1
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Fan T, Ren J, Liu C, Li Z, Liu J, Sun Y, Wang Y, Jin X, Zhang F. Evidence of Surface-Tension Lowering of Atmospheric Aerosols by Organics from Field Observations in an Urban Atmosphere: Relation to Particle Size and Chemical Composition. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:11363-11375. [PMID: 38900148 DOI: 10.1021/acs.est.4c03141] [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: 06/21/2024]
Abstract
Surface-active organics lower the aerosol surface tension (σs/a), leading to enhanced cloud condensation nuclei (CCN) activity and potentially exerting impacts on the climate. Quantification of σs/a is mainly limited to laboratory or modeling work for particles with selected sizes and known chemical compositions. Inferred values from ambient aerosol populations are deficient. In this study, we propose a new method to derive σs/a by combining field measurements made at an urban site in northern China with the κ-Köhler theory. The results present new evidence that organics remarkably lower the surface tension of aerosols in a polluted atmosphere. Particles sized around 40 nm have an averaged σs/a of 53.8 mN m-1, while particles sized up to 100 nm show σs/a values approaching that of pure water. The dependence curve of σs/a with the organic mass resembles the behavior of dicarboxylic acids, suggesting their critical role in reducing the surface tension. The study further reveals that neglecting the σs/a lowering effect would result in lowered ultrafine CCN (diameter <100 nm) concentrations by 6.8-42.1% at a typical range of supersaturations in clouds, demonstrating the significant impact of surface tension on the CCN concentrations of urban aerosols.
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Affiliation(s)
- Tianyi Fan
- Faculty of Geographical Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China
| | - Jingye Ren
- Xi'an Institute for Innovative Earth Environment Research, Xi'an 710061, China
| | - Chenxi Liu
- Faculty of Geographical Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China
| | - Z Li
- Department of Atmospheric and Oceanic Science, Earth System Science Interdisciplinary Center, University of Maryland, College Park, Maryland 20742, United States
| | - Jieyao Liu
- Faculty of Geographical Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China
| | - Yele Sun
- Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Yuying Wang
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Xiaoai Jin
- State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture & Forestry University, Hangzhou 311300, China
| | - Fang Zhang
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
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2
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Freedman MA, Huang Q, Pitta KR. Phase Transitions in Organic and Organic/Inorganic Aerosol Particles. Annu Rev Phys Chem 2024; 75:257-281. [PMID: 38382569 DOI: 10.1146/annurev-physchem-083122-115909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
The phase state of aerosol particles can impact numerous atmospheric processes, including new particle growth, heterogeneous chemistry, cloud condensation nucleus formation, and ice nucleation. In this article, the phase transitions of inorganic, organic, and organic/inorganic aerosol particles are discussed, with particular focus on liquid-liquid phase separation (LLPS). The physical chemistry that determines whether LLPS occurs, at what relative humidity it occurs, and the resultant particle morphology is explained using both theoretical and experimental methods. The known impacts of LLPS on aerosol processes in the atmosphere are discussed. Finally, potential evidence for LLPS from field and chamber studies is presented. By understanding the physical chemistry of the phase transitions of aerosol particles, we will acquire a better understanding of aerosol processes, which in turn impact human health and climate.
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Affiliation(s)
- Miriam Arak Freedman
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, USA; ,
- Department of Meteorology and Atmospheric Science, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Qishen Huang
- Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China;
| | - Kiran R Pitta
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, USA; ,
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3
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Jose C, Singh A, Kalkura KN, Jose GV, Srivastava S, Ammini RK, Yadav S, Ravikrishna R, Andreae MO, Martin ST, Liu P, Gunthe SS. Complex Hygroscopic Behavior of Ambient Aerosol Particles Revealed by a Piezoelectric Technique. ACS EARTH & SPACE CHEMISTRY 2024; 8:983-991. [PMID: 38774361 PMCID: PMC11103707 DOI: 10.1021/acsearthspacechem.3c00347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 03/22/2024] [Accepted: 03/28/2024] [Indexed: 05/24/2024]
Abstract
Understanding the complex interactions between atmospheric aerosols and water vapor in subsaturated regions of the atmosphere is crucial for modeling and predicting aerosol-cloud-radiation-climate interactions. However, the microphysical mechanisms of these interactions for ambient aerosols remain poorly understood. For this study, size-resolved samples were collected from a high-altitude, relatively clean site situated in the Western Ghats of India during the monsoon season, in order to study background and preindustrial processes as a baseline for climate functioning within the context of the most polluted region of the world. Measurements of humidity-dependent mass-based growth factors, hygroscopicity, deliquescence behavior, and aerosol liquid water content (ALWC) were made by a novel approach using a quartz crystal microbalance based on a piezo-electric sensor. The climate-relevant fine-mode aerosols (≤2.5 μm) exhibited strong size-dependent variations in their interactions with water vapor and contributed a high fraction of ALWC. Deliquescence occurred for relatively large aerosols (diameter >180 nm) but was absent for smaller aerosols. The deliquescence relative humidity for ambient aerosols was significantly lower than that of pure inorganic salts, suggesting a strong influence of organic species. Our study establishes an improved approach for accurately measuring aerosol water uptake characteristics of ambient aerosols in the subsaturated regime, aiding in the assessment of radiative forcing effects and improving climate models.
