Experimental study of an internal beam in stratification of non-constant buoyancy frequency

The internal wave brings in non-trivial influence in the ocean. A large number of investigations have focused on the internal wave in linear stratification, which has a constant buoyancy frequency representing a typical and widespread stratification configuration in the ocean. For the non-constant buoyancy frequency configuration, a typical situation in pycnocline in the ocean, the behavior of the internal wave has been far less understood and is experimentally investigated in this study. We use the synthetic schlieren technique to study the internal wave in three cases of characteristic stratification. The cross-beam profiles and the intensity decay of the internal wave are particularly examined and compared with those of the linear stratification.