Articles | Volume 21, issue 3
https://doi.org/10.5194/acp-21-1987-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-21-1987-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Measurement report
| 
10 Feb 2021
Measurement report |
| 10 Feb 2021
| 10 Feb 2021
Measurement report: Sulfuric acid nucleation and experimental conditions in a photolytic flow reactor
David R. Hanson
CORRESPONDING AUTHOR
Chemistry Department, Augsburg University, Minneapolis, MN, USA
Seakh Menheer
Chemistry Department, Augsburg University, Minneapolis, MN, USA
Michael Wentzel
Chemistry Department, Augsburg University, Minneapolis, MN, USA
Joan Kunz
Chemistry Department, Augsburg University, Minneapolis, MN, USA
Related authors
David R. Hanson, Hussein Abdullahi, Seakh Menheer, Joaquin Vences, Michael R. Alves, and Joan Kunz
Atmos. Chem. Phys., 19, 8999–9015, https://doi.org/10.5194/acp-19-8999-2019, https://doi.org/10.5194/acp-19-8999-2019, 2019
Short summary
Short summary
Particle formation was studied in a flow reactor with photolytic generation of sulfuric acid. Comparisons with previous results are a mixed bag with plenty of outliers. Addition of bases (dimethylamine and ammonia) led to large increases in particle numbers. Model simulations suggest that previous dimethylamine–sulfuric acid cluster thermodynamics are good, while a new set of the free energies of ammonia–sulfuric acid clusters was needed.
Haihan Chen, Anna L. Hodshire, John Ortega, James Greenberg, Peter H. McMurry, Annmarie G. Carlton, Jeffrey R. Pierce, Dave R. Hanson, and James N. Smith
Atmos. Chem. Phys., 18, 311–326, https://doi.org/10.5194/acp-18-311-2018, https://doi.org/10.5194/acp-18-311-2018, 2018
Short summary
Short summary
Much of what we know about atmospheric new particle formation (NPF) is based on ground-level measurements. We used tethered balloon measurements and remote sensing to study the location in the boundary layer in which NPF events are initiated, the degree to which the boundary layer is well-mixed during NPF, and the potential role that water may play in aerosol particle chemical evolution. This information will improve the representativeness of process level models and laboratory experiments.
Coty N. Jen, Jun Zhao, Peter H. McMurry, and David R. Hanson
Atmos. Chem. Phys., 16, 12513–12529, https://doi.org/10.5194/acp-16-12513-2016, https://doi.org/10.5194/acp-16-12513-2016, 2016
Short summary
Short summary
Chemical ionization mass spectrometry measurements of clusters formed from sulfuric acid and dimethylamine or various diamines show that these clusters are not as efficiently ionized by nitrate as they are by acetate. These clusters are atmospherically relevant, and our results suggest that traditional methods may under-measure cluster concentrations by up to a factor of 10.
Anna L. Hodshire, Michael J. Lawler, Jun Zhao, John Ortega, Coty Jen, Taina Yli-Juuti, Jared F. Brewer, Jack K. Kodros, Kelley C. Barsanti, Dave R. Hanson, Peter H. McMurry, James N. Smith, and Jeffery R. Pierce
Atmos. Chem. Phys., 16, 9321–9348, https://doi.org/10.5194/acp-16-9321-2016, https://doi.org/10.5194/acp-16-9321-2016, 2016
Short summary
Short summary
Processes that control the growth of newly formed particles are not well understood and limit predictions of aerosol climate impacts. We combine state-of-the-art measurements at a central-US site with a particle-growth model to investigate the species and processes contributing to growth. Observed growth was dominated by organics, sulfate salts, or a mixture of these two. The model qualitatively captures the variability between different days.
N. A. Freshour, K. K. Carlson, Y. A. Melka, S. Hinz, B. Panta, and D. R. Hanson
Atmos. Meas. Tech., 7, 3611–3621, https://doi.org/10.5194/amt-7-3611-2014, https://doi.org/10.5194/amt-7-3611-2014, 2014
Short summary
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Amine permeation tubes were quantified via absorption of gaseous amines by dilute acid solutions. Calibrations of an amine mass spectrometer with these permeation tubes show that the mass spectrometer is very sensitive to amines. Measurements of ambient amines are presented from two recent field campaigns. The amine mass spectrometer instrumentation and sampling arrangements are extensively discussed.
David R. Hanson, Hussein Abdullahi, Seakh Menheer, Joaquin Vences, Michael R. Alves, and Joan Kunz
Atmos. Chem. Phys., 19, 8999–9015, https://doi.org/10.5194/acp-19-8999-2019, https://doi.org/10.5194/acp-19-8999-2019, 2019
Short summary
Short summary
Particle formation was studied in a flow reactor with photolytic generation of sulfuric acid. Comparisons with previous results are a mixed bag with plenty of outliers. Addition of bases (dimethylamine and ammonia) led to large increases in particle numbers. Model simulations suggest that previous dimethylamine–sulfuric acid cluster thermodynamics are good, while a new set of the free energies of ammonia–sulfuric acid clusters was needed.
Haihan Chen, Anna L. Hodshire, John Ortega, James Greenberg, Peter H. McMurry, Annmarie G. Carlton, Jeffrey R. Pierce, Dave R. Hanson, and James N. Smith
Atmos. Chem. Phys., 18, 311–326, https://doi.org/10.5194/acp-18-311-2018, https://doi.org/10.5194/acp-18-311-2018, 2018
Short summary
Short summary
Much of what we know about atmospheric new particle formation (NPF) is based on ground-level measurements. We used tethered balloon measurements and remote sensing to study the location in the boundary layer in which NPF events are initiated, the degree to which the boundary layer is well-mixed during NPF, and the potential role that water may play in aerosol particle chemical evolution. This information will improve the representativeness of process level models and laboratory experiments.
Coty N. Jen, Jun Zhao, Peter H. McMurry, and David R. Hanson
Atmos. Chem. Phys., 16, 12513–12529, https://doi.org/10.5194/acp-16-12513-2016, https://doi.org/10.5194/acp-16-12513-2016, 2016
Short summary
Short summary
Chemical ionization mass spectrometry measurements of clusters formed from sulfuric acid and dimethylamine or various diamines show that these clusters are not as efficiently ionized by nitrate as they are by acetate. These clusters are atmospherically relevant, and our results suggest that traditional methods may under-measure cluster concentrations by up to a factor of 10.
