Tropical Cyclone Translation Speed and Wind Intensity Effects on Ocean Surface Temperature and Chlorophyll-a

Tropical cyclones (TCs) are a key component of the Earth system, characterized by extremely intense air-sea interactions. This interaction influences the formation and intensity of TCs and governs biogeochemical processes in the upper ocean. This study investigates whether slower-moving TCs yield stronger Sea Surface Temperature (SST) and chlorophyll-a (Chl-a) anomalies as a response of air-sea interaction. It further examines whether the combination of low translation speed and strong winds induces the strongest cooling and Chl-a anomalies and evaluates the relationship between cold wakes and Chl-a responses. Six TCs of categories 1-5 in the Indian Ocean were analyzed using vertical profiles of temperature from ARGO floats, satellite-derived SST and Chl-a, and meteorological reanalysis data. The results demonstrate that lower translation speed TCs (≤ 14.4 km/h) induced the most significant SST anomalies (-4 °C), and the highest Chl-a anomalies (2 mg m-3). The strongest anomalies occurred when slow translation speeds coincided with high wind speeds. The results indicate that the magnitude of anomalies is sustained not only by translation speed and wind intensity, but also by the stratification of the upper ocean. These contribute to our understanding of the correlation between translation speed, wind strength, atmospheric and oceanic preconditions on SST- and Chl-a anomalies.