Origin and propagation of M2 internal tides in the Arabian Sea

Abstract

Internal tides (ITs) generated by the interaction of barotropic tides and rough topography in stratified oceans play a significant role in turbulent mixing and thermohaline circulation. The baroclinic modes, propagation, energy, and origin of M₂ ITs in the Arabian Sea are analyzed using Multivariate Inversion of Ocean Surface Topography Internal Tide Model product (MIOST-IT). The M₂ ITs are generated in the northeast Arabian Sea, around the Socotra Island, and around the Maldive Islands, dominated by the mode-1 component with a wavelength of approximately 110 km. The most energetic M₂ ITs radiate from the continental shelf of the northeast Arabian Sea for more than one thousand kilometers with mode-1 and mode-2 energy of approximately 0.56 GW and 0.04 GW, respectively. M₂ ITs generated around the ridges southeast of the Gulf of Oman propagate southeastward, whereas they radiate in all directions from the Socotra Island. The northeastward-propagated M₂ ITs from the Socotra Island and the southwestward-propagated M₂ ITs from the continental shelf form standing waves. The M₂ ITs propagate westward on the western side of the Maldive Islands and eastward on the eastern side, dominated by mode-1 with energy of 0.17 GW and 0.08 GW, respectively. The study presents the characteristics of multi-directionally propagated and multi-modally M₂ ITs in the Arabian Sea, which addresses the characteristics of M₂ ITs in the region, therefore contributing to the understanding of the Arabian Sea's role in regional and global overturning circulation, energy budget, climate dynamics, and ecological environments.