Anna L. Hodshire, Michael J. Lawler, Jun Zhao, John Ortega, Coty Jen, Taina Yli-Juuti, Jared F. Brewer, Jack K. Kodros, Kelley C. Barsanti, Dave R. Hanson, Peter H. McMurry, James N. Smith, and Jeffery R. Pierce
Atmos. Chem. Phys., 16, 9321–9348, https://doi.org/10.5194/acp-16-9321-2016, https://doi.org/10.5194/acp-16-9321-2016, 2016
Short summary
Short summary
Processes that control the growth of newly formed particles are not well understood and limit predictions of aerosol climate impacts. We combine state-of-the-art measurements at a central-US site with a particle-growth model to investigate the species and processes contributing to growth. Observed growth was dominated by organics, sulfate salts, or a mixture of these two. The model qualitatively captures the variability between different days.
N. A. Freshour, K. K. Carlson, Y. A. Melka, S. Hinz, B. Panta, and D. R. Hanson
Atmos. Meas. Tech., 7, 3611–3621, https://doi.org/10.5194/amt-7-3611-2014, https://doi.org/10.5194/amt-7-3611-2014, 2014
Short summary
Short summary
Amine permeation tubes were quantified via absorption of gaseous amines by dilute acid solutions. Calibrations of an amine mass spectrometer with these permeation tubes show that the mass spectrometer is very sensitive to amines. Measurements of ambient amines are presented from two recent field campaigns. The amine mass spectrometer instrumentation and sampling arrangements are extensively discussed.
Related subject area
Subject: Aerosols | Research Activity: Laboratory Studies | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)
Characterization of the particle size distribution, mineralogy, and Fe mode of occurrence of dust-emitting sediments from the Mojave Desert, California, USA
Measurement report: Effects of transition metal ions on the optical properties of humic-like substances (HULIS) reveal a structural preference – a case study of PM2.5 in Beijing, China
The Impact of Aqueous Phase Replacement Reaction on the Phase State of Internally Mixed Organic/ammonium Aerosols
Probing Iceland's dust-emitting sediments: particle size distribution, mineralogy, cohesion, Fe mode of occurrence, and reflectance spectra signatures
Photoenhanced sulfate formation by the heterogeneous uptake of SO2 on non-photoactive mineral dust
Comparison of water-soluble and water-insoluble organic compositions attributing to different light absorption efficiency between residential coal and biomass burning emissions
Technical note: High-resolution analyses of concentrations and sizes of black carbon particles deposited on northwest Greenland over the past 350 years – Part 1. Continuous flow analysis of the SIGMA-D ice core using a Wide-Range Single-Particle Soot Photometer and a high-efficiency nebulizer
Suppressed atmospheric chemical aging of cooking organic aerosol particles in wintertime conditions
Formation and loss of light absorbance by phenolic aqueous SOA by ●OH and an organic triplet excited state
Nocturnal Atmospheric Synergistic Oxidation Reduces the Formation of Low-volatility Organic Compounds from Biogenic Emissions
Technical Note: A technique to convert NO2 to NO2− with S(IV) and its application to measuring nitrate photolysis
Measurement report: The Fifth International Workshop on Ice Nucleation Phase 1 (FIN-01): Intercomparison of Single Particle Mass Spectrometers
Distribution, chemical, and molecular composition of high and low molecular weight humic-like substances in ambient aerosols
Desorption lifetimes and activation energies influencing gas–surface interactions and multiphase chemical kinetics
Molecular analysis of secondary organic aerosol and brown carbon from the oxidation of indole
Secondary organic aerosol formed by Euro 5 gasoline vehicle emissions: chemical composition and gas-to-particle phase partitioning
Assessment of the contribution of residential waste burning to ambient PM10 concentrations in Hungary and Romania
Source differences in the components and cytotoxicity of PM2.5 from automobile exhaust, coal combustion, and biomass burning contributing to urban aerosol toxicity
Chamber studies of OH + dimethyl sulfoxide and dimethyl disulfide: insights into the dimethyl sulfide oxidation mechanism
Low-temperature ice nucleation of sea spray and secondary marine aerosols under cirrus cloud conditions
Temperature-dependent aqueous OH kinetics of C2–C10 linear and terpenoid alcohols and diols: new rate coefficients, structure–activity relationship, and atmospheric lifetimes
A possible unaccounted source of nitrogen-containing compound formation in aerosols: amines reacting with secondary ozonides
Seasonal variations in photooxidant formation and light absorption in aqueous extracts of ambient particles
Variability in sediment particle size, mineralogy, and Fe mode of occurrence across dust-source inland drainage basins: the case of the lower Drâa Valley, Morocco
Gas–particle partitioning of toluene oxidation products: an experimental and modeling study
Chemically speciated air pollutant emissions from open burning of household solid waste from South Africa
Bulk and molecular-level composition of primary organic aerosol from wood, straw, cow dung, and plastic burning
Volatile oxidation products and secondary organosiloxane aerosol from D5 + OH at varying OH exposures
Molecular fingerprints and health risks of smoke from home-use incense burning
High enrichment of heavy metals in fine particulate matter through dust aerosol generation
Production of ice-nucleating particles (INPs) by fast-growing phytoplankton
Technical note: In situ measurements and modelling of the oxidation kinetics in films of a cooking aerosol proxy using a quartz crystal microbalance with dissipation monitoring (QCM-D)
Particulate emissions from cooking activities: emission factors, emission dynamics, and mass spectrometric analysis for different preparation methods
Contrasting impacts of humidity on the ozonolysis of monoterpenes: insights into the multi-generation chemical mechanism
Quantifying the seasonal variations in and regional transport of PM2.5 in the Yangtze River Delta region, China: characteristics, sources, and health risks
Opinion: Atmospheric multiphase chemistry – past, present, and future
Distinct photochemistry in glycine particles mixed with different atmospheric nitrate salts
Effects of storage conditions on the molecular-level composition of organic aerosol particles
Characterization of gas and particle emissions from open burning of household solid waste from South Africa
Chemically distinct particle-phase emissions from highly controlled pyrolysis of three wood types
Predicting photooxidant concentrations in aerosol liquid water based on laboratory extracts of ambient particles
Physicochemical characterization of free troposphere and marine boundary layer ice-nucleating particles collected by aircraft in the eastern North Atlantic
Large differences of highly oxygenated organic molecules (HOMs) and low-volatile species in secondary organic aerosols (SOAs) formed from ozonolysis of β-pinene and limonene
Impact of fossil and non-fossil fuel sources on the molecular compositions of water-soluble humic-like substances in PM2.5 at a suburban site of Yangtze River Delta, China
Technical note: Improved synthetic routes to cis- and trans-(2-methyloxirane-2,3-diyl)dimethanol (cis- and trans-β-isoprene epoxydiol)
Technical note: Intercomparison study of the elemental carbon radiocarbon analysis methods using synthetic known samples
Chemical evolution of primary and secondary biomass burning aerosols during daytime and nighttime
Formation of highly oxygenated organic molecules from the oxidation of limonene by OH radical: significant contribution of H-abstraction pathway
Measurement report: Atmospheric aging of combustion-derived particles – impact on stable free radical concentration and its ability to produce reactive oxygen species in aqueous media
Photoaging of phenolic secondary organic aerosol in the aqueous phase: evolution of chemical and optical properties and effects of oxidants
Adolfo González-Romero, Cristina González-Flórez, Agnesh Panta, Jesús Yus-Díez, Patricia Córdoba, Andres Alastuey, Natalia Moreno, Melani Hernández-Chiriboga, Konrad Kandler, Martina Klose, Roger N. Clark, Bethany L. Ehlmann, Rebecca N. Greenberger, Abigail M. Keebler, Phil Brodrick, Robert Green, Paul Ginoux, Xavier Querol, and Carlos Pérez García-Pando
Atmos. Chem. Phys., 24, 9155–9176, https://doi.org/10.5194/acp-24-9155-2024, https://doi.org/10.5194/acp-24-9155-2024, 2024
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In this research, we studied the dust-emitting properties of crusts and aeolian ripples from the Mojave Desert. These properties are key to understanding the effect of dust upon climate. We found two different playa lakes according to the groundwater regime, which implies differences in crusts' cohesion state and mineralogy, which can affect the dust emission potential and properties. We also compare them with Moroccan Sahara crusts and Icelandic top sediments.
