A case study of analyzed versus satellite-derived water vapor distributions over the Atlantic Ocean
The paper compares two estimates (one derived from the ECMF analysis and the other from the DMSP Special Sensor Microwave/Imager, SSM/I) of precipitable water content (PWC) over the North Atlantic Ocean during a period of intense cyclone and frontal activity between September 20 and 29, 1987, when two tropical cyclones, Dennis and Emily, moved into midlatitudes and took on extratropical characteristics. The values from the ECMWF analyses consisted of vertical integrals of specific humidity from 1000-300 mb, on a 2.5-deg latitude/longitude grid. The PWC values from the SSM/I were computed using the technique described by Wentz (1983) and were based on retrievals at increments of 25 km. The two distributions of PWC showed very good agreement with each other and with the synoptic patterns depicted.