The Atmospheric Infrared Sounder (AIRS) and its two companion microwave sounders, AMSU and HSB were launched into polar orbit onboard the NASA Aqua Satellite in May 2002. NASA required the sounding system to provide high-quality research data for climate studies and to meet NOAA's requirements for improving operational weather forecasting. The NOAA requirement translated into global retrieval of temperature and humidity profiles with accuracies approaching those of radiosondes. AIRS also provides new measurements of several greenhouse gases, such as CO2, CO, CH4, O3, SO2, and aerosols.

The assimilation of AIRS data into operational weather forecasting has already demonstrated significant improvements in global forecast skill. At NOAA/NCEP, the improvement in the forecast skill achieved at 6 days is equivalent to gaining an extension of forecast capability of six hours. This improvement is quite significant when compared to other forecast improvements over the last decade. In addition to NCEP, ECMWF and the Met Office have also reported positive forecast impacts due AIRS.

AIRS is a hyperspectral sounder with 2,378 infrared channels between 3.7 and 15.4 μm. NOAA/NESDIS routinely distributes AIRS data within 3 hours to NWP centers around the world. The AIRS design represents a breakthrough in infrared space instrumentation with measurement stability and accuracies far surpassing any current research or operational sounder..The results we describe in this paper are “work in progress,” and although significant accomplishments have already been made much more work remains in order to realize the full potential of this suite of instruments.

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Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California

NASA Goddard Space Flight Center, Greenbelt, Maryland

NOAA/NESDIS, Camp Springs, Maryland

SAIC, Beltsville, Maryland

STG, Inc., Reston, Virginia

University of California, Santa Barbara, Santa Barbara, California

NASA Headquarters, Washington, DC

University of Maryland, College Park, College Park, Maryland

Joint Center for Satellite Data Assimilation, Camp Springs, Maryland

University of Maryland, Baltimore County, Baltimore, Maryland

University of Wisconsin—Madison, Madison, Wisconsin

Massachusetts Institute of Technology, Cambridge, Massachusetts

Hampton University, Hampton, Virginia

QSS Group, Lanham, Maryland

NOAA Atlantic Oceanographic and Meteorological Laboratory, Miami, Florida