Juanjuan Qin, Leiming Zhang, Yuanyuan Qin, Shaoxuan Shi, Jingnan Li, Zhao Shu, Yuwei Gao, Ting Qi, Jihua Tan, and Xinming Wang
Atmos. Chem. Phys., 24, 7575–7589, https://doi.org/10.5194/acp-24-7575-2024, https://doi.org/10.5194/acp-24-7575-2024, 2024
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The present research unveiled that acidity dominates while transition metal ions harmonize with the light absorption properties of humic-like substances (HULIS). Cu2+ has quenching effects on HULIS by complexation, hydrogen substitution, or electrostatic adsorption, with aromatic structures of HULIS. Such effects are less pronounced if from Mn2+, Ni2+, Zn2+, and Cu2+. Oxidized HULIS might contain electron-donating groups, whereas N-containing compounds might contain electron-withdrawing groups.
Hui Yang, Fengfeng Dong, Li Xia, Qishen Huang, Shufeng Pang, and Yunhong Zhang
EGUsphere, https://doi.org/10.5194/egusphere-2024-1556, https://doi.org/10.5194/egusphere-2024-1556, 2024
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Atmospheric secondary aerosols often contain a mix of organic and inorganic components, which can undergo complex reactions, leading to significant uncertainty in their phase state. Using molecular spectroscopic methods, we demonstrated that the aqueous replacement reaction, unique to these mixed aerosols and promoted by the presence of ammonium, significantly alters their phase behavior. This effect complicates the prediction of aerosol phase states and the corresponding atmospheric processes.
Adolfo González-Romero, Cristina González-Flórez, Agnesh Panta, Jesús Yus-Díez, Patricia Córdoba, Andres Alastuey, Natalia Moreno, Konrad Kandler, Martina Klose, Roger N. Clark, Bethany L. Ehlmann, Rebecca N. Greenberger, Abigail M. Keebler, Phil Brodrick, Robert O. Green, Xavier Querol, and Carlos Pérez García-Pando
Atmos. Chem. Phys., 24, 6883–6910, https://doi.org/10.5194/acp-24-6883-2024, https://doi.org/10.5194/acp-24-6883-2024, 2024
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The knowledge of properties from dust emitted in high latitudes such as in Iceland is scarce. This study focuses on the particle size, mineralogy, cohesion, and iron mode of occurrence and reflectance spectra of dust-emitting sediments. Icelandic top sediments have lower cohesion state, coarser particle size, distinctive mineralogy, and 3-fold bulk Fe content, with a large presence of magnetite compared to Saharan crusts.
Wangjin Yang, Jiawei Ma, Hongxing Yang, Fu Li, and Chong Han
Atmos. Chem. Phys., 24, 6757–6768, https://doi.org/10.5194/acp-24-6757-2024, https://doi.org/10.5194/acp-24-6757-2024, 2024
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We provide evidence that light enhances the conversion of SO2 to sulfates on non-photoactive mineral dust, where triplet states of SO2 (3SO2) can act as a pivotal trigger to generate sulfates. Photochemical sulfate formation depends on H2O, O2, and basicity of mineral dust. The SO2 photochemistry on non-photoactive mineral dust contributes to sulfates, highlighting previously unknown pathways to better explain the missing sources of atmospheric sulfates.
Lu Zhang, Jin Li, Yaojie Li, Xinlei Liu, Zhihan Luo, Guofeng Shen, and Shu Tao
Atmos. Chem. Phys., 24, 6323–6337, https://doi.org/10.5194/acp-24-6323-2024, https://doi.org/10.5194/acp-24-6323-2024, 2024
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Brown carbon (BrC) is related to radiative forcing and climate change. The BrC fraction from residential coal and biomass burning emissions, which were the major source of BrC, was characterized at the molecular level. The CHOS aromatic compounds explained higher light absorption efficiencies of biomass burning emissions compared to coal. The unique formulas of coal combustion aerosols were characterized by higher unsaturated compounds, and such information could be used for source appointment.
Kumiko Goto-Azuma, Remi Dallmayr, Yoshimi Ogawa-Tsukagawa, Nobuhiro Moteki, Tatsuhiro Mori, Sho Ohata, Yutaka Kondo, Makoto Koike, Motohiro Hirabayashi, Jun Ogata, Kyotaro Kitamura, Kenji Kawamura, Koji Fujita, Sumito Matoba, Naoko Nagatsuka, Akane Tsushima, Kaori Fukuda, and Teruo Aoki
EGUsphere, https://doi.org/10.5194/egusphere-2024-1496, https://doi.org/10.5194/egusphere-2024-1496, 2024
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We developed a continuous flow analysis system to analyse an ice core from northwest Greenland, and coupled it with an improved BC measurement technique. This coupling allowed accurate high-resolution analyses of BC particles' size distributions and concentrations with diameters between 70 nm and 4 μm for the past 350 years. Our results provide crucial insights into BC's climatic effects. We also found that previous ice core studies substantially underestimated the BC mass concentrations.