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Affiliation(s)
- Christi Jose
- Environemntal
Engineering Division, Dept of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, India
- Centre
for Atmospheric and Climate Sciences, Indian
Institute of Technology Madras, Chennai 600036, India
| | - Aishwarya Singh
- Environemntal
Engineering Division, Dept of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, India
- Centre
for Atmospheric and Climate Sciences, Indian
Institute of Technology Madras, Chennai 600036, India
| | - Kavyashree N. Kalkura
- Environemntal
Engineering Division, Dept of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, India
- Centre
for Atmospheric and Climate Sciences, Indian
Institute of Technology Madras, Chennai 600036, India
| | - George V. Jose
- Dept
of Civil Engineering, Indian Institute of
Technology Bombay, Mumbai 400076, India
| | - Shailina Srivastava
- Environemntal
Engineering Division, Dept of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, India
- Centre
for Atmospheric and Climate Sciences, Indian
Institute of Technology Madras, Chennai 600036, India
| | | | - Shweta Yadav
- Dept
of Environmental Sciences, Central University
of Jammu, Jammu and Kashmir, Samba 181143, India
| | - Raghunathan Ravikrishna
- Centre
for Atmospheric and Climate Sciences, Indian
Institute of Technology Madras, Chennai 600036, India
- Dept of Chemical
Engineering, Indian Institute of Technology
Madras, Chennai 600036, India
| | - Meinrat O. Andreae
- Max
Planck Institute for Chemistry, Mainz 55128, Germany
- Scripps
Institution of Oceanography, University
of California San Diego, La Jolla, California 92093, United States
- Department
of Geology and Geophysics, King Saud University, Riyadh 11451, Saudi Arabia
| | - Scot T. Martin
- Department
of Earth and Planetary Sciences, Harvard
University, Cambridge, Massachusetts 02138, United States
- John
A. Paulson School of Engineering & Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Pengfei Liu
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Sachin S. Gunthe
- Environemntal
Engineering Division, Dept of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, India
- Centre
for Atmospheric and Climate Sciences, Indian
Institute of Technology Madras, Chennai 600036, India
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4
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Shi R, Zhang F, Shen Y, Shen J, Xu B, Kuang B, Xu Z, Jin L, Tang Q, Tian X, Wang Z. Aerosol liquid water in PM 2.5 and its roles in secondary aerosol formation at a regional site of Yangtze River Delta. J Environ Sci (China) 2024; 138:684-696. [PMID: 38135431 DOI: 10.1016/j.jes.2023.04.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 04/22/2023] [Accepted: 04/22/2023] [Indexed: 12/24/2023]
Abstract
Aerosol liquid water content (ALWC) plays an important role in secondary aerosol formation. In this study, a whole year field campaign was conducted at Shanxi in north Zhejiang Province during 2021. ALWC estimated by ISORROPIA-II was then investigated to explore its characteristics and relationship with secondary aerosols. ALWC exhibited a highest value in spring (66.38 µg/m3), followed by winter (45.08 µg/m3), summer (41.64 µg/m3), and autumn (35.01 µg/m3), respectively. It was supposed that the secondary inorganic aerosols (SIA) were facilitated under higher ALWC conditions (RH > 80%), while the secondary organic species tended to form under lower ALWC levels. Higher RH (> 80%) promoted the NO3- formation via gas-particle partitioning, while SO42- was generated at a relative lower RH (> 50%). The ALWC was more sensitive to NO3- (R = 0.94) than SO42- (R = 0.90). Thus, the self-amplifying processes between the ALWC and SIA enhanced the particle mass growth. The sensitivity of ALWC and OX (NO2 + O3) to secondary organic carbon (SOC) varied in different seasons at Shanxi, more sensitive to aqueous-phase reactions (daytime R = 0.84; nighttime R = 0.54) than photochemical oxidation (daytime R = 0.23; nighttime R = 0.41) in wintertime with a high level of OX (daytime: 130-140 µg/m3; nighttime: 100-140 µg/m3). The self-amplifying process of ALWC and SIA and the aqueous-phase formation of SOC will enhance aerosol formation, contributing to air pollution and reduction of visibility.
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Affiliation(s)
- Ruifang Shi
- College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou 310058, China
| | - Fei Zhang
- College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou 310058, China
| | - Yemin Shen
- Zhejiang Ecological and Environmental Monitoring Center, Hangzhou 310012, China
| | - Jiasi Shen
- Zhejiang Ecological and Environmental Monitoring Center, Hangzhou 310012, China
| | - Bingye Xu
- Zhejiang Ecological and Environmental Monitoring Center, Hangzhou 310012, China
| | - Binyu Kuang
- College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou 310058, China
| | - Zhengning Xu
- College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou 310058, China
| | - Lingling Jin
- Zhejiang Ecological and Environmental Monitoring Center, Hangzhou 310012, China
| | - Qian Tang
- Zhejiang Ecological and Environmental Monitoring Center, Hangzhou 310012, China
| | - Xudong Tian
- Zhejiang Ecological and Environmental Monitoring Center, Hangzhou 310012, China
| | - Zhibin Wang
- College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou 310058, China; ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, China.
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5
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Lee WC, Liu P, Han Y, Martin ST, Kuwata M. Accounting for Cloud Nucleation Activation Mechanism of Secondary Organic Matter from α-Pinene Oxidation Using Experimentally Retrieved Water Solubility Distributions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:13439-13448. [PMID: 37647587 DOI: 10.1021/acs.est.3c03039] [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: 09/01/2023]
Abstract
Activation of cloud droplets of aerosol particles from biogenic precursors plays a critical role in Earth's climate system. However, the molecular-level understanding of the cloud condensation nuclei (CCN) activation process for secondary organic matter (SOM) is still lacking. Here, we reduced the gap by segregating SOM from α-pinene based on water solubility. The chemical composition and CCN activity of the solubility-segregated fractions of SOM were measured. The results demonstrated for the first time by laboratory experiment that highly oxygenated compounds such as hydroperoxides and highly oxygenated organic molecules are important contributors for the CCN activity of α-pinene SOM. Meanwhile, relatively less water-soluble species were also abundant. Analysis based on the Köhler theory demonstrated that less water-soluble compounds in SOM remain undissolved during the cloud activation process, suggesting that the traditional single-parameter parameterization for CCN activation would not be sufficient for representing the process. In combination with the recent developments in SOM formation chemistry, the present study helps in understanding the interactions between the biosphere and climate.
