Significant wildfires occurred during the summer of 2022 in Europe, particularly in the Landes region. These wildfires generate significant local air pollution due to combustion products. A first aspect of the study involved quantifying this pollution by conducting a two-month simulation using the coupled WRF-CHIMERE models. However, wildfires also alter land surfaces, making them more erodible and drier (resulting in increased mineral aerosol emissions), and by destroying vegetation (resulting in reduced ozone deposition and biogenic emissions of volatile organic compounds). All these secondary effects are incorporated into the model, and the additional impact on pollution is also quantified. Whether through direct emissions or longer-term surface modifications, wildfires significantly increase air pollution on large spatial and temporal scales.

Figure: Map of surface concentration differences of PM10 (in ug/m3) for a simulation without and with vegetation fires for July 19, 2022, at noon.

Publication: Menut, L., Cholakian, A., Siour, G., Lapere, R., Pennel, R., Mailler, S., and Bessagnet, B.: Impact of Landes forest fires on air quality in France during the summer 2022, Atmos. Chem. Phys., 23, 7281-7296, 2023 Edited