Event-Scale Fire Behaviour Characterization from MTG/FCI Observations and Airborne Observation

The characterization of fire behavior from observations and its coupling with plume dynamics and atmospheric composition remains a major challenge for coupled fire–atmosphere modeling systems. In this context, that is the frame work of the EUBURN initiative, this work presents recent developments in the processing and exploitation of MTG-FCI (Meteosat Third Generation - Flexible Combined Imager) observations for the derivation of fire behavior descriptors, and exercise of validation against airborne infrared measurements acquired during the SILEX experimental airborne campaign conducted in southern France in summer 2025.

A dedicated processing framework based on the Fire Event Tracker (FET) algorithm is introduced. FET performs a spatio-temporal clustering of FCI hotspot detections provided by LSA-SAF to delineate individual fire events and derive event-scale fire behavior descriptors, including fire duration, Fire Radiative Energy (FRE), and time series of Fire Radiative Power (FRP), Forward Rate of Spread (FROS), and Fire Line Intensity (FLI). During the SILEX campaign, FET was operated in Near-Real-Time (NRT) and coupled with the ForeFire–MesoNH modeling system through automated now-casting system (FireCast) to simulate plume rise and dispersion, supporting the design of flight plans for the SAFIRE ATR42 research aircraft.

This summer, FET was also made operational over Portugal in collaboration with the Portuguese civil protection authority (ANEPC), with support from the VOST association. In this operational context, FET products mainly consisted of event-scale FRP time series that were used to monitor fire activity and detect reactivation during prolonged fire episodes.
More recently, FET has been extended to a retrospective processing mode, allowing the integration of the complete 2025 LSA-SAF hotspot archive over the Mediterranean basin. This provides a unique dataset of fire behavior descriptors at the scale of fire regime zones, from which initial sub-regional analyses are presented.

To support satellite product validation and provide high-resolution fire behavior characterization, Middle Wave Infrared (MWIR) thermal cameras were operated onboard the ATR42 during SILEX. These airborne observations provide meter-scale snapshots of active fire fronts and their radiative structure, enabling the assessment of sub-pixel fire heterogeneity and radiative variability and serving as a reference for evaluating FCI-derived FRP and their linkage to FET-derived fire perimeters.

In addition, FCI-derived FRE estimates are compared with fuel consumption measurements obtained by INRAE through post-fire field sampling at the Sigean site. This comparison provides an experimental evaluation of the consistency between satellite-based radiative estimates of biomass consumption and ground-based measurements, contributing to efforts to constrain relationships between FRE, fuel properties, and consumed biomass.

Overall, this work supports the development of an integrated fire characterization framework combining satellite and airborne observations, with direct relevance for the validation of coupled fire–atmosphere modeling systems such as ForeFire–MesoNH. By jointly addressing fire behavior, plume development, aerosol emissions, and atmospheric chemistry, the EUBURN project contributes to advancing event-based wildfire representations in next-generation fire–atmosphere and air quality models.