Current Research

Wildland fire is a fascinating and complex phenomenon. My current research focuses on the development of new understanding into the fundamental physics governing wildland fire ignition, spread, and intensity, along with improved methods for quantifying wildland fire intensity using in-situ instrumentation. I am particularly interested in quantifying how wind and slope affect fire behavior. The applications for this work include public and firefighter safety, improved capability to predict fire behavior, and the development of new tools, guides, and methods for understanding and managing fire more effectively.

Research Interests

My primary research interests include the development of tools for simulating wind flow at fine resolution, fire induced tree mortality, and improvement of existing firefighter safety zone guidelines. I am the lead scientist for the quantitative safety zone guidelines used throughout the world. I am also the lead scientist for the high resolution surface wind models that have been developed by the US Forest Service.

Past Research

Wildland fire is a complex process that involves biology, chemistry, fluid dynamics and energy transfer. It is an everpresent phenomena in many natural ecosystems. Advances in our understanding of the fundamental physics governing fire facilitate improved methods and tools for managing fire safely and effectively. In the past I have developed tools for predicting the effects of fire on trees and shrubs. Particularly effects of plant mortality caused by heating and necrosis of the cambiuam layer of the plant stem. This work has wide application to wildland fire management where managers are attempting to enhance or exclude a particular species through regular management practices.

Why This Research is Important

One of the fascinations of wildland fire is its complexity. This also leads to its associated danger. Much of the my work focuses on providing improved tools and methods for understanding and effectively and safely using fire as a ecological managmeent tool. Information, methods, and guidelines developed in my work are being used around the world to manage fire with less risk and greater success.

Education

• Brigham Young University, Ph.D. Mechanical Engineering with an emphasis on energy transport in particle-laden flames. 1992
• Brigham Young University, M.S. Cum Laude Mechanical Engineering 1988
• Brigham Young University, B.S. Mechanical Engineering 1986

Professional Organizations

• International Journal of Wildland Fire (1998 - Current)
  The Editorial Advisory Committee, provides strategic direction to the International Journal of Wildland Fire. Members meet 1-2 times per year. Dr. Butler has been a committee member since 1998 and served as chair of the committee for several years in the early 2000s. Dr. Butler also serves as an associate editor for the Journal.

Featured Publications & Products

• Butler, B. W. 2014. Wildland firefighter safety zones: A review of past science and summary of future needs.
• Frankman, David; Webb, Brent W.; Butler, Bret W.; Jimenez, Daniel; Forthofer, Jason M.; Sopko, Paul; Shannon, Kyle S.; Hiers, J. Kevin; Ottmar, Roger D. 2012. Measurements of convective and radiative heating in wildland fires.
• Butler, Bret W.; Dickinson, Matthew B. 2010. Tree injury and mortality in fires: developing process-based models.
• Butler, B. W.; Wagenbrenner, N. S.; Forthofer, J. M.; Lamb, B. K.; Shannon, K. S.; Finn, D.; Eckman, R. M.; Clawson, K.; Bradshaw, L.; Sopko, P.; Beard, S.; Jimenez, D.; Wold, C.; Vosburgh, M. 2015. High-resolution observations of the near-surface wind field over an isolated mountain and in a steep river canyon.
• Butler, B.W.; Ottmar, R.D.; Rupp, T.S.; Jandt, R.; Miller, E.; Howard, K.; Schmoll, R.; Theisen, S.; Vihnanek, R.E.; Jimenez, D. 2013. Quantifying the effect of fuel reduction treatments on fire behavior in boreal forests.
• Butler, Bret W.; Bartlette, Roberta A.; Bradshaw, Larry S.; Cohen, Jack D.; Andrews, Patricia L.; Putnam, Ted; Mangan, Richard J. 1998. Fire behavior associated with the 1994 South Canyon fire on Storm King Mountain, Colorado.
• Butler, Bret W.; Finney, Mark; Bradshaw, Larry; Forthofer, Jason; McHugh, Chuck; Stratton, Rick; Jimenez, Dan. 2006. WindWizard: A New Tool for Fire Management Decision Support.
• Frankman, David; Webb, Brent W.; Butler, Bret W.; Latham, Don J. 2010. Fine fuel heating by radiant flux.
• Pickett, Brent M.; Isackson, Carl; Wunder, Rebecca; Fletcher, Thomas H.; Butler, Bret W.; Weise, David R. 2009. Flame interactions and burning characteristics of two live leaf samples.
• Butler, Bret W.; Cook, Wayne. 2007. The fire environment--innovations, management, and policy; conference proceedings.

