Study On Group Velocity Of Oceanic Internal Solitary Wave

Abstract

Internal solitary wave is one of difficult problems in ocean field, scholars have applied different methods to investigate parameters of internal solitary wave, and group velocity is an important parameter for the internal solitary wave prediction. In this paper, equation used to describe group velocity of internal solitary wave was developed based on the Laplace equation and Bernoulli equation. Factors affecting the group velocity was also discussed, such as density difference of upper and lower layer, change of stratification, depth of water and wavelength of internal solitary wave. The results show that the group velocity became larger while the density difference and depth upper layer became bigger and the water became deeper, analysis also found that long-wavelength internal solitary wave travel faster that short-wavelength internal solitary wave. The calculation of group velocity in both South China Sea and Malin Shelf show good agreements with situ data, this means the equation is suitable for the description of group velocity of oceanic internal solitary wave.