Managing the Chemical Complexity of Wildland Fire Emissions in Highly Parameterized Air Quality Models 

Abstract

Emissions from wildland fires strongly influence tropospheric chemistry and climate. Fires emit high levels of trace gases, including semi-volatile and volatile organic compounds (S/VOCs); and primary (directly emitted) particulate matter (PM). During plume evolution, S/VOCs react to form ozone (O₃) and secondary PM, thereby degrading air quality downwind. The amount of pollutants formed depends on fuel and fire characteristics, and plume dynamics and chemistry. In the western US and Canada, fire activity has been increasing over the last twenty years, attributed to changes in climate and fire management practices. Fire activity in the region is projected to worsen in future years, undoubtedly with severe impacts on air quality and climate. Unfortunately, model predictions of O₃ and PM are characterized by significant uncertainties; limiting the utility of models to stakeholders tasked with minimizing potential impacts of fires on downwind communities. While there are a number of factors that lead to poor model predictions, research in our group has focused on three particular limitations: 1) incomplete identification and quantification of gaseous compounds emitted from fires that may serve as pollutant precursors; 2) incomplete understanding of the transformations of the precursors that lead to pollutant formation in smoke plumes; and 3) over-simplified representation of emissions and processes in current smoke and air quality models. In this talk, I will present an overview of our efforts in these areas, using advanced analytical techniques to characterize the S/VOCs in smoke as a function of fuel species and component, and chemically detailed box models to develop air quality model parameterizations.

Biography

Kelley Barsanti is an Associate Professor in the Department of Chemical & Environmental Engineering and the Center for Environmental Research & Technology at UC Riverside. Her research interests are in improving the process-level understanding and model representation of fine particulate matter (PM) in air quality models. Her primary research tools include comprehensive two-dimensional gas chromatography and multi-scale mechanistic models. Current research projects include improving the speciation of organic compounds in emissions inventories for wildland fires; advancing the model representation of secondary organic PM formation in smoke plumes; and evaluating the effects of COVD-19 shelter-in-place restrictions on air quality in the South Coast Air Basin. She has authored or co-authored over 40 papers on these and related topics. She earned her PhD in Environmental Science & Engineering from the Oregon Health & Science University in Portland, OR; and served as a postdoctoral fellow at the National Center for Atmospheric Research in Boulder, CO.

Seminar Recording