Observations of ambient noises induced by the internal solitary waves on the continental slope of the northern South China Sea:: Ambient noises by ISW in SCS

摘要

The “Sand Dunes” moored array in the upper slope of the northern South China Sea provided an unprecedented look at internal solitary wave (ISW) arrival patterns and transformations under shoaling as they propagate northwestward passed the sand dunes. The data sets also shown the underwater ambient noise induced by the ISW. The mode-1 depression ISW could generate the surface wave breaking in the convergence zone and produce ocean noises. These ocean noises in high sonic bands would be enhanced in the convergence zone and reduced in the divergence zone due to rough and smooth sea surface conditions, respectively. Besides, the strong horizontal currents induced by internal solitary waves would produce self-noise in the infra and low sonic bands. In addition, sometime, the acoustic data also show the marine mammal sounds behind the ISW. This result might due to the marine mammals follow the ISWs to prey on fish and squid.