87th AMS Annual Meeting

Monday, 15 January 2007
Assessing The Forecast Impact Of WindSat/Coriolis Data In The NCEP GDAS/GFS
212B (Henry B. Gonzalez Convention Center)
Li Bi, CIMSS/Univ. of Wisconsin, Madison, WI; and J. F. Le Marshall, T. H. Zapotocny, J. Jung, and M. C. Morgan
Poster PDF (300.8 kB)
In January 2003, WindSat/Coriolis was successfully launched by NASA. WindSat is the first polarimetric microwave radiometer to measure ocean surface wind speed and direction. In collaboration with NASA, NAVY, NOAA and NCEP personnel, the JCSDA (Joint Center for Satellite Data Assimilation) has been evaluating the forecast impact of assimilating WindSat data in the NCEP GFS (Global Forecast System) model.

For this poster, forecast impacts will be compared with that of QuikSCAT surface winds. QuikSCAT winds have been proven to provide a positive forecast impact in the GFS during both seasons and in each hemisphere.

Results will be shown from a series of experiments involving GFS simulations: 1) with QuikSCAT and no WindSat, 2) without either QuikSCAT or WindSat, 3) with WindSat (windsob1254 and windsob0.5254) and QuikSCAT, 4) with WindSat no QuikSCAT. Quality Control (QC) techniques are developed to verify the current retrieval algorithm. The results have shown that the combination of WindSat and QuikSCAT data provides the largest positive forecast impact by day 7 in the GFS. The T254 WindSat experiments also demonstrated larger anomaly correlation gains with a 1 superob of the data than a 0.5 superob of the data. As the next step for acceptance into operations, these previously tested WindSat experiments have now entered daily real time testing at NCEP.

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