Publications

• Skowronski, Nicholas ; Butler, Bret ; Hiers, J. Kevin; O'Brien, Joseph ; Varner, J. Morgan. 2021. The Prescribed Fire Science Consortium.
• Sullivan, Patrick R.; Campbell, Michael J.; Dennison, Philip E.; Brewer, Simon C.; Butler, Bret W. 2020. Modeling wildland firefighter travel rates by terrain slope: Results from GPS-tracking of Type 1 crew movement.
• Hiers, J. Kevin; O’Brien, Joseph J.; Varner, J. Morgan; Butler, Bret W.; Dickinson, Matthew ; Furman, James ; Gallagher, Michael ; Godwin, David ; Goodrick, Scott L.; Hood, Sharon M.; Hudak, Andrew ; Kobziar, Leda N.; Linn, Rodman ; Loudermilk, E. Louise; McCaffrey, Sarah ; Robertson, Kevin ; Rowell, Eric M.; Skowronski, Nicholas ; Watts, Adam C.; Yedinak, Kara M. 2020. Prescribed fire science: the case for a refined research agenda.
• Page, Wesley G.; Freeborn, Patrick H.; Butler, Bret W.; Jolly, W. Matt. 2019. A classification of US wildland firefighter entrapments based on coincident fuels, weather, and topography.
• Page, Wesley G.; Freeborn, Patrick H.; Butler, Bret W.; Jolly, W. Matt. 2019. A review of US wildland firefighter entrapments: Trends, important environmental factors and research needs.
• Page, Wesley G.; Wagenbrenner, Natalie S.; Butler, Bret W.; Blunck, David L. 2019. An analysis of spotting distances during the 2017 fire season in the Northern Rockies, USA.
• Page, Wesley G.; Butler, Bret W. 2019. Assessing wildland firefighter entrapment.
• Wagenbrenner, Natalie S.; Forthofer, Jason M.; Page, Wesley G.; Butler, Bret W. 2019. Development and evaluation of a Reynolds-Averaged Navier-Stokes solver in WindNinja for operational wildland fire applications.
• Sanchez-Monroy, X. ; Mell, W. ; Torres-Arenas, J. ; Butler, B. W. 2019. Fire spread upslope: Numerical simulation of laboratory experiments.
• Dickinson, Matthew B.; Butler, Bret W.; Hudak, Andrew T.; Bright, Benjamin C.; Kremens, Robert L.; Klauberg, Carine . 2019. Inferring energy incident on sensors in low-intensity surface fires from remotely sensed radiation and using it to predict tree stem injury.
• Jolly, W. Matt; Freeborn, Patrick H.; Page, Wesley G.; Butler, Bret W. 2019. Severe Fire Danger Index: A forecastable metric to inform firefighter and community wildfire risk management.
• Clements, Craig B.; Kochanski, Adam K.; Seto, Daisuke ; Davis, Braniff ; Camacho, Christopher ; Lareau, Neil P.; Contezac, Jonathan ; Restaino, Joseph ; Heilman, Warren E.; Krueger, Steven K.; Butler, Bret ; Ottmar, Roger D.; Vihnanek, Robert ; Flynn, James ; Filippi, Jean-Baptiste ; Barboni, Toussaint ; Hall, Dianne E.; Mandel, Jan ; Jenkins, Mary Ann; O'Brien, Joseph ; Hornsby, Ben ; Teske, Casey . 2019. The FireFlux II experiment: a model-guided field experiment to improve understanding of fire-atmosphere interactions and fire spread.
• Campbell, Michael J.; Dennison, Philip E.; Butler, Bret W.; Page, Wesley G. 2019. Using crowdsourced fitness tracker data to model the relationship between slope and travel rates.
• Weise, David R.; Fletcher, Thomas H.; Johnson, Timothy J.; Hao, WeiMin ; Dietenberger, Mark ; Princevac, Marko ; Butler, Bret ; McAllister, Sara ; O’Brien, Joseph ; Loudermilk, Louise ; Ottmar, Roger ; Hudak, Andrew ; Kato, Akira ; Shotorban, Babak ; Mahalingam, Shankar ; Mell, William E. 2018. A project to measure and model pyrolysis to improve prediction of prescribed fire behavior.
