Synthetic aperture radar observations and numerical simulations of wakes associated with the island Yakushima, Japan during Super Typhoon Shanshan (2024)

This paper for the first time documents the wakes associated with Yakushima island of Japan in a super typhoon based on synthetic aperture radar (SAR) ocean surface winds, and explores the feasibility of simulating the major features of the wakes using higher spatial resolution numerical weather prediction model for comparison with the actual SAR observation. Three images during Super Typhoon Shanshan (2024) are considered. The model simulations are found to reproduce reasonably well the main features of the wakes. They capture much finer details, such as wakes associated with individual mountains of the island, and the waves in the wakes, which are not apparent in the SAR images. On the other hand, SAR images indicate recirculation in the edges of the island, though not very apparent, while the suspected recirculation does not show up in the numerical simulation. The quantitative comparison reveals some discrepancies, particularly in the wake region, where the model predicts low wind speeds that are not seen in the SAR data. These findings emphasize the necessity for enhanced observational and modeling techniques to improve the accuracy of wind field evaluation over complex terrain during tropical cyclones. © 2026 The authors