Wenli Liu, Longkun He, Yingjun Liu, Keren Liao, Qi Chen, and Mikinori Kuwata
Atmos. Chem. Phys., 24, 5625–5636, https://doi.org/10.5194/acp-24-5625-2024, https://doi.org/10.5194/acp-24-5625-2024, 2024
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Cooking is a major source of particles in urban areas. Previous studies demonstrated that the chemical lifetimes of cooking organic aerosols (COAs) were much shorter (~minutes) than the values reported by field observations (~hours). We conducted laboratory experiments to resolve the discrepancy by considering suppressed reactivity under low temperature. The parameterized k2–T relationships and observed surface temperature data were used to estimate the chemical lifetimes of COA particles.
Stephanie Arciva, Lan Ma, Camille Mavis, Chrystal Guzman, and Cort Anastasio
Atmos. Chem. Phys., 24, 4473–4485, https://doi.org/10.5194/acp-24-4473-2024, https://doi.org/10.5194/acp-24-4473-2024, 2024
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We measured changes in light absorption during the aqueous oxidation of six phenols with hydroxyl radical (●OH) or an organic triplet excited state (3C*). All the phenols formed light-absorbing secondary brown carbon (BrC), which then decayed with continued oxidation. Extrapolation to ambient conditions suggest ●OH is the dominant sink of secondary phenolic BrC in fog/cloud drops, while 3C* controls the lifetime of this light absorption in particle water.
Han Zang, Zekun Luo, Chenxi Li, Ziyue Li, Dandan Huang, and Yue Zhao
EGUsphere, https://doi.org/10.5194/egusphere-2024-1131, https://doi.org/10.5194/egusphere-2024-1131, 2024
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Atmospheric organics are subject to synergistic oxidation by different oxidants, yet the mechanisms of such processes are poorly understood. Here, using direct measurements and kinetic modelling, we probe the nocturnal synergistic oxidation mechanism of α-pinene by O3 and NO3 radicals and in particular the fate of peroxy radical intermediates of different origins, which will deepen our understanding of the monoterpene oxidation chemistry and its contribution to atmospheric particle formation.
Aaron Lieberman, Julietta Picco, Murat Onder, and Cort Anastasio
Atmos. Chem. Phys., 24, 4411–4419, https://doi.org/10.5194/acp-24-4411-2024, https://doi.org/10.5194/acp-24-4411-2024, 2024
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We developed a method that uses aqueous S(IV) to quantitatively convert NO2 to NO2−, which allows both species to be quantified using the Griess method. As an example of the utility of the method, we quantified both photolysis channels of nitrate, with and without a scavenger for hydroxyl radical (·OH). The results show that without a scavenger, ·OH reacts with nitrite to form nitrogen dioxide, suppressing the apparent quantum yield of NO2− and enhancing that of NO2.
Xiaoli Shen, David M. Bell, Hugh Coe, Naruki Hiranuma, Fabian Mahrt, Nicholas A. Marsden, Claudia Mohr, Daniel M. Murphy, Harald Saathoff, Johannes Schneider, Jacqueline Wilson, Maria A. Zawadowicz, Alla Zelenyuk, Paul J. DeMott, Ottmar Möhler, and Daniel J. Cziczo
EGUsphere, https://doi.org/10.5194/egusphere-2024-928, https://doi.org/10.5194/egusphere-2024-928, 2024
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Single particle mass spectrometer (SPMS) is commonly used to measure chemical composition and mixing state of aerosol particles. Intercomparison of SPMSs was conducted. All instruments reported similar size ranges and common spectral features. The instrument-specific detection efficiency was found to be more dependent on particle size than type. All instruments differentiated secondary organic aerosol, soot, and soil dust, but had difficulties differentiating among specific minerals and dusts.
Xingjun Fan, Ao Cheng, Xufang Yu, Tao Cao, Dan Chen, Wenchao Ji, Yongbing Cai, Fande Meng, Jianzhong Song, and Ping'an Peng
Atmos. Chem. Phys., 24, 3769–3783, https://doi.org/10.5194/acp-24-3769-2024, https://doi.org/10.5194/acp-24-3769-2024, 2024
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Molecular-level characteristics of high molecular weight (HMW) and low MW (LMW) humic-like substances (HULIS) were comprehensively investigated, where HMW HULIS had larger chromophores and larger molecular size than LMW HULIS and exhibited higher aromaticity and humification. Electrospray ionization high-resolution mass spectrometry revealed more aromatic molecules in HMW HULIS. HMW HULIS had more CHON compounds, while LMW HULIS had more CHO compounds.
Daniel A. Knopf, Markus Ammann, Thomas Berkemeier, Ulrich Pöschl, and Manabu Shiraiwa
Atmos. Chem. Phys., 24, 3445–3528, https://doi.org/10.5194/acp-24-3445-2024, https://doi.org/10.5194/acp-24-3445-2024, 2024
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The initial step of interfacial and multiphase chemical processes involves adsorption and desorption of gas species. This study demonstrates the role of desorption energy governing the residence time of the gas species at the environmental interface. A parameterization is formulated that enables the prediction of desorption energy based on the molecular weight, polarizability, and oxygen-to-carbon ratio of the desorbing chemical species. Its application to gas–particle interactions is discussed.
Feng Jiang, Kyla Siemens, Claudia Linke, Yanxia Li, Yiwei Gong, Thomas Leisner, Alexander Laskin, and Harald Saathoff
Atmos. Chem. Phys., 24, 2639–2649, https://doi.org/10.5194/acp-24-2639-2024, https://doi.org/10.5194/acp-24-2639-2024, 2024
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We investigated the optical properties, chemical composition, and formation mechanisms of secondary organic aerosol (SOA) and brown carbon (BrC) from the oxidation of indole with and without NO2 in the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) simulation chamber. This work is one of the very few to link the optical properties and chemical composition of indole SOA with and without NO2 by simulation chamber experiments.
Evangelia Kostenidou, Baptiste Marques, Brice Temime-Roussel, Yao Liu, Boris Vansevenant, Karine Sartelet, and Barbara D'Anna
Atmos. Chem. Phys., 24, 2705–2729, https://doi.org/10.5194/acp-24-2705-2024, https://doi.org/10.5194/acp-24-2705-2024, 2024
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Secondary organic aerosol (SOA) from gasoline vehicles can be a significant source of particulate matter in urban areas. Here the chemical composition of secondary volatile organic compounds and SOA produced by photo-oxidation of Euro 5 gasoline vehicle emissions was studied. The volatility of the SOA formed was calculated. Except for the temperature and the concentration of the aerosol, additional parameters may play a role in the gas-to-particle partitioning.