• O’Brien, J. J.; Hiers, J. K.; Varner, J. M.; Hoffman, C. M.; Dickinson, M. B.; Michaletz, S. T.; Loudermilk, E. L.; Butler, B. W. 2018. Advances in Mechanistic Approaches to Quantifying Biophysical Fire Effects.
• Page, Wesley G.; Wagenbrenner, Natalie S.; Butler, Bret W.; Forthofer, Jason M.; Gibson, Chris . 2018. An evaluation of NDFD weather forecasts for wildland fire behavior prediction.
• Page, Wesley G.; Butler, Bret W. 2018. Fuel and topographic influences on wildland firefighter burnover fatalities in Southern California.
• Wagenbrenner, Natalie S.; Forthofer, Jason M.; Gibson, Chris ; Indreland, Abby ; Lamb, Brian K.; Butler, Bret W. 2018. Observations and predictability of gap winds in the Salmon River Canyon of Central Idaho, USA.
• Campbell, Michael J.; Dennison, Philip E.; Hudak, Andrew T.; Parham, Lucy M.; Butler, Bret W. 2018. Quantifying understory vegetation density using small-footprint airborne lidar.
• Hudak, Andrew T.; Freeborn, Patrick H.; Lewis, Sarah A.; Hood, Sharon M.; Smith, Helen Y.; Hardy, Colin C.; Kremens, Robert J.; Butler, Bret W.; Teske, Casey; Tissell, Robert G.; Queen, Lloyd P.; Nordgren, Bryce L.; Bright, Benjamin C.; Morgan, Penelope; Riggan, Philip J.; Macholz, Lee; Lentile, Leigh B.; Riddering, James P.; Mathews, Edward E. 2018. The Cooney Ridge Fire Experiment: An early operation to relate pre-, active, and post-fire field and remotely sensed measurements.
• Campbell, Michael J.; Dennison, Philip E.; Butler, Bret W. 2017. A LiDAR-based analysis of the effects of slope, vegetation density, and ground surface roughness on travel rates for wildland firefighter escape route mapping.
• Page, Wesley G.; Butler, Bret W. 2017. An empirically based approach to defining wildland firefighter safety and survival zone separation distances.
• Adams, Theodore Ted; Butler, Bret W.; Brown, Sara; Wright, Vita; Black, Anne. 2017. Bridging the divide between fire safety research and fighting fire safely: How do we convey research innovation to contribute more effectively to wildland firefighter safety.
• Sikkink, Pamela G.; Jain, Theresa B.; Reardon, James; Heinsch, Faith Ann; Keane, Robert E.; Butler, Bret; Baggett, L. Scott. 2017. Effect of particle aging on chemical characteristics, smoldering, and fire behavior in mixed-conifer masticated fuel.
• Wagenbrenner, Natalie S.; Forthofer, Jason M.; Lamb, Brian K.; Shannon, Kyle S.; Butler, Bret W. 2016. Downscaling surface wind predictions from numerical weather prediction models in complex terrain with a mass-consistent wind model.
• Finn, D.; Reese, B.; Butler, B.; Wagenbrenner, N.; Clawson, K. L.; Rich, J.; Russell, E.; Gao, Z.; Liu, H. 2016. Evidence for gap flows in the Birch Creek Valley, Idaho.
• Clements, Craig B.; Lareau, Neil P.; Seto, Daisuke; Contezac, Jonathan; Davis, Braniff; Teske, Casey; Zajkowski, Thomas J.; Hudak, Andrew T.; Bright, Benjamin C.; Dickinson, Matthew B.; Butler, Bret W.; Jimenez, Daniel; Hiers, J. Kevin. 2016. Fire weather conditions and fire-atmosphere interactions observed during low-intensity prescribed fires - RxCADRE 2012.
• Ottmar, Roger D.; Hiers, J. Kevin; Butler, Bret W.; Clements, Craig B.; Dickinson, Matthew B.; Hudak, Andrew T.; O'Brien, Joseph; Potter, Brian E.; Rowell, Eric M.; Strand, Tara M.; Zajkowski, Thomas J. 2016. Measurements, datasets and preliminary results from the RxCADRE project-2008, 2011 and 2012.
