2024年第11号台风“摩羯”在菲律宾以东海域生成后向西北方向移动，在南海海域迅速增强为超强台风等级，给珠江三角洲地区带来严重风雨与洪涝灾害。本文基于多源合成孔径雷达（Synthetic Aperture Radar, SAR）星载卫星多时相观测数据，利用500米分辨率海面风场反演产品，经过陆地掩膜、噪声滤除、扇贝效应去除及台风中心定位等处理，提取分析台风“摩羯”演变过程中的风场精细结构参数。结果表明，“摩羯”在快速增强阶段最大风速和风圈半径均显著增大，风场结构不对称性增强，在达到超强台风后保持稳定。基于二维傅立叶变换的谱分析发现，SAR海面风场能够清晰呈现台风边界层千米尺度滚涡结构，其方向与台风外围切变场基本一致，波长集中在2–3公里，且其分布不随台风强度变化而显著改变，与当前滚涡形成及维持主要受局地风切变不稳定动力影响的认识一致。虽然本文研究数据样本有限，但初步证实了SAR在揭示台风海面风场精细结构及边界层千米尺度过程方面的巨大潜力，为后续开展多台风案例大数据统计，深入理解台风不同强度阶段的海气相互作用动力机制提供重要参考。

Objective: Typhoon Yagi (No. 202411) is formed east of the Philippines and moved northwestward. After entering the South China Sea, it rapidly intensified into a super typhoon and brought severe winds, heavy rainfall, and flooding to the Pearl River Delta, including Guangzhou and Haikou. This study uses multi-temporal synthetic aperture radar (SAR) observations to analyze the fine-scale sea surface winds during Yagi’s evolution. Method: The 500 m resolution wind products were processed with land masking, noise filtering, scalloping correction, and typhoon center detection. Result: Results show that during the rapid intensification phase, both maximum wind speed and wind radii increased notably, and the winds became more asymmetric. After Yagi reached its peak intensity, these parameters stabilized. Spectral analysis based on two-dimensional Fourier transforms reveals clear kilometer-scale roll vortices in the typhoon boundary layer. Their orientations align with the outer shear flow, and the dominant wavelength ranges from 2–3 km. The spatial distribution of these rolls shows little dependence on typhoon intensity, consistent with the idea that roll formation is mainly driven by local shear instability. Conclusion: Although the dataset is limited, the results demonstrate that SAR observations are effective for capturing fine-scale wind structures and boundary-layer processes. This work provides a useful reference for future large-sample studies on air–sea interaction mechanisms in different typhoon stages.