Thomas F. Mentel

Forschungszentrum Jülich

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Astrid Kiendler‐Scharr

Forschungszentrum Jülich

161

Ralf Tillmann

Forschungszentrum Jülich

135

Andreas Wahner

Forschungszentrum Jülich

106

Mattias Hallquist

University of Gothenburg

Hendrik Fuchs

Forschungszentrum Jülich

E. Kleist

Forschungszentrum Jülich

Franz Röhrer

Forschungszentrum Jülich

Defeng Zhao

Fudan University

Sungah Kang

Forschungszentrum Jülich

Iida Pullinen

University of Eastern Finland

Cooperative Institutions

Forschungszentrum Jülich

125

University of Helsinki

Helsinki Institute of Physics

Centre National de la Recherche Scientifique

Max Planck Institute for Chemistry

Finnish Meteorological Institute

Leibniz Institute for Tropospheric Research

National Centre for Atmospheric Science

Peking University

Chinese Academy of Sciences

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Ambient and laboratory observations of organic ammonium salts in PM₁

Faraday Discussions (2017)

Patrick Schlag Florian Rubach Thomas F. Mentel David Reimer Francesco Canonaco

Ambient measurements of PM1 aerosol chemical composition at Cabauw, the Netherlands, implicate higher ammonium concentrations than explained by the formation of inorganic ammonium salts. This additional particulate ammonium is called excess ammonium (eNH4). Height profiles over the Cabauw Experimental Site for Atmospheric Research (CESAR) tower, of combined ground based and airborne aerosol mass spectrometric (AMS) measurements on a Zeppelin airship show higher concentrations of eNH4 at higher altitudes compared to the ground. Through flights across the Netherlands, the Zeppelin based measurements furthermore substantiate eNH4 as a regional phenomenon in the planetary boundary layer. The excess ammonium correlates with mass spectral signatures of (di-)carboxylic acids, making a heterogeneous acid-base reaction the likely process of NH3 uptake. We show that this excess ammonium was neutralized by the organic fraction forming particulate organic ammonium salts. We discuss the significance of such organic ammonium salts for atmospheric aerosols and suggest that NH3 emission control will have benefits for particulate matter control beyond the reduction of inorganic ammonium salts.

Mass fraction

10.1039/c7fd00027h

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Citations (17)

Highly Oxygenated Organic Molecules (HOM) from Gas-Phase Autoxidation Involving Peroxy Radicals: A Key Contributor to Atmospheric Aerosol

Chemical Reviews (2019)

Federico Bianchi Theo Kurtén Matthieu Riva Claudia Mohr Matti Rissanen

Highly oxygenated organic molecules (HOM) are formed in the atmosphere via autoxidation involving peroxy radicals arising from volatile organic compounds (VOC). HOM condense on pre-existing particles and can be involved in new particle formation. HOM thus contribute to the formation of secondary organic aerosol (SOA), a significant and ubiquitous component of atmospheric aerosol known to affect the Earth's radiation balance. HOM were discovered only very recently, but the interest in these compounds has grown rapidly. In this Review, we define HOM and describe the currently available techniques for their identification/quantification, followed by a summary of the current knowledge on their formation mechanisms and physicochemical properties. A main aim is to provide a common frame for the currently quite fragmented literature on HOM studies. Finally, we highlight the existing gaps in our understanding and suggest directions for future HOM research.

Autoxidation

Organic molecules

Particle (ecology)

10.1021/acs.chemrev.8b00395

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Citations (977)

Extremely Low Volatile Organic Compounds: A New Class of Intermediates in Gas-Phase Chemistry and Particle Formation

Thomas F. Mentel

Particle (ecology)

Source

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Citations (0)

CCN activation and hygroscopic growth measurements of secondary organic aerosols from tree emissions

EGU General Assembly Conference Abstracts (2010)

Angela Buchholz C. Spindler Ralf Tillmann Astrid Kiendler‐Scharr J. Wildt

Tree (set theory)

Source

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On the Reactive Uptake of Gaseous Compounds by Organic-Coated Aqueous Aerosols: Theoretical Analysis and Application to the Heterogeneous Hydrolysis of N₂O₅

The Journal of Physical Chemistry A (2006)

