Optical properties and aging of light-absorbing secondary organic aerosol

By Jiu-meng Liu, P. Lin, A. Laskin, Julia Laskin, S. Kathmann, M. Wise, Ryan Caylor, Felisha Imholt, Vanessa Selimovic, J. Shilling. 2016

177 citations recorded by the source corpus.

Abstract. The light-absorbing organic aerosol (OA) commonly referred to as “brown carbon” (BrC) has attracted considerable attention in recent years because of its potential to affect atmospheric radiation balance, especially in the ultraviolet region and thus impact photochemical processes. A growing amount of data has indicated that BrC is prevalent in the atmosphere, which has motivated numerous laboratory and field studies; however, our understanding of the relationship between the chemical composition and optical properties of BrC remains limited. We conducted chamber experiments to investigate the effect of various volatile organic carbon (VOC) precursors, NOx concentrations, photolysis time, and relative humidity (RH) on the light absorption of selected secondary organic aerosols (SOA). Light absorption of chamber-generated SOA samples, especially aromatic SOA, was found to increase with NOx concentration, at moderate RH, and for the shortest photolysis aging times. The highest mass absorption coefficient (MAC) value is observed from toluene SOA products formed under high-NOx conditions at moderate RH, in which nitro-aromatics were previously identified as the major light-absorbing compounds. BrC light absorption is observed to decrease with photolysis time, correlated with a decline of the organic nitrate fraction of SOA. SOA formed from mixtures of aromatics and isoprene absorb less visible (Vis) and ultraviolet (UV) light than SOA formed from aromatic precursors alone on a mass basis. However, the mixed SOA absorption was underestimated when optical properties were predicted using a two-product SOA formation model, as done in many current climate models. Further investigation, including analysis on detailed mechanisms, are required to explain the discrepancy.

Subfields: Atmospheric Science, Global and Planetary Change

View Paper: https://www.semanticscholar.org/paper/4e5d581fe52c53e71c58f22f6c410eba70d8ffab

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atmospheric Science

1. Jiu-meng Liu
2. Xuan Wang
3. R. Weber
4. Joshua P. Schwarz
5. C. Heald
6. A. Perring

In Global and Planetary Change

1. Xuan Wang
2. Joshua P. Schwarz
3. C. Heald
4. A. Perring

Citations in the corpus

• Exploring the observational constraints on the simulation of brown carbon (2017, background): “In laboratory studies, the absorption of BrC is found to both increase during the formation or chemical aging of certain types of OA and decrease during oxidation or photolysis (Zhong and Jang, 2011; Flores et al., 2014; Lee et al., 2014; Liu et al., 2016).”