Error characteristics of satellite derived water vapor winds as compared to ECMWF model analyses

Satellite derived water vapor winds typically are treated as single level data when assimilated in numerical models. This is in spite of the fact that energy received at a satellite is emitted from a finite layer of the atmosphere rather than from a specific level.This research attempts to investigate using these important data in a more realistic manner.

GOES-8/9 satellite derived water vapor winds (WVwnds) are statistically compared to collocated ECMWF large scale analyses. When all the collocated data are considered, mean vector differences (MVDs) between the WVwnds and ECMWF analyses generally are near 5 m/s at the assigned height of the WVwnds. In addition, MVDs typically are less than 7.5 m/s in the layer extending 2.5 km both above and below the assigned height. As expected, these values are lower (higher) for small (large) shear environments.

These data, along with the error characteristics described above, may have a significant impact on model simulations.

Theme: #3. Operational Applications.