Investigating fire-induced ozone production from local to global scales
Palmo, J. O., Heald, C. L., Blake, D. R., Bourgeois, I., Coggon, M., et al. (2025). Investigating fire-induced ozone production from local to global scales. Atmospheric Chemistry and Physics, doi:https://doi.org/10.5194/acp-25-17107-2025
| Title | Investigating fire-induced ozone production from local to global scales |
|---|---|
| Genre | Article |
| Author(s) | J. O. Palmo, C. L. Heald, D. R. Blake, I. Bourgeois, M. Coggon, J. Collett, Frank M. Flocke, A. Fried, G. Gkatzelis, Samuel R. Hall, L. Hu, J. L. Jimenez, P. Campuzano-Jost, I. Ku, B. Nault, Brett B. Palm, J. Peischl, I. Pollack, A. Sullivan, J. Thornton, C. Warneke, A. Wisthaler, L. Xu |
| Abstract | Abstract. Tropospheric ozone (O3) production from wildfires is highly uncertain; previous studies have identified both production and loss of O3 in fire-influenced air masses. To capture the total ozone production attributable to a smoke plume, we bridge the gap between near-field fire plume chemistry and aged smoke in the remote troposphere. Using airborne measurements from several major campaigns, we find that fire-ozone production increases with age, with a regime transition from NOx-saturated to NOx-limited conditions, showing that O3 production in well-aged plumes is largely controlled by nitrogen oxides (NOx). Observations in fresh smoke demonstrate that suppressed photochemistry reduces O3 production by ∼ 70 % in units of ppb Ox (O3 + NO2) per ppm CO in the near-field (age < 20 h). We demonstrate that anthropogenic NOx injection into VOC-rich fire plumes drives additional O3 production, sometimes exceeding 50 ppb above background. Using a box model, we explore the evolving sensitivity of O3 production to fire emissions and chemical parameters. We demonstrate the importance of aerosol-induced photochemical suppression over heterogeneous HO2 uptake, validate HONO's importance as an oxidant precursor, and confirm evolving NOx sensitivity. We evaluate GEOS-Chem's performance against these observations, finding the model captures fire-induced O3 enhancements at older ages but overestimates near-field enhancements, fails to capture the magnitude and variability of fire emissions, and does not capture the chemical regime transition. These discrepancies drive biases in normalized ozone production (ΔO3/ΔCO) across plume lifetime, though the model generally captures observed absolute O3 enhancements in fire plumes. GEOS-Chem attributes 2.4 % of the global tropospheric ozone burden and 3.1 % of surface ozone concentrations to fire emissions in 2020, with stronger impacts in regions of frequent burning. |
| Publication Title | Atmospheric Chemistry and Physics |
| Publication Date | Nov 28, 2025 |
| Publisher's Version of Record | https://doi.org/10.5194/acp-25-17107-2025 |
| OpenSky Citable URL | https://n2t.net/ark:/85065/d77h1q3w |
| OpenSky Listing | View on OpenSky |
| ACOM Affiliations | ESS |