At NASA GSFC, we are conducting a series of data assimilation experiments to evaluate the impact of AIRS data on weather analysis and forecasting. In these experiments, we assimilate AIRS data in several different forms, using multiple data assimilation systems. The results from our initial experiments indicate that (1) in the Southern Hemisphere, there is a significant impact on analyses, and both anomaly correlations and objective cyclone tracking show an overall positive impact of AIRS temperatures on forecast accuracy. (2) In the Northern Hemisphere, the impact is smaller. However, a modest overall positive impact on cyclone position and intensity is observed. (3) A substantial portion of the impact comes from high latitude data (poleward of 40 deg latitude), and (4) both clear and partially cloudy data contribute to the impact.

At the conference, we will present the results from these experiments as well as ongoing experiments aimed at assessing the impact of AIRS moisture retrievals and radiances.