Abstract View
Investigating the Impact of Biomass Burning Aerosols on Urban Air Quality in Los Angeles
MITCHELL ROGERS, Benjamin Schulze, Christopher Kenseth, John Crounse, Paul Wennberg, John Seinfeld, California Institute of Technology
Abstract Number: 716
Working Group: Wildfire Aerosols
Abstract
The frequency and severity of wildfire events have escalated dramatically in recent years, particularly in the western United States. Despite the ubiquity and effects of wildfires, however, there is a limited understanding of how biomass burning aerosols impact urban air quality, particularly in regions with pervasive air pollution. Here, we characterize the influence of wildfire emissions on urban aerosol mass loadings and composition measured in Los Angeles, CA using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) during the 2020 Bobcat Fire. Positive matrix factorization (PMF) is employed to identify and apportion sources of airborne particulate matter typical of urban atmospheres (e.g. combustion and cooking) as well as those unique to biomass burning. Wildfire plume transport and aging is evaluated using HYbrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) backward air mass trajectories. Compared to typical levels in Los Angeles, non-refractory submicron organic aerosol concentrations increased by over a factor of 10 during periods impacted by smoke from the wildfire. Future work will reconcile results with past models of simulated aerosol formation and chamber measurements.