Understanding Rapid Intensification of Tropical Cyclones in the Bay of Bengal Through Energetics Perspective

Abstract Rapid intensification (RI) of tropical cyclones (TCs) is challenging to understand and predict. This study investigates the dynamics and energetics of TCs that underwent RI and non‐RI in the Bay of Bengal (BoB) from 2005 to 2023. Eulerian and quasi‐Lagrangian frameworks were employed to study the energetics of TCs. Results reveal that the quasi‐Lagrangian captures the intensity and its variabilities more robustly during RI than the Eulerian framework, particularly highlighting the rapid increase in EKE (Eddy Kinetic Energy). Energy budget analysis shows that warm BoB regions serve as primary energy sources for RI, with the baroclinic conversion term emerging as the dominant driver of EKE during intensification. Additionally, the study shows that RI and non‐RI TC trajectories are statistically distinct, with RI TCs showing more northward movement and non‐RI TCs predominantly moving westward. Analysis of composite sea surface temperature (SST) anomalies reveals correlations with RI TC tracks, indicating a positive anomaly during RI phases. RI events are associated with more negative Surface Latent Heat Flux anomalies along the cyclone track, suggesting more substantial ocean‐to‐atmosphere heat transfer. Moreover, RI TCs experience weaker vertical wind shear than non‐RI events, further supporting RI. These distinctions underscore the relevance of RI and the role of energetics emphasizing the importance of baroclinic conversion in driving cyclone intensification. This comparative analysis between these frameworks sheds light on the complexities of cyclone energetics and accentuates the quasi‐Lagrangian framework's efficacy in capturing subtle yet critical variations in RI dynamics.