochemical process may enhance the coatings on BC in summer. At nighttime, the reduced and stabilized planetary boundary layer and the nighttime secondary formation may also lead to BC becoming well mixed with other components. Moreover, BC was shown to be less coated when the NOx concentration was high. However, during all seasons, the BC coating was strongly correlated with other non-BC particulate mass, which suggests that at higher pollution levels BC was more significantly coated with other existing materials through coagulation or condensation by other secondary species.
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Affiliation(s)
- Yifan Yang
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu Province, China
| | - Xiaofeng Xu
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu Province, China.
| | - Yunjiang Zhang
- Institut National de l'Environnement Industriel et des Risques, Verneuil-en-Halatte 60550, France; Laboratoire des Sciences du Climat et de l'Environnement, CNRS-CEA-UVSQ, Université Paris-Saclay, Gif sur Yvette 91191, France
| | - Shanshan Zheng
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu Province, China
| | - Lingrui Wang
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu Province, China
| | - Dantong Liu
- Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310058, China; Centre for Atmospheric Science, School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester M139PL, UK
| | - Williamson Gustave
- Department of Environment Science, Xi'an Jiangtong Liverpoor University, Suzhou 215123, China
| | - Lei Jiang
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Yan Hua
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Songshan Du
- Jiangsu Environmental Monitoring Center, Nanjing 210036, China
| | - Lili Tang
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China; Jiangsu Environmental Monitoring Center, Nanjing 210036, China
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Zhang JY, Qi H, Wang YF, Gao BH, Ruan LM. Retrieval of fractal dimension and size distribution of non-compact soot aggregates from relative intensities of multi-wavelength angular-resolved light scattering. OPTICS EXPRESS 2019; 27:1613-1631. [PMID: 30696225 DOI: 10.1364/oe.27.001613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 12/10/2018] [Indexed: 06/09/2023]
Abstract
A new technique is developed to retrieve the fractal dimension and size distribution of soot aggregates simultaneously from the relative intensities of multi-wavelength angular-resolved light scattering. Compared with other techniques, the main advantage of this method is its independence of knowing complex refractive index, number density of aggregate, fractal prefactor and primary particle diameter. The forward light scattering procedure of soot aggregate is described by Rayleigh-Debye-Gans polydisperse fractal aggregate (RDG-PFA) scattering theory, and the retrieval process is performed by using the covariance matrix adaption-evolution strategy algorithm (CMA-ES). Three different measurement models, i.e. absolute scattering and transmittance, absolute scattering, relative scattering (RS), are investigated in present research. Numerical experiments have been performed to test the feasibility of the CMA-ES algorithm. Combined with the multi-wavelength RDG-PFA strategy, the retrieval accuracy of soot aggregate size distribution is proved to be more effectively by using the RS model. Satisfactory results under 10% Gaussian measurement noise have demonstrated the feasibility of the proposed method.
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Chakrabarty RK, Heinson WR. Scaling Laws for Light Absorption Enhancement Due to Nonrefractory Coating of Atmospheric Black Carbon Aerosol. PHYSICAL REVIEW LETTERS 2018; 121:218701. [PMID: 30517814 DOI: 10.1103/physrevlett.121.218701] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 08/08/2018] [Indexed: 06/09/2023]
Abstract
Black carbon (BC) aerosol, the strongest absorber of visible solar radiation in the atmosphere, contributes to a large uncertainty in direct radiative forcing estimates. A primary reason for this uncertainty is inaccurate parametrizations of the BC mass absorption cross section (MAC_{BC}) and its enhancement factor (E_{MAC_{BC}})-resulting from internal mixing with nonrefractory and nonlight absorbing materials-in climate models. Here, applying scaling theory to numerically exact electromagnetic calculations of simulated BC particles and observational data on BC light absorption, we show that MAC_{BC} and E_{MAC_{BC}} evolve with increasing internal mixing ratios in simple power-law exponents of 1/3. Remarkably, MAC_{BC} remains inversely proportional to the wavelength of light at any mixing ratio. When mixing states are represented using mass-equivalent core-shell spheres, as is done in current climate models, it results in significant underprediction of MAC_{BC}. We elucidate the responsible mechanism based on shielding of photons by a sphere's skin depth and establish a correction factor that scales with a ¾ power-law exponent.
