Cyclone Chido: Sentinel-1 Captures the Storm’s fury

Cyclone Chido, a powerful tropical storm, swept across Mayotte, leaving a significant impact on the affected regions. Using Sentinel-1 radar data, we analyzed its structure and dynamics through high-resolution imagery and wind field data. On 2024-12-13, Sentinel-1 captured this striking image of Cyclone Chido, showcasing its spiraling rain bands and calm eye. The radar’s ability to penetrate clouds revealed critical details about the storm’s structure, including areas of intense surface roughness caused by strong winds (Figure 1).

Interestingly, beyond the surface roughness of the sea, the radar also detected atmospheric features likely linked to the storm. While Sentinel-1’s radar operates in the C-band, which is generally unaffected by clouds, it can reflect off structures in the atmosphere larger than its wavelength, such as dense cloud formations or heavy rain bands. These features, visible in the radar imagery, highlight not only the interaction of wind and sea but also the complex dynamics of the cyclone’s atmosphere.

The Ocean Wind Field (OWI) product derived from Sentinel-1’s OCN dataset provided additional insights into the storm’s wind dynamics. The map reveals the highest wind speeds near the eye, depicted in red, indicating the storm’s intensity (Figure 2 and Figure 3) .

Written by giovanna palumbo