The Atmospheric Infrared Sounder (AIRS) was the first of the hyperspectral sounders able to provide real time data for operational and research meteorology. Over subsequent years new generation advanced sounders will become part of an upgrade to the Global Observing System. These instruments include the US Cross-track Infrared Sounder (CrIS) and Hyperspectral Environmental Suite (HES), as well as the European Infrared Atmospheric Sounding Interferometer (IASI). Demonstration of the benefits of hyperspectral data on Numerical Weather Prediction (NWP) remains a high priority. Observing System Experiments (OSEs) designed to examine effective methods to use hyperspectral radiances in NWP are summarized here.

First we discuss the range of satellite data being used in the operational NCEP global forecast system. Then experiments showing the benefit of using hyperspectral radiance data, available in real-time from the AIRS instrument, in systems already using the full operational data base, are reviewed. Effective methods of data thinning and noise reduction are noted. The importance of using the full spatial resolution of the data used is documented. The importance of channel selection for NWP is shown. We also describe the current use of variable hyperspectral emissivity over the entire globe and related studies. We also note a number of methods being used to detect cloud in hyperspectral fields of view. Finally, note is made of the benefits to be gained by the enhanced use of hyperspectral data in NWP and some discussion is provided on desirable characteristics for infrared sounders related to their efficient application to NWP.