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Affiliation(s)
- Rajan K Chakrabarty
- Center for Aerosol Science and Engineering, Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, USA
- McDonnell Center for the Space Sciences, Washington University in St. Louis, St. Louis, Missouri 63130, USA
| | - William R Heinson
- Center for Aerosol Science and Engineering, Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, USA
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Scattering and Radiative Properties of Morphologically Complex Carbonaceous Aerosols: A Systematic Modeling Study. REMOTE SENSING 2018. [DOI: 10.3390/rs10101634] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This paper provides a thorough modeling-based overview of the scattering and radiative properties of a wide variety of morphologically complex carbonaceous aerosols. Using the numerically-exact superposition T-matrix method, we examine the absorption enhancement, absorption Ångström exponent (AAE), backscattering linear depolarization ratio (LDR), and scattering matrix elements of black-carbon aerosols with 11 different model morphologies ranging from bare soot to completely embedded soot–sulfate and soot–brown carbon mixtures. Our size-averaged results show that fluffy soot particles absorb more light than compact bare-soot clusters. For the same amount of absorbing material, the absorption cross section of internally mixed soot can be more than twice that of bare soot. Absorption increases as soot accumulates more coating material and can become saturated. The absorption enhancement is affected by particle size, morphology, wavelength, and the amount of coating. We refute the conventional belief that all carbonaceous aerosols have AAEs close to 1.0. Although LDRs caused by bare soot and certain carbonaceous particles are rather weak, LDRs generated by other soot-containing aerosols can reproduce strong depolarization measured by Burton et al. for aged smoke. We demonstrate that multi-wavelength LDR measurements can be used to identify the presence of morphologically complex carbonaceous particles, although additional observations can be needed for full characterization. Our results show that optical constants of the host/coating material can significantly influence the scattering and absorption properties of soot-containing aerosols to the extent of changing the sign of linear polarization. We conclude that for an accurate estimate of black-carbon radiative forcing, one must take into account the complex morphologies of carbonaceous aerosols in remote sensing studies as well as in atmospheric radiation computations.
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Tóth Á, Hoffer A, Pósfai M, Ajtai T, Kónya Z, Blazsó M, Czégény Z, Kiss G, Bozóki Z, Gelencsér A. Chemical characterization of laboratory-generated tar ball particles. ATMOSPHERIC CHEMISTRY AND PHYSICS 2018. [DOI: 10.5194/acp-18-10407-2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract. The chemical properties of laboratory-generated tar ball (Lab-TB) particles
produced from dry distillate (wood tars) of three different wood species in
the laboratory were investigated by analytical techniques that had never been
used before for their characterization. The elemental compositions of
laboratory-generated tar balls (Lab-TBs) from three tree species were very
similar to one another and to those characteristic of atmospheric tar balls
(TBs) collected from the savanna fire during the SAFARI 2000 sampling
campaign. The O ∕ C and H ∕ C molar ratios of the generated Lab-TBs
were at the upper limit characteristic of soot particles. The Fourier
transform infrared spectroscopy (FT-IR) spectra of the generated Lab-TBs were
very similar to one another as well and also showed some similarity with
those of atmospheric humic-like substances (HULIS). The FT-IR measurements
indicated that Lab-TBs have a higher proportion of aromatic structure than
HULIS and the oxygen atoms of Lab-TBs are mainly found in hydroxyl and keto
functional groups. Whereas Raman activity was detected in the starting
materials of the Lab-TBs (wood tars) in the range of 1000–1800 cm−1,
the Raman spectra of TBs were dominated by two pronounced bands with
intensity maxima near 1580 (G band) and 1350 cm−1 (D band), indicating
the presence of sp2-hybridized carbon structures and disorder in them,
respectively. In the Py-GC-MS chromatograms of the Lab-TBs mostly aromatic
compounds (aromatic hydrocarbons, oxygenated aromatics and heterocyclic
aromatics) were identified in accordance with the results of Raman and FT-IR
spectroscopy. According to organic carbon ∕ elemental carbon
(OC ∕ EC) analysis using EUSAAR_2 thermal protocol, 22 % of the
total carbon content of Lab-TBs was identified as EC, contrary to
expectations based on the current understanding that negligible if any EC is
present in this sub-fraction of the brown carbon family. Our results suggest
that spherical atmospheric TBs with high C ∕ O molar ratios are closer to
BC in many of their properties than to weakly absorbing HULIS.
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Wu Y, Cheng T, Liu D, Allan JD, Zheng L, Chen H. Light Absorption Enhancement of Black Carbon Aerosol Constrained by Particle Morphology. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:6912-6919. [PMID: 29783837 DOI: 10.1021/acs.est.8b00636] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The radiative forcing of black carbon aerosol (BC) is one of the largest sources of uncertainty in climate change assessments. Contrasting results of BC absorption enhancement ( Eabs) after aging are estimated by field measurements and modeling studies, causing ambiguous parametrizations of BC solar absorption in climate models. Here we quantify Eabs using a theoretical model parametrized by the complex particle morphology of BC in different aging scales. We show that Eabs continuously increases with aging and stabilizes with a maximum of ∼3.5, suggesting that previous seemingly contrast results of Eabs can be explicitly described by BC aging with corresponding particle morphology. We also report that current climate models using Mie Core-Shell model may overestimate Eabs at a certain aging stage with a rapid rise of Eabs, which is commonly observed in the ambient. A correction coefficient for this overestimation is suggested to improve model predictions of BC climate impact.
