The Atmospheric Infrared Sounder (AIRS) and its two companion microwave sounders were launched into Earth orbit onboard the NASA Aqua Satellite in May 2002. The AIRS design represents a breakthrough in infrared space instrumentation with measurement accuracies far surpassing any current research or operational sounder. Experience gained on AIRS will apply to future programs using infrared sounding including CrIS on NPOESS and IASI on ENVISAT and HES on GOES-R

The primary AIRS scientific mission is to address questions related to improving weather prediction, studying the global water and energy cycle and providing environmental observations of minor gases in the atmosphere. In this presentation we describe the performance of AIRS and the accuracy and applications of its results, two years after launch

AIRS views the infrared atmospheric spectrum in 2,378 infrared channels with spectral resolution of greater than 1,200 covering more than 95% of the Earth’s surface every day. One measure of the capability of AIRS was to demonstrate that temperature and humidity profiles with radiosonde accuracy can be obtained in the presence of clouds in all fields of view. Within a few months after launch, the AIRS Science Team produced cloud-cleared infrared radiances from AIRS and retrieved temperature profiles globally with 1 Kelvin accuracy per 1km thick layers in the troposphere. The AIRS cloud-clearing algorithm to eliminate the cloud effects worked successfully in the presence of up to 80% cloud opacity in the fields of view. Without this cloud-clearing capability, it would have been impossible to achieve global coverage. Soon after launch, the AIRS Science Team found out that very few AIRS footprints, less than 1%, were actually “cloud-free” (to the extent that they can be used directly to produce temperature profiles within 1K/1km accuracy, without applying any cloud correction.) Overall, AIRS has met or exceeded all of the design performance and the retrieval accuracies specified at the start of the Mission.