András Hoffer, Aida Meiramova, Ádám Tóth, Beatrix Jancsek-Turóczi, Gyula Kiss, Ágnes Rostási, Erika Andrea Levei, Luminita Marmureanu, Attila Machon, and András Gelencsér
Atmos. Chem. Phys., 24, 1659–1671, https://doi.org/10.5194/acp-24-1659-2024, https://doi.org/10.5194/acp-24-1659-2024, 2024
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Specific tracer compounds identified previously in controlled test burnings of different waste types in the laboratory were detected and quantified in ambient PM10 samples collected in five Hungarian and four Romanian settlements. Back-of-the-envelope calculations based on the relative emission factors of individual tracers suggested that the contribution of solid waste burning particulate emissions to ambient PM10 mass concentrations may be as high as a few percent.
Xiao-San Luo, Weijie Huang, Guofeng Shen, Yuting Pang, Mingwei Tang, Weijun Li, Zhen Zhao, Hanhan Li, Yaqian Wei, Longjiao Xie, and Tariq Mehmood
Atmos. Chem. Phys., 24, 1345–1360, https://doi.org/10.5194/acp-24-1345-2024, https://doi.org/10.5194/acp-24-1345-2024, 2024
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PM2.5 are air pollutants threatening health globally, but they are a mixture of chemical compositions from many sources and result in unequal toxicity. Which composition from which source of PM2.5 as the most hazardous object is a question hindering effective pollution control policy-making. With chemical and toxicity experiments, we found automobile exhaust and coal combustion to be priority emissions with higher toxic compositions for precise air pollution control, ensuring public health.
Matthew B. Goss and Jesse H. Kroll
Atmos. Chem. Phys., 24, 1299–1314, https://doi.org/10.5194/acp-24-1299-2024, https://doi.org/10.5194/acp-24-1299-2024, 2024
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The chemistry driving dimethyl sulfide (DMS) oxidation and subsequent sulfate particle formation in the atmosphere is poorly constrained. We oxidized two related compounds (dimethyl sulfoxide and dimethyl disulfide) in the laboratory under varied NOx conditions and measured the gas- and particle-phase products. These results demonstrate that both the OH addition and OH abstraction pathways for DMS oxidation contribute to particle formation via mechanisms that do not involve the SO2 intermediate.
Ryan J. Patnaude, Kathryn A. Moore, Russell J. Perkins, Thomas C. J. Hill, Paul J. DeMott, and Sonia M. Kreidenweis
Atmos. Chem. Phys., 24, 911–928, https://doi.org/10.5194/acp-24-911-2024, https://doi.org/10.5194/acp-24-911-2024, 2024
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In this study we examined the effect of atmospheric aging on sea spray aerosols (SSAs) to form ice and how newly formed secondary marine aerosols (SMAs) may freeze at cirrus temperatures (< −38 °C). Results show that SSAs freeze at different relative humidities (RHs) depending on the temperature and that the ice-nucleating ability of SSA was not hindered by atmospheric aging. SMAs are shown to freeze at high RHs and are likely inefficient at forming ice at cirrus temperatures.
Bartłomiej Witkowski, Priyanka Jain, Beata Wileńska, and Tomasz Gierczak
Atmos. Chem. Phys., 24, 663–688, https://doi.org/10.5194/acp-24-663-2024, https://doi.org/10.5194/acp-24-663-2024, 2024
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This article reports the results of the kinetic measurements for the aqueous oxidation of the 29 aliphatic alcohols by hydroxyl radical (OH) at different temperatures. The data acquired and the literature data were used to optimize a model for predicting the aqueous OH reactivity of alcohols and carboxylic acids and to estimate the atmospheric lifetimes of five terpenoic alcohols. The kinetic data provided new insights into the mechanism of aqueous oxidation of aliphatic molecules by the OH.
Junting Qiu, Xinlin Shen, Jiangyao Chen, Guiying Li, and Taicheng An
Atmos. Chem. Phys., 24, 155–166, https://doi.org/10.5194/acp-24-155-2024, https://doi.org/10.5194/acp-24-155-2024, 2024
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We studied reactions of secondary ozonides (SOZs) with amines. SOZs formed from ozonolysis of β-caryophyllene and α-humulene are found to be reactive to ethylamine and methylamine. Products from SOZs with various conformations reacting with the same amine had different functional groups. Our findings indicate that interaction of SOZs with amines in the atmosphere is very complicated, which is potentially a hitherto unrecognized source of N-containing compound formation.
Lan Ma, Reed Worland, Laura Heinlein, Chrystal Guzman, Wenqing Jiang, Christopher Niedek, Keith J. Bein, Qi Zhang, and Cort Anastasio
Atmos. Chem. Phys., 24, 1–21, https://doi.org/10.5194/acp-24-1-2024, https://doi.org/10.5194/acp-24-1-2024, 2024
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We measured concentrations of three photooxidants – the hydroxyl radical, triplet excited states of organic carbon, and singlet molecular oxygen – in fine particles collected over a year. Concentrations are highest in extracts of fresh biomass burning particles, largely because they have the highest particle concentrations and highest light absorption. When normalized by light absorption, rates of formation for each oxidant are generally similar for the four particle types we observed.
Adolfo González-Romero, Cristina González-Flórez, Agnesh Panta, Jesús Yus-Díez, Cristina Reche, Patricia Córdoba, Natalia Moreno, Andres Alastuey, Konrad Kandler, Martina Klose, Clarissa Baldo, Roger N. Clark, Zongbo Shi, Xavier Querol, and Carlos Pérez García-Pando
Atmos. Chem. Phys., 23, 15815–15834, https://doi.org/10.5194/acp-23-15815-2023, https://doi.org/10.5194/acp-23-15815-2023, 2023
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The effect of dust emitted from desertic surfaces upon climate and ecosystems depends on size and mineralogy, but data from soil mineral atlases of desert soils are scarce. We performed particle-size distribution, mineralogy, and Fe speciation in southern Morocco. Results show coarser particles with high quartz proportion are near the elevated areas, while in depressed areas, sizes are finer, and proportions of clays and nano-Fe oxides are higher. This difference is important for dust modelling.
Victor Lannuque, Barbara D'Anna, Evangelia Kostenidou, Florian Couvidat, Alvaro Martinez-Valiente, Philipp Eichler, Armin Wisthaler, Markus Müller, Brice Temime-Roussel, Richard Valorso, and Karine Sartelet
Atmos. Chem. Phys., 23, 15537–15560, https://doi.org/10.5194/acp-23-15537-2023, https://doi.org/10.5194/acp-23-15537-2023, 2023
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Large uncertainties remain in understanding secondary organic aerosol (SOA) formation from toluene oxidation. In this study, speciation measurements in gaseous and particulate phases were carried out, providing partitioning and volatility data on individual toluene SOA components at different temperatures. A new detailed oxidation mechanism was developed to improve modeled speciation, and effects of different processes involved in gas–particle partitioning at the molecular scale are explored.