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Affiliation(s)
- Wen-Chien Lee
- Department of Atmospheric and Oceanic Sciences, Laboratory for Climate and Ocean-Atmosphere Studies, Peking University, Beijing 100871, China
- Beijing Innovation Center for Engineering Science and Advanced Technology (BIC-ESAT), Peking University, Beijing 100871, China
- Division of Chemistry and Biochemistry, Nanyang Technological University, Singapore 639798, Singapore
- Earth Observatory of Singapore, Nanyang Technological University, Singapore 639798, Singapore
- John A. Paulson School of Environment and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Pengfei Liu
- John A. Paulson School of Environment and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Yuemei Han
- John A. Paulson School of Environment and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Scot T Martin
- John A. Paulson School of Environment and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Mikinori Kuwata
- Department of Atmospheric and Oceanic Sciences, Laboratory for Climate and Ocean-Atmosphere Studies, Peking University, Beijing 100871, China
- Beijing Innovation Center for Engineering Science and Advanced Technology (BIC-ESAT), Peking University, Beijing 100871, China
- Division of Chemistry and Biochemistry, Nanyang Technological University, Singapore 639798, Singapore
- Earth Observatory of Singapore, Nanyang Technological University, Singapore 639798, Singapore
- Campus for Research Excellence and Technological Enterprise (CREATE) Programme, Singapore 138602, Singapore
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6
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Li X, Bourg IC. Phase State, Surface Tension, Water Activity, and Accommodation Coefficient of Water-Organic Clusters Near the Critical Size for Atmospheric New Particle Formation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:13092-13103. [PMID: 37607019 PMCID: PMC10483925 DOI: 10.1021/acs.est.2c09627] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 08/11/2023] [Accepted: 08/11/2023] [Indexed: 08/24/2023]
Abstract
Interactions between water and organic molecules in sub-4 nm clusters play a significant role in the formation and growth of secondary organic aerosol (SOA) particles. However, a complete understanding of the relevant water microphysics has not yet been achieved due to challenges in the experimental characterization of soft nuclei. Here, we use molecular dynamics simulations to study the phase-mixing states, surface tension, water activity, and water accommodation coefficient of organic-water clusters representative of freshly nucleated SOA particles. Our results reveal large deviations from the behavior expected based on continuum theories. In particular, the phase-mixing state has a strong dependence on cluster size; surface tension displays a minimum at a specific organic-water mass ratio (morg/mw ∼ 4.5 in this study) corresponding to a minimum inhibition of droplet nucleation associated with the Kelvin effect; and the water accommodation coefficient increases by a factor of 2 with nanocluster hygroscopic growth, in agreement with recent experimental studies. Overall, our results yield parametric relations for water microphysical properties in sub-4 nm clusters and provide insight into the role of water in the initial stages of SOA nucleation and growth.
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Affiliation(s)
- Xiaohan Li
- Department
of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Ian C. Bourg
- Department
of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey 08544, United States
- High
Meadows Environmental Institute, Princeton
University, Princeton, New Jersey 08544, United States
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7
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Zhang Z, Wang C, Zhao Y, Zhao Y, Li G, Xie H, Jiang L. Autoxidation Mechanism and Kinetics of Methacrolein in the Atmosphere. J Phys Chem A 2023; 127:2819-2829. [PMID: 36939326 DOI: 10.1021/acs.jpca.3c00128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
Elucidating the autoxidation of volatile organic compounds (VOCs) is crucial to understanding the formation mechanism of secondary organic aerosols, but it has been proven to be challenging due to the complexity of reactions under atmospheric conditions. Here, we report a comprehensive theoretical study of atmospheric autoxidation in VOCs exemplified by the atmospherically important methacrolein (MACR), a major oxidation product of isoprene. The results indicate that the Cl-adducts and H-abstraction products of MACR readily react with O2 and undergo subsequent isomerizations via H-shift and cyclization, forming a large variety of lowly and highly oxygenated organic molecules. In particular, the first- and third-generation oxidation products derived from the Cl-adducts and the methyl-H-abstraction complexes are dominated in the atmospheric autoxidation, for which the fractional yields are remarkably affected by the NO concentration. The present findings have important implications for a systematical understanding of the oxidation processes of isoprene-derived compounds in the atmospheric environments.
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Affiliation(s)
- Zhaoyan Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Chong Wang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Yingqi Zhao
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Ya Zhao
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Gang Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Hua Xie
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Ling Jiang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.,Hefei National Laboratory, Hefei 230088, China
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8
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Bouzidi H, Fayad L, Coeur C, Houzel N, Petitprez D, Faccinetto A, Wu J, Tomas A, Ondráček J, Schwarz J, Ždímal V, Zuend A. Hygroscopic growth and CCN activity of secondary organic aerosol produced from dark ozonolysis of γ-terpinene. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 817:153010. [PMID: 35026240 DOI: 10.1016/j.scitotenv.2022.153010] [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: 07/20/2021] [Revised: 12/30/2021] [Accepted: 01/05/2022] [Indexed: 06/14/2023]
Abstract
The hygroscopic growth factor (GF) and cloud condensation nuclei (CCN) activity of secondary organic aerosol (SOA) particles produced during dark ozonolysis of γ-terpinene under different reaction conditions were investigated. The SOA particles were produced in the presence or absence of cyclohexane, an OH scavenger; 1,3,5-trimethylbenzene, an anthropogenic volatile organic compound; and (NH4)2SO4 seed particles. A hygroscopicity tandem differential mobility analyzer was used to determine the GFs of the SOA particles at RHs ≤ 93%. For some experiments, a CCN counter was used for size-resolved measurement of CCN activation at supersaturation (S) in the range of 0.1 to 1%. The single hygroscopicity parameter κ was derived from both the GF and CCN measurements. Under subsaturated conditions, all the SOA (except those in the presence of the (NH4)2SO4 seeds) showed small GF values. These GFs demonstrated that SOA mass loading affected the GF. A decrease in the SOA mass loading led to increased GF and corresponding κGFvalues. However, in a supersaturation regime, the SOA mass loading and the size of the particles did not significantly alter the CCN activity of the SOA. Our CCN measurements showed higher κCCN values (κCCN = 0.20-0.24) than those observed in most monoterpene ozonolysis studies (κCCN = 0.1-0.14). This difference may have been due to the presence of the two endocyclic double bonds in the γ-terpinene structure, which may have affected the SOA chemical composition, in contrast to monoterpenes that contain an exocyclic double bond. Our comparisons of sub- and supersaturated conditions showed a larger range of κ values than other experiments. Average κCCN/κGF ratios of ~7 and 14 were obtained in the unseeded SOA experiments at low and high SOA mass loadings, respectively. The average κCCN of 0.23 indicated that the SOA produced during ozonolysis of γ-terpinene exhibited fairly high CCN activity.
