Global Distribution of the Phase State and Mixing Times Within Secondary Organic Aerosol Particles in the Troposphere Based on Room-Temperature Viscosity Measurements
Published In
Acs Earth and Space Chemistry
Document Type
Citation
Publication Date
12-16-2021
Abstract
Information on the global distributions of secondary organic aerosol (SOA) phase state and mixing times within SOA is needed to predict the impact of SOA on air quality, climate, and atmospheric chemistry; nevertheless, such information is rare. In this study, we developed parameterizations for viscosity as a function of relative humidity (RH) and temperature based on room-temperature viscosity data for simulated pine tree SOA and toluene SOA. The viscosity parameterizations were then used together with tropospheric RH and temperature fields to predict the SOA phase state and mixing times of water and organic molecules within SOA in the troposphere for 200 nm particles. Based on our results, the glassy state can often occur, and the mixing times of water can often exceed 1 h within SOA at altitudes >6 km. Furthermore, the mixing times of organic molecules within SOA can often exceed 1 h throughout most of the free troposphere (i.e., ≳1 km in altitude). In most of the planetary boundary layer (i.e., ≲1 km in altitude), the glassy state is not important, and the mixing times of water and organic molecules are less than 1 h. Our results are qualitatively consistent with the results from Shiraiwa et al. (Nat. Commun., 2017), although there are quantitative differences. Additional studies are needed to better understand the reasons for these differences.
Rights
Copyright © 2021 American Chemical Society
Locate the Document
DOI
10.1021/acsearthspacechem.1c00296
Citation Details
Maclean, A. M., Li, Y., Crescenzo, G. V., Smith, N. R., Karydis, V. A., Tsimpidi, A. P., ... & Bertram, A. K. (2021). Global Distribution of the Phase State and Mixing Times within Secondary Organic Aerosol Particles in the Troposphere Based on Room-Temperature Viscosity Measurements. ACS Earth and Space Chemistry, 5(12), 3458-3473.