Conference Agenda

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.

Several anthropogenic activities emit considerable quantities of carbonyl compounds (aldehydes and ketones) and nitrogen oxides (NO_x), 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).

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.

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.

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.

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.