T. Anttila Astrid Kiendler‐Scharr Ralf Tillmann Thomas F. Mentel

The presence of organic coatings on aerosols may have important consequences to the atmospheric chemistry, in particular to the N2O5 heterogeneous hydrolysis. This is demonstrated by recent experiments which show that the uptake of N2O5 by aqueous aerosols is slowed considerably when an organic coating consisting of monoterpene oxidation products is added on the particles. To treat the mechanisms behind the suppression, an extension of the resistor model, which has been widely applied in investigation of the heterogeneous uptake by aerosols, was derived. The extension accounts for dissolution, diffusion, and chemical reactions in a multilayered organic coating, and it provides a parametrization for the heterogeneous uptake by organic-coated aerosols that can be applied in large-scale models. Moreover, the framework was applied to interpret the findings regarding the decreased uptake of N2O5 by the organic-coated aerosols. Performed calculations suggested that the reaction rate constant of N2O5 in the coating is decreased by 3−5 orders of magnitude, in addition to which the product of the solubility of N2O5 and its diffusion coefficient in the coating is reduced more than an order of magnitude compared to the corresponding value for the aqueous phase. The results suggest also that the accommodation coefficient of N2O5 to such coatings is no more than a factor of 2 smaller than that to pure water surfaces. Finally, the relevance of the results to the atmospheric N2O5 heterogeneous hydrolysis is discussed and implications to planning further laboratory studies focusing on secondary organic aerosol formation are pointed out.

10.1021/jp062403c

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Citations (192)

Impact of HO₂∕RO₂ ratio on highly oxygenated α-pinene photooxidation products and secondary organic aerosol formation potential

Atmospheric chemistry and physics (2024)

Yarê Baker Sungah Kang Hui Wang Rongrong Wu Jian Xu

Abstract. Highly oxygenated molecules (HOMs) from the atmospheric oxidation of biogenic volatile organic compounds are important contributors to secondary organic aerosol (SOA). Organic peroxy radicals (RO2) and hydroperoxy radicals (HO2) are key species influencing the HOM product distribution. In laboratory studies, experimental requirements often result in overemphasis on RO2 cross-reactions compared to reactions of RO2 with HO2. We analyzed the photochemical formation of HOMs from α-pinene and their potential to contribute to SOA formation under high (≈1/1) and low (≈1/100) HO2/RO2 conditions. As HO2/RO2 > 1 is prevalent in the daytime atmosphere, sufficiently high HO2/RO2 is crucial to mimic atmospheric conditions and to prevent biases by low HO2/RO2 on the HOM product distribution and thus SOA yield. Experiments were performed under steady-state conditions in the new, continuously stirred tank reactor SAPHIR-STAR at Forschungszentrum Jülich. The HO2/RO2 ratio was increased by adding CO while keeping the OH concentration constant. We determined the HOM's SOA formation potential, considering its fraction remaining in the gas phase after seeding with (NH4)2SO4 aerosol. An increase in HO2/RO2 led to a reduction in SOA formation potential, with the main driver being a ∼ 60 % reduction in HOM-accretion products. We also observed a shift in HOM-monomer functionalization from carbonyl to hydroperoxide groups. We determined a reduction of the HOM's SOA formation potential by ∼ 30 % at HO2/RO2 ≈1/1 compared to HO2/RO2 ≈ 1/100. Particle-phase observations measured a similar decrease in SOA mass and yield. Our study shows that too low HO2/RO2 ratios compared to the atmosphere can lead to an overestimation of SOA yields.

Pinene

10.5194/acp-24-4789-2024

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Citations (2)

Secondary aerosol formation from stress-induced biogenic emissions and possible climate feedbacks

Atmospheric chemistry and physics (2013)

Thomas F. Mentel E. Kleist S. Andres Miikka Dal Maso Thorsten Hohaus

Abstract. Atmospheric aerosols impact climate by scattering and absorbing solar radiation and by acting as ice and cloud condensation nuclei. Biogenic secondary organic aerosols (BSOAs) comprise an important component of atmospheric aerosols. Biogenic volatile organic compounds (BVOCs) emitted by vegetation are the source of BSOAs. Pathogens and insect attacks, heat waves and droughts can induce stress to plants that may impact their BVOC emissions, and hence the yield and type of formed BSOAs, and possibly their climatic effects. This raises questions of whether stress-induced changes in BSOA formation may attenuate or amplify effects of climate change. In this study we assess the potential impact of stress-induced BVOC emissions on BSOA formation for tree species typical for mixed deciduous and Boreal Eurasian forests. We studied the photochemical BSOA formation for plants infested by aphids in a laboratory setup under well-controlled conditions and applied in addition heat and drought stress. The results indicate that stress conditions substantially modify BSOA formation and yield. Stress-induced emissions of sesquiterpenes, methyl salicylate, and C17-BVOCs increase BSOA yields. Mixtures including these compounds exhibit BSOA yields between 17 and 33%, significantly higher than mixtures containing mainly monoterpenes (4–6% yield). Green leaf volatiles suppress SOA formation, presumably by scavenging OH, similar to isoprene. By classifying emission types, stressors and BSOA formation potential, we discuss possible climatic feedbacks regarding aerosol effects. We conclude that stress situations for plants due to climate change should be considered in climate–vegetation feedback mechanisms.

