FOR IMMEDIATE RELEASE: August 20, 1998
NCAR Scientists and Instruments to Fly Over Raging Wildfires
Contact:
Anatta
UCAR Communications
Boulder, CO 80307-3000
Telephone: 303-497-8604
[email protected]
BOULDER--Beginning September 1, scientists from the National Center for
Atmospheric Research (NCAR) will fly a highly instrumented C-130
research aircraft around and over dangerous wildfires that may ignite
this season within the United States. To seize wildfire opportunities,
the airplane is reserved for four or five flights over a six-week period
out of Jefferson County Airport, northwest of Denver.
"We're most interested in understanding the violent, unpredictable fires
that kill firefighters," says Lawrence Radke, NCAR co-principal
investigator for the Wildfire Experiment (WiFE). "We need to be able to
predict the course of a dangerous fire to develop the most effective
strategy for suppressing it."
WiFE is funded by the National Science Foundation, which also sponsors
NCAR and owns the NCAR-operated research aircraft. The National
Aeronautics and Space Administration (NASA) Ames Research Center and the
U.S. Forest Service's Riverside Fire Research Laboratory will provide
additional scientists, observers, and instruments. The Rocky Mountain
Area Aviation and Fire Coordination Center will help the scientists
decide which fires to observe and will coordinate flights around the
fires.
The ultimate goal of the research is to understand wildfire behavior
well enough to predict the course of a particular fire. The flights will
test a unique set of remote-sensing tools to determine their combined
effectiveness in observing fires. In addition, NCAR chemists will
analyze emissions from the burning biomass.
Wildfires typically burn five million acres in the United States
annually, costing hundreds of millions of dollars. The price tag will
mount as urban development continues to encroach on forests nationwide.
According to Radke, large, violent wildfires often generate their own
controlling weather. The released heat can spawn deep convection, even
thunderstorms, with strong and dangerous winds. So-called fire whirls,
cousins of tornadoes, can hurl flaming logs and other burning debris
miles away, setting other areas ablaze. Such vortices already occur at
all scales in our solar-heated atmosphere, and they intensify locally
near fires.
The C-130's speed, range, and endurance will improve the researchers'
chances of getting to a fire in time to observe it during a dramatic and
dangerous phase. The plane will circle the fires at 150 knots or less,
cruising between the minimum safe altitude and 10,000 feet.
Among the instruments on board will be NCAR's new Thermacam, a digital,
high-resolution infrared imager with a sensing range between -40 and
3600 degrees Fahrenheit. Fires can reach 2200 degrees F; a glowing
candle tip, 1300. Built by Inframetrics, Inc., the Thermacam will gaze
out of an opening in one of the airplane's windows and straight through
smoke. The result will be color video images of hot, swirling air and
flames, detailing their motion, size, structure, and temperature. Other
instruments aboard the C-130 include a passive microwave imager, an
electric field meter, and NASA's fire-imaging spectrometer. The
microwave imager targets areas of woody, fire-feeding vegetation by
measuring the weight of burnable biomass per square meter. Spotting the
blaze's next meal can help observers determine its future path. The
instrument may also prove useful in detecting the moisture content of
surface vegetation, a key factor in fire intensity and spread.
Co-leader of WiFE is NCAR's Terry Clark, whose atmospheric fire models
reproduce in computers many of the fine-scale structures frequently
observed in wildfires. Clark and Radke are now eager to observe these
"fire fingers" in nature and to quantify their structures. Both
radiation and the convection that results from fire-atmosphere
interactions affect fire spread. To understand those effects, Clark must
first see how fire fronts lap at or "finger" unburned fuel. WiFE
measurements will be used to validate physically based models like
Clark's, which can then help improve the fire-spread models used by
firefighters.
Meanwhile, chemists on board will be measuring emissions above the
blaze, some of which will shed light on the chemical reactivity of the
fire plume, its combustion efficiency, and the total carbon emitted.
Other chemicals of interest emitted by fires are methyl halides, which
have properties similar to those of chlorofluorocarbons, the infamous
CFCs that attack the ozone layer and also contribute to global warming.
Many of the human-produced halides have been banned, but naturally
formed ones are still rising into the stratosphere, where they join in
the ozone-destruction cycle. WiFE will help clarify how much wildfires
contribute to the methyl halide balance in the stratosphere. Says NCAR
chemist Elliot Atlas, "We chemists don't get to explore big fires very
much. This is a real opportunity for us."
NCAR is managed by the University Corporation for Atmospheric Research,
a consortium of more than 60 universities offering Ph.D.s in atmospheric
and related sciences.
-The End-
Note to Editors: Journalists may be allowed on flights on a first-
come, first-served basis. To view an animation of Terry Clark's
atmosphere/fire model on the Web, go to
http://www.scd.ucar.edu/vg/FIRE/ClarkFire.html. Videotapes of the Clark
animation and the Thermacam's color images will be available. Please
contact Anatta (303-497-8604, [email protected]) for flight schedules and
video tapes.
The image accompanying this story is available through the Internet in
two formats:
Low-resolution color GIF:
http://www.ucar.edu/staffnotes/9808/larry2.gif
High-resolution B&W TIFF: Use anonymous ftp: Log on to
ftp.ucar.edu, using the userid: anonymous; password: [your e-mail
address]; directory: /communications [include the slash]; filename:
radke.tiff
Find this news release on the World Wide Web at
http://www.ucar.edu/publications/newsreleases/1998/wife.html
###
RSS