Rainband Feature Tracking for Wind Speeds around Typhoon Eye Using Multiple Sensors

No direct measurements of surface winds are available now except that by aircraft at a high cost, thus tracking and monitoring ocean features which have short coherent time periods from sequential satellite images is a good option to estimate extreme wind speeds associated with typhoons. In this study, five typhoon cases observed by quasi-concurrent satellite-based Synthetic Aperture Radar (SAR) and Moderate Resolution Imaging Spectroradiometer (MODIS) data, and one of the cases also by ground-based Doppler radar observations have been studied. The rainband features around typhoon eyes are first delineated using wavelet analysis, and then the wind speeds are estimated by feature tracking using quasi-concurrent multi-sensor images. The resulting wind speeds are reasonable compared with the maximum wind speed reported from the Joint Typhoon Warning Center (JTWC). In a special case, with the aid of the Doppler radar near the coast, the wind speed estimates based on the multi-sensor also show consistent results. Therefore, it has been demonstrated that a reasonable wind speed around typhoon eyes can be derived from the rainband feature tracking using quasi-concurrent multi-sensor images. This technique may offer useful wind information for typhoon simulations and forecasts.