The Effects of Branch on Interfacial Long Waves Induced by Tide in Bifurcating Bay

Abstract

In a bay, density stratified layer develops from spring to summer. Following the development of density stratified layer, internal wave which was caused by tide is induced. The scale of induction is related to degrees of development of density stratified layer or the shapes of bay. In a long and slender bay like Uranouchi Bay which is composed of many branches, the influences of branch upon internal wave are supposed very remarkable.
In this study, an equation for calculating interfacial long wave which is induced by tide in branch, was derived, then investigated the influences of branch on interfacial wave, and following results were obtained.
(1) Neumann's impedance method is applicable to natural oscillation of interfacial long wave of branch.
(2) The influences of branch upon natural oscillation of interfacial wave are as follows. The longer the length of bay, the smaller the wave number of natural oscillation, and the influence upon natural oscillation is smaller when branch is located nearer to node of interfacial wave.
(4) The nearer the natural period approach to tidal period, the larger the scale of induced interfacial wave.
(4) Interfacial wave in not induced to branch which is located at the node of interfacial wave.