Page 28 - aruba-today-20170222

A28 SCIENCE
Wednesday 22 February

NASA aims to measure vital snow data from satellites

DAN ELLIOTT measure snow depth: to produce daily state-by-
Associated Press Radar and LIDAR, which state reports and maps on
DENVER (AP) — Instrument- stands for light detection how the current snow wa-
laden aircraft are surveying and ranging. LIDAR uses ter equivalent compares to
the Colorado high coun- laser pulses to measure dis- the long-term average.
try this month as scientists tance. Water utilities, farmers, pub-
search for better ways to Four sensors will measure lic safety agencies and
measure how much water snow density: three other wildland firefighters track
is locked up in the world’s types of radar, plus a pas- the updates closely to help
mountain snows — water sive microwave instrument, predict how much drink-
that sustains a substantial which detects how much ing and irrigation water will
share of the global popula- of the Earth’s natural micro- be available in the spring
tion. wave radiation the snow is and whether they will face
A NASA-led experiment blocking. floods or fire-inducing
called SnowEx is using five Two thermal infrared sen- droughts.
aircraft to test 10 sensors This Feb. 17, 2017, photo shows a Navy P-3 Orion aircraft used for sors will measure tempera- SNOTEL collects data from
that might one day be a NASA-led experiment called SnowEx, on an airfield at Peter- ture. individual points, but the
used to monitor snow from son Air Force Base in Colorado Springs, Colo. A hyperspectral imager “holy grail of mountain
satellites. The goal: Find the Associated Press and a multispectral imag-
ideal combination to over- researcher and lead scien- snow melts down to 3 inch- er will measure how much hydrology” is a way to es-
come multiple obstacles, tist for SnowEx. “Right there, es of water. sunlight the snow is reflect- timate the distribution of
including how to analyze it’s hugely important for But a single mountain snow- ing, which helps determine snow water equivalent
snow hidden beneath for- people,” he said. bank contains multiple how fast it will melt. across broad mountain
est canopies. Snow has other conse- layers with different snow Aircraft will take the instru- landscapes, said Molotch,
“It would be, I would say, quences for society as well, water equivalents, making ments on multiple passes who is also director of the
a monumental leap in our including floods, droughts measurement difficult. The over two areas in western University of Colorado’s
ability to forecast water and even political stability layers were dropped by Colorado, Grand Mesa Center for Water, Earth Sci-
supply if we had this kind when water is scarce, Kim successive storms with dif- and Senator Beck Basin. ence and Technology.
of information,” said Noah said. ferent moisture contents, Ground crews will also ana- SnowEx could be a step to-
Molotch, a member of The key to predicting how and then lingered under lyze the snow to verify how ward that, he said.
the science team for the much water will pour out different weather condi- accurate the instruments Government agencies that
experiment. of mountain snows each tions before the next storm are. forecast the spring runoff
One-sixth of the world’s spring is a measurement covered them. One key technology used say satellite data on snow
population gets most of its called snow water equiva- A further complication: At to predict snow runoff in water equivalent would
fresh water from snow that lent. The global average is times during the winter, the American West is the help them, although they
melts and runs into water- 30 percent of snow depth, some snow melts, so water Snow Telemetry Network, base their predictions on
ways, said Ed Kim, a NASA Kim said — 10 inches of will flow through the interior or SNOTEL, operated by the multiple sources of informa-
of the snowbank, distorting U.S. Department of Agricul- tion, including rain, tem-
or absorbing signals from ture’s Natural Resources perature and current river
remote sensors. Conservation Service. flows.
No single instrument can More than 800 automated The Colorado Basin River
overcome all the obsta- SNOTEL ground stations Forecast Center in Salt Lake
cles. scattered across the West City, one of 13 National
“We have these different measure the depth and Weather Service centers
sensing techniques. Each weight of the snow, the that predict floods or river
one works to a certain de- temperature and other shortages nationwide, uses
gree,” Kim said. “What’s data and transmit them to some NASA satellite data
the optimal combination?” a central database. Fed- now, hydrologist Paul Miller
Two SnowEx sensors will eral agencies use SNOTEL said.q