Modelling of a wildfire in Portugal using a fully coupled atmosphere-fire spread modelling system

This work investigates the physical interactions and feedback between wildfires and the atmosphere using the coupled atmosphere-fire spread modelling system, WRF-SFIRE. The Figueira da Foz forest fire, occurred in Portugal in October 2017, which ocurred in association with hurricane Ophelia, was simulated under two different scenarios of fuel moisture settings, one static and one dynamic. Results show an underestimation of burnt area in the dynamic case, while static fuel moisture has shown a very high agreement. Pyrocumulus formed during late afternoon with a very dry base and more humid top, creating conditions favourable for the occurrence of downbursts, with very high Convective Available Potential Energy values. Lifted Condensation Level increased above the fire front as moisture was transported upwards, increasing surface temperature. Official reports show an overestimation of fuel moisture near the surface, leading to high CAPE values, compared to near zero values reported by vertical soundings. Relative Humidity values were higher by 30% when compared to weather station observations, and temperatures approximately 4ºC lower. Further model testing is needed to provide more accurate surface temperature and moisture simulations, to allow a more accurate fire progression representation and energy exchange, and improve the modelling of potential convective events.