CAN SYNTHETIC APERTURE RADAR DATA IMPROVE HURRICANE FORECASTS*

摘要

Wind fields under hurricane conditions are retrieved from the synthetic aperture radar (SAR) utilizing an algorithm, which has shown to give good results under low and moderate wind conditions. The algorithm extracts wind directions from wind-induced streaks imaged by the SAR at scales above 200 m. Wind speeds are derived from the SAR measured normalized radar cross section (NRCS) utilizing the geophysical model functions CMOD4 and CMOD5, which describes the dependency of the NRCS on wind. It will be shown that the algorithm is capable to determine wind directions as well as wind speeds of over 50 ms ms-1 -1. The SAR-retrieved wind fields are compared to results of a high resolution numerical tropical cyclone model.