Observation of the Semidiurnal Internal Tides in the Northwest Pacific Ocean

Abstract

Internal tides are internal waves occurring in the tidal frequency bands of stable stratified oceans, which are formed by the interaction between barotropic tides and different submarine topographical features such as ridges, sills, trough, trench and continental shelf break. In-depth study of tidal energy and tidal dynamics in this area is of great significance for understanding the multi-scale energy cascade structure in this ocean. Based on the 16-day mooring observation data of a set of high spatial and temporal resolution in the Northwest Pacific Ocean from 21°N to 22°N,124°E to 126°E, this paper reveals the amplitude distribution characteristics of the semidiurnal tidal wave in the northwest Pacific Ocean. The results show that the amplitude of the semidiurnal internal tides increases first and then decreases during the change of the depth from small to large. The amplitude is small at the surface and bottom of the ocean, and reaches the maximum at the middle of the ocean, with the maximum value of 40m