SJSU Wildfire Scientists Trailblaze Unprecedented Canyon Fire Research
This week, researchers from the Wildfire Interdisciplinary Research Center (WIRC) at San José State University conducted an unparalleled experiment to study extreme fire behavior and fast-moving fire spread in steep canyons. It is the first time a canyon wildfire study of this magnitude has been undertaken anywhere in the world.
The ground-breaking California Canyon Fire Experiment is the brainchild of Professor of Meteorology and WIRC Director Craig Clements, and Adam Kochanski, assistant professor of wildfire modeling that was made possible through a collaboration with the California Department of Forestry and Fire Protection (CAL FIRE).
What they hope to learn is how fires in steep canyons intensify due to the interactions between fire, local weather conditions and topography. The work is a significant advancement in fire science as increasing extreme wildfires become a shared global challenge.
CAL FIRE arranged to conduct a large prescribed burn on private land located on the outskirts of Salinas and allowed SJSU to lead the unique experiment concurrently. Scientists from the University of Melbourne, Australia, and Worcester Polytechnic Institute in Massachusetts, traveled to California to contribute to SJSU’s study.
Alex Filkov, senior research fellow from University of Melbourne, deployed special fire behavior sensor packages in the canyon to measure heat flux and fire properties. Albert Simeoni, professor and head of the Fire Protection Engineering Department at WPI, along with a post-doctoral researcher and visiting professor from Chile, installed fire behavior sensors and cameras in the canyon to measure fire behavior properties.
Representatives from PG&E, Hexion and Stella-Jones Corporation, and Technosylva also participated in SJSU’s study. These partners are members of WIRC’s board of industry innovators, which was established through its designation of an Industry-University Cooperative Research Center (IUCRC).
The designation enables WIRC to be part of a program designed to accelerate the impact of research by establishing close relationships with industry innovators, government leaders and world-class academic teams.
Last week, ahead of SJSU’s experiment, CAL FIRE set an initial prescribed burn on part of the property, creating a fire break in preparation for the Canyon Fire Experiment. On Monday, CAL FIRE conducted a second prescribed burn on a 100-acre canyon on the property while WIRC researchers and partners collected critical weather and fire observations using advanced on-site technology, including:
- A helicopter equipped with SJSU’s Wildfire Infrared Imaging System (SWIS) (recently deployed over the Mosquito Fire on a NOAA aircraft).
- Truck-mounted Doppler radar and a scanning Doppler wind lidar, also known as.
- A 106-foot tower with sensors and 3D sonic anemometers, devices that measure three-dimensional winds and turbulence.
- Coupled fire-atmosphere computer modeling of the experimental fire.
- Drone imaging and mapping using infrared imagers and hyperspectral cameras.
The technology allowed researchers to measure fire spread, flame heat flux, fire perimeter, fire weather and fire-atmosphere interactions. In particular, the airborne imaging system aboard the helicopter is a central part of this experiment and was designed and built by WIRC’s own remote-sensing team, led by Assistant Professor Mario Miguel Valero. Collectively, the study’s data will help determine how local atmospheric conditions affect wildfire spread in canyons and how fire-induced winds in the canyon impact fire behavior.
It is well known that canyon geometry is the most dangerous terrain type for wildfire. As such, it is challenging to measure and obtain data on fire behavior in those conditions, according to Clements.
“Fire behavior in canyons is often characterized as ‘explosive fire behavior’ where the rate of spread increases exponentially as the fire progresses up the canyon, burning up the canyon sidewalls and increasing the fire area growth,” said Clements.
Aurélien Costes, a fire modeler and post-doctoral researcher from France who recently started in September, was onsite to assist the many students and research assistants who were observing and collecting data.
Costes shared that from a modeling point of view, this canyon is unique because [WIRC] doesn’t currently have comprehensive data collected during fires in a complex topography like this needed to calibrate or evaluate fire models. He hopes to continue to develop new ways to represent fire numerically and improve prediction, and believes this experiment is very valuable to do so.
“This experiment helps us understand what happens with fires in complex terrains such as canyons from a smaller scale and how to improve our forecast for firefighters,” said Costes.
Second-year graduate student and WIRC Graduate Research Assistant Kate Forrest, ’23 MS Meteorology, was operating the mobile Doppler radar and doing measurements with weather balloons, which she said helps capture what the conditions are at the surface and aloft during the experiment. Her research focus is in plume dynamics and fire tornadoes, for which she won this year’s 2022 Grad Slam at SJSU.
Forrest shared her impressions of what it was like to see the experiment and collect that data in real time. “Watching the California Canyon Fire Experiment unfold was an unreal experience as we watched years of interagency planning, collaboration, and hardwork culminate in fire and data,” she recalled.
“Shortly after ignition, there were multiple reports of counter-rotating smoke columns being observed over the fire which also showed up on radar. These observations were nearly identical to those myself and others recorded on radar at California’s 2021 Dixie Fire, which are the main focus of my thesis.
“We weren’t sure if we’d see counter rotation (two opposing, rotating smoke columns) embedded in the main plume, but when I saw it and recorded it on radar, I was overcome with emotion. It was the fire-weather equivalent to Christmas morning.”
Clements was thrilled with the results of the experiment and the immense collaboration it took to execute the study. “This is the first time we’ve been able to put all sorts of different instruments together and measure one fire in a canyon,” he reflected.
“The data from this experiment will be used to develop next generation fire behavior models, so we can predict extreme wildfires in the future.”
Top drone video: courtesy of Assistant Professor Bo Yang.