Recent Study on Tidal Resonance in the Gulf of Thailand

Abstract

The Gulf of Thailand (GOT) is characterised by diurnal tides, which may indicate that the gulf's resonance frequency is close to one cycle per day. The standard quarter-wavelength resonance hypothesis, however, fails to produce a diurnal resonant frequency when applied to the gulf. Therefore, the mechanism of the resonance in the gulf should examined. There is a lot of scholarly interest in the GOT's resonant responses to tidal and storm forcings. In this work, we first conduct a series of numerical experiments that reveal that the gulf has a strong reaction approximately one cycle per day and that the resonance of the South China Sea main area has a vital impact on the gulf's resonance. In contrast, the Gulf of Thailand has little impact on the main area of the South China Sea. This work then establishes an idealised two-channel model that can adequately explain the dynamics of the tidal resonance in the Gulf of Thailand. We discover that the quarter-wavelength resonance theory can describe the resonant frequency in the South China Sea main area around one cycle per day, and that the large-amplitude response at this frequency in the Gulf of Thailand is primarily a passive reaction of the gulf to the increased amplitude of the wave in the southern part of the South China Sea main area.