TY - JOUR
T1 - Formation and temperature dependence of highly oxygenated organic molecules (HOMs) from δ3-carene ozonolysis
AU - Luo, Yuanyuan
AU - Thomsen, Ditte
AU - Iversen, Emil Mark
AU - Roldin, Pontus
AU - Skønager, Jane Tygesen
AU - Li, Linjie
AU - Priestley, Michael
AU - Pedersen, Henrik B.
AU - Hallquist, Mattias
AU - Bilde, Merete
AU - Glasius, Marianne
AU - Ehn, Mikael
N1 - Publisher Copyright:
© 2024 Yuanyuan Luo et al.
PY - 2024/8/29
Y1 - 2024/8/29
N2 - δ3-carene is a prominent monoterpene in the atmosphere, contributing significantly to secondary organic aerosol (SOA) formation. However, knowledge about δ3-carene oxidation pathways, particularly regarding their ability to form highly oxygenated organic molecules (HOMs), is still limited. In this study, we present HOM measurements during δ3-carene ozonolysis under various conditions in two simulation chambers. We identified numerous HOMs (monomers: C7-10H10-18O6-14; dimers: C17-20H24-34O6-18) using a chemical ionization mass spectrometer (CIMS). δ3-carene ozonolysis yielded higher HOM concentrations than α-pinene, with a distinct distribution, indicating differences in formation pathways. All HOM signals decreased considerably at lower temperatures, reducing the estimated molar HOM yield from ∼ 3 % at 20 °C to ∼ 0.5 % at 0 °C. Interestingly, the temperature change altered the HOM distribution, increasing the observed dimer-to-monomer ratios from roughly 0.8 at 20 °C to 1.5 at 0 °C. HOM monomers with six or seven O atoms condensed more efficiently onto particles at colder temperatures, while monomers with nine or more O atoms and all dimers condensed irreversibly even at 20 °C. Using the gas- and particle-phase chemistry kinetic multilayer model ADCHAM, we were also able to reproduce the experimentally observed HOM composition, yields, and temperature dependence.
AB - δ3-carene is a prominent monoterpene in the atmosphere, contributing significantly to secondary organic aerosol (SOA) formation. However, knowledge about δ3-carene oxidation pathways, particularly regarding their ability to form highly oxygenated organic molecules (HOMs), is still limited. In this study, we present HOM measurements during δ3-carene ozonolysis under various conditions in two simulation chambers. We identified numerous HOMs (monomers: C7-10H10-18O6-14; dimers: C17-20H24-34O6-18) using a chemical ionization mass spectrometer (CIMS). δ3-carene ozonolysis yielded higher HOM concentrations than α-pinene, with a distinct distribution, indicating differences in formation pathways. All HOM signals decreased considerably at lower temperatures, reducing the estimated molar HOM yield from ∼ 3 % at 20 °C to ∼ 0.5 % at 0 °C. Interestingly, the temperature change altered the HOM distribution, increasing the observed dimer-to-monomer ratios from roughly 0.8 at 20 °C to 1.5 at 0 °C. HOM monomers with six or seven O atoms condensed more efficiently onto particles at colder temperatures, while monomers with nine or more O atoms and all dimers condensed irreversibly even at 20 °C. Using the gas- and particle-phase chemistry kinetic multilayer model ADCHAM, we were also able to reproduce the experimentally observed HOM composition, yields, and temperature dependence.
UR - http://www.scopus.com/inward/record.url?scp=85202807571&partnerID=8YFLogxK
U2 - 10.5194/acp-24-9459-2024
DO - 10.5194/acp-24-9459-2024
M3 - Journal article
AN - SCOPUS:85202807571
SN - 1680-7316
VL - 24
SP - 9459
EP - 9473
JO - Atmospheric Chemistry and Physics
JF - Atmospheric Chemistry and Physics
IS - 16
ER -