First Look at Typhoon Thermal Structures Revealed from Compact Atmospheric Microwave Sounder onboard TianYan-16 Commercial Small Satellite

Polar-orbiting microwave sounders provide an important means of characterizing the vertical thermal structure of tropical cyclones (TCs), but their temporal sampling is limited by orbital revisit intervals. Commercial small-satellite constellations may complement existing operational meteorological satellites by providing more frequent microwave observations. This study presents the first use of observations from the Compact Atmospheric Microwave Sounder (CAMS) onboard the TianYan-16 commercial small satellite to retrieve temperature anomalies within TCs. A retrieval framework combining striping-noise mitigation, limb radiance correction, cloud screening, and scene-dependent statistical regression was developed. Application to Typhoon Ragasa showed a warm anomaly mainly within 150–500 hPa, reaching approximately 5–6 K at 250 hPa; its spatial displacement and temporal evolution were broadly consistent with ERA5. For the weaker Typhoon Podul, the retrieval also depicted positive temperature anomalies mainly within 150–400 hPa and their strengthening during the observed period, although differences from ERA5 remained in magnitude and vertical extent. These two cases provide a proof of concept for using CAMS observations to examine TC thermal structure and demonstrate the potential of commercial microwave small satellites to complement existing polar-orbiting observations.