Wind field retrieval under high wind condition by combined scatterometer and radiometer data

With the availability of scatterometer data, surface wind vectors can be estimated from the backscatter measurement over oceans, guarantee global, long-term monitoring of the winds on the oceans, which make them very valuable for climate studies and other applications. At moderate wind speeds, the wind speed derived by scatterometer is considered reliable. But at higher wind speeds, scatterometers appear to underestimate the wind speed, especially in tropical cyclones, because of deficiencies of the geophysical model function for high winds, attenuation caused by rain, influence of wind gradient, and the saturation of the backscattering under high wind. As a passive microwave sensor, radiometer does not show obvious saturation phenomena under high wind, therefore it is an appropriate candidate to be used to retrieve high wind speed. In this paper, combined scatterometer and radiometer data is used to retrieve wind field under high wind condition. Using in situ data and meteorological data as a criterion, we compared the wind retrieval performances of scatterometer and radiometer. Results show that it is better to use radiometer data as a replacement of scatterometer while observing high wind speed.