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July
25, 2007
NEW NASA AIRS DATA TO AID
WEATHER, CLIMATE
RESEARCH
There's
an old saying, "You can't see the forest for
the trees." When it comes to global climate change, it's not hard to
spot
the "trees" -- they're in the news headlines nearly every day. To see
the "forest," however--that is, to gain a more complete understanding
of the climate variations we're seeing--scientists use satellite remote
sensing. With these technologies, they can directly measure factors
that affect
our climate, such as levels of water vapor and other greenhouse gases,
ozone
and concentrations of airborne dust. Scientists feed these data into
computerized climate models to project how our climate might change in
the
future.
A key
contributor to this new generation of climate change
research tools is the Atmospheric Infrared Sounder, or AIRS, instrument
on
NASA's Aqua spacecraft. Developed under the direction of NASA's Jet
Propulsion
Laboratory, Pasadena,
Calif.,
AIRS measures the key atmospheric
gases affecting climate. It's the first in a series of planned advanced
infrared sounders that provide accurate, detailed atmospheric
measurements for
weather and climate applications. Its observations complement existing
sensors
from NASA and other organizations by providing broad global coverage
day and
night, even in the presence of clouds.
Newly released AIRS measurements include better temperature and water
vapor
profiles; profiles of carbon monoxide, methane and ozone; and warning
'flags'
to identify concentrations of sulfur dioxide and dust.
"These new data will significantly improve our ability to observe and
characterize today's climate with greater accuracy, which is key to
increasing
our confidence in climate prediction models," said Moustafa Chahine,
AIRS
science team leader at JPL. "With its nearly 2,400 separate frequency
channels sensing different regions of the atmosphere, AIRS creates a
global, 3-D
map of atmospheric temperature, water vapor, clouds and greenhouse
gases with
the same accuracy currently possible only through direct measurements
by
sensors on weather balloons." AIRS provides these measurements
continuously, all over the globe, including over Earth's vast oceans,
where
weather balloon data are extremely limited.
Highlights of the new AIRS measurements include:
- Ozone
AIRS provides a global daily 3-D view of Earth's ozone layer, showing
how ozone
is transported. This is critical to identify events and places at risk
of high
solar ultraviolet exposure, which affects the health of humans and
other living
things. The new AIRS infrared imaging gives scientists the best view of
the
Antarctic region during the polar winter. It also allows scientists to
image
the transport of stratospheric ozone into Earth's lowermost atmospheric
layer,
the troposphere, with broader coverage.
- Carbon monoxide
Carbon monoxide emissions from the burning of plant materials and
animal waste
by humans in rainforests and large cities can be seen from space using
data
from the new AIRS measurements. AIRS sees giant plumes of gas being
transported
across the planet from these large burns. AIRS provides better global
coverage
than prior instruments, allowing scientists to better monitor pollution
transport patterns. See:
http://airs.jpl.nasa.gov/News/Features/Features20060403/
- Methane
Methane is a
much more potent greenhouse gas on a per
molecule basis than carbon dioxide and is responsible for five to 10
percent of
the greenhouse effect -- the warming of Earth's atmosphere that occurs
when
radiation from the sun is trapped in Earth's atmosphere by gases. The
first
released AIRS methane product has not yet been validated, but will
allow
scientists to assess its value among the few other sources of global
data on
methane. Eventually, AIRS data will allow scientists to monitor the
global
distribution and transport of methane and to address key questions
about how
this gas affects our climate.
- Sulfur dioxide
Volcanoes emit large quantities of sulfur dioxide. AIRS tracks both ash
and
emitted sulfur dioxide plumes. AIRS provides global, daily coverage of
sulfur
dioxide day and night to complement other sensors with more
sensitivity. AIRS
data are currently being used to alert the National Oceanic and
Atmospheric
Administration's Volcanic
Ash Advisory
Center in Washington
of volcanic events in remote
areas. AIRS data also help the airline industry fly safely and avoid
costly
damage to flight systems from volcanic emissions. The new AIRS
measurements
include a warning 'flag' to identify locations where volcanic events
are
occurring.
- Dust and Aerosols
AIRS measures dust and aerosols using infrared, or heat-seeking,
detectors. Not
only does this allow dust to be viewed day and night, but it also helps
us
better understand the role dust plays in maintaining Earth's thermal
energy
balance. Dust storms can affect atmospheric chemistry and rainfall
patterns,
and can transport micronutrients and microorganisms. Changes in land
use such
as deforestation or overgrazing have contributed to more frequent dust
storms
worldwide. AIRS provides a global daily view of the infrared properties
of
dust, monitoring its transport and distinguishing between different
types of
dust. The new AIRS measurements include a dust warning 'flag' to allow
scientists to identify regions of high-dust concentration, worthy of
more
detailed examination.
- Real-Time Data for Weather Forecasters
AIRS' contributions to the field of weather forecasting have already
been
considerable. Weather forecasting centers around the world, using less
than one
percent of available AIRS data, have extended reliable mid-range
weather
forecasts by more than six hours. These centers have also demonstrated
that
AIRS can improve forecasts of the location and magnitude of predicted
storms.
The improved AIRS temperature and water vapor profiles are now
available in
real time to regional weather forecasters, giving them another source
of daily
weather measurements for the entire Pacific
Ocean,
once in the morning and once in the evening.
The
new AIRS measurements are available on the web at:
http://daac.gsfc.nasa.gov/AIRS/index.shtml
For animations of the new measurements and more information on AIRS,
please
visit: http://airs.jpl.nasa.gov/
For more information on Aqua, please visit: http://aqua.nasa.gov/
##
Contact:
Alan Buis
Jet Propulsion Laboratory
818-354-0474
This
text is derived from:
http://www.nasa.gov/vision/earth/lookingatearth/airsf-20070725.html
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