Extended Abstract (60K)P3.8
The Impact Of Satellite Winds On Two Versions of NCEP Global Data Assimilation And Forecast Systems
Xiujuan Su, NOAA/EMC, Camp Springs, MD; and J. Derber and S. Lord
Low density satellite winds from EUMETSAT, GMS and INSAT and high density GOES cloud drift infrared and water vapor winds are used operationally at NCEP. The impact of satellite winds on the forecast skill is studied for two versions of data assimilation and model systems at NCEP: the current operational version of T62 and the version of T62 in the near future. The primary difference between the two versions is a change to the convective parameterization and the assimilation of cloud water in the second version. These changes have resulted in the significant improvement in the tropical wind field, which is confirmed by this study. The impact on the mid-latitude 500mb geopotential height for both versions of model is less than 1%. The impact on the tropical wind for the first model is small and positive while the impact for the second version is much smaller and mixed with a negative impact at 850mb and a positive impact at 200mb. However, the tropical wind forecasts for the second model are consistently better. These results conclude that the impact of satellite winds is dependent of the quality of the forecast and data assimilation system.
Poster Session 3, Operational Applications
Tuesday, 16 October 2001, 9:15 AM-11:00 AM
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