The next generation of NCEP's Global Data Assimilation System (GSI/GFS) became operational on May 1st 2007. This system incorporates the assimilation of profiles from the COSMIC mission launched in April 2006.

The GSI/GFS has the capability to assimilate observations of refractivity and bending angle. The use of refractivities was selected for implementation in operations, while the tuning of the assimilation of bending angles with the newer version of the analysis system is being finalized at NCEP.

The data assimilation experiments that led NOAA/NCEP to assimilate COSMIC into operations show significant improvement of the anomaly correlation skill and global reduction of the model bias and root-mean-squared errors when COSMIC observations are assimilated. The improvement is found for the temperature, geopotential heights and moisture fields. Larger benefits are found in the Southern Hemisphere, although a positive impact is also found in the Northern Hemisphere and Tropics.

In this presentation several impact studies with COSMIC will be discussed. The benefits of using COSMIC refractivities and bending angles will be evaluated for different variables and meteorological situations. NCEP's future plans to enhance the use of GPS radio occultation observations in weather forecasting also will be presented.