Estimating the Energy Flux of Internal Tides in the Northern South China Sea Using Underwater Gliders

Abstract

AbstractThe characteristics of the energy flux of internal tides in the northern South China Sea (SCS) were explored by analyzing a fleet of underwater gliders. It was found that the low‐mode diurnal internal tides with ∼300 km wavelength in the middle basin are generated predominantly in the Luzon Strait (LS) and propagate over 1,000 km to the western SCS. However, the semidiurnal internal tides are generated in multiple regions, including the LS in the east part, the continental shelf, and the islands in the west. The energy flux of the mode‐1 diurnal internal tides attenuated rapidly within 450 km of the LS and was less pronounced after that. The estimated dissipation rate based on the mode‐1 energy flux is about 10−8 W/kg, underling the significant role of mode‐1 diurnal internal tides in bolstering far‐field mixing. This study provides a unique view of the spatial pattern, energy flux, and energy sink of the internal tides in the northern SCS, which could supplement the altimetry‐based results and improve the parameterization in ocean models.