A Study on the Evolution of Smoke from Prescribed Fires in Southeastern US
RIME EL ASMAR, Rodney J. Weber, M. Talat Odman, Greg Huey, David Tanner, Zongrun Li,
Georgia Institute of Technology Abstract Number: 464
Working Group: Remote and Regional Atmospheric Aerosol
AbstractIncreasing wildfires in the US are emitting high amounts of pollutants. The negative impact of emissions on air quality may be reduced by using prescribed burning as a fire management tool to limit the occurrence of wildfires. While prescribed burning can be controlled, it can still substantially contribute to air pollution due to emissions of particulate matter (PM) and hazardous gaseous compounds. In this work, we studied smoke from prescribed fires of forested training lands at Fort Benning, Fort Stewart, and Eglin Air Force Base, located in the Southeastern US, during the burning seasons of 2021, 2022, and 2023. We measured CO, O
3, NO
x, PM
2.5 mass, and BC, and inferred brown carbon (BrC) from multiwavelength aethalometers. Our approach to study smoke emissions at Fort Stewart and Eglin was to move and locate instruments across smoke receptor areas predicted by models just prior to burning events. At Fort Benning, we located five instrumented trailers in different sites throughout the fort, based on a burning plan set prior to the burning season and sampled continuously throughout the burning season. Smoke age, estimated based on fire and wind data, was used to study the evolution of O
3, PM
2.5, and BrC. For smoke of different ages, consistent O
3 enhancements relative to CO were observed during photochemically active periods. PM
2.5 mass and BrC relative to CO were higher for smoke transported 1-4 hours relative to fresh smoke less than 1 hour old. This indicates secondary PM
2.5 formation, including BrC species. The goal of this work is to provide data on prescribed fire emissions and smoke evolution for the testing and development of models used in burning management to decrease their adverse air quality impacts.