Wildfire: Energy That’s Tough To Control

Photograph by Jonathan Blair, Corbis

Smoke and flames enveloped Yellowstone National Park in 1988. A number of smaller fires merged into flames that burned or partially burned about 800,000 acres, affecting more than one third of the park and closing portions from visitors at times.

That much destruction involves massive energy—about 77.9 billion megajoules over the fire's life of 71 days, according to a calculation by Bob Kremens, a research associate professor  at the Rochester Institute of Technology who studies wildfires.

That's 22 million megawatt-hours, as much as  all of the electricity generated in all of California and Oregon over the course of a month.

Kremens worked in cooperation with the Missoula Fire Sciences Laboratory, a part of the U.S. Forest Service's Research and Development branch., which has developed data and formulas for calculating rates of spread and energy released in forest fires.

The lab has studied and mapped the nation's wild lands, their ecology, and their relationships to wildland fire, as well as their potential to burn. Scientists also conduct experiments to measure the energy produced by burning different types of vegetation and other fuels, using the world's largest suite of controlled wind tunnels and burn chamber, says Colin Hardy, the lab's program manager.

The data help guide "fire behavior analysts" who, as part of efforts to contain wild land fires, project how fast and in what direction they might burn, and what resources are at risk. The same data contribute to the rating system that alerts land managers and visitors to the local risk of forest fires with Smokey Bear signs and colors from green (low) to red (high).

Published March 8, 2012