Wildfire-Induced Smoke Aerosols Simulated by the Aerosol Chemistry Model Intercomparison Project (AerChemMIP) Models.

Wildfire-Induced smoke aerosols cause adverse health effects. Wildfires, classified as Near-term climate forcers (NTCF), contribute to climate change by releasing aerosols and chemically reactive gases, impacting global and regional air quality and climate. Over the past decade, wildfire occurrence has dramatically increased, with projections indicating further escalation by the end of the century, exposing millions to harmful health effects from these aerosols, particularly PM2.5. However, simulating the air quality impacts of smoke aerosols remains a big challenge. Here, we analyzed aerosol optical depth (AOD) simulations from the preindustrial era using the Aerosol Chemistry Model Intercomparison Project (AerChemMIP). Specifically, we evaluated the experiments PiClim-Control and PiClim-2xFire against satellite observations to estimate the impact of double fire emission on AOD and the uncertainty of AerChemMIP simulations. PiClim-Control simulates pre-industrial concentrations of well-mixed greenhouse gases and emissions, while PiClim-2xFire simulates double the aerosol emissions from wildfires. In conclusion, the AOD difference between the two experiments over Central Africa and Southeast Asia highlights the high emission of aerosols in these regions. We also separated remote sensing observations of AOD into wildfire-induced aerosols and those from other anthropogenic sources.