Xiaoliang Wang, Hatef Firouzkouhi, Judith C. Chow, John G. Watson, Steven Sai Hang Ho, Warren Carter, and Alexandra S. M. De Vos
Atmos. Chem. Phys., 23, 15375–15393, https://doi.org/10.5194/acp-23-15375-2023, https://doi.org/10.5194/acp-23-15375-2023, 2023
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Open burning of municipal solid waste emits chemicals that are harmful to the environment. This paper reports source profiles and emission factors for PM2.5 species and acidic/alkali gases from laboratory combustion of 10 waste categories (including plastics and biomass) that represent open burning in South Africa. Results will be useful for health and climate impact assessments, speciated emission inventories, source-oriented dispersion models, and receptor-based source apportionment.
Jun Zhang, Kun Li, Tiantian Wang, Erlend Gammelsæter, Rico K. Y. Cheung, Mihnea Surdu, Sophie Bogler, Deepika Bhattu, Dongyu S. Wang, Tianqu Cui, Lu Qi, Houssni Lamkaddam, Imad El Haddad, Jay G. Slowik, Andre S. H. Prevot, and David M. Bell
Atmos. Chem. Phys., 23, 14561–14576, https://doi.org/10.5194/acp-23-14561-2023, https://doi.org/10.5194/acp-23-14561-2023, 2023
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We conducted burning experiments to simulate various types of solid fuel combustion, including residential burning, wildfires, agricultural burning, cow dung, and plastic bag burning. The chemical composition of the particles was characterized using mass spectrometers, and new potential markers for different fuels were identified using statistical analysis. This work improves our understanding of emissions from solid fuel burning and offers support for refined source apportionment.
Hyun Gu Kang, Yanfang Chen, Yoojin Park, Thomas Berkemeier, and Hwajin Kim
Atmos. Chem. Phys., 23, 14307–14323, https://doi.org/10.5194/acp-23-14307-2023, https://doi.org/10.5194/acp-23-14307-2023, 2023
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D5 is an emerging anthropogenic pollutant that is ubiquitous in indoor and urban environments, and the OH oxidation of D5 forms secondary organosiloxane aerosol (SOSiA). Application of a kinetic box model that uses a volatility basis set (VBS) showed that consideration of oxidative aging (aging-VBS) predicts SOSiA formation much better than using a standard-VBS model. Ageing-dependent parameterization is needed to accurately model SOSiA to assess the implications of siloxanes for air quality.
Kai Song, Rongzhi Tang, Jingshun Zhang, Zichao Wan, Yuan Zhang, Kun Hu, Yuanzheng Gong, Daqi Lv, Sihua Lu, Yu Tan, Ruifeng Zhang, Ang Li, Shuyuan Yan, Shichao Yan, Baoming Fan, Wenfei Zhu, Chak K. Chan, Maosheng Yao, and Song Guo
Atmos. Chem. Phys., 23, 13585–13595, https://doi.org/10.5194/acp-23-13585-2023, https://doi.org/10.5194/acp-23-13585-2023, 2023
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Incense burning is common in Asia, posing threats to human health and air quality. However, less is known about its emissions and health risks. Full-volatility organic species from incense-burning smoke are detected and quantified. Intermediate-volatility volatile organic compounds (IVOCs) are crucial organics accounting for 19.2 % of the total emission factors (EFs) and 40.0 % of the secondary organic aerosol (SOA) estimation, highlighting the importance of incorporating IVOCs into SOA models.
Qianqian Gao, Shengqiang Zhu, Kaili Zhou, Jinghao Zhai, Shaodong Chen, Qihuang Wang, Shurong Wang, Jin Han, Xiaohui Lu, Hong Chen, Liwu Zhang, Lin Wang, Zimeng Wang, Xin Yang, Qi Ying, Hongliang Zhang, Jianmin Chen, and Xiaofei Wang
Atmos. Chem. Phys., 23, 13049–13060, https://doi.org/10.5194/acp-23-13049-2023, https://doi.org/10.5194/acp-23-13049-2023, 2023
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Dust is a major source of atmospheric aerosols. Its chemical composition is often assumed to be similar to the parent soil. However, this assumption has not been rigorously verified. Dust aerosols are mainly generated by wind erosion, which may have some chemical selectivity. Mn, Cd and Pb were found to be highly enriched in fine-dust (PM2.5) aerosols. In addition, estimation of heavy metal emissions from dust generation by air quality models may have errors without using proper dust profiles.
Daniel C. O. Thornton, Sarah D. Brooks, Elise K. Wilbourn, Jessica Mirrielees, Alyssa N. Alsante, Gerardo Gold-Bouchot, Andrew Whitesell, and Kiana McFadden
Atmos. Chem. Phys., 23, 12707–12729, https://doi.org/10.5194/acp-23-12707-2023, https://doi.org/10.5194/acp-23-12707-2023, 2023
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A major uncertainty in our understanding of clouds and climate is the sources and properties of the aerosol on which clouds grow. We found that aerosol containing organic matter from fast-growing marine phytoplankton was a source of ice-nucleating particles (INPs). INPs facilitate freezing of ice crystals at warmer temperatures than otherwise possible and therefore change cloud formation and properties. Our results show that ecosystem processes and the properties of sea spray aerosol are linked.
Adam Milsom, Shaojun Qi, Ashmi Mishra, Thomas Berkemeier, Zhenyu Zhang, and Christian Pfrang
Atmos. Chem. Phys., 23, 10835–10843, https://doi.org/10.5194/acp-23-10835-2023, https://doi.org/10.5194/acp-23-10835-2023, 2023
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Aerosols and films are found indoors and outdoors. Our study measures and models reactions of a cooking aerosol proxy with the atmospheric oxidant ozone relying on a low-cost but sensitive technique based on mass changes and film rigidity. We found that film morphology changed and film rigidity increased with evidence of surface crust formation during ozone exposure. Our modelling results demonstrate clear potential to take this robust method to the field for reaction monitoring.
Julia Pikmann, Frank Drewnick, Friederike Fachinger, and Stephan Borrmann
EGUsphere, https://doi.org/10.5194/egusphere-2023-2172, https://doi.org/10.5194/egusphere-2023-2172, 2023
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Cooking activities can contribute substantially to indoor and ambient aerosol. We performed a comprehensive study with laboratory measurements cooking 19 different dishes and ambient measurements at two Christmas markets measuring various particle properties and trace gases of the emissions in real time. Similar emission characteristics were observed for dishes with the same preparation method, mainly due to similar cooking temperature and use of oil, with barbecues as especially strong source.
