AGS-PRF: Improved Model Representations of Biomass Burning Organic Aerosol Formation for Prediction of its Impacts on Air Quality and Climate

Hatch Lindsay, La Jolla CA

Investigators

Abstract

The aim of this research is to (1) leverage collaborative measurements of biomass burning (BB) emissions and chemistry to better understand the essential compounds and processes contributing to secondary organic aerosol (SOA) in smoke plumes, and (2) develop an SOA model framework to improve predictions of organic aerosol formation and transport in fire-influenced regions. In this study, detailed chemical analyses of SOA precursors in fire emissions and their reaction products will be conducted at the US Forest Service Fire Science Laboratory using two-dimensional gas chromatography/time-of-flight mass spectrometry (GCxGC/TOFMS) during the fourth Fire Lab at Missoula Experiment (FLAME-IV). GCxGC analyses, augmented by complementary gas- and particle-phase measurements from the FLAME-IV campaign, will be used to develop a process-level model describing SOA formation, including the contribution of components evaporating from primary particles during plume dilution. The SOA module will be subsequently integrated into a comprehensive smoke plume model that includes calculations of aerosol water uptake and optical properties, thereby allowing improved assessments of fire-induced radiative forcing, as well as predictions of BB pollutant formation and transport for assessment of air quality downwind of fires. The work will be conducted under the mentorship of Prof. Kelley Barsanti at Portland State University (PSU). Potential broader impacts of several kinds are associated with this research. The FLAME-IV campaign will bring together researchers and their associated instrumentation from ten other institutions, creating new partnerships and datasets that are complementary to the PSU analyses. The smoke plume SOA model framework can be adapted and integrated into publically-available models (e.g., EPA's Community Multiscale Air Quality model, CMAQ) for access by the broader scientific community and policymakers nationwide. For example, such enhancements of CMAQ for predictions of BB-SOA formation and transport may be used by municipalities throughout the U.S. to inform scheduling of prescribed burns to maintain compliance with national particulate matter standards or to provide air quality alerts during wildfire activity. The project will provide the principal investigator with career development training in addition to enhanced opportunities for networking and outreach (e.g., mentoring underrepresented high-school students as part of the Apprenticeships in Science and Engineering program at PSU). Under the Center for Climate and Aerosol Research (CCAR) at PSU, additional opportunities exist for direct involvement in community engagement by assisting in the coordination of climate-related seminars accessible to the public and participating in K-12 classroom visits. These various outreach activities will provide important avenues for enhancing atmospheric science education and facilitating integration of research and education.