Plinius Conference Abstracts
Vol. 18, Plinius18-90, 2024, updated on 11 Jul 2024
https://doi.org/10.5194/egusphere-plinius18-90
18th Plinius Conference on Mediterranean Risks
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

The link between temperature and wind extremes with fire activity in Portugal in the 21st century

Patrícia Páscoa1,2, Soraia Pereira3, Patrícia de Zea Bermudez3, and Célia M. Gouveia1,4
Patrícia Páscoa et al.
  • 1Universidade de Lisboa, Faculdade de Ciências, Instituto Dom Luiz, Lisbon, 1749-016, Lisbon, Portugal (ppramos@ciencias.ulisboa.pt)
  • 2Centro de Investigación Mariña, Environmental Physics Laboratory (EPhysLab), Universidade de Vigo, Campus As Lagoas s/n, 32004, Ourense, Spain
  • 3Centro de Estatística e Aplicações da Universidade de Lisboa (CEAUL), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisbon, Portugal
  • 4Instituto Português do Mar e da Atmosfera, Rua C do Aeroporto, 1749-077, Lisbon, Portugal

Portugal is a fire-prone country, due to climate conditions that drive high fuel availability. In the 21st century, several catastrophic fire seasons have occurred, with an extremely high total burned area and the loss of human lives. Extreme fire seasons typically occur under hot and dry conditions, such as 2003, 2005, and 2017, although wind is known to facilitate fire spread, as occurred in October of 2017 due to the Ophelia storm.

In this work, the bivariate relationship between Fire Radiative Power (FRP), daily temperature, and wind speed was assessed, using copula functions, which estimate the joint distribution of two variables. This method is specially suited to analyse extreme events, since it is possible to model asymmetrical relationships, namely tail dependences. FRP was retrieved from MODIS, with a spatial resolution of 1 km, and hourly temperature and hourly wind components were obtained from the ERA Land dataset, with a spatial resolution of 0.1°. Only the maximum FRP value occurring on each ERA Land grid point was used. Copula functions were fitted to FRP and the weather variables on the day of the fire and on the previous days, for the period 2001-2020. Conditional probabilities of FRP were then computed, given extreme values of temperature and wind intensity. Forests and shrublands are very prone to burn in Portugal, but since the fuel accumulation and availability is very different in these land covers, they were assessed separately.

The results show that extreme values of temperature and wind intensity increase the probability of high values of FRP, when compared to lower temperatures and weaker winds, and that the probability is higher for the case of temperature extremes.

Ackowledgements: This study was supported by FCT I.P./MCTES (Fundação para a Ciência e Tecnologia, Portugal)  through national funds (PIDDAC):  UIDB/50019/2020 (https://doi.org/10.54499/UIDB/50019/2020), UIDP/50019/2020 (https://doi.org/10.54499/UIDP/50019/2020) and LA/P/0068/2020 (https://doi.org/10.54499/LA/P/0068/2020), “Fundos próprios para desenvolvimento de projetos de I&D” Project MEDCEX - reference: 100SPID8106.

How to cite: Páscoa, P., Pereira, S., de Zea Bermudez, P., and M. Gouveia, C.: The link between temperature and wind extremes with fire activity in Portugal in the 21st century, 18th Plinius Conference on Mediterranean Risks, Chania, Greece, 30 Sep–3 Oct 2024, Plinius18-90, https://doi.org/10.5194/egusphere-plinius18-90, 2024.