Modelling atmospheric conditions leading to large fires in Portugal

Abstract

The extensive study of wildfires is crucial to better understand how fire may be influenced by the atmospheric conditions [1]. The study explores the meteorological conditions associated with the mega fires occurred in Portugal on 15 October 2017. For that purpose, the MesoNH [2] atmospheric model was used. The model can represent the atmospheric motions in different scales and was configured in different resolutions aiming to investigate the events in different temporal and spatial scales. For example, one of the simulations was configured in a large domain (300x250 grid points) and 15 km resolution aiming to represent the synoptic conditions. In this context, the simulation well represented the evolution of the hurricane Ophelia near Portugal [Figure 1], indicating the important role played by the weather system inducing strong south-westerly winds over Portugal in the late afternoon of 15 October. An experiment at higher resolution confirms the generation of intense gusts that favoured the rapid spread of the fires.