A11G-03 Exploring Wildfire-Influenced Ozone Production from Local to Global Scales

Tropospheric ozone (O₃) production from wildfires is highly uncertain; previous studies have identified both production and loss of O₃ in fire-influenced air masses. Understanding O₃ formation in fire plumes is essential for assessing the global impact of fires on O₃, especially as wildfires become more frequent and intense. From an air quality policy standpoint, it is critical to understand the relationship between ground-level ozone and the long-range transport of smoke into metropolitan urban areas. Predicting wildfire impact is complicated by uncertainty in emissions estimates, nonlinear smoke chemistry, and urban mixing. To capture the total ozone production that may be attributed to a smoke plume, we must bridge the gap between near-field fire plume chemistry and aged smoke across the troposphere. We exploit in-situ airborne measurements from several major airborne campaigns (FIREX-AQ, WE-CAN, ARCTAS, DC3, ATom) to probe wildfire-induced ozone production during the lifetime of a plume. We find that ozone production increases with age, and that production in well-aged air masses is largely controlled by the abundance of NO_x. We use a box model to explore the evolving sensitivity of ozone production in fire plumes to emissions and chemical parameters (e.g. photolysis suppression, heterogeneous uptake onto aerosol, oxidant precursors, etc.). Using satellite observations from TROPOMI (vertical columns of HCHO, NO₂, CO, and aerosol layer height), we track the evolving chemistry within transported smoke plumes that ultimately impact urban air quality. We evaluate the performance of GEOS-Chem, a global three-dimensional chemical transport model, against the dataset we compile, and explore whether the model can capture the near-field, far-field, and urban-mixed ozone production in fire-influenced air masses. In the future, our findings may be used to improve smoke chemistry parameterizations at the plume-scale and inform future policy and health impact analyses.