http://hdl.handle.net/10174/37664 2026-04-12T15:33:03Z http://hdl.handle.net/10174/41699 Title: Coupled Fire-Atmosphere modelling: Some Findings and current challenges based on Portuguese case studies Authors: Salgado, Rui; Couto, Flavio Tiago; Campos, Cátia; Santos, Filippe L. M.; Baggio, Roberta; Filippi, Jean-Baptiste Abstract: High-resolution atmospheric models and their coupling with fire propagation models are powerful tools for better understanding the behaviour of rural fires and their effects on the atmosphere. Portugal is one of the European countries with most burned area and numerous ignitions. In 2017, Portugal was affected by several megafires with burned areas larger than 10 000 hectares, some of which led to the formation of convective clouds: pyro-cumulus (pyroCu) and pyro-cumulonimbus (pyroCb). These phenomena can significantly influence the evolution of fire fronts by altering surface winds and raising spread rates, creating extra difficulties for firefighting and increasing burned areas. These rural fires of 2017 were the starting point for studying the atmospheric environment that favours ignitions and fire spread and the effects of fires on the atmosphere, particularly the generation of pyroconvection. In this study, Pedrogão Grande (June 17) and the Quiaios (October 15) mega-fires are chosen as case studies for numerical simulations with the MesoNH atmospheric model coupled with the ForeFire fire propagation model. The simulations show the development of pyroCu and pyroCb clouds produced by intense convective updrafts due the heat fluxes generated generated during combustion. The simulations have improved our understanding of the evolution of the fire environment and the role played by downbursts originating from pyroCb clouds and provided insights about numerical modelling of pyroconvective clouds using Meso-NH/ForeFire simulations. Finally, we use the results obtained in this work to illustrate the current state-of-the art of coupled fire-atmosphere modelling, its limitations and challenges. 2025-05-18T23:00:00Z http://hdl.handle.net/10174/41697 Title: Live fuel moisture content estimation using remote sensing and numerical modelling approach Authors: Santos, Filippe L. M.; Couto, Flavio Tiago; Monteiro, Maria José; Ribeiro, Nuno Almeida; Le Moigne, Patrick; Salgado, Rui Abstract: Climate change has led to an increase in wildfires, particularly on the Iberian Peninsula. In recent years, Portugal suffered several devastating wildfires, such as in 2003, 2005, and 2017. In 2024, the situation repeated itself, with several large-scale wildfires occurring in the Central region during September. Wildfires are directly related to the availability of combustible material, weather conditions, and ignition factors. Currently, land use and occupation management is a way to reduce wildfires. Identifying areas with higher fuel availability is essential for wildfire prevention in this context. This work aims to improve the live fuel moisture content (LFMC) representation across mainland Portugal, using remote sensing and numerical modelling through a machine learning approach. First, a product was developed to estimate LFMC for Portugal based on remote sensing, through satellite imagery, and machine learning (LFMC-RS). Next, numerical simulations were performed with the MESO-NH (research) and AROME (operational) models, non-hydrostatic mesoscale atmospheric models, producing forcing files to initialize the SURFEX surface model. All output variables from the SURFEX model were utilized as predictors in a machine learning classifier to estimate the LFMC (LFMC-SFX). These results are useful for understanding the FMC spatiotemporal variability in Portugal The research received financial support from the Foundation for Science and Technology, I.P. (FCT) through the PyroC.pt initiative (Ref. PCIF/MPG/0175/2019) along with a PhD Grant (2022.11960.BD). This work also was cofounded by the European Union through the European Regional Development Fund (FEDER) in the framework of the Interreg VI-A España-Portugal (POCTEP) 2021–2027, FIREPOCTEP+ (0139_FIREPOCTEP_MAS_6_E). 2025-05-18T23:00:00Z http://hdl.handle.net/10174/41686 Title: Estimativa do conteúdo de humidade da vegetação através da modelação numérica Authors: Santos, Filippe L. M.; Couto, Flavio Tiago; Monteiro, Maria José; Ribeiro, Nuno Almeida; Le Moigne, Patrick; Salgado, Rui Abstract: In recent years, Portugal suffered several devastating wildfires, such as in 2003, 2005, and 2017. Wildfires are related to fuel load, climate, and ignition factors. Currently, land use and occupation management is a way to reduce wildfires. The work’s objective is to improve the fuel moisture content (FMC) representation across mainland Portugal, through numerical modelling and machine learning. Initially, numerical simulations were performed using the Applications of Research to Operations at MEsoscale (AROME), a limited-area non-hydrostatic operational atmospheric model, creating forcing files to initialize the SURFEX surface model. SURFEX output variables were used as predictors to estimate the FMC through a machine learning-based classifier. These results are useful for understanding the FMC spatiotemporal variability in Portugal and important to identify high-fuel load areas which is crucial for integrated fire management. This work was funded by the Foundation for Science and Technology, I.P., under the PyroC.pt project (Ref. PCIF/MPG/0175/2019) and PhD Grant (2022.11960.BD). 2025-03-24T00:00:00Z http://hdl.handle.net/10174/41685 Title: Synoptic and Regional Meteorological Drivers of a Wildfire in the Wildland–Urban Interface of Faro (Portugal) Authors: Couto, Flavio Tiago; Campos, Cátia; Purificação, Carolina; Santos, Filippe Lemos Maia; Andrade, Hugo Nunes; Andrade, Nuno; Nunes, André Becker; Guiomar, Nuno; Salgado, Rui Abstract: A major fire occurred in the wildland–urban interface in southern Portugal, on 13 July 2022, becoming uncontrolled due to weather conditions. This study investigates how atmospheric dynamics increased fire danger in Mainland Portugal during early July 2022. The synoptic circulation from European Centre for Medium-Range Weather Forecasts (ECMWF) analysis and mesoscale conditions from Meso-NH model simulation at 1.5 km resolution revealed atmospheric conditions before and during the fire. Fire risk was assessed using the Fire Weather Index (FWI) from Meso-NH outputs. A blocking pattern was configured by an upper-level low-pressure system in early July, remaining semi-stationary west of Mainland Portugal until 18 July. The counter-clockwise circulation of the cut-off low resulted in dry, warm air advection from North Africa, enhancing fire danger over the Iberian Peninsula. In southern Portugal, a jet-like wind with strong east/southeasterly flow from Gibraltar Strait favored rapid fire spread. This circulation below 1 km altitude from the Mediterranean Sea enhanced fire danger through strong winds, independent of the large-scale blocking pattern. This study presents an atmospheric scenario for evaluating fire danger in Southern Portugal, important for pre-firefighting management that complemented previous studies for the region. Also, high-resolution FWI calculations using Meso-NH emphasized the importance of improved temporal and spatial resolution for fire danger assessment. 2025-09-10T23:00:00Z