AIRS: Improving Weather Forecasting and Providing New Data on Greenhouse Gases.

SUMMARY AND CONCLUSIONS. The AIRS instrument has met its primary scientific objective to improve weather prediction and to retrieve tem-perature and precipitable water vapor profiles with accuracies approaching those of radiosondes. AIRS also has provided new information on the concen-tration of tropospheric mi-nor constituents, includ-ing several greenhouse gases essential for climate studies.The foundation of all AIRS data products is the physical retrieval algorithm (PRA) that is being main-tained and continuously upgraded by the AIRS Sci-ence Team. The results described in this paper are “work in progress,” and al-though significant accom-plishments have already been made, much more work remains in order to realize the full potential of this instrument. The AIRS Science Team is currently pursuing improvements to the retrieval algorithm, in particular 1) determina-tion of land surface emissivity, 2) modification of the radiative transfer algorithm (RTA) to account for nonlocal thermodynamic equilibrium (NLTE) effects on the shortwave channels, 3) development of a cloud-clearing algorithm based on AIRS spectra only, and 4) incorporation of variable atmospheric CO