Analytical Chemistry Seminar: Shantanu Jathar

Jointly sponsored by the Department of Chemistry and Biochemistry, CIRES, and the Environmental Program

Secondary Organic Aerosol Modeling using the Statistical Oxidation Mode

Shantanu Jathar Colorado State University

Multi-generational gas-phase oxidation of organic vapors can influence the abundance, composition and properties of organic particulate matter or organic aerosol. Most air quality and climate models lack or include an ad hoc treatment of multi-generational oxidation. In this seminar, I will highlight our recent work where we coupled a semi-explicit multi-generational oxidation model for organics (fully constrained by experimental smog chamber data that includes both functionalization and fragmentation reactions) with a gas-phase chemical mechanism in a regional 3-D air quality model. The seminar will discuss results where we (a) investigated the role of multi-generational gas-phase chemistry on the mass, composition, volatility and oxidation state of SOA and (b) explored the influence of vapor wall-losses on ambient concentrations and properties of SOA. Based on those results, I will argue that 3-D models need to include (this or similar) multi-generational oxidation schemes to accurately describe the atmospheric evolution of OA in air quality and climate models.