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February
2005
An
overview of projects throughout the organization
Winter roads
Keep an eye out for five weather stations
along E-470 this winter. The stations work in conjunction
with the Maintenance Decision Support System (MDSS), a groundbreaking
software system that was developed by RAL with support from
colleagues at several other institutions. The program will
help road managers keep roads as safe as possible when winter
weather hits.
Bill Mahoney (RAL) and staff have been working on the MDSS
since 1999. After testing the system in Iowa for two years,
they are evaluating it on E-470 and other highways in Colorado.
Sponsored by the Federal Highway Administration, the MDSS
promises to save lives, cut costs, and keep drivers on the
move. The program works by integrating real-time information
from weather forecasts and surface weather and road condition
measurements, and analyzing the information in different
ways to predict road conditions. Road crews receive expected
pavement temperatures, humidity, precipitation amounts and
types, and wind speeds for short segments of roads, followed
by recommendations for when and where to plow and use anti-icing
chemicals.
The E-470 Public Highway Authority asked to be involved in
testing the MDSS after it learned about the new software
program. Commercial weather service providers are currently
working with several state departments of transportation
in the upper Midwest to implement the program, and weather
service providers in Canada and northern Europe have expressed
interest as well.
Antarctica
forecasts
Staffers in MMM and SCD who work on
weather forecasts for Antarctica acquired a new supercomputer
in January that will help them produce faster, better forecasts
for the remote continent.
The computer, an IBM e1350 nicknamed “pegasus,” runs
faster and has more capacity than the current system,
a Compaq ES40 cluster. It has a peak computational capability
of nearly 600 billion calculations per second, with
more than 270 gigabytes of memory and
3 terabytes of disk capacity.
Scientists will use the Mesa Lab-based computer to run the
Antarctic Mesoscale Prediction System (AMPS), which makes
twice-daily weather forecasts for Antarctica. The forecasts
are important for researchers on the continent and are critical
during rescue operations.
The computer’s speed and capacity will allow AMPS project
leader Jordan Powers and scientist Kevin
Manning, both from
MMM, to run the forecasting
program at higher resolution and produce forecasts more quickly.
They plan to boost the resolution for even the most remote
areas of Antarctica to 20 kilometers
(12 miles) so that the model can capture small-scale cloud
systems and other atmospheric events. They also intend to
incorporate NCAR’s newest forecasting system, the Weather
Research and Forecasting (WRF) model,
into AMPS.
Increased drought
A new analysis by CGD’s Aiguo
Dai,
Kevin Trenberth, and Taotao
Qian has found that the percentage
of Earth’s land area stricken by serious drought more
than doubled from the 1970s to the
early 2000s. Rising global temperatures appear to be
a major factor.
The team, which looked at a variety of long-term records
of temperature and precipitation, found that the fraction
of global land experiencing very dry conditions (defined
as -3 or less on the Palmer Drought Severity Index) rose
from about 10–15% in the early 1970s to about 30% by
2002. By factoring out rainfall and snowfall, the scientists
estimated that almost half of the drought increase was due
to rising temperatures rather than decreases in precipitation.
This depiction of linear
trends in the Palmer Drought Severity Index from
1948 to 2002 shows drying (reds and pinks) across
much of Canada, Europe, Asia, and Africa and moistening
(green) across parts of the United States, Argentina,
Scandinavia, and western Australia. (Illustration
courtesy Aiguo Dai and the American
Meteorological Society.)
The Palmer index results are consistent with simulations
using a comprehensive land surface model.
Aiguo presented the new findings at the American Meteorological
Society’s annual meeting last month. The research also
appeared in the December issue of the Journal
of Hydrometeorology.
Permian extinction
One of the great mysteries of paleontology
is the Permian extinction of about 251 million years ago.
Scientists have speculated that as many as 96% of Earth’s
marine species may have disappeared, along with about three-quarters
of terrestrial species—but they don’t know the
cause.
CGD’s Jeff Kiehl and Christine
Shields are working
to shed light on the Permian extinction by simulating its
climate. Using the paleoclimate component of the Community
Climate System Model, version 3, they are studying how the
period’s sharply rising levels of atmospheric carbon
dioxide and massive volcanic eruptions may have affected
global temperatures, oceanic currents, and other phenomena.
The modeling presents unique challenges because of limited
data and significant geographic differences between the Permian
and present-day Earth. Jeff and Christine have had to estimate,
for example, how thermohaline circulation (the movement of
heat and salinity in the oceans) may have differed at a time
when all the continents were consolidated into the giant
land mass known as Pangaea. Over the next year, in collaboration
with Jean-Francois Lamarque (ACD), they hope to incorporate
additional features into the model, including concentrations
of sulfates and other chemicals in the atmosphere.
This image, from a CCSM simulation, shows
annual mean surface temperatures at the time of the Permian
extinction about 251 million years ago. (Illustration
courtesy
Jeff Kiehl.)
Also in this issue...
An
eye on Washington
ISSE reflections
on the tsunami
Random profile:
Shu-Peng “Ben” Ho
NCAR
to survey scientists, engineers
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