Ozone production from wildfires: A critical review

• Published in: Atmospheric environment (1994) Vol. 51; pp. 1 - 10
• Main Authors: Jaffe, Daniel A., Wigder, Nicole L.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-05-2012; Elsevier
• Subjects: aerosols; air quality; Air quality impacts; anthropogenic activities; Applied sciences; atmospheric chemistry; Atmospheric pollution; combustion; Combustion and energy production; ecosystems; emissions; Exact sciences and technology; Fire emissions; greenhouse gases; human health; monitoring; ozone; Ozone exceedances; Ozone photochemistry; Ozone production; photochemical reactions; Pollution; Pollution sources. Measurement results; troposphere; uncertainty; volatile organic compounds; Wildfires; United States; North America; America; NO; O3; Ozone production; JO3; NO2; CARB; Tg; Ozone photochemistry; Ozone exceedances; AOD; NOx; PM2.5; ppmv; NMHC; OVOC; ppbv; Wildfires; AQS; JNO2; HONO; CO; MCE; Air quality impacts; EPA; NMOC; NAAQS; Fire emissions; PAN; Natural origin pollution; Photochemical oxidants; Troposphere; Ozone; Air quality; Review; Emission inventory; Biogenic factor; Biome; Greenhouse gas; Air pollution; Vegetation fire
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2011.11.063

Tropospheric ozone (O3) negatively impacts human health and ecosystems, and is a greenhouse gas. Wildfires are a source of tropospheric O3, and studies show that wildfires are increasing in North America. In this study, we present a critical review of O3 production from wildfires focusing on three key topics: the influence of wildfire emissions on O3 production; the influence of photochemistry on wildfire O3 production; and regulatory issues associated with wildfire O3 production in the United States. Observations of ΔO3/ΔCO range from approximately −0.1 to 0.9, and are caused by the interplay of numerous factors including fire emissions, efficiency of combustion, chemical and photochemical reactions, aerosol effects on chemistry and radiation, and local and downwind meteorological patterns. Using average ΔO3/ΔCO ratios for major biomes, we estimate global wildfires produce approximately 170 Tg of O3 per year, which is 3.5% of all global tropospheric O3 production. Areas of uncertainty in wildfire O3 production include the net effect of aerosols on chemical and photochemical reactions within a fire plume, the impact of oxygenated volatile organic compounds and nitrous acid on O3 production, and the interplay of variables that lead to extreme ΔO3/ΔCO values. Because wildfire frequencies are likely increasing and have been shown to contribute to elevated O3 at air quality monitoring sites, it is important to better understand the emissions, photochemistry and impacts of these fires.
► Wildfires produce approximately 170 Tg of O3 globally per year. ► Observations of ΔO3/ΔCO in fire plumes range from approximately −0.1 to 0.9. ► O3 production depends on fire emissions, photochemical reactions, meteorology and aerosol effects. ► Wildfires can contribute to exceedances of the ozone air quality standard.