3:00pm - 3:15pmMO4-2: 1
Study in the atmospheric simulation chamber CHARME of the reactivity of monoterpenes first-generation oxidation products: Implications on air quality and climate
Sandy Solaiman1,2, Cécile COEUR1, Nicolas HOUZEL1, Reem AL MAWLA1, Manolis N. ROMANIAS2
1Laboratoire de Physico-Chimie de l’Atmosphère (LPCA), Université du Littoral Côté d'Opale, Dunkerque, France; 2IMT Nord Europe, Institut Mines-Télécom, Univ. Lille, Centre for Energy and Environment, F-59000 Lille, France
Biogenic volatile organic compounds (BVOCs) are emitted by vegetation, with monoterpenes playing a key role in atmospheric chemistry. This study examines the oxidation of first-generation terpene oxidation products (FGTOPs), myrtenal and ketolimonene, by nitrate radicals (NO₃) in the CHARME simulation chamber under controlled conditions. The room temperature rate coefficients for myrtenal and ketolimonene were determined as (3.4 ± 0.3) × 10-14 and (1.05 ± 0.24) × 10-11 cm³ molecule⁻¹ s⁻¹, respectively. Myrtenal showed a significant secondary organic aerosol (SOA) yield of 32%. These results highlight NO₃ oxidation as a major atmospheric sink and contributor to SOA formation for FGTOPs.
3:15pm - 3:30pmMO4-2: 2
Can carbonyl compounds (aldehydes and ketones) form aerosol precursors in NOx rich urban atmosphere?
Shawon Barua1, Avinash Kumar1, Prasenjit Seal1, Siddharth Iyer1, Mojtaba Bezaatpour1, Sakshi Jha1, Matti Rissanen1,2
1Aerosol Physics Laboratory, Tampere University, Tampere, Finland; 2Department of Chemistry, University of Helsinki, Helsinki, Finland
Several anthropogenic activities emit considerable quantities of carbonyl compounds (aldehydes and ketones) and nitrogen oxides (NOx), and they are key constituents of polluted air. The oxidation of a range of carbonyl compounds including aliphatic and aromatic systems initiated by OH radical has been thoroughly studied in a laboratory flow reactor setup. We observe the rapid formation of highly oxygenated organic molecules (HOMs) which are condensable materials and known to contribute to atmospheric SOA. In presence of NO, the studied systems showed significant enhancement of HOM yields, contrary to the traditional understanding of NO’s suppressing effect on HOM (and hence SOA).
3:30pm - 3:45pmMO4-2: 3
Gas-particle partitioning of levoglucosan under controlled conditions: influence of relative humidity, aerosol mass, particle size, and surfactant
Junteng WU1,2, Jian Xu1, Brice Temime-roussel1, Julien Kammer1, Jim Grisillon1, Nicolas Brun1, Beiping Luo3, Judith Kleinheins3, Mayur Gajanan Sapkal3, Shravan Deshmukh4, Silvia Henning4, Bénédicte Picquet-Varrault5, Edouard Pangui5, Mathieu Cazaunau5, Zamin A. Kanji3, Claudia Marcolli3, Anne Monod1
1Aix Marseille Université, CNRS, LCE, Marseille, France; 2Université Clermont Auvergne, CNRS, OPGC, LaMP, F-63000 Clermont Ferrand, France; 3Institute for Atmospheric and Climate Science, ETH Zürich, Zürich, Switzerland; 4Leibniz Institute for Tropospheric Research (TROPOS), 04318 Leipzig, Germany; 5LISA, UMR CNRS 7583, Université Paris-Est Créteil, Université de Paris, Institut Pierre Simon Laplace (IPSL), Créteil, France
Cloud droplet formation remains uncertain due to limited understanding of semi-volatile organic compound (SVOC) partitioning. This study investigates the condensation and evaporation behavior of levoglucosan, a biomass burning tracer, using controlled chamber experiments. Results show that levoglucosan undergoes co-condensation with increasing relative humidity and co-evaporation with decreasing humidity, influenced by sulfate mass ratio, concentration, and temperature. Net evaporation rate constant range from 9.1 × 10⁻⁶ to 2.9 × 10⁻⁴ s⁻¹, corresponding to half-lifetimes of 40 min to 21 h. These findings improve knowledge of aerosol hygroscopicity and aging, refining atmospheric models and climate predictions.
