Laboratory experiments on the influence of stratification and a bottom sill on seiche damping

Abstract. The damping of water surface standing waves (seiche modes) and the associated excitation baroclinic internal are studied experimentally in a quasi-two-layer laboratory setting with topographic obstacle at bottom representing seabed sill. We find that topography-induced wave drag contributes markedly to seiche such systems. Two major pathways barotropic–baroclinic energy conversions were observed: stronger one – involving short-wavelength modes large amplitudes may occur when node is situated above close vicinity weaker, less significant other pathway long or seiches along pycnocline resonate low-frequency components decaying forcing.