• Butler, Bret; Teske, C.; Jimenez, Dan; O'Brien, Joseph; Sopko, Paul; Wold, Cyle; Vosburgh, Mark; Hornsby, Ben; Loudermilk, E. Louise. 2016. Observations of energy transport and rate of spreads from low-intensity fires in longleaf pine habitat-RxCADRE 2012.
• Campbell, Michael J.; Dennison, Philip E.; Butler, Bret W. 2016. Safe separation distance score: A new metric for evaluating wildland firefighter safety zones using lidar.
• Mueller, Eric; Skowronski, Nicholas; Clark, Kenneth; Kremens, Robert; Gallagher, Michael; Thomas, Jan; El Houssami, Mohamad; Filkod, Alexander; Butler, Bret; Hom, John; Mell, William; Simeoni, Albert. 2015. Initial results from a field experiment to support the assessment of fuel treatment effectiveness in reducing wildfire intensity and spread rate.
• Butler, Bret; Parsons, Russ; Mell, William. 2015. Recent findings relating to firefighter safety zones.
• Butler, B. W.; Webb, J.; Hogge, J.; Wallace, T. 2015. Vegetation clearance distances to prevent wildland fire caused damage to telecommunication and power transmission infrastructure.
• Butler, B. W.; Wallace, T.; Hogge, J. 2015. Vegetation clearance distances to prevent wildland fire caused damage to telecommunication and power transmission infrastructure (2).
• Forthofer, Jason M.; Butler, Bret W.; McHugh, Charles W.; Finney, Mark A.; Bradshaw, Larry S.; Stratton, Richard D.; Shannon, Kyle S.; Wagenbrenner, Natalie S. 2014. A comparison of three approaches for simulating fine-scale surface winds in support of wildland fire management. Part II. An exploratory study of the effect of simulated winds on fire growth simulations.
• Forthofer, Jason M.; Butler, Bret W.; Wagenbrenner, Natalie S. 2014. A comparison of three approaches for simulating fine-scale surface winds in support of wildland fire management: Part I. Model formulation and comparison against measurements.
• Mueller, Eric; Skowronski, Nicholas; Simeoni, Albert; Clark, Kenneth; Kremens, Robert; Mell, William; Gallagher, Michael; Thomas, Jan; Filkov, Alexander; Houssami, Mohamad El; Hom, John; Butler, Bret. 2014. Fuel treatment effectiveness in reducing fire intensity and spread rate - An experimental overview.
• Wear, David N.; Joyce, Linda A.; Butler, Bret; Johnson, Cassandra; Stewart, Susan; Nowak, David. 2012. Climate change, human communities, and forests in rural, urban, and wildland-urban interface environments.
• Jolly, W. Matt; Parsons, Russell; Varner, J. Morgan; Butler, Bret W.; Ryan, Kevin C.; Gucker, Corey L. 2012. Do mountain pine beetle outbreaks change the probability of active crown fire in lodgepole pine forests.
• Nelson, Ralph M., Jr..; Butler, Bret W.; Weise, David R. 2012. Entrainment regimes and flame characteristics of wildland fires.
• Frankman, David; Webb, Brent W.; Butler, Bret W.; Jimenez, Daniel; Harrington, Michael. 2012. The effect of sampling rate on interpretation of the temporal characteristics of radiative and convective heating in wildland flames.
• Cruz, Miguel G.; Butler, Bret W.; Viegas, Domingos X.; Palheiro, Pedro. 2011. Characterization of flame radiosity in shrubland fires.
• Butler, Bret; Jimenez, D.; Forthofer, J.; Shannon, K.; Sopko, Paul. 2010. A portable system for characterizing wildland fire behavior.
• Butler, Bret. 2010. Characterization of convective heating in full scale wildland fires.
