David E. Steitz
Headquarters, Washington        August 6, 2002
(Phone: 202/358-1730)

Alan Buis
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-0474)

RELEASE: 02-151

FIRST IMAGES FROM NASA'S "THERMOMETER IN THE SKY" SIZZLE

     The old adage that everyone complains about the weather, 
but no one does anything about it may soon fall by the 
wayside, thanks to the quality of data from NASA's new 
"thermometer in the sky" -- a suite of three advanced weather 
instruments aboard the Aqua spacecraft. 

First images from the Atmospheric Infrared Sounder 
spectrometer and its two companion instruments, the Advanced 
Microwave Sounding Unit  and the Humidity Sounder for Brazil, 
are exceeding the expectations of the world meteorological 
community. The results, project scientists say, will be 
substantially improved short-term weather-prediction accuracy 
and tracking of severe weather events like hurricanes, as 
well as advances in climate research.  

"The three sounding instruments of the Atmospheric Infrared 
Sounder experiment system will comprehensively capture a 
continuous, detailed picture of Earth's atmosphere for use in 
global weather prediction and climate studies," said Dr. 
Moustafa Chahine, experiment science-team leader at NASA's 
Jet Propulsion Laboratory, Pasadena, Calif.  "The instruments 
are in excellent health and are ready to serve NASA, the 
National Oceanic and Atmospheric Administration -- or NOAA, 
and the broader climate research community." 

The first-light images may be found at:

www.jpl.nasa.gov/airs

The sounding-package experiment, with its visible, infrared 
and microwave detectors, provides a three-dimensional look at 
Earth's weather. Working in tandem, the three instruments can 
make simultaneous observations from space all the way to the 
Earth's surface, even in the presence of heavy clouds. With 
more than 2,000 channels sensing different regions of the 
atmosphere, the system creates a global, 3-D map of 
atmospheric temperature and humidity and provides information 
on clouds, greenhouse gases and many other atmospheric 
phenomena.

Chahine said the key to increasing the useful range of 
weather forecasts from the current two-to-three days to five 
days is to observe today's weather with much higher accuracy. 

"The accuracy of computer models is dependent upon the 
quality of today's weather information," he said. "Our 
experiment will effectively multiply by 100 our existing 
global armada of 4,000 weather balloons, giving us global 
coverage over land and sea from space with the same data 
quality as ground-launched balloons. This additional data 
will dramatically reduce errors that have traditionally 
limited the range of current weather forecast models." 

Claire Parkinson, Aqua project scientist at NASA's Goddard 
Space Flight Center, Greenbelt, Md., said the impact on world 
commerce from improved weather and climate prediction may be 
enormous. "From the data measured by these three instruments, 
we can better understand the global water cycle and its 
implications for managing fresh water resources. Improved 
temperature predictions will help commerce move merchandise 
and fuel where needed to meet cold- or warm-weather demands. 
Other industries that are strongly dependent on weather will 
also benefit, including aviation, transportation and 
agriculture." 

The experiment recently completed calibration and is now 
transmitting continuous, uninterrupted data to the project 
science team and NOAA. Instrument validation will continue 
through next June, as NOAA evaluates the new data set, learns 
how to integrate it and gains confidence in its accuracy. 

Following instrument validation, the data will be integrated 
into existing weather prediction models by NOAA's National 
Centers for Environmental Prediction and six of the world's 
leading weather-prediction centers. The data will also will 
be distributed to the World Meteorological Organization in 
Switzerland, where it will be made available to 105 
countries.  

Aqua's planned six-year mission will collect data from the 
six instruments aboard on global temperature variations, 
cycling of water, global precipitation, evaporation, changes 
in ocean circulation and how clouds and surface-water 
processes affect climate. The information will help 
scientists better understand how global ecosystems change and 
how they respond to and affect global environmental change.

                           -end-