Observation of Internal Tides in the Andaman Sea: Energetics, Spatiotemporal Variability and Modulation by Equatorial Kelvin Waves

Abstract The Andaman Sea, a global hotspot for multi‐source internal tide generation, exhibits complex tidal dynamics that remain poorly understood. Combining 22‐month mooring measurements with satellite data, this study comprehensively investigates the energetics, spatiotemporal variability, and equatorial Kelvin wave modulation of the internal tides in the Andaman Sea. Results reveal that semidiurnal internal tides (SITs) significantly dominate diurnal counterparts and exhibit an average energy flux of 2.45 kW m −1 , comparable to levels near the Hawaiian Ridge. High‐mode SITs, contributing 48% of the total energy and prone to rapid dissipation, help explain the exceptionally intense diapycnal mixing within the Andaman Basin. Semidiurnal internal tides (SITs) exhibit dramatically monthly, seasonal, and interannual variability, peaking in summer with a 23% interannual energy difference. Satellite‐derived observations identify six primary generation sites, with internal tides radiating predominantly northeast‐southwest and forming complex interference patterns due to multi‐source interactions. Strikingly, SITs lose >80% phase coherence within ∼2 wavelengths of propagation, posing challenges for accurate tidal signal removal in the Andaman Sea's SWOT data. Furthermore, equatorial Kelvin waves intruding into the Andaman Sea significantly modulate thermocline structure and circulation, altering SIT energy by >30% and driving most intraseasonal and seasonal variations in internal tidal energetics. This study advances understanding of internal tide dynamics in multi‐source regimes and establishes the first observational link between equatorial Kelvin waves and internal tidal energetics. Our results provide a new perspective for modeling energy redistribution in tropical marginal seas, with implications for improving SWOT‐based submesoscale studies and regional mixing parameterizations critical to Indo‐Pacific climate simulations.