Abstract
Secondary organic aerosol (SOA) is known to impact both climate and air quality, yet molecular-level composition measurements remain challenging, hampering our understanding of SOA formation and evolution. Here, we reveal the importance of underestimated reaction pathways for the (trans) formation of SOA from monoterpenes, one of the largest SOA precursors globally. Utilizing mass spectrometric techniques to achieve a comprehensive characterization of molecular-level changes in the SOA, we were able to link the appearance of high-molecular weight (HMW) organic molecules to the concentration and level of neutralization of particulate sulfate. Interestingly, this oligomerization coincided with a decrease of highly oxygenated molecules (HOMs). Our findings highlight the role of particle-phase processing, and the underestimated importance of sulfate aerosol for monoterpene-SOA formation. The observations of these processes directly in the atmosphere reveal the need to account for the formation of HMW oligomers to fully understand the physicochemical properties of organic aerosol.
Original language | English |
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Journal | npj climate and atmospheric science |
Volume | 2 |
DOIs | |
Publication status | Published - 2019 |
Externally published | Yes |
Publication type | A1 Journal article-refereed |
Keywords
- 114 Physical sciences
- GAS
- ACIDITY
- ANTHROPOGENIC EMISSIONS
- EVAPORATION KINETICS
- ISOPRENE
- MULTIPHASE CHEMISTRY
- OLIGOMER FORMATION
- PHASE
- REACTIVE UPTAKE
- VOLATILITY