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Affiliation(s)
- Hichem Bouzidi
- Laboratoire de Physico-Chimie de l'Atmosphère, Université du Littoral Côte d'Opale, Dunkerque 59140, France; Institute of Chemical Process Fundamentals of the CAS, Department of Aerosols Chemistry and Physics, Prague CZ-16502, Czech Republic; IMT Lille Douai, Institut Mines-Télécom, Univ. Lille, Centre for Energy and Environment, 59000 Lille, France.
| | - Layal Fayad
- Laboratoire de Physico-Chimie de l'Atmosphère, Université du Littoral Côte d'Opale, Dunkerque 59140, France
| | - Cecile Coeur
- Laboratoire de Physico-Chimie de l'Atmosphère, Université du Littoral Côte d'Opale, Dunkerque 59140, France
| | - Nicolas Houzel
- Laboratoire de Physico-Chimie de l'Atmosphère, Université du Littoral Côte d'Opale, Dunkerque 59140, France
| | | | | | - Junteng Wu
- Univ. Lille, CNRS PC2A, 59000 Lille, France
| | - Alexandre Tomas
- IMT Lille Douai, Institut Mines-Télécom, Univ. Lille, Centre for Energy and Environment, 59000 Lille, France
| | - Jakub Ondráček
- Institute of Chemical Process Fundamentals of the CAS, Department of Aerosols Chemistry and Physics, Prague CZ-16502, Czech Republic
| | - Jaroslav Schwarz
- Institute of Chemical Process Fundamentals of the CAS, Department of Aerosols Chemistry and Physics, Prague CZ-16502, Czech Republic
| | - Vladimír Ždímal
- Institute of Chemical Process Fundamentals of the CAS, Department of Aerosols Chemistry and Physics, Prague CZ-16502, Czech Republic
| | - Andreas Zuend
- Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec H3A 0B9, Canada
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9
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Mahrt F, Huang Y, Zaks J, Devi A, Peng L, Ohno PE, Qin YM, Martin ST, Ammann M, Bertram AK. Phase Behavior of Internal Mixtures of Hydrocarbon-like Primary Organic Aerosol and Secondary Aerosol Based on Their Differences in Oxygen-to-Carbon Ratios. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:3960-3973. [PMID: 35294833 PMCID: PMC8988305 DOI: 10.1021/acs.est.1c07691] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The phase behavior, the number and type of phases, in atmospheric particles containing mixtures of hydrocarbon-like organic aerosol (HOA) and secondary organic aerosol (SOA) is important for predicting their impacts on air pollution, human health, and climate. Using a solvatochromic dye and fluorescence microscopy, we determined the phase behavior of 11 HOA proxies (O/C = 0-0.29) each mixed with 7 different SOA materials generated in environmental chambers (O/C 0.4-1.08), where O/C represents the average oxygen-to-carbon atomic ratio. Out of the 77 different HOA + SOA mixtures studied, we observed two phases in 88% of the cases. The phase behavior was independent of relative humidity over the range between 90% and <5%. A clear trend was observed between the number of phases and the difference between the average O/C ratios of the HOA and SOA components (ΔO/C). Using a threshold ΔO/C of 0.265, we were able to predict the phase behavior of 92% of the HOA + SOA mixtures studied here, with one-phase particles predicted for ΔO/C < 0.265 and two-phase particles predicted for ΔO/C ≥ 0.265. The threshold ΔO/C value provides a relatively simple and computationally inexpensive framework for predicting the number of phases in internal SOA and HOA mixtures in atmospheric models.
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Affiliation(s)
- Fabian Mahrt
- Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T1Z1, Canada
- Laboratory
of Environmental Chemistry, Paul Scherrer
Institute, 5232 Villigen, Switzerland
| | - Yuanzhou Huang
- Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T1Z1, Canada
| | - Julia Zaks
- Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T1Z1, Canada
| | - Annesha Devi
- Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T1Z1, Canada
| | - Long Peng
- Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T1Z1, Canada
- Institute
for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
| | - Paul E. Ohno
- John
A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
- Center
for the Environment, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Yi Ming Qin
- John
A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Scot T. Martin
- John
A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
- Department
of Earth and Planetary Sciences, Harvard
University, Cambridge, Massachusetts 02138, United States
| | - Markus Ammann
- Laboratory
of Environmental Chemistry, Paul Scherrer
Institute, 5232 Villigen, Switzerland
| | - Allan K. Bertram
- Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T1Z1, Canada
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10
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Zaveri RA, Wang J, Fan J, Zhang Y, Shilling JE, Zelenyuk A, Mei F, Newsom R, Pekour M, Tomlinson J, Comstock JM, Shrivastava M, Fortner E, Machado LAT, Artaxo P, Martin ST. Rapid growth of anthropogenic organic nanoparticles greatly alters cloud life cycle in the Amazon rainforest. SCIENCE ADVANCES 2022; 8:eabj0329. [PMID: 35020441 PMCID: PMC8754412 DOI: 10.1126/sciadv.abj0329] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 11/18/2021] [Indexed: 05/31/2023]
Abstract
Aerosol-cloud interactions remain uncertain in assessing climate change. While anthropogenic activities produce copious aerosol nanoparticles smaller than 10 nanometers, they are too small to act as efficient cloud condensation nuclei (CCN). The mechanisms responsible for particle growth to CCN-relevant sizes are poorly understood. Here, we present aircraft observations of rapid growth of anthropogenic nanoparticles downwind of an isolated metropolis in the Amazon rainforest. Model analysis reveals that the sustained particle growth to CCN sizes is predominantly caused by particle-phase diffusion-limited partitioning of semivolatile oxidation products of biogenic hydrocarbons. Cloud-resolving numerical simulations show that the enhanced CCN concentrations in the urban plume substantially alter the formation of shallow convective clouds, suppress precipitation, and enhance the transition to deep convective clouds. The proposed nanoparticle growth mechanism, expressly enabled by the abundantly formed semivolatile organics, suggests an appreciable impact of anthropogenic aerosols on cloud life cycle in previously unpolluted forests of the world.