Isoprene

Green leaf volatiles

Cloud condensation nuclei

10.5194/acp-13-8755-2013

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Citations (131)

Gas-Particle Partitioning and SOA Yields of Organonitrate Products from NO₃-Initiated Oxidation of Isoprene under Varied Chemical Regimes

ACS Earth and Space Chemistry (2021)

Bellamy Brownwood Avtandil Turdziladze Thorsten Hohaus Rongrong Wu Thomas F. Mentel

Alkyl nitrate (AN) and secondary organic aerosol (SOA) from the reaction of nitrate radicals (NO3) with isoprene were observed in the Simulation of Atmospheric PHotochemistry In a large Reaction (SAPHIR) chamber during the NO3Isop campaign in August 2018. Based on 15 day-long experiments under various reaction conditions, we conclude that the reaction has a nominally unity molar AN yield (observed range 90 ± 40%) and an SOA mass yield of OA + organic nitrate aerosol of 13–15% (with ∼50 μg m–3 inorganic seed aerosol and 2–5 μg m–3 total organic aerosol). Isoprene (5–25 ppb) and oxidant (typically ∼100 ppb O3 and 5–25 ppb NO2) concentrations and aerosol composition (inorganic and organic coating) were varied while remaining close to ambient conditions, producing similar AN and SOA yields under all regimes. We observe the formation of dinitrates upon oxidation of the second double bond only once the isoprene precursor is fully consumed. We determine the bulk partitioning coefficient for ANs (Kp ∼ 10–3 m3 μg–1), indicating an average volatility corresponding to a C5 hydroxy hydroperoxy nitrate.

Isoprene

10.1021/acsearthspacechem.0c00311

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Citations (35)

Highly Oxygenated Organic Nitrates Formed from NO₃ Radical-Initiated Oxidation of β-Pinene

Environmental Science & Technology (2021)

Hongru Shen Defeng Zhao Iida Pullinen Sungah Kang Luc Vereecken

The reactions of biogenic volatile organic compounds (BVOC) with the nitrate radicals (NO3) are major night-time sources of organic nitrates and secondary organic aerosols (SOA) in regions influenced by BVOC and anthropogenic emissions. In this study, the formation of gas-phase highly oxygenated organic molecules-organic nitrates (HOM-ON) from NO3-initiated oxidation of a representative monoterpene, β-pinene, was investigated in the SAPHIR chamber (Simulation of Atmosphere PHotochemistry In a large Reaction chamber). Six monomer (C = 7–10, N = 1–2, O = 6–16) and five accretion product (C = 17–20, N = 2–4, O = 9–22) families were identified and further classified into first- or second-generation products based on their temporal behavior. The time lag observed in the peak concentrations between peroxy radicals containing odd and even number of oxygen atoms, as well as between radicals and their corresponding termination products, provided constraints on the HOM-ON formation mechanism. The HOM-ON formation can be explained by unimolecular or bimolecular reactions of peroxy radicals. A dominant portion of carbonylnitrates in HOM-ON was detected, highlighting the significance of unimolecular termination reactions by intramolecular H-shift for the formation of HOM-ON. A mean molar yield of HOM-ON was estimated to be 4.8% (−2.6%/+5.6%), suggesting significant HOM-ON contributions to the SOA formation.

Pinene

Monoterpene

10.1021/acs.est.1c03978

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Citations (72)

A study of nighttime nitrogen oxide oxidation in a large reaction chamber—the fate of NO2, N2O5, HNO3, and O3 at different humidities

Atmospheric Environment (1996)

Thomas F. Mentel D. Bleilebens Andreas Wahner

Nitrogen dioxide

Reaction rate

Mixing ratio

Nitrogen oxides

10.1016/1352-2310(96)00117-3

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Citations (123)