Internal solitary wave generation by the tidal flows beneath ice keel in the Arctic Ocean

A series of non-hydrostatic, non-linear numerical simulations were carried out to investigate the generation and evolution of internal solitary waves (ISWs) through the interaction of a barotropic tidal current with an ice keel in the Arctic Ocean. During the interaction process, the internal surge was generated at first, and then the wave gradually steepened due to non-linearity during its propagation away from the ice keel. The internal surge eventually disintegrated into multi-modal and rank-ordered ISW packets with the largest having an amplitude of O(10) m. Sensitivity experiments demonstrated that the ISWs’ amplitudes and energy were proportional to the varying ice keel depths and barotropic tidal flow amplitudes, but were insensitive to the changing ice keel widths. Typical ISWs can enhance the turbulent dissipation rate of O(10-6) W/kg along their propagation path. Further, heat entrainment induced by the wave-ice interaction can reach O(10) MJ/m per tidal cycle. This study reveals a particular ISW generation mechanism and process in the polar ice environment, which could be important in impacting the energy transfer and heat balance in the Arctic Ocean.