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Affiliation(s)
- Rahul A. Zaveri
- Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Jian Wang
- Washington University in Saint Louis, Saint Louis, MO 63130, USA
| | - Jiwen Fan
- Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Yuwei Zhang
- Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | | | - Alla Zelenyuk
- Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Fan Mei
- Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Rob Newsom
- Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Mikhail Pekour
- Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Jason Tomlinson
- Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | | | | | | | - Luiz A. T. Machado
- National Institute for Space Research, São José dos Campos, São Paulo 12227-010, Brazil
| | - Paulo Artaxo
- Institute of Physics, University of São Paulo, São Paulo 05508-090, Brazil
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11
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Asadzadeh B, Bouzidi H, Bisson R, Ondráček J, Schwarz J, Lahib A, Ždímal V. Hygroscopicity of secondary marine organic aerosols: Mixtures of alkylammonium salts and inorganic components. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 790:148131. [PMID: 34107406 DOI: 10.1016/j.scitotenv.2021.148131] [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: 02/11/2021] [Revised: 05/26/2021] [Accepted: 05/26/2021] [Indexed: 06/12/2023]
Abstract
Field studies have identified alkylammonium salts as important components of secondary marine organic aerosols. In this work, we study the hygroscopic behavior of laboratory-generated alkylammonium aerosol particles, including monomethylammonium chloride (MMACl), dimethylammonium chloride (DMACl), trimethylammonium chloride (TMACl), diethylammonium chloride (DEACl), and their mixtures with inorganic salts containing ammonium sulfate (NH4)2SO4, sodium chloride NaCl, calcium nitrate Ca(NO3)2 and sodium sulfate Na2SO4 at different dry mass ratios with a hygroscopicity tandem differential mobility analyzer (HTDMA). The hygroscopic growth of pure alkylammonium salt particles (except for DEACl) reveals gradual water uptake over the whole studied range of relative humidities (RHs). In general, the impact of the presence of alkylammonium chloride on the phase behavior and hygroscopic growth of mixtures depends on the chemical composition of particles and volume fraction of the alkylammonium chloride in the mixtures. For alkylammonium/(NH4)2SO4 mixed particles (except for TMACl/(NH4)2SO4), the hygroscopic growth shows a smooth growth tendency when the organic content is high, while the deliquescence transition is observed for alkylammonium salt/NaCl mixtures at all mass ratios. Regarding the different mixtures of alkylammonium/Ca(NO3)2 particles, continuous water uptake without phase transition is observed over the studied RH range, indicating that alkylammonium salts impose no effect on the liquid-like state of calcium nitrate. The alkylammonium/Na2SO4 mixtures show obvious particle shrinkage prior to the deliquescence point. A similar behavior is also observed for alkylammonium salt/NaCl mixtures. The observed diameter reduction can be attributed to the transformation of porous or irregularly shaped solid particles into more compact near-spherical particles. In the following, measured growth factors (GFs) are compared with values predicted with the Zdanovskii-Stokes-Robinson (ZSR) mixing rule and ideal solution model. The ZSR predictions for different alkylammonium/inorganic mixtures are similar to the measured GFs as long as the mixed particles are in a liquid-like state.
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Affiliation(s)
- Behnaz Asadzadeh
- Department of Aerosols Chemistry and Physics, AS CR, Institute of Chemical Process Fundamentals of the CAS, Prague CZ-16502, Czech Republic
| | - Hichem Bouzidi
- Department of Aerosols Chemistry and Physics, AS CR, Institute of Chemical Process Fundamentals of the CAS, Prague CZ-16502, Czech Republic; IMT Lille Douai, Institut Mines-Télécom, Univ. Lille, Centre for Energy and Environment, 59000 Lille, France.
| | - Robin Bisson
- Polytech Nantes-Département Génie des Procédés et Bioprocédés, Site Universitaire de Gavy-Océanis, Boulevard de l'Université, 44600 Saint Nazaire Cedex, France
| | - Jakub Ondráček
- Department of Aerosols Chemistry and Physics, AS CR, Institute of Chemical Process Fundamentals of the CAS, Prague CZ-16502, Czech Republic
| | - Jaroslav Schwarz
- Department of Aerosols Chemistry and Physics, AS CR, Institute of Chemical Process Fundamentals of the CAS, Prague CZ-16502, Czech Republic
| | - Ahmad Lahib
- IMT Lille Douai, Institut Mines-Télécom, Univ. Lille, Centre for Energy and Environment, 59000 Lille, France
| | - Vladimír Ždímal
- Department of Aerosols Chemistry and Physics, AS CR, Institute of Chemical Process Fundamentals of the CAS, Prague CZ-16502, Czech Republic
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12
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Mahrt F, Newman E, Huang Y, Ammann M, Bertram AK. Phase Behavior of Hydrocarbon-like Primary Organic Aerosol and Secondary Organic Aerosol Proxies Based on Their Elemental Oxygen-to-Carbon Ratio. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:12202-12214. [PMID: 34473474 DOI: 10.1021/acs.est.1c02697] [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] [Indexed: 05/28/2023]
Abstract
A large fraction of atmospheric aerosols can be characterized as primary organic aerosol (POA) and secondary organic aerosol (SOA). Knowledge of the phase behavior, that is, the number and type of phases within internal POA + SOA mixtures, is crucial to predict their effect on climate and air quality. For example, if POA and SOA form a single phase, POA will enhance the formation of SOA by providing organic mass to absorb SOA precursors. Using microscopy, we studied the phase behavior of mixtures of SOA proxies and hydrocarbon-like POA proxies at relative humidity (RH) values of 90%, 45%, and below 5%. Internal mixtures of POA and SOA almost always formed two phases if the elemental oxygen-to-carbon ratio (O/C) of the POA was less than 0.11, which encompasses a large fraction of atmospheric hydrocarbon-like POA from fossil fuel combustion. SOA proxies mixed with POA proxies having 0.11 ≤ O/C ≤ 0.29 mostly resulted in particles with one liquid phase. However, two liquid phases were also observed, depending on the type of SOA and POA surrogates, and an increase in phase-separated particles was observed when increasing the RH in this O/C range. The results have implications for predicting atmospheric SOA formation and policy strategies to reduce SOA in urban environments.
