Smoke emissions from the extreme wildfire events in central Portugal in October 2017

Abstract

In the last decades, numerous large forest fires have been recorded in Portugal. On 15 and 16 October 2017, seven extreme wildfires events (EWEs) took place in the central region of Portugal. Aiming to contribute to the assessment of the smoke impact of these EWEs, this study estimates their atmospheric emissions using a bottom-up approach with high spatial and temporal resolution. To this end, fire data were used, such as ignition location and time, propagation, burned area, and fuel load and emission factors according to forest species. A particular fire – EWE in Lousã with a high fuel load – emitted ~50% of the sum of the emissions of the six other case studies. The spatial distribution of the EWE emissions indicates that fuel load is an important component of emissions estimation. The obtained results were compared with remote sensing data, showing good agreement in terms of total values. During these EWEs, particulate matter and carbon monoxide emissions were higher than Portuguese anthropogenic emissions in 2017. This approach contributes to the state of the art on forest fire emissions, reducing uncertainty and obtaining the best possible and detailed quantification of the temporal and spatial variability of EWE emissions.