AIRS/AMSU/HSB First-Light Images

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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 increased accuracy of short-term weather predictions, improved tracking of severe weather events like hurricanes and advances in climate research.

“The three sounding instruments of the Atmospheric Infrared Sounder 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, science-team leader at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., which manages the experiment. “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 images may be found at www.jpl.nasa.gov/airs.

The three sounding instruments, with visible, infrared and microwave detectors, provide 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 2,400 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 our existing global armada of 4,000 weather balloons by 100, 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,” she said. “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 be distributed to the World Meteorological Organization in Switzerland, where they 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, the 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.

JPL is a division of the California Institute of Technology in Pasadena.

 

AIRS

AMSU

HSB

VIS

Four images of the Mediterranean obtained concurrently on June 14, 2002 from the three instruments that make up the Atmospheric Infrared Sounder experiment system aboard NASA's Aqua spacecraft. The system features thousands of individual channels that observe Earth in the visible, infrared and microwave spectral regions. Each channel has a unique sensitivity to temperature, moisture, surface conditions and clouds.

The visible light picture (labeled VIS) at bottom from the AIRS instrument shows a band of white clouds extending from the Adriatic Sea over Greece to the Black Sea.

The AIRS image (labeled AIRS) at 900 cm-1 (11 micrometers) at the far left measures actual surface or cloud top temperatures. In it, land and ocean boundaries are well defined, with land appearing as warmer (darker red) than the ocean. The band of cold high cumulus clouds appears blue, with the darkest blue most likely a large thunderstorm.

The 150 gigahertz channel from the Humidity Sounder for Brazil instrument (labeled HSB) is sensitive to moisture, ice particles and precipitation. The dry land temperature is comparable to the 11 micrometer temperatures, but over ocean this channel measures the temperature of moisture in the mid troposphere. The cold, blue areas off Sicily and in the Aegean Sea represent unusually dry areas over the ocean. There, clouds appear as green filaments--likely areas of precipitation.

The 31.4 gigahertz channel from the Advanced Microwave Sounding Unit instrument (labeled AMSU) is not affected by clouds.