U.S. Joint Fire Science Program


Date of this Version


Document Type



Project Active ID: 05-3-1-06


U.S. Government Work


Carbonaceous aerosols, which include contributions from industrial and mobile source emissions and biomass combustion, exert a significant impact on regional air quality. Some preliminary semi-quantitative analyses suggest that smoke from fire-related activity may contribute significantly to observed organic mass concentrations. Further, these emissions have resulted in increased conflicts with the need to attain air quality standards, especially for particulate matter (PM) and visibility, as mandated by the Clean Air Act. However, federal land managers and policy makers currently lack several important tools needed for air quality assessments: composition profiles and analytical techniques necessary to differentiate carbonaceous aerosols originating from industrial and mobile source activity and those from fire emissions; measurement-based PM mass emissions rates for relevant fuels and combustion conditions; and reasonable optical properties and optical property emission rates to attach to fire emissions. In this project, we addressed these needs via a comprehensive, multi-investigator approach that included both laboratory studies and validation of findings via field measurements. Specific elements included: (1) development and validation of promising new, inexpensive methods suitable for quantitative measurement of smoke marker (levoglucosan and K+) concentrations from aerosol filter samples, such as those routinely collected by the IMPROVE or EPA STN networks; (2) laboratory measurements of smoke emission composition profiles for several important fuel types burned under a variety of conditions to provide urgently-needed source profiles for classes of fires believed to severely impact air quality in the western and southeastern U.S.; (3) concurrent with smoke emission profile measurements, measurement of key physical and optical properties and emission rates in the laboratory; and (4) field measurements of fresh smoke plumes to validate whether laboratory smoke studies, conducted under well controlled conditions, can simulate PM2.5 mass, composition, and optical property emissions characteristics of more complex, actual prescribed and wild fires. Further, the field study was to be complemented by lidar measurements to demonstrate the feasibility of using remote sensing methods for continuous monitoring of smoke-polluted atmospheres adjacent to severe wildfires, providing diurnal and spatial variation of aerosol properties, plume heights and dynamics, and direction and rate of smoke plume movement in near real-time. Our project resulted in the generation of a large database of emissions data, and numerous refereed publications describing the methods, findings and implications. Together, the results and methods developed during this study “support the needs of wildland fire managers and policy makers in determining the contribution of biomass burning to PM2.5 and visibility on a regional basis,” as requested in the Call for Proposals, with our work specifically focusing on the western and southeastern U.S. regions.