Permalink : http://hdl.handle.net/2115/44759

KEYWORDS : shelf waves;higher-mode;vortex eddies;conservation of potential vorticity;scattering process

Shelf waves have many modal-dependent structures in their cross-shelf dimension. The current fluctuations on the shelf areas in the world oceans were frequently dominated by the second or third mode. Theoretical studies show that all mode waves excited within the wind forcing area starts propagating after the sudden onset of forcing. Thus,the generation of higher-mode waves can be predicted theoretically,but intuitive understanding for its physical mechanism is not easy. This study suggests that modal-dependent structures are temporally formed as regarded as the scattering process of vortex eddies. The scattering gives repeated rise to an eddy with positive/ negative vorticity generated by a former-formed eddy with opposite-sign vorticity,according to the conservation of potential vorticity.