Changes in the Seasonality of Fire Activity and Fire Weather in Portugal: Is the Wildfire Season Really Longer?

The length of the fire season has not garnered much attention within the broad field of meteorological research on fire regime change. Fire weather research on the Iberian Peninsula is no exception in this case; there is no solid understanding on fire season lengthening in Portugal, although recent...

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Main Authors: Pedro Silva, Miguel Carmo, João Rio, Ilda Novo
Format: Article
Language:English
Published: MDPI AG 2023-02-01
Series:Meteorology
Subjects:
Online Access:https://www.mdpi.com/2674-0494/2/1/6
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author Pedro Silva
Miguel Carmo
João Rio
Ilda Novo
author_facet Pedro Silva
Miguel Carmo
João Rio
Ilda Novo
author_sort Pedro Silva
collection DOAJ
description The length of the fire season has not garnered much attention within the broad field of meteorological research on fire regime change. Fire weather research on the Iberian Peninsula is no exception in this case; there is no solid understanding on fire season lengthening in Portugal, although recent decades do suggest ongoing transitions. Based on a complete record of fire occurrence and burned area between 1980 and 2018, we first searched for consistent trends in the monthly distribution of fire activity. To determine day-scale changes, an exceedance date method based on annual cumulative burned area was developed. Results show an early onset of fire activity in a range of 23–50 days and no significant extension into autumn, suggesting that existing projections of the lengthening of the fire season in Portugal over the present century have been already achieved. Fire weather results show a trend in the cumulative Daily Severity Rating (DSR), with the last two decades (2000–2018) displaying an early build-up of meteorological fire danger in late spring and early summer. The detailed spatio-temporal analysis based on the daily Fire Weather Index (FWI) shows that June stands out with the largest increase (year-round) in days per month with an FWI above 38.3, the threshold above which fire conditions make suppression uncertain. This aggravated fire weather is likely sustaining early fire activity, thus contributing to a longer critical fire season.
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spelling doaj.art-f4252961a10948969e766fca2b55d5312023-11-17T12:40:36ZengMDPI AGMeteorology2674-04942023-02-0121748610.3390/meteorology2010006Changes in the Seasonality of Fire Activity and Fire Weather in Portugal: Is the Wildfire Season Really Longer?Pedro Silva0Miguel Carmo1João Rio2Ilda Novo3Departamento de Meteorologia e Geofísica, Instituto Português do Mar e da Atmosfera (IPMA), Rua C do Aeroporto, 1749-077 Lisbon, PortugalInstitute of Contemporary History, School of Social Sciences and Humanities, NOVA University Lisbon (IHC-NOVA FCSH), Campus de Campolide, 1749-077 Lisbon, PortugalDepartamento de Meteorologia e Geofísica, Instituto Português do Mar e da Atmosfera (IPMA), Rua C do Aeroporto, 1749-077 Lisbon, PortugalDepartamento de Meteorologia e Geofísica, Instituto Português do Mar e da Atmosfera (IPMA), Rua C do Aeroporto, 1749-077 Lisbon, PortugalThe length of the fire season has not garnered much attention within the broad field of meteorological research on fire regime change. Fire weather research on the Iberian Peninsula is no exception in this case; there is no solid understanding on fire season lengthening in Portugal, although recent decades do suggest ongoing transitions. Based on a complete record of fire occurrence and burned area between 1980 and 2018, we first searched for consistent trends in the monthly distribution of fire activity. To determine day-scale changes, an exceedance date method based on annual cumulative burned area was developed. Results show an early onset of fire activity in a range of 23–50 days and no significant extension into autumn, suggesting that existing projections of the lengthening of the fire season in Portugal over the present century have been already achieved. Fire weather results show a trend in the cumulative Daily Severity Rating (DSR), with the last two decades (2000–2018) displaying an early build-up of meteorological fire danger in late spring and early summer. The detailed spatio-temporal analysis based on the daily Fire Weather Index (FWI) shows that June stands out with the largest increase (year-round) in days per month with an FWI above 38.3, the threshold above which fire conditions make suppression uncertain. This aggravated fire weather is likely sustaining early fire activity, thus contributing to a longer critical fire season.https://www.mdpi.com/2674-0494/2/1/6wildfire seasonalityextended burning seasonpre-season fire weatherdaily severity ratingclimate changewestern Iberia
spellingShingle Pedro Silva
Miguel Carmo
João Rio
Ilda Novo
Changes in the Seasonality of Fire Activity and Fire Weather in Portugal: Is the Wildfire Season Really Longer?
Meteorology
wildfire seasonality
extended burning season
pre-season fire weather
daily severity rating
climate change
western Iberia
title Changes in the Seasonality of Fire Activity and Fire Weather in Portugal: Is the Wildfire Season Really Longer?
title_full Changes in the Seasonality of Fire Activity and Fire Weather in Portugal: Is the Wildfire Season Really Longer?
title_fullStr Changes in the Seasonality of Fire Activity and Fire Weather in Portugal: Is the Wildfire Season Really Longer?
title_full_unstemmed Changes in the Seasonality of Fire Activity and Fire Weather in Portugal: Is the Wildfire Season Really Longer?
title_short Changes in the Seasonality of Fire Activity and Fire Weather in Portugal: Is the Wildfire Season Really Longer?
title_sort changes in the seasonality of fire activity and fire weather in portugal is the wildfire season really longer
topic wildfire seasonality
extended burning season
pre-season fire weather
daily severity rating
climate change
western Iberia
url https://www.mdpi.com/2674-0494/2/1/6
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AT joaorio changesintheseasonalityoffireactivityandfireweatherinportugalisthewildfireseasonreallylonger
AT ildanovo changesintheseasonalityoffireactivityandfireweatherinportugalisthewildfireseasonreallylonger