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Expert Spotlight: Jack D. Cohen, Research Physical Scientist, U.S. Forest Service

You’ll see a lot of Jack Cohen on The Cascadel Ranch Fire Safe Council. You’ll see a lot of Jack Cohen everywhere you go regarding Firewise.

Jack D. Cohen, Research Physical Scientist, U.S. Forest Service, coined the term ‘home ignition zone‘. Jack has been studying wildfire behavior and home ignitions in the Wildland Urban Interface for decades.
From the National Building Museum Youtube Channel:

Published on May 5, 2014
No one has done more to define the wildland-urban interface problem and empower homeowners to reduce their risk of wildfire than Jack Cohen. His post-fire field examinations and laboratory-based research on fire dynamics led to the concept of the home ignition zone, a phrase he coined. Cohen also co-developed the U.S. National Fire Danger Rating System and contributed to the U.S. fire behavior prediction systems.
Jack D. Cohen, Research Physical Scientist, Missoula Fire Sciences Laboratory, U.S. Forest Service, Missoula, Montana
See more at the National Building Museum’s exhibition Designing for Disaster:

Jack has an extensive body of work over decades of research.
From’s Jack Cohen files:

The Jack Cohen Files

Jack D. Cohen is a Research Physical Fire Scientist with the USDA Forest Service Missoula Fire Sciences Laboratory. Cohen is the pre-eminent researcher on wildfire and home ignitions, and a founder of the Firewise Communities/USA recognition program. Jack coined the concept and phrase “home ignition zone”. Read his papers on preventing home loss disasters during wildfire, and review his post-fire examinations of home destruction.
Mapping Wildland Fire Risk to Flammable Structures for the Conterminous United States
James P. Menakis, Jack Cohen, Larry Bradshaw
The threat of wildland fire burning flammable structures is a national issue. Every year the risk increases from the accumulation of wildland fuel and the building of flammable structures adjacent to wildlands. Flammable structures are structures that have a low resistance to ignition. The article defines and maps the risk of wildland fire burning flammable structures for the conterminous United States.
Modeling Potential Structure Ignitions from Flame Radiation Exposure with Implications for Wildland / Urban Interface Fire Management
Jack D. Cohen and Bret W. Butler, USFS
Residential losses associated with wildland fires have become a serious international fire protection problem. The radiant heat flux from burning vegetation adjacent to a structure is a principal ignition factor.
Objectives and considerations for wildland fuel treatment in forested ecosystems of the interior western United States
Elizabeth D. Reinhardt, Robert E. Keane, David E. Calkin, Jack D. Cohen
Many natural resource agencies and organizations recognize the importance of fuel treatments as tools for reducing fire hazards and restoring ecosystems. However, there continues to be confusion and misconception about fuel treatments and the implementation and effects in fire-prone landscapes across the United States.
Preventing Disaster: Home Ignitability in the Wildland-Urban Interface
Jack D. Cohen
Research using modeling, experiments, and W-UI case studies indicates that home ignitability during wildland fires depends on the characteristics of the home and its immediate surroundings.
Reducing the Wildland Fire Threat to Homes: Where and How Much?
Jack D. Cohen, USFS
Understanding how ignitions occur is critical for effectively mitigating home fire losses during wildland fires. The threat of life and property losses during wildland fires is a significant issue for Federal, State, and local agencies that have responsibilities involving homes within and adjacent to wildlands.
A Site-Specific Approach for Assessing the Fire Risk to Structures at the Wildland / Urban Interface
Jack D. Cohen, USFS
The essence of the wildland/urban interface fire problem is the loss of homes. The problem is not new, but is becoming increasingly important as more homes with inadequate adherence to safety codes are built at the wildland/urban interface.
Structure Ignition Assessment Can Help Reduce Fire Damages in the WUI
Jack D. Cohen and Jim Saveland, USFS
To assess potential ignitions, SIAM uses an analytical approach and worst-case assumptions to establish relationships between the design of a structure and its exposure to fire.
Structure Ignition Assessment Model (SIAM)
Jack D. Cohen, USFS
In response to the need for a better understanding of wildland/urban interface ignition mechanisms and a method of assessing the ignition risk, USDA Forest Service Fire Research is developing the Structure Ignition Assessment Model (SIAM).
Thoughts on the Wildland-Urban Interface Fire Problem, June 2003
Jack D. Cohen, USFS
The USDA Forest Service along with the National Fire Protection Association generated the National Wildland-Urban Interface Initiative in response to the residential fire destruction during the 1985 fire season.
What is the Wildland Fire Threat to Homes?
Jack D. Cohen, USFS
Thompson Memorial Lecture, April 10, 2000. School of Forestry, Northern Arizona University, Flagstaff, Arizona. The threat of life and property losses related to wildfires is a significant issue for federal, state, and local fire and planning agencies who consider the mix of residential areas and wildlands.
The Wildland-Urban Interface Fire Problem: A Consequence of the Fire Exclusion Paradigm
Jack Cohen in Forest History Today, Fall 2008
We cannot assume a direct causal linkage between extreme wildfires and WUI fire disasters. An examination is required as to how homes ignite and cause WUI fire disasters.
Wildland-Urban Fire – A Different Approach
Jack D. Cohen, USFS
Research results indicate that the home and its immediate surroundings within 100-200 feet (30-60 meters) principally determines the home ignition potential during severe wildland/urban fires. Research has also established that fire is an intrinsic ecological process of nearly all North American ecosystems.

Jack Cohen Post-Fire Examinations

Examination of the Home Destruction in Los Alamos Associated with the Cerro Grande Fire, July 10, 2000
Jack D. Cohen, USFS
The homes were destroyed as the main body of the Cerro Grande Fire burned past Los Alamos to the north-northeast and then toward the northeast between about 1700 on May 10 to the early morning hours of May 11. About 200 single and multi-family structures were totally destroyed or irreparably damaged.
Home Destruction Examination: Grass Valley Fire, Lake Arrowhead, California
Jack D. Cohen, Richard D. Stratton
This report documents the sequence of events and factors contributing to the residential destruction associated with the Grass Valley Fire.  One hundred ninety-nine homes were destroyed or damaged in this October 2007 fire in the San Bernardino Mountains of California.