Interactive modelling of forest fires and their impacts on atmospheric composition

Forest and wildland fires are a significant emission source of gases and aerosols to the atmosphere. In particular, biomass burning has been shown to be a significant driver of interannual variability and short-term climate forcings. Fires emit a wide variety of compounds to the atmosphere, from greenhouse gases to aerosols. Conversely, weather and climate also drive fire occurrence, creating potential feedbacks between climate, atmospheric composition, and fire. Here, we will present INFERNO (INteractive Fires and Emissions algoRithm for Natural envirOnments, described in Mangeon et al., 2016), a reduced complexity approach to global fire modelling coupled to interactive atmospheric composition in the UK Met Office's Unified Model. We will first show the coupled model's performance in capturing burnt area and fire emissions. We will then demonstrate how fires impact atmospheric composition in the global model for present-day scenarios: with our interactive scheme but also with reference datasets of global fire emissions, as well as in simulations assuming no fire emissions. In particular, we will investigate the role of fires on the mean present-day state, the seasonal cycle, and the interannual variability of important atmospheric constituents (e.g., CO and aerosols).