Effects of Pycnocline Parameters on Evolution of Internal Solitons

Internal solitons have drawn much attention from ocean engineering and oceanography, due to the significant impacts on ocean structures, submarines and sonar communication. In order to investigate the evolution law of internal solitary waves, we have formulated a mathematical model for sharply stratified oceans. The model involves the effects of topography, dissipation, bottom friction and shoaling, with the related coefficients calibrated by field data over the Continental Slope in South China Sea. Then, we have explored shoreward propagation process of internal solitons generated in deep ocean by using the formulated model, particularly aiming at the variation of internal soliton’s amplitude. Detailed discussions focus on the effects of physical parameters of pycnocline, i.e. its location or depth and the density difference between water layers below and above pycnocline, on the variation of internal soliton’s amplitude. Results show that internal soliton’s amplitude decreases when it propagates from deep sea to shallow continental shelf. The shallower the pycnocline and the smaller the density difference between water layers below and above pycnocline, the faster the internal soliton’s amplitude decreases.