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Affiliation(s)
- Fabian Mahrt
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T1Z1 Canada
- Laboratory of Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Elli Newman
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T1Z1 Canada
| | - Yuanzhou Huang
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T1Z1 Canada
| | - Markus Ammann
- Laboratory of Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Allan K Bertram
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T1Z1 Canada
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13
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Abstract
Aerosol particles are ubiquitous in the atmosphere and play an important role in air quality and the climate system. These particles can contain mixtures of primary organic aerosol, secondary organic aerosol, and secondary inorganic aerosol. We show that such internally mixed particles can contain three liquid phases. We also demonstrate that the presence of three liquid phases impacts the time needed for the particles to reach equilibrium with the surrounding gas phase and likely impacts the ability of the particles to activate into cloud droplets. A framework is presented for predicting conditions needed for the formation of three liquid phases in the atmosphere. These results will lead to improved representations of aerosols in models for air quality and climate predictions. Individual atmospheric particles can contain mixtures of primary organic aerosol (POA), secondary organic aerosol (SOA), and secondary inorganic aerosol (SIA). To predict the role of such complex multicomponent particles in air quality and climate, information on the number and types of phases present in the particles is needed. However, the phase behavior of such particles has not been studied in the laboratory, and as a result, remains poorly constrained. Here, we show that POA+SOA+SIA particles can contain three distinct liquid phases: a low-polarity organic-rich phase, a higher-polarity organic-rich phase, and an aqueous inorganic-rich phase. Based on our results, when the elemental oxygen-to-carbon (O:C) ratio of the SOA is less than 0.8, three liquid phases can coexist within the same particle over a wide relative humidity range. In contrast, when the O:C ratio of the SOA is greater than 0.8, three phases will not form. We also demonstrate, using thermodynamic and kinetic modeling, that the presence of three liquid phases in such particles impacts their equilibration timescale with the surrounding gas phase. Three phases will likely also impact their ability to act as nuclei for liquid cloud droplets, the reactivity of these particles, and the mechanism of SOA formation and growth in the atmosphere. These observations provide fundamental information necessary for improved predictions of air quality and aerosol indirect effects on climate.
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14
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Yu H, Holopainen JK, Kivimäenpää M, Virtanen A, Blande JD. Potential of Climate Change and Herbivory to Affect the Release and Atmospheric Reactions of BVOCs from Boreal and Subarctic Forests. Molecules 2021; 26:2283. [PMID: 33920862 PMCID: PMC8071236 DOI: 10.3390/molecules26082283] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 11/17/2022] Open
Abstract
Compared to most other forest ecosystems, circumpolar boreal and subarctic forests have few tree species, and are prone to mass outbreaks of herbivorous insects. A short growing season with long days allows rapid plant growth, which will be stimulated by predicted warming of polar areas. Emissions of biogenic volatile organic compounds (BVOC) from soil and vegetation could be substantial on sunny and warm days and biotic stress may accelerate emission rates. In the atmosphere, BVOCs are involved in various gas-phase chemical reactions within and above forest canopies. Importantly, the oxidation of BVOCs leads to secondary organic aerosol (SOA) formation. SOA particles scatter and absorb solar radiation and grow to form cloud condensation nuclei (CCN) and participate in cloud formation. Through BVOC and moisture release and SOA formation and condensation processes, vegetation has the capacity to affect the abiotic environment at the ecosystem scale. Recent BVOC literature indicates that both temperature and herbivory have a major impact on BVOC emissions released by woody species. Boreal conifer forest is the largest terrestrial biome and could be one of the largest sources of biogenic mono- and sesquiterpene emissions due to the capacity of conifer trees to store terpene-rich resins in resin canals above and belowground. Elevated temperature promotes increased diffusion of BVOCs from resin stores. Moreover, insect damage can break resin canals in needles, bark, and xylem and cause distinctive bursts of BVOCs during outbreaks. In the subarctic, mountain birch forests have cyclic outbreaks of Geometrid moths. During outbreaks, trees are often completely defoliated leading to an absence of BVOC-emitting foliage. However, in the years following an outbreak there is extended shoot growth, a greater number of leaves, and greater density of glandular trichomes that store BVOCs. This can lead to a delayed chemical defense response resulting in the highest BVOC emission rates from subarctic forest in the 1-3 years after an insect outbreak. Climate change is expected to increase insect outbreaks at high latitudes due to warmer seasons and arrivals of invasive herbivore species. Increased BVOC emission will affect tropospheric ozone (O3) formation and O3 induced oxidation of BVOCs. Herbivore-induced BVOC emissions from deciduous and coniferous trees are also likely to increase the formation rate of SOA and further growth of the particles in the atmosphere. Field experiments measuring the BVOC emission rates, SOA formation rate and particle concentrations within and above the herbivore attacked forest stands are still urgently needed.
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Affiliation(s)
- H. Yu
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland; (H.Y.); (J.K.H.); (M.K.)
| | - J. K. Holopainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland; (H.Y.); (J.K.H.); (M.K.)
| | - M. Kivimäenpää
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland; (H.Y.); (J.K.H.); (M.K.)
| | - A. Virtanen
- Department of Applied Physics, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland;
| | - J. D. Blande
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland; (H.Y.); (J.K.H.); (M.K.)
