Biomass burning in Amazonia: Emissions, long-range transport of smoke and its regional and remote impacts

Every year, biomass burning in Amazonia continues to release large amounts of trace gases and aerosol particles into the atmosphere. The consequent change from low to very high atmospheric concentrations of oxidants and aerosols therefore affects the radiative, cloud physical, and chemical properties of the atmosphere over Amazonia. This represents a dramatic perturbation to the regional climate, ecology, water cycle, and human activities. Given the magnitude of burning in Amazonia and the efficiency of the atmospheric transport processes of fire emissions, these perturbations can affect the climate system even on a global scale. This chapter summarizes the knowledge acquired in the ambit of the Large-Scale Biosphere-Atmosphere Experiment in Amazonia program about vegetation fire as a driving force of atmospheric disturbances over Amazonia. We describe the different fire behaviors for the region and present an updated review of emission and combustion factors for Amazonia. We discuss some of the available biomassburning emission inventories for the Amazonian region, discussing their assets and limitations. We further discuss atmospheric transport processes that are the main drivers of the dispersion of fire emissions, introduce the most relevant concepts for numerical modeling of smoke transport, and show the general pattern of smoke transport over the South American continent. Finally, we present the current status of the understanding of local and remote impacts of smoke trace gases and aerosol particles, discussing the oxidizing power of the Amazonian atmosphere, as well as the radiation and heat budgets and consequences on cloud properties and distribution.