Estimating peak response frequencies in a tidal band in the seas adjacent to China with a numerical model

Abstract

A numerical method is designed to examine the response properties of real sea areas to open ocean forcing. The application of this method to modeling the China’s adjacent seas shows that the Bohai Sea has a highest peak response frequency (PRF) of 1.52 d⁻¹; the northern Yellow Sea has a PRF of 1.69 d⁻¹; the Gyeonggi Bay has a high amplitude gain plateau in the frequency band roughly from 1.7 to 2.7 d⁻¹; the Yellow Sea (including the Gyeonggi Bay), the East China Sea shelf and the Taiwan Strait have a common high amplitude gain band with frequencies around 1.76 to 1.78 d⁻¹ and are shown to be a system that responds to the open ocean forcing in favor of amplifying the waves with frequencies in this band; the Beibu Gulf, the Gulf of Thailand and the South China Sea deep basin have PRFs of 0.91, 1.01 and 0.98 d⁻¹ respectively. In addition, the East China Sea has a Poincare mode PRF of 3.91 d⁻¹. The PRFs of the Bohai Sea, the northern Yellow Sea, the Beibu Gulf and the South China Sea can be explained by a classical quarter (half for the Bohai Sea) wavelength resonance theory. The results show that further investigations are needed for the response dynamics of the Yellow Sea-East China Sea-Taiwan Strait system, the East China Sea Poincare mode, the Taiwan Strait, and the Gulf of Thailand.