Acoustic Detection of Microstructure and Internal Waves in the Stratified Flow

Experimental study of the large- and micro-scale structure in the salt stratified flow is carried out using optical (schlieren) and acoustical (backscattering) techniques. Juxtaposition of the processed shadowgraphs with backscattering profiles reveals the scattering objects which are represented by fine scale elements of the flow – continuous density wake and microstructure formed by the multi-strip and volume micro-scale objects. Spectral processing of the backscattering data discovers character- istic frequencies of the oscillations in the wake interior. Some of the frequencies may be associated with internal waves; oth- ers are the results of harmonics formed due to square-law detection peculiar to backscattering method.