• Butler, Bret; Forthofer, Jason. 2010. Firefighter Safety Zone: The effect of terrain slope of separation distance.
• Butler, Bret; Jimenez, D.; Forthofer, J.; Sopko, Paul; Shannon, K.; Reardon, Jim. 2010. In-situ characterization of wildland fire behavior.
• Forthofer, J.; Shannon, K.; Butler, Bret. 2010. Initialization of high resolution surface wind simulations using NWS gridded data.
• Forthofer, J.; Butler, Bret. 2010. Large scale fire whirls: Can their formation be predicted.
• Butler, Bret; Forthofer, J.; Shannon, K.; Jimenez, D.; Frankman, D. 2010. The effect of terrain slope on firefighter safety zone effectiveness.
• Butler, Bret. 2009. Efforts to update firefighter safety zone guidelines.
• Jimenez, D.; Butler, B.; Hiers, K.; Ottmar, R.; Dickinson, M.; Kremens, R.; O'Brien, J.; Hudak, A.; Clements, C. 2009. Rx-CADRE (Prescribed Fire Combustion-Atmospheric Dynamics Research Experiments) collaborative research in the core fire sciences.
• Forthofer, Jason ; Shannon, Kyle ; Butler, Bret . 2009. Simulating diurnally driven slope winds with WindNinja.
• Frankman, D.; Webb, B. W.; Butler, B. W. 2008. Influence of absorption by environmental water vapor on radiation transfer in wildland fires.
• Forthofer, Jason; Butler, Bret. 2007. Differences in simulated fire spread over Askervein Hill using two advanced wind models and a traditional uniform wind field.
• Jimenez, Dan; Forthofer, Jason; Reardon, James; Butler, Bret. 2007. Fire behavior sensor package remote trigger design.
• Frankman, David; Webb, Brent W.; Butler, Bret W. 2007. Influence of radiation absorption by environmental water vapor on radiation transfer in wildland fires.
• Cook, Wayne; Butler, Bret W. 2007. Introduction-2nd Fire Behavior and Fuels Conference: The fire environment-innovations, management, and policy.
• Andrews, Patricia L.; Butler, Bret W. 2006. Fuels Management-How to Measure Success: Conference Proceedings.
• Weise, David R.; Fletcher, Thomas; Baxter, Larry; Mahalingam, Shankar; Zhou, Xiangyang; Pagni, Patrick; Linn, Rod; Butler, Bret. 2004. A fundamental look at fire spread in California chaparral.
• Jimenez, D. M.; Butler, B. W.; Reardon, J. 2003. Stem mortality in surface fires: Part II, experimental methods for characterizing the thermal response of tree stems to heating by fires.
• Cohen, Jack D.; Butler, Bret W. 1998. Modeling potential structure ignitions from flame radiation exposure with implications for wildland/urban interface fire management.
• Butler, Bret W.; Reynolds, Timothy D. 1997. Wildfire case study: Butte City Fire, southeastern Idaho, July 1, 1994.

Research Highlights

Highlight	Title	Year
RMRS-2014-120	Forest Service Researchers Focus on Firefighter Safety Wildland firefighters continue to be injured or killed in fire entrapments. Past entrapment data indicates that policy changes, work practices, ...	2014
RMRS-2018-84	Improving firefighter escape route mapping through LiDAR-based analysis Wildland fires place firefighters in a dangerous working environment and their safety relies on knowing the safest pathways to a safety zone bef ...	2018
RMRS-2019-23	To Masticate or Not to Masticate: Useful tips for Treating Vegetation Recently, several large fires have burned through masticated sites in Colorado, Washington, New Mexico and elsewhere. Burning under extreme weat ...	2019