4A.4
What can wildland fire research learn from severe storms?

- Indicates paper has been withdrawn from meeting
- Indicates an Award Winner
Monday, 3 November 2014: 12:00 AM
Madison Ballroom (Madison Concourse Hotel)
Brian Potter, USDA Forest Service, Seattle, WA

Despite many years of research on wildland fires, scientific understanding of their plume circulations is extremely limited. This is true despite the fact that the fire's circulation, is important for both fire behavior and smoke dispersion. The role of the circulation in the behavior of the fire at the ground is qualitatively acknowledged in many studies, but very little data or analysis of this circulation exists. The plume is most commonly considered for questions of smoke transport and dispersion, with theoretical and numerical models tuned for those purposes. These models assume weak buoyancy, no added moisture from combustion, and constant vertical velocity. Yet some fires generate convective columns with lightning, rain, hail, and downbursts, and there are some observations of accelerating updrafts.

Technology and research on storms and cumulus convection have made some advances that could make wildfire plume convection more tractable. Digital photography, unmanned aerial platforms, and satellite imagery all provide opportunities for velocity analysis. Lidar can provide insight into the processes hidden within the smoke plume. Numerical models that include explicit, coupled combustion physics at the ground and atmospheric dynamics are gaining credibility. And fire-hardened in situ instruments are allowing collection of data previously unavailable for analysis and model development.

I will present an overview of existing wildfire plume studies, theory and models, discussing key similarities and differences between these plumes and severe storms. I will illustrate how the models do or do not realistically represent fire behavior and smoke dispersion. I will also suggest some aspects of the wildfire circulation that may be more conducive to study, and how better understanding of the circulation can improve wildland fire fighter safety and smoke impact forecasts.