Fire Behavior and Smoke Dispersion in Forested Environments: Don’t Ignore Turbulent Fluxes of Heat and Momentum

2019 Research Highlights – Northern Research Station, USDA Forest Service, www.fs.fed.us/nrs/highlights/400.

The atmospheric redistribution of heat and momentum in the vicinity of wildland fires is a highly turbulent process, and this redistribution can have a direct and indirect effect on fire behavior and smoke dispersion. Northern Research Station scientists are investigating how fire-induced atmospheric turbulence can impact heat and momentum fluxes in the vicinity of wildland fires in forested environments.

Wildland fires generate their own meteorology, including turbulent winds. These turbulent winds act to redistribute heat and momentum in the fire environment, which in turn affects how wildland fires spread across the landscape and how smoke is transported away from those fires. Northern Research Station scientists have provided new and valuable insight into the connections between fire-induced turbulent winds, forest-canopy-induced turbulent winds, and the fluxes of heat and momentum in the vicinity of wildland fires occurring in forested environments. Observational wind and temperature data collected during wildland (prescribed) fire events in forested environments were used to assess directional differences in how heat and momentum are redistributed through forest vegetation layers, which is an important factor in anticipating how fires will spread and how smoke will disperse. The temporal variability of turbulent heat and momentum fluxes before, during, and after fire-front-passage was also examined. The study results suggest that interactions between wildland fires, the local atmosphere, and forest canopies, manifested via turbulent circulations, should not be ignored in the development of operational and research tools for predicting the local effects of heat and momentum transfer on fuel heating, fire behavior, and smoke dispersion.

Research Partners

External Partners

  • Shiyuan (Sharon) Zhong, Department of Geography, Michigan State University.
  • Craig B. Clements, Department of Meteorology and Climate Science, San José State University
  • New Jersey Forest Fire Service