Monitoring Emission, Chemistry and Transport of Vegetation Fires from IASI and Comparison with Simulations
Résumé
Vegetation fires are a major source of atmospheric trace gases and aerosols. Many studies have been conducted in the past to characterize locally the composition of biomass burning plumes and the chemistry that takes place within the vicinity of the source. However, there are fewer analyses of the plume chemistry during long-range transport and, as a consequence, the impact of fires on e.g. regional air quality, remains subject to large uncertainties. Remote sounding of atmospheric composition from satellite instruments offers the possibility to track fire plumes from the source to regions downwind, sometimes for periods of several days. This work provides an extensive analysis of fire plume composition, as measured by the Infrared Atmospheric Sounding Interferometer (IASI) on board the MetOp-A satellite. Different events are considered, including the Greece fires in 2007, the bush fires of Southern Australia in 2009, and the Russian fires in 2010. For these events, we report and compare primary (i.e. CO, C2H2, C2H4, NH3...) and secondary (i.e. HCOOH, PAN) trace gas concentrations. Total masses are calculated. We also derive for the different species enhancement ratios with respect to CO, which are followed in time to infer in-plume chemistry. To support the interpretation of the data, we provide for some events a comparison with model simulations.