Central Tropical Indian Ocean heat Budget Analysis During Indian Ocean Tripole events

Abstract

The Indian Ocean Tripole (IOT) mode, associated with the third mode of sea surface temperature anomaly (SSTA) variability, exhibits a unique pattern characterized by positive SSTA dominating the central Tropical Indian Ocean (TIO), while negative SSTA prevail in the western and eastern regions. This distinct mode of variability significantly influences the surrounding climate. In this study, the underlying causes of SSTA variability in the central TIO during tripole events are investigated through an SST heat budget analysis. Specifically, the anomalous warming in the central TIO is examined. A multiple linear regression analysis is performed using climate indices linked to most dominant SSTA-based climate modes, El Nino Southern Oscillations (ENSO), Indian Ocean Dipole (IOD), and IOT on SST budget terms to determine key drivers. The results reveal that net heat flux is the primary contributor to the positive SSTA in the central TIO. To further disentangle this influence, the individual contributions of radiative and turbulent heat flux components are analysed. This study enhances our understanding of TIO dynamics during IOT events and their broader implications for regional and global climate systems.