25 May 2021

25 May 2021

Review status: this preprint is currently under review for the journal ACP.

Evolution of volatility and composition in sesquiterpene-mixed and α-pinene secondary organic aerosol particles during isothermal evaporation

Zijun Li1, Angela Buchholz1, Arttu Ylisirniö1, Luis Barreira1,2, Liqing Hao1, Siegfried Schobesberger1, Taina Yli-Juuti1, and Annele Virtanen1 Zijun Li et al.
  • 1Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
  • 2Atmospheric Composition Research, Finnish Meteorological Institute, Helsinki, Finland

Abstract. Efforts have been spent on investigating the isothermal evaporation of α-pinene SOA particles at ranges of conditions and decoupling the impacts of viscosity and volatility on evaporation. However, little is known about the evaporation behavior of SOA particles from biogenic organic compounds other than α-pinene. In this study, we investigated the isothermal evaporation behaviors of α-pinene (αpin) and sesquiterpene mixture (SQTmix) SOA particles under a series of relative humidity (RH) conditions. With a set of in-situ instruments, we monitored the evolution of particle size, volatility, and composition during evaporation. Our finding demonstrates that the SQTmix SOA particles evaporated slower than the αpin ones at any set of RH (expressed with the volume fraction remaining (VFR)), which is primarily due to their lower volatility and possibly aided by higher viscosity under dry conditions. We further applied positive matrix factorization (PMF) to thermal desorption data containing volatility and composition information. Analyzing the net change ratios (NCRs) of each PMF-resolved factor, we can quantitatively compare how each sample factor evolves with increasing evaporation time/RH. When sufficient particulate water content was present in either SOA system, the most volatile sample factor was primarily lost via evaporation and changes in other sample factors were mainly governed by aqueous-phase processes. The evolution of each sample factor of SQTmix SOA particles was controlled by a single type of process, whereas for αpin SOA particles it was regulated by multiple processes. As indicated by the coevolution of VFR and NCR, the effect of aqueous-phase processes could vary from one to another according to particle type, sample factors and evaporation timescale.

Zijun Li et al.

Status: open (until 20 Jul 2021)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse

Zijun Li et al.


Total article views: 246 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
180 61 5 246 18 3 4
  • HTML: 180
  • PDF: 61
  • XML: 5
  • Total: 246
  • Supplement: 18
  • BibTeX: 3
  • EndNote: 4
Views and downloads (calculated since 25 May 2021)
Cumulative views and downloads (calculated since 25 May 2021)

Viewed (geographical distribution)

Total article views: 231 (including HTML, PDF, and XML) Thereof 231 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 18 Jun 2021
Short summary
We compared the evolution of two types of secondary organic aerosol (SOA) particles during isothermal evaporation. The sesquiterpene SOA particles demonstrated higher resilience to evaporation than α-pinene SOA particles generated under comparable conditions. In-depth analysis showed that under high relative humidity conditions, particulate water drove the evolution of particulate constituents by reducing the particle viscosity and initiating chemical aqueous-phase processes.