Background*. Fire managers need science and tools that they can readily use to accurately characterize fire behavior and associated fire effects, such as emissions and burn severity. This is especially the case in large fires occurring in remote or inaccessible areas that threaten resources people value, such as clean air and water, and pleasing aesthetics for recreation. Remote sensing approaches have the potential to provide consistent assessments of fire location, intensity, and other aspects of fire behavior over an entire fire, while minimizing the risks to field crews.

Following early research at the Missoula Fire Lab, remote sensing in the middle to thermal  infrared (3.9-11 μm) has enabled physical measures of the energy radiated by the combustion of fuels within each fire-affected pixel to be measured by ground, aerial, and satellite sensor systems. This quantity is called the fire radiative power (FRP), while the total energy radiated over the enitre duration of a fire is called the fire radiative energy (FRE). If the heat yield of the fuels is known then the biomass combusted per pixel can be simply calculated by dividing the FRE by the heat yield (Andrews and Rothermel 1982) or by applying experimental regressions. The image above is from a MIR sensor and shows the radiative heat flux from burning duff in Idaho.

* see the following references for more detailed information:

Kaufman, Y.J., Kleidman, R.G. and King, M.D. (1998) SCAR-B fires in the tropics: Properties and remote sensing from EOS-MODIS, J. Geophys. Res., 103, 31,955-31,968

Lentile,L.B, Holden, Z., Smith A.M.S, Falkowski M.J., Hudak, A.T.,  Morgan, P., Gessler, P.E.and Benson, N.C., 2006 Remote sensing techniques to assess active fire and post-fire effects, International Journal of Wildland Fire, 15, 3, 319-345

Wooster, M.J., Roberts, G., Perry, G.L.W. and Kaufman, Y.J., (2005) Retrieval of biomass combustion rates and totals from fire radiative power observations: Part 1 - Calibration relationships between biomass consumption and fire radiative energy release, J. Geophys. Res., 110, D21111: doi: 10.1029/2005JD006318.

Emissions and Air Quality Research.  Current regulatory restrictions and land management mandates are substantially increasing fire managers’ need for accurate emissions information. The 2006 revision of the National Ambient Air Quality Standards lowered the 24-hour standard from 65 μg m^-3 to 35 μg m^-3, almost cutting them in half.  Healthy Forest Initiative and fuel management targets require land managers to reduce fuels on a scale never before achieved; national discussions of “appropriate suppression response” would blur the current distinction between fire use fires and wildland fires and make these targets even more difficult to attain.

The lab alongside collaborators such as Dr Brian Lamb (Washington State University) and Dr Brian Potter (USFS - PNW) are investigating the incorporation of radiant heat flux information into regional emission and transport models such as BlueSky-Rains and the AIRPACT-3 system. This project is funded by the Interagency Joint Fire Sciences Program.

 (Left panel) BlueSky-RAINS wildfire map showing location and relative size of wildfires for September 5, 2006; (Center panel)  MODIS image of wildfire locations and smoke plumes compared to accumulated monthly maximum PM2.5 surface concentrations forecast (right panel) with the AIRPACT-3 system. Images produced by Dr Brian Lamb (Washington State University)

Fire Behavior and Severity Research. In a recent study by this lab, Smith and Wooster (2005)** demonstrated that within southern African savanna grass-woodland environments, the MODIS-derived FRP was a reasonable discriminator between whether a fire front was the result of a heading or backing fire. Indeed, the FRP for heading fires was observed to be an order of magnitude greater than backing fires (Smith and Wooster 2005). Therefore we can say that MODIS FRP is sensitive enough to differentiate between heading and backing fires in S. African grass-woodland savannas. The lab is continuing this research by investigating the utility of MODIS FRP to characterize fire behavior in N. American forest fires.

** Smith A.M.S., and Wooster, M.J., 2005, Remote classification of head and backfire types from MODIS fire radiative power observations, International Journal of Wildland Fire, 14, 249-254. (PDF)