Wind Speed Retrieval of Hurricane Florence (2018) Using Sentinel-1 Synthetic Aperture Radar Image

Over the ocean, the radar cross section (RCS) of C-band synthetic aperture radar (SAR) is dependent on sea surface wind. For both co-polarization and cross-polarization (CP) SAR, a large number of geophysical model functions (GMF) have been presented to simulate RCS and derive sea surface wind information from SAR images. In this paper, a case study was carried out to retrieve wind speed of Hurricane Florence (2018) from Sentinel-1 VH-polarized SAR image by the newly proposed G19 model. Based on the asymmetric Holland hurricane wind model, the retrieval results are analyzed with the model results in the azimuth direction. For validation, the SAR-retrieved wind speeds are compared with the SAR-collocated wind references from the tropical cyclone report provided by the National Hurricane Center (NHC) and the fifth generation European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis of the global climate (ERA5). The results show the reliability of G19 model and the capability of hurricane wind monitoring by Sentinel-1.