Shan Zhang, Lin Du, Zhaomin Yang, Narcisse Tsona Tchinda, Jianlong Li, and Kun Li
Atmos. Chem. Phys., 23, 10809–10822, https://doi.org/10.5194/acp-23-10809-2023, https://doi.org/10.5194/acp-23-10809-2023, 2023
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In this study, we have investigated the distinct impacts of humidity on the ozonolysis of two structurally different monoterpenes (limonene and Δ3-carene). We found that the molecular structure of precursors can largely influence the SOA formation under high RH by impacting the multi-generation reactions. Our results could advance knowledge on the roles of water content in aerosol formation and inform ongoing research on particle environmental effects and applications in models.
Yangzhihao Zhan, Min Xie, Wei Zhao, Tijian Wang, Da Gao, Pulong Chen, Jun Tian, Kuanguang Zhu, Shu Li, Bingliang Zhuang, Mengmeng Li, Yi Luo, and Runqi Zhao
Atmos. Chem. Phys., 23, 9837–9852, https://doi.org/10.5194/acp-23-9837-2023, https://doi.org/10.5194/acp-23-9837-2023, 2023
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Although the main source contribution of pollution is secondary inorganic aerosols in Nanjing, health risks mainly come from industry sources and vehicle emissions. Therefore, the development of megacities should pay more attention to the health burden of vehicle emissions, coal combustion, and industrial processes. This study provides new insight into assessing the relationship between source apportionment and health risks and can provide valuable insight into air pollution strategies.
Jonathan P. D. Abbatt and A. R. Ravishankara
Atmos. Chem. Phys., 23, 9765–9785, https://doi.org/10.5194/acp-23-9765-2023, https://doi.org/10.5194/acp-23-9765-2023, 2023
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With important climate and air quality impacts, atmospheric multiphase chemistry involves gas interactions with aerosol particles and cloud droplets. We summarize the status of the field and discuss potential directions for future growth. We highlight the importance of a molecular-level understanding of the chemistry, along with atmospheric field studies and modeling, and emphasize the necessity for atmospheric multiphase chemists to interact widely with scientists from neighboring disciplines.
Zhancong Liang, Zhihao Cheng, Ruifeng Zhang, Yiming Qin, and Chak K. Chan
Atmos. Chem. Phys., 23, 9585–9595, https://doi.org/10.5194/acp-23-9585-2023, https://doi.org/10.5194/acp-23-9585-2023, 2023
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In this study, we found that the photolysis of sodium nitrate leads to a much quicker decay of free amino acids (FAAs, with glycine as an example) in the particle phase than ammonium nitrate photolysis, which is likely due to the molecular interactions between FAAs and different nitrate salts. Since sodium nitrate likely co-exists with FAAs in the coarse-mode particles, particulate nitrate photolysis can possibly contribute to a rapid decay of FAAs and affect atmospheric nitrogen cycling.
Julian Resch, Kate Wolfer, Alexandre Barth, and Markus Kalberer
Atmos. Chem. Phys., 23, 9161–9171, https://doi.org/10.5194/acp-23-9161-2023, https://doi.org/10.5194/acp-23-9161-2023, 2023
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Detailed chemical analysis of organic aerosols is necessary to better understand their effects on climate and health. Aerosol samples are often stored for days to months before analysis. We examined the effects of storage conditions (i.e., time, temperature, and aerosol storage on filters or as solvent extracts) on composition and found significant changes in the concentration of individual compounds, indicating that sample storage can strongly affect the detailed chemical particle composition.
Xiaoliang Wang, Hatef Firouzkouhi, Judith C. Chow, John G. Watson, Warren Carter, and Alexandra S. M. De Vos
Atmos. Chem. Phys., 23, 8921–8937, https://doi.org/10.5194/acp-23-8921-2023, https://doi.org/10.5194/acp-23-8921-2023, 2023
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Open burning of household and municipal solid waste is a common practice in developing countries and is a significant source of air pollution. However, few studies have measured emissions from open burning of waste. This study determined gas and particulate emissions from open burning of 10 types of household solid-waste materials. These results can improve emission inventories, air quality management, and assessment of the health and climate effects of open burning of household waste.
Anita M. Avery, Mariam Fawaz, Leah R. Williams, Tami Bond, and Timothy B. Onasch
Atmos. Chem. Phys., 23, 8837–8854, https://doi.org/10.5194/acp-23-8837-2023, https://doi.org/10.5194/acp-23-8837-2023, 2023
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Pyrolysis is the thermal decomposition of fuels like wood which occurs during combustion or as an isolated process. During combustion, some pyrolysis products are emitted directly, while others are oxidized in the combustion process. This work describes the chemical composition of particle-phase pyrolysis products in order to investigate both the uncombusted emissions from wildfires and the fuel that participates in combustion.
Lan Ma, Reed Worland, Wenqing Jiang, Christopher Niedek, Chrystal Guzman, Keith J. Bein, Qi Zhang, and Cort Anastasio
Atmos. Chem. Phys., 23, 8805–8821, https://doi.org/10.5194/acp-23-8805-2023, https://doi.org/10.5194/acp-23-8805-2023, 2023
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Although photooxidants are important in airborne particles, little is known of their concentrations. By measuring oxidants in a series of particle dilutions, we predict their concentrations in aerosol liquid water (ALW). We find •OH concentrations in ALW are on the order of 10−15 M, similar to their cloud/fog values, while oxidizing triplet excited states and singlet molecular oxygen have ALW values of ca. 10−13 M and 10−12 M, respectively, roughly 10–100 times higher than in cloud/fog drops.
Daniel A. Knopf, Peiwen Wang, Benny Wong, Jay M. Tomlin, Daniel P. Veghte, Nurun N. Lata, Swarup China, Alexander Laskin, Ryan C. Moffet, Josephine Y. Aller, Matthew A. Marcus, and Jian Wang
Atmos. Chem. Phys., 23, 8659–8681, https://doi.org/10.5194/acp-23-8659-2023, https://doi.org/10.5194/acp-23-8659-2023, 2023
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Ambient particle populations and associated ice-nucleating particles (INPs)
were examined from particle samples collected on board aircraft in the marine
boundary layer and free troposphere in the eastern North Atlantic during
summer and winter. Chemical imaging shows distinct differences in the
particle populations seasonally and with sampling altitudes, which are
reflected in the INP types. Freezing parameterizations are derived for
implementation in cloud-resolving and climate models.
