Vertical Momentum Transfer by Internal Waves with Regard for the Horizontal Component of Angular Velocity of the Earth’s Rotation

Free internal waves in a uniformly stratified fluid are considered in the Boussinesq approximation with regard for the Earth’s rotation. It is shown that the dispersion relation, derived with taking into account the horizontal component of the angular velocity of the Earth’s rotation at constant wave frequency, is reduced to the canonical equation for second-order curves in the plane of horizontal wave numbers. If the wave frequency is higher than the inertial frequency and less than the Brunt-Väisälä frequency, the frequency isolines are ellipses. If the wave frequency is higher than the buoyancy frequency, then the frequency isolines are hyperbolas; and if the wave frequency is equal to the Brunt-Väisälä frequency, then the isolines are two straight lines parallel the direction to the east. The vertical wave momentum fluxes are obtained as functions of the direction of wave propagation. It is shown that the fluxes are maximum in absolute value when the wave propagates to the north or to the south. A comparison of the vertical momentum fluxes of internal and sub-inertial waves at the same length and the maximum wave amplitude is carried out. It is shown that the vertical momentum flux of sub-inertial waves is higher than that of internal waves and weakens with weakening of stratification.