Developing Strategies to Use Chemical Transport Models to Effectively Predict the Air Quality Impact of Single Prescribed Burns

Abstract Description: Prescribed burning is a critical tool in ecosystems management and the prevention of wildfires. Moreover, these burns may mitigate severe air pollution episodes by lessening the severity and likelihood of uncontrolled wildfires. While chemical transport models included state-of-the-science representations of the chemical and physical processes that determine the transport and transformation of fire emissions, modeling small, short-lived prescribed fire plumes can be challenging with gridded, regional-scale models.

Here we use a state-of-the-science air quality modeling framework based on the CMAQ model to quantify the air quality impacts of prescribed burns, particularly within North Carolina state parks. We use the BlueSky Pipeline modeling system to characterize emissions from prescribed burns based on their size, location, and duration. These emissions data are then integrated with meteorological information derived from the WRF simulations using the SMOKE emission processing model.

Our research aims to evaluate the ability of the CMAQ modeling framework to represent the air quality impacts of prescribed burns conducted across all state parks in North Carolina in 2022. By examining burns of varying sizes across diverse regions, we analyze how smoke dispersion is influenced by geographical location and seasonal timing. Using a high-resolution (1 km x 1 km) modeling setup, we assess CMAQ's performance in capturing smoke plumes from prescribed fires compared to larger-scale configurations. Our analysis also explores the duration and spatial extent of pollution plumes from specific prescribed fires, ensuring simulations effectively capture pollution impacts on neighboring populations while maintaining computational efficiency. Additionally, we evaluate the sensitivity of PM formation in plumes to initial and boundary conditions, emissions from vegetation, and other anthropogenic sources. To better understand the composition of fine particulate matter in the plume, we examine secondary organic aerosols formation. Ultimately, this research aims to provide actionable recommendations for the effective use of CTMs in modeling the air pollution impacts of prescribed fire projects.