Space Tools

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Scientists use NASA technology to measure the consequences of global climate change.
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OSU hydrologist John Selker measures climate change
with the world's largest thermometer.

Who knew that technology developed for space would end up being the best
tools to study ecosystems here on Earth? John Selker got it early on. As
a professor of biological and ecological engineering
at Oregon State University,
he’s been pioneering the use of NASA spinoffs like sensors, wireless, and
fiber optics to measure both natural and managed earth-bound environments.
His real mission now, he says, is to find new and better ways to apply these
spiffy technologies in his own work, and for other researchers, educators,
and information-providing businesses.

Lots of NASA technologies have been successfully commercialized, as in memory
foam or Speedo Racers. But the ones used for environmental monitoring have
wider ramifications, according to Selker.

fiber optic cable photo by Lynn Ketchum

And he sees urgency in measuring environmental change. With greenhouse gas
levels rising, glaciers are melting, sea levels are rising, and weather patterns
are changing in ways that vary unpredictably. But until recently, the high
cost of field sensors made it difficult to track these changes. Measuring
more than one thing in more than one place at a time was a vast and spendy
challenge. The new environmental monitoring systems make it possible to track
various factors at play and to figure out how one thing affects another.

Selker started out by using fiber optics to measure water temperature over
long distances (such as the length of a river). This technology—called distributed
temperature sensing (DTS)—uses the same sort of fiber optic communication
cables that make your telephone work. Temperatures are measured at one-meter
intervals over several miles. An intense laser pulse is sent down the cable
and temperatures are computed from the light that bounces back. The warmer
the fiber, the more blue-shifted light returns.

splicing fiber optics
OSU graduate students Julie Gabrielli (foreground)
and Aida Arik place a fiber optic cable into Big Boulder Creek to measure
water temperature all along this tributary of the Middle Fork of the
John Day River.

“It’s like listening for the echoes,” Selker said.

With distributed temperature sensing, scientists can track tiny changes
in temperature, as small as one hundredth of one degree Celsius. If you consider
this amount of precision and the huge number of points that can be monitored,
DTS provides something like 10,000 times the resolution possible a few years
ago, according to Selker.

Another NASA innovation has improved the ability for scientists to collect
all those measurements without walking from sensor to sensor in rain, snow,
sleet, or hail. Using networks of radio-linked stations, data from sensors
can now be gathered remotely. These stations don’t cost much to buy or to
run, and they can send signals over long distances, pumping out quality data
that can be updated as they are received.

The sensors themselves are smaller, work better, and are much less expensive
than ever before, according to Selker. He uses cameras and microphones and
infrared thermopiles (originally developed for electronic ear thermometers).

laying fiber optic cable
Chances are, fiber optics power your telephone, your
TV, and your Internet connection. John Selker has adapted this same technology
to take the pulse of rivers, forests, and mountains. Photo by Lynn Ketchum.

Applying these new tools, Selker has joined other scientists to measure
the nighttime respiration of forests in the Cascade Mountains, snowmelt in
the Sierra Nevada, water quality in Lake Tahoe, contaminated water in the
Czech Republic, and glacial melt in the Swiss Alps. He’s also looked at the
success of salmon habitat restoration efforts in the John Day and Walla Walla

“The strongly collaborative community of scientists at OSU puts us leagues
ahead in these cross-disciplinary efforts,” said Selker, noting the expertise
in both systems ecology and the new technologies. He lights up when he talks
about helping other researchers figure these systems out. “There’s a lot
of new cool stuff available,” he said, “stuff that’s guaranteed to help researchers
learn how earth systems are changing.”

For more information about John Selker's work in the H.J. Andrews Experimental Forest, see the
"Wired Watershed"
article in OSU's Terra magazine.

Published in: Innovations