Ozone in Wildfire Smoke and Its Influence on Urban Ozone As Observed from Recent Field Campaigns

The frequency, burned area and emissions from wildfires have been increasing in North America for the last four decades. Wildfires are known sources of ozone precursors, nitrogen oxides (NO_x) and volatile organic compounds (VOCs). Increasing wildfire emissions have influenced trends in North American urban ozone. The pyrogenic influence on ozone occurs either through ozone production within smoke plumes that is then transported to urban regions, or through the mixing of pyrogenic VOCs with urban NO_x to enhance local and regional ozone production. This presentation will use data from recent airborne and ground-based field campaigns to quantify these processes. The 2019 Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) sampled wildfire smoke across the U.S. with multiple research aircraft. The 2022 California Fire Dynamics Experiment (CalFiDE) conducted focused in-situ and remote sensing measurements in California and Oregon. Ground-based measurements in Boulder, Colorado intercepted periods of smoke influence in the Northern Front Range urban area in 2020 and 2021. Finally, the 2023 Atmospheric Emissions and Reactivity Observed from Megacities to Marine Areas (AEROMMA) campaign on the NASA DC-8 and the Coastal Urban Plume Dynamics Study (CUPiDS) on the NOAA Twin Otter observed long range smoke transported to U.S. urban areas and the associated impacts on ozone.