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15
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Zheng G, Sedlacek AJ, Aiken AC, Feng Y, Watson TB, Raveh-Rubin S, Uin J, Lewis ER, Wang J. Long-range transported North American wildfire aerosols observed in marine boundary layer of eastern North Atlantic. ENVIRONMENT INTERNATIONAL 2020; 139:105680. [PMID: 32272293 DOI: 10.1016/j.envint.2020.105680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 03/18/2020] [Accepted: 03/20/2020] [Indexed: 06/11/2023]
Abstract
Wildfire is a major source of biomass burning aerosols, which greatly impact Earth climate. Tree species in North America (NA) boreal forests can support high-intensity crown fires, resulting in elevated injection height and longer lifetime (on the order of months) of the wildfire aerosols. Given the long lifetime, the properties of aged NA wildfire aerosols are required to understand and quantify their effects on radiation and climate. Here we present comprehensive characterization of climatically relevant properties, including optical properties and cloud condensation nuclei (CCN) activities of aged NA wildfire aerosols, emitted from the record-breaking Canadian wildfires in August 2017. Despite the extreme injection height of ~12 km, some of the wildfire plumes descended into the marine boundary layer in the eastern North Atlantic over a period of ~2 weeks, owing to the dry intrusions behind mid-latitude cyclones. The aged wildfire aerosols have high single scattering albedos at 529 nm (ω529; 0.92-0.95) while low absorption Ångström exponents (Åabs) at 464 nm/648 nm (0.7-0.9). In comparison, Åabs of fresh/slightly aged ones are typically 1.4-3.5. This low Åabs indicates a nearly complete loss of brown carbon, likely due to bleaching and/or evaporation, during the long-range transport. The nearly complete loss suggests that on global average, direct radiative forcing of BrC may be minor. Combining Mie calculations and the measured aerosol hygroscopicity, volatility and size distributions, we show that the high ω529 and low Åabs values are best explained by an external mixture of non-absorbing organic particles and absorbing particles of large BC cores (>~110 nm diameter) with thick non-absorbing coatings. The accelerated descent of the wildfire plume also led to strong increase of CCN concentration at the supersaturation levels representative of marine low clouds. The hygroscopicity parameter, κCCN, of the aged wildfire aerosols varies from 0.2 to 0.4, substantially lower than that of background marine boundary layer aerosols. However, the high fraction of particles with large diameter (i.e., within accumulation size ranges, ~100-250 nm) compensates for the low values of κ, and as a result, the aged NA wildfire aerosols contribute more efficiently to CCN population. These results provide direct evidence that the long-range transported NA wildfires can strongly influence CCN concentration in remote marine boundary layer, therefore the radiative properties of marine low clouds. Given the expected increases of NA wildfire intensity and frequency and regular occurrence of dry intrusion following mid-latitude cyclones, the influence of NA wildfire aerosols on CCN and clouds in remote marine environment need to be further examined.
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Affiliation(s)
- Guangjie Zheng
- Center for Aerosol Science and Engineering, Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, MO, USA; Environmental and Climate Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Arthur J Sedlacek
- Environmental and Climate Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Allison C Aiken
- Earth System Observations, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Yan Feng
- Environmental Science Division, Argonne National Laboratory, Lemont, IL, USA
| | - Thomas B Watson
- Environmental and Climate Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Shira Raveh-Rubin
- Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Janek Uin
- Environmental and Climate Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Ernie R Lewis
- Environmental and Climate Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Jian Wang
- Center for Aerosol Science and Engineering, Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, MO, USA; Environmental and Climate Science Department, Brookhaven National Laboratory, Upton, NY, USA.
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16
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Zaveri RA, Shilling JE, Zelenyuk A, Zawadowicz MA, Suski K, China S, Bell DM, Veghte D, Laskin A. Particle-Phase Diffusion Modulates Partitioning of Semivolatile Organic Compounds to Aged Secondary Organic Aerosol. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:2595-2605. [PMID: 31994876 DOI: 10.1021/acs.est.9b05514] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The diffusivity of semivolatile organic compounds (SVOCs) in the bulk particle phase of a viscous atmospheric secondary organic aerosol (SOA) can have a profound impact on aerosol growth and size distribution dynamics. Here, we investigate the bulk diffusivity of SVOCs formed from photo-oxidation of isoprene as they partition to a bimodal aerosol consisting of an Aitken (potassium sulfate) and accumulation mode (aged α-pinene SOA) particles as a function of relative humidity (RH). The model analysis of the observed size distribution evolution shows that liquid-like diffusion coefficient values of Db > 10-10 cm2 s-1 fail to explain the growth of the Aitken mode. Instead, much lower values of Db between 2.5 × 10-15 cm2 s-1 at 32% RH and 8 × 10-15 cm2 s-1 at 82% RH were needed to successfully reproduce the growth of both modes. The diffusivity within the aged α-pinene SOA remains appreciably slow even at 80% RH, resulting in hindered partitioning of SVOCs to large viscous particles and allowing smaller and relatively less viscous particles to effectively absorb the available SVOCs and grow much faster than would be possible otherwise. These results have important implications for modeling SOA formation and growth in the ambient atmosphere.
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Affiliation(s)
- Rahul A Zaveri
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - John E Shilling
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Alla Zelenyuk
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Maria A Zawadowicz
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Kaitlyn Suski
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Swarup China
- William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - David M Bell
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Daniel Veghte
- William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Alexander Laskin
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
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17
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Christiansen AE, Carlton AG, Henderson BH. Differences in fine particle chemical composition on clear and cloudy days. ATMOSPHERIC CHEMISTRY AND PHYSICS 2020; 20:10.5194/acp-20-11607-2020. [PMID: 34381496 PMCID: PMC8353954 DOI: 10.5194/acp-20-11607-2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Clouds are prevalent and alter PM2.5 mass and chemical composition. Cloud-affected satellite retrievals are often removed from data products, hindering estimates of tropospheric chemical composition during cloudy times. We examine surface fine particulate matter (PM2.5) chemical constituent concentrations in the Interagency Monitoring of PROtected Visual Environments network during Cloudy and Clear Sky times defined using Moderate Resolution Imaging Spectroradiometer (MODIS) cloud flags from 2010-2014 with a focus on differences in particle hygroscopicity and aerosol liquid water (ALW). Cloudy and Clear Sky periods exhibit significant differences in PM2.5 and chemical composition that vary regionally and seasonally. In the eastern US, relative humidity alone cannot explain differences in ALW, suggesting emissions and in situ chemistry exert determining impacts. An implicit clear sky bias may hinder efforts to quantitatively to understand and improve model representation of aerosol-cloud interactions.
