Oregon State Researcher Studies Wildfire Embers

An Oregon State University professor is using federal funds to conduct research on how embers form and spread during devastating wildfires.

Assistant professor David Blunck’s team is testing variables such as temperature, wind speed, timber species and branch diameter to figure out how to predict when embers will form, the Statesman Journal reported Friday.

The project is being funded by the federal government’s Joint Fire Science Program and the team is sharing results with the U.S. Forest Service, the newspaper reported.

Wind-blown embers that jump far ahead of the fire line and start new spot fires have long been the bane of firefighters in the American West. In extreme fire weather, the blaze can create its own winds and toss embers hundreds of feet – or even miles – ahead of the main blaze.

Last fall’s fire in the Columbia River Gorge jumped across the Columbia River to Washington when the wind carried an ember two miles (3.2 kilometers) across the water.

That blaze burned for three months and scorched 78 square miles (202 square kilometers) before it was contained.

Researchers at OSU hope their results can be used to create a model that would calculate probabilities for how many embers could form and how far away they might land.

In the lab, they’ve used a small-scale wind tunnel to study ember formation in dowels made of different types of timber.

“With a camera, we determine how long it takes for a large piece of dowel to break off,” Blunck said. “Ultimately, how long it takes to break off is indicative of how long it takes to generate embers.”

In the field, they’ve burned more than 120 trees that are 12 to 14 feet (3 to 4.5 meters) tall, counting and measuring the embers that are released.

The researchers also use an infrared camera to look at embers lost into the air.

So far, the team has tentatively found that branch diameter is the biggest factor determining the formation of embers.

“Our working hypothesis now is that ponderosa generates a lot of embers because it has a very high fuel loading, or more needles,” said Tyler Hudson, a graduate student in the College of Engineering who is working on the project.

And, working with the Nature Conservancy of Oregon, they’ve observed controlled burns in the forest.

“We were able to put fireproof fabric around and collect embers on that, getting data representative of an actual fire,” Blunck said.