Changes in ozone and precursors during two aged wildfire smoke events in the Colorado Front Range in summer 2015

Aged wildfire smoke from the Pacific Northwest and Canada significantly increased ozone (O3) levels by approximately 10 ppbv during two distinct events in summer 2015 over the Colorado Front Range, including at the Boulder Atmospheric Observatory. This enhancement persisted even after accounting for temperature effects, suggesting that wildfire smoke can substantially contribute to O3 abundances across urban-rural gradients. The study analyzed in situ measurements of O3, volatile organic compounds (VOCs), and reactive oxidized nitrogen species during smoke-impacted periods, revealing elevated levels of peroxyacyl nitrates, VOCs, carbon monoxide, particulate matter, and morning/evening nitrogen dioxide. These findings provide a case study on how aged wildfire smoke influences atmospheric composition, with implications for air quality as anthropogenic emissions decline.

Lindaas, J., Farmer, D. K., Pollack, I. B., Abeleira, A., Flocke, F., Roscioli, R., Herndon, S., & Fischer, E. V. (2017). Changes in ozone and precursors during two aged wildfire smoke events in the Colorado Front Range in summer 2015. Atmospheric Chemistry and Physics, 17(17), 10691–10707. https://doi.org/10.5194/acp-17-10691-2017