Quantification of Biomass Burning Organic Aerosol in the Greater Atlanta Area: Insights From Historic Data and ASCENT Measurements
RUIZHE LIU, Sohyeon Jeon, Alison Fankhauser, Yutong Liang, David Pando, Lu Xu, Ting Fang, Rodney J. Weber, Roya Bahreini, Ann M. Dillner, Armistead G. Russell, Nga Lee Ng, Georgia Institute of Technology
Abstract Number: 550
Working Group: Aerosol Processes and Properties in Changing Environments in the Anthropocene
Abstract
Fine organic aerosol (OA) in the southeastern U.S. is often characterized by strong interactions of biogenic and anthropogenic emissions. Results from prior short intensive campaigns have shown that biogenic hydrocarbons contribute substantially to secondary organic aerosol (SOA) in the greater Atlanta area, especially in summer. However, quantifications of specific SOA sources remain a challenge. This study utilizes measurements from the South Dekalb site in Atlanta, which is a part of the ASCENT (Atmospheric Science and Chemistry mEasurement NeTwork) observational network. In this work, positive matrix factorization (PMF) is applied to combined datasets from a Time of Flight-Aerosol Chemical Speciation Monitor (ToF-ACSM, PM2.5) and an XRF-based trace metal monitor (Xact-625i, PM2.5, Sailbri Cooper, Inc.). Integrating organic aerosol composition with elemental data, particularly potassium (K) as a tracer, enables a more robust apportionment of fresh and aged biomass burning OA (BBOA). Our results show that biomass burning contributes approximately 26% to the total OA in the region, with 33% of the SOA attributed to emissions from biomass burning sources. Building on this approach, we reanalyze historic aerosol mass spectrometry datasets from the greater Atlanta area to evaluate the influences of biomass burning emissions and quantify previously unrecognized BB-SOA contributions. The ubiquitous presence of BB-SOA, even in an area dominated by biogenic emissions, highlights the need to improve our understanding of their sources, properties, and impacts on air quality.