3:45pm - 4:00pmMO4-2: 4
Low-volatility products formed from ortho-cresol oxidation and their contribution to secondary organic aerosol
Rongrong Wu1,2, Yarê Baker1,3, Quanfu He1,4, Sungah Kang1, Annika Zanders1, Sören Zorn1, Thomas F. Mentel1
1Institute of Climate and Energy Systems: Troposphere (ICE-3), Forschungszentrum Juelich GmbH, Juelich, 52428, Germany; 2Department of Earth and Environmental Science, University of Manchester, Manchester. M13 9PL, UK; 3Leibniz Institute for Tropospheric Research (TROPOS), Leipzig, 04318, Germany; 4Thrust of Earth, Ocean and Atmospheric Sciences, the Hong Kong University of Science and Technology (Guangzhou), Guangzhou, 511453, China
Ortho-cresol is important products of toluene photo-oxidation that contribute to SOA formation. Its gas-phase oxidation chemistry is less known and is of atmospheric interest. In this work, a series of chamber experiments were conducted in the continuously stirred tank reactor. Gas-phase products formed from o-cresol photo-oxidation were detected by nitrate chemical ionization mass spectrometry, and their volatilities were assessed. The effects of NO on SOA formation were also investigated. This study gives an insight into the products and volatility distributions of the o-cresol photo-oxidation system and the role of NO in SOA formation.
4:00pm - 4:15pmMO4-2: 5
Simulating marine aerosolization of microalgae
Bernadette Rosati1,2, Jane Tygesen Skønager1, Marat Bektasov1,3, Marta Barbato4, Merete Bilde1, Kasper Kristensen5, Sylvie V.M. Tesson4,6
1Department of Chemistry, Aarhus University, Aarhus, 8000, Denmark; 2Institute of Meteorology and Climatology, BOKU University, Vienna, 1180, Austria; 3Faculty of Chemistry and Chemical Technology, Al-Farabi Kazakh National University, Almaty, Kazakhstan; 4Department of Biology, Aarhus University, Aarhus, 8000, Denmark; 5Department of Biological and Chemical Engineering, Aarhus University, Aarhus, 8000, Denmark; 6Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, 8000, Denmark
Up to 25% of aerosols are of biological origin and observations indicate that specific biological aerosols play an essential role in the atmosphere by initiating cloud ice formation and potentially serving as giant cloud condensation nuclei. Aerosolized microalgae have been studied regarding their transport to new environments and their negative effects on the environment and society, while there is still a clear lack concerning the implications of aerosolized microalgae for climate. In this work, we performed laboratory experiments mimicking wave breaking over the oceans and exploring the potential release of microalgae and concurrent VOCs from the oceans into the atmosphere.
4:15pm - 4:30pmMO4-2: 6
Formation and composition of organic aerosols from the uptake of glyoxal on natural mineral dust aerosols: a laboratory study
Francesco Battaglia1,2, Formenti Paola1, Giorio Chiara3, Cazaunau Mathieu4, Pangui Edouard4, Bergé Antonin4, Gratien Aline1, Bertin Thomas4, de Brito Joel F.5, Romanias Manolis N.5, Michoud Vincent1, Baldo Clarissa1,4, Chevaillier Servanne4, Noyalet Gael4, Decorse Philippe6, Picquet-Varrault Bénédicte4, Doussin Jean-François4
1Université Paris Cité and Univ Paris Est Creteil, CNRS, LISA, F-75013 Paris, France; 2Department of Chemical Sciences, University of Padova, Padua, Italy; 3Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK; 4Univ Paris Est Creteil and Université Paris Cité, CNRS, LISA, F-94010 Créteil, France; 5IMT Nord Europe, Institut Mines-Télécom, Université de Lille, Centre for Energy and Environment, 59000, Lille, France; 6Université Paris Cité, CNRS, Itodys, F-75013 Paris, France
Mineral dust accounts for 40% of global aerosol emissions and interacts with gases, influencing atmospheric chemistry. Glyoxal, which forms from the oxidation of aromatics and isoprene, can deposit on dust particles and oligomerize, contributing to secondary organic aerosol formation.This study investigates the uptake of glyoxal on submicron dust particles from the Gobi Desert and the resulting formation of organic aerosols. Laboratory experiments conducted in the CESAM simulation chamber reveal that glyoxal rapidly absorbs onto dust particles, with uptake increasing with relative humidity (observed above 30%). At 80% RH, glyoxal forms oligomers ranging from C4 to C10, permanently altering the dust composition.
|