Preliminary Analysis of Tropical Cyclone Ocean Waves Using Sentinel-1 SAR Data

Sentinel-1 SAR Wave Mode (WV) contributes to the global ocean wave (wind sea and swell) measurements upon the ERS-1&2 and Envisat ASAR. It is a wave product that contains image and ocean spectra, as well as certain wave parameters, which is valuable observational data for global ocean wave studies. In this study, we focused on the characteristics of ocean swell generated by the Tropical Cyclone (TC) and their relations with TC properties. To this end, the Firework method was adopted to track the TC generated swells. Swell data with low quality or unmatched with the expected waves are filtered out. This quality control procedure was performed for each acquired track and relied on the expected swell consistency between successive acquisitions along any given track. The preliminary analysis involves LANE TC cases and S1A&B WV observations were collected. The results showed clear swell asymmetry emerging at the front and the rear of TCs. The wavelength asymmetry at forwarding propagation discretion and the opposite direction was determined by wave development in the front area. Maximum wavelength asymmetry could be found in the medium intensity and translation speed TCs. The data confirm the previous measurement that fetch-law could be used to the represent such wavelength asymmetry.