Abstract View
Improving the Representation of Secondary Organic Aerosol from VCP Sources in Air Quality Models
SREEJITH SASIDHARAN, Qi Li, David R. Cocker III, Mackenzie Humes, Albert Presto, Neil Donahue, Jo Machesky, Drew Gentner, Jeffrey R. Pierce, Shantanu Jathar, Colorado State University
Abstract Number: 224
Working Group: Missing contributors to SOA: The Role of Volatile Chemical Products (VCPS)
Abstract
Volatile chemical products (VCPs) that include consumer products, pesticides, paints, and surface coatings are emerging as dominant sources of volatile organic compounds (VOCs) to the urban atmosphere. These VCP VOCs can oxidize in the atmosphere to form secondary organic aerosol (SOA), yet there are large uncertainties surrounding the oxidation pathways that lead to SOA formation and the contribution of VCP sources to the urban SOA budget. In this work, we leverage two unique laboratory datasets and a state-of-the-science model (i.e., SOM-TOMAS) to develop parameters to represent the SOA formation from key VCP VOCs. The datasets currently represent the only chamber and flow reactor data available for SOA formation from VCP VOCs. The SOM-TOMAS (Statistical Oxidation Model-TwO Moment Aerosol Sectional) model simulates the chemistry, thermodynamic properties, and microphysics of SOA. SOA parameters were developed for several different classes (glycols, glycol ethers, esters and oxygenated aromatics) of VCP VOCs that accounted for the effects of multi-generational aging and losses of vapors to the reactor walls. A chemical scheme, based on the branching ratio of the peroxy radical, allowed for the development of a universal set of parameters that explained the SOA formation under both low and high NOX conditions. Ongoing work is focused on box model applications that quantify the (i) SOA mass yields for VCP VOCs under atmospherically-relevant conditions and (ii) SOA formation from anthropogenic sources, including VCPs, in Los Angeles (CalNex-2010) and New York City (NYICE-2018). Future work will incorporate these parameterizations into a chemical transport model to study air quality and atmospheric chemistry in urban environments.