Dandan Liu, Yun Zhang, Shujun Zhong, Shuang Chen, Qiaorong Xie, Donghuan Zhang, Qiang Zhang, Wei Hu, Junjun Deng, Libin Wu, Chao Ma, Haijie Tong, and Pingqing Fu
Atmos. Chem. Phys., 23, 8383–8402, https://doi.org/10.5194/acp-23-8383-2023, https://doi.org/10.5194/acp-23-8383-2023, 2023
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Based on ultra-high-resolution mass spectrometry analysis, we found that β-pinene oxidation-derived highly oxygenated organic molecules (HOMs) exhibit higher yield at high ozone concentration, while limonene oxidation-derived HOMs exhibit higher yield at moderate ozone concentration. The distinct molecular response of HOMs and low-volatile species in different biogenic secondary organic aerosols to ozone concentrations provides a new clue for more accurate air quality prediction and management.
Mengying Bao, Yan-Lin Zhang, Fang Cao, Yihang Hong, Yu-Chi Lin, Mingyuan Yu, Hongxing Jiang, Zhineng Cheng, Rongshuang Xu, and Xiaoying Yang
Atmos. Chem. Phys., 23, 8305–8324, https://doi.org/10.5194/acp-23-8305-2023, https://doi.org/10.5194/acp-23-8305-2023, 2023
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The interaction between the sources and molecular compositions of humic-like substances (HULIS) at Nanjing, China, was explored. Significant fossil fuel source contributions to HULIS were found in the 14C results from biomass burnng and traffic emissions. Increasing biogenic secondary organic aerosol (SOA) products and anthropogenic aromatic compounds were detected in summer and winter, respectively.
Molly Frauenheim, Jason D. Surratt, Zhenfa Zhang, and Avram Gold
Atmos. Chem. Phys., 23, 7859–7866, https://doi.org/10.5194/acp-23-7859-2023, https://doi.org/10.5194/acp-23-7859-2023, 2023
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We report synthesis of the isoprene-derived photochemical oxidation products trans- and cis-β-epoxydiols in high overall yields from inexpensive, readily available starting compounds. Protection/deprotection steps or time-consuming purification is not required, and the reactions can be scaled up to gram quantities. The procedures provide accessibility of these important compounds to atmospheric chemistry laboratories with only basic capabilities in organic synthesis.
Xiangyun Zhang, Jun Li, Sanyuan Zhu, Junwen Liu, Ping Ding, Shutao Gao, Chongguo Tian, Yingjun Chen, Ping'an Peng, and Gan Zhang
Atmos. Chem. Phys., 23, 7495–7502, https://doi.org/10.5194/acp-23-7495-2023, https://doi.org/10.5194/acp-23-7495-2023, 2023
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The results show that 14C elemental carbon (EC) was not only related to the isolation method but also to the types and proportions of the biomass sources in the sample. The hydropyrolysis (Hypy) method, which can be used to isolate a highly stable portion of ECHypy and avoid charring, is a more effective and stable approach for the matrix-independent 14C quantification of EC in aerosols, and the 13C–ECHypy and non-fossil ECHypy values of SRM1649b were –24.9 ‰ and 11 %, respectively.
Amir Yazdani, Satoshi Takahama, John K. Kodros, Marco Paglione, Mauro Masiol, Stefania Squizzato, Kalliopi Florou, Christos Kaltsonoudis, Spiro D. Jorga, Spyros N. Pandis, and Athanasios Nenes
Atmos. Chem. Phys., 23, 7461–7477, https://doi.org/10.5194/acp-23-7461-2023, https://doi.org/10.5194/acp-23-7461-2023, 2023
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Organic aerosols directly emitted from wood and pellet stove combustion are found to chemically transform (approximately 15 %–35 % by mass) under daytime aging conditions simulated in an environmental chamber. A new marker for lignin-like compounds is found to degrade at a different rate than previously identified biomass burning markers and can potentially provide indication of aging time in ambient samples.
Hao Luo, Luc Vereecken, Hongru Shen, Sungah Kang, Iida Pullinen, Mattias Hallquist, Hendrik Fuchs, Andreas Wahner, Astrid Kiendler-Scharr, Thomas F. Mentel, and Defeng Zhao
Atmos. Chem. Phys., 23, 7297–7319, https://doi.org/10.5194/acp-23-7297-2023, https://doi.org/10.5194/acp-23-7297-2023, 2023
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Oxidation of limonene, an element emitted by trees and chemical products, by OH, a daytime oxidant, forms many highly oxygenated organic molecules (HOMs), including C10-20 compounds. HOMs play an important role in new particle formation and growth. HOM formation can be explained by the chemistry of peroxy radicals. We found that a minor branching ratio initial pathway plays an unexpected, significant role. Considering this pathway enables accurate simulations of HOMs and other concentrations.
Heather L. Runberg and Brian J. Majestic
Atmos. Chem. Phys., 23, 7213–7223, https://doi.org/10.5194/acp-23-7213-2023, https://doi.org/10.5194/acp-23-7213-2023, 2023
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Environmentally persistent free radicals (EPFRs) are an emerging pollutant found in soot particles. Understanding how these change as they move through the atmosphere is important to human health. Here, soot was generated in the laboratory and exposed to simulated sunlight. The concentrations and characteristics of EPFRs in the soot were measured and found to be unchanged. However, it was also found that the ability of soot to form hydroxyl radicals was stronger for fresh soot.
Wenqing Jiang, Christopher Niedek, Cort Anastasio, and Qi Zhang
Atmos. Chem. Phys., 23, 7103–7120, https://doi.org/10.5194/acp-23-7103-2023, https://doi.org/10.5194/acp-23-7103-2023, 2023
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We studied how aqueous-phase secondary organic aerosol (aqSOA) form and evolve from a phenolic carbonyl commonly present in biomass burning smoke. The composition and optical properties of the aqSOA are significantly affected by photochemical reactions and are dependent on the oxidants' concentration and identity in water. During photoaging, the aqSOA initially becomes darker, but prolonged aging leads to the formation of volatile products, resulting in significant mass loss and photobleaching.
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Short summary
We report experimental measurements of particle formation in a flow reactor that extend the results from this experiment to a total of more than 270 runs over a time period of ~3 years. This has allowed us to detect a general increase in the cleanliness of the system and improve our knowledge of its chemistry. In-house simulations allowed us to construct phenomenological free energies of molecular clusters of sulfuric acid and ammonia that are appropriate for application to the atmosphere.
We report experimental measurements of particle formation in a flow reactor that extend the...
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