Experimental and observational analysis of vertical characteristics of internal solitary waves

Abstract The basic elements of internal solitary waves (ISWs) were obtained by vertically placed sensors in the laboratory experiment and in-situ observation. The vertical characteristics of the amplitude and waveform are analysed experimentally and observationally. Then the experimental and observational results were compared with the theoretical model. The study shows that the experimental amplitude-frequency relationship is closer to that in the two-layer model while the observational amplitude-frequency relationship is more approaching to that in the continuously stratified model. Experimental and observational results reveal that the amplitude of ISWs increase first and then decrease with an increasing depth. The sech 2 function of the KdV theory can describe the waveforms of ISWs at different depths well.