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Affiliation(s)
- A E Christiansen
- Department of Chemistry, University of California, Irvine, CA 92697
| | - A G Carlton
- Department of Chemistry, University of California, Irvine, CA 92697
| | - B H Henderson
- Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, NC 27709
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18
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Gorkowski K, Donahue NM, Sullivan RC. Aerosol Optical Tweezers Constrain the Morphology Evolution of Liquid-Liquid Phase-Separated Atmospheric Particles. Chem 2020. [DOI: 10.1016/j.chempr.2019.10.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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19
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Key drivers of cloud response to surface-active organics. Nat Commun 2019; 10:5214. [PMID: 31740670 PMCID: PMC6861266 DOI: 10.1038/s41467-019-12982-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 10/15/2019] [Indexed: 11/17/2022] Open
Abstract
Aerosol-cloud interactions constitute the largest source of uncertainty in global radiative forcing estimates, hampering our understanding of climate evolution. Recent empirical evidence suggests surface tension depression by organic aerosol to significantly influence the formation of cloud droplets, and hence cloud optical properties. In climate models, however, surface tension of water is generally assumed when predicting cloud droplet concentrations. Here we show that the sensitivity of cloud microphysics, optical properties and shortwave radiative effects to the surface phase are dictated by an interplay between the aerosol particle size distribution, composition, water availability and atmospheric dynamics. We demonstrate that accounting for the surface phase becomes essential in clean environments in which ultrafine particle sources are present. Through detailed sensitivity analysis, quantitative constraints on the key drivers – aerosol particle number concentrations, organic fraction and fixed updraft velocity – are derived for instances of significant cloud microphysical susceptibilities to the surface phase. Aerosol-cloud interactions are a large source of uncertainty in radiative forcing estimates. Here, the authors show that the radiative effects of clouds are influenced by a combination of aerosol particle distribution, environmental conditions and atmosphere dynamics.
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20
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Blanco YS, Topel Ö, Bajnóczi ÉG, Werner J, Björneholm O, Persson I. Chemical equilibria of aqueous ammonium-carboxylate systems in aqueous bulk, close to and at the water-air interface. Phys Chem Chem Phys 2019; 21:12434-12445. [PMID: 31143906 DOI: 10.1039/c9cp02449b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Previous studies have shown that the water-air interface and a number of water molecule layers just below it, the surface region, have significantly different physico-chemical properties, such as lower relative permittivity and density, than bulk water. The properties in the surface region of water favor weakly hydrated species as neutral molecules, while ions requiring strong hydration and shielding of their charge are disfavored. In this study the equilibria NH4+(aq) + RCOO-(aq) ⇌ NH3(aq) + RCOOH(aq) are investigated for R = CnH2n+1, n = 0-8, as open systems, where ammonia and small carboxylic acids in the gas phase above the water surface are removed from the system by a gentle controlled flow of nitrogen to mimic the transport of volatile compounds from water droplets into air. It is shown that this non-equilibrium transport of chemicals can be sufficiently large to cause a change of the chemical content of the aqueous bulk. Furthermore, X-ray photoelectron spectroscopy (XPS) has been used to determine the relative concentration of alkyl carboxylic acids and their conjugated alkyl carboxylates in aqueous surfaces using a micro-jet. These studies confirm that neutral alkyl carboxylic acids are accumulated in the surface region, while charged species, as alkyl carboxylates, are depleted. The XPS studies show also that the hydrophobic alkyl chains are oriented upwards into regions with lower relative permittivity and density, thus perpendicular to the aqueous surface. These combined results show that there are several chemical equilibria between the aqueous bulk and the surface region. The analytical studies show that the release of mainly ammonia is dependent on its concentration in the surface region, as long as the solubility of the carboxylic acid in the surface region is sufficiently high to avoid a precipitation in/on the water-air interface. However, for n-octyl- and n-nonylcarboxylic acid the solubility is sufficiently low to cause precipitation. The combined analytical and surface speciation studies in this work show that the equilibria involving the surface region are fast. The results from this study increase the knowledge about the distribution of chemical species in the surface region at and close to the water-air interface, and the transport of chemicals from water to air in open systems.
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Affiliation(s)
- Yina Salamanca Blanco
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden.
| | - Önder Topel
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden.
| | - Éva G Bajnóczi
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden.
| | - Josephina Werner
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden. and Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - Olle Björneholm
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - Ingmar Persson
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden.
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21
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Resolving the mechanisms of hygroscopic growth and cloud condensation nuclei activity for organic particulate matter. Nat Commun 2018; 9:4076. [PMID: 30287821 PMCID: PMC6172236 DOI: 10.1038/s41467-018-06622-2] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 09/14/2018] [Indexed: 12/02/2022] Open
Abstract
Hygroscopic growth and cloud condensation nuclei activation are key processes for accurately modeling the climate impacts of organic particulate matter. Nevertheless, the microphysical mechanisms of these processes remain unresolved. Here we report complex thermodynamic behaviors, including humidity-dependent hygroscopicity, diameter-dependent cloud condensation nuclei activity, and liquid–liquid phase separation in the laboratory for biogenically derived secondary organic material representative of similar atmospheric organic particulate matter. These behaviors can be explained by the non-ideal mixing of water with hydrophobic and hydrophilic organic components. The non-ideality-driven liquid–liquid phase separation further enhances water uptake and induces lowered surface tension at high relative humidity, which result in a lower barrier to cloud condensation nuclei activation. By comparison, secondary organic material representing anthropogenic sources does not exhibit complex thermodynamic behavior. The combined results highlight the importance of detailed thermodynamic representations of the hygroscopicity and cloud condensation nuclei activity in models of the Earth’s climate system. The interactions between organic particulate matter and water vapour affect climate predictions, yet the mechanisms of these interactions remain unresolved. Here, the authors propose a phase separation mechanism that reconciles the observed hygroscopicity and cloud condensation nuclei activity.
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Bzdek BR, Reid JP. Perspective: Aerosol microphysics: From molecules to the chemical physics of aerosols. J Chem Phys 2017; 147:220901. [DOI: 10.1063/1.5002641] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- Bryan R. Bzdek
- School of Chemistry, University of Bristol, Bristol BS8 1TS,
United Kingdom
| | - Jonathan P. Reid
- School of Chemistry, University of Bristol, Bristol BS8 1TS,
United Kingdom
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Abstract
Liquid–liquid phase separation is prevalent in aerosol particles composed of organic compounds and salts and may impact aerosol climate effects.
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