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Affiliation(s)
- Yu Wu
- State Key Laboratory of Remote Sensing Science , Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences , No. 20 Datun Road , Beijing 100101 , China
| | - Tianhai Cheng
- State Key Laboratory of Remote Sensing Science , Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences , No. 20 Datun Road , Beijing 100101 , China
| | - Dantong Liu
- Centre for Atmospheric Sciences, School of Earth and Environmental Sciences , University of Manchester , Manchester M13 9PL , United Kingdom
| | - James D Allan
- Centre for Atmospheric Sciences, School of Earth and Environmental Sciences , University of Manchester , Manchester M13 9PL , United Kingdom
- National Centre for Atmospheric Science , University of Manchester , Manchester M13 9PL , United Kingdom
| | - Lijuan Zheng
- China Aero Geophysical Survey and Remote Sensing Center for Land and Resources , No. 31 Xueyuan Road , Beijing 100083 , China
| | - Hao Chen
- State Key Laboratory of Remote Sensing Science , Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences , No. 20 Datun Road , Beijing 100101 , China
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Luo J, Zhang Y, Zhang Q, Wang F, Liu J, Wang J. Sensitivity analysis of morphology on radiative properties of soot aerosols. OPTICS EXPRESS 2018; 26:A420-A432. [PMID: 29801263 DOI: 10.1364/oe.26.00a420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 03/19/2018] [Indexed: 06/08/2023]
Abstract
Absorption cross section (Cabs), scattering cross section (Csca) and asymmetry parameter (ASY) of soot particles in different atmospheric aging status were investigated under fixed equivalent volume radius (RV) using the numerically exact multiple-sphere T-matrix method. The radiative properties of soot particles would be largely diverse in different aging status even RV is fixed. However, there are many insensitive parameters under different aging status. The Cabs and ASY is insensitive to monomers number (Ns) when Ns is larger than a threshold value. For bare and thinly coated soot aggregates, Cabs is insensitive to fractal dimension (Df) when the RV is small, where the relative errors of Cabs for different Df are within 2.5%. However, the effects of Df is obvious for large soot due to the shielding effects of large monomers, and the relative errors for different Df can reach to 18% for bare soot. For thinly coated soot, the changes of ASY with soot volume fraction (fsoot) is small due to the little changes of the fractal structure when the RV is fixed. In addition, for thickly coated soot, ASY is insensitive to Ns due to the unchanged overall spherical structure. Our results give a further understanding of the influences of morphology on radiative properties. It may be helpful for model selection and model simplification.
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50
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Wang L, Gong H, Peng N, Zhang JZ. Molecular Adsorption Mechanism of Elemental Carbon Particles on Leaf Surface. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:5182-5190. [PMID: 29608842 DOI: 10.1021/acs.est.7b06088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Plant leaves can effectively capture and retain particulate matter (PM), improving air quality and human health. However, little is known about the adsorption mechanism of PM on leaf surface. Black carbon (BC) has great adverse impact on climate and environment. Four types of elemental carbon (EC) particles, carbon black as a simple model for BC, graphite, reduced graphene oxide, and graphene oxide, and C36H74/C44H88O2 as model compounds for epicuticular wax were chosen to study their interaction and its impact at the molecular level using powder X-ray diffraction and vibrational spectroscopy (infrared and Raman). The results indicate that EC particles and wax can form C-H···π type hydrogen bonding with charge transfer from carbon to wax; therefore, strong attraction is expected between them due to the cooperativity of hydrogen bonding and London dispersion from instantaneous dipoles. In reality, once settled on the leaf surface, especially without wax ultrastructures, BC with extremely large surface-to-volume ratio will likely stick and stay. On the other hand, BC particles can lead to phase transition of epicuticular wax from crystalline to amorphous structures by creating packing disorder and end- gauche defects of wax molecular chain, potentially causing water loss and thereby damage of plants.
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Affiliation(s)
- Lei Wang
- College of Resource Environment and Tourism , Capital Normal University , Beijing 100048 , China
| | - Huili Gong
- College of Resource Environment and Tourism , Capital Normal University , Beijing 100048 , China
| | - Nian Peng
- College of Resource Environment and Tourism , Capital Normal University , Beijing 100048 , China
| | - Jin Z Zhang
- Department of Chemistry and Biochemistry , University of California , Santa Cruz , California 95064 , United States
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