Coupled fire-atmosphere modelling

A newer generation of models that interactively couple the atmosphere with fire behaviour.

J. coehn (2018) some requirements for simulating wildland fire behaviour using insight from coupled weather – wildland fire models. Fire 1, 6.

Coupled fire-atmosphere modelling systems do have great potential to support wildfire incident management.

T.M. Giannaros (2020) PErformance evaluation of an operational rapid response fire spread forecasting system in the southeast Mediterranean (greece). Atmosphere 11, 1264.

The trade-off solution of coupled models

Coupled fire-atmosphere models provide the necessary balance between the realism of the represented physical processes and the computational demands for carrying out real-time forecasts.

While they can be adapted to real-time response, coupled fire-atmosphere models have been proven to be capable of reproducing fire spread and smoke dispersion with a high level of accuracy.

Coupled fire-atmosphere models have shown increased potential in terms of predicting complex and rapidly changing fire behaviour, while they have also shown ability with respect to anticipating transient fire phenomena, such as convective plumes, fire-induced winds, and horizontal roll vortices.

In that regard, coupled fire-atmosphere modes are able to account for what has been long known as that “wildfires make their own weather”.

The coupled IRIS forecasting system

IRIS is a rapid response fire spread forecasting system that is based on the coupled fire-atmosphere WRF-Fire model, properly adapted to the pyric environment of Greece.

The system was developed to operationally support the wildfire suppression activities of the Hellenic Fire Corps. During the 2019 – 2020 period, IRIS has been called to provide fire spread predictions for more than 40 wildfire events.

The performance of IRIS is continually monitored and evaluated, both quantitatively and qualitatively. Analyses of its results reveal great potential in terms of providing forecast guidance of added-value for real-time wildfire incident management.

The development of the system is continued, focusing on adding new capabilities (e.g., spotting) and enhancing its predictive accuracy.

Our contribution

✔︎ FLAME will advance the capabilities of IRIS by explicitly accounting for the influence of the stability of the atmospheric flow on fire behaviour.

✔︎ A wind gust parameterisation scheme will be developed and implemented within the computational framework of WRF-Fire, linked to the algorithm used for simulating fire spread and behaviour.

✔︎ The impact of employing wind gusts for predicting fire spread will be assessed by carrying out retrospective simulations of past wildfires with the upgraded IRIS system.

✔︎ Several numerical experiments will be carried out with the upgraded IRIS system in order to gain a better understanding of the influence of atmospheric stability on fire behaviour.