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

Ocean Science Discussions

article

Medjdoub, Karim¹  Jánosi, Imre M.³  Vincze, Miklós¹ 

[1]von Kármán Laboratory of Environmental Flows

[2]Eötvös Loránd University

[3]Max Planck Institute for the Physics of Complex Systems

[4]University of Public Service, Faculty of Water Sciences

[5]MTA-ELTE Theoretical Physics Research Group

DOI  :  10.5194/os-17-997-2021

学科分类：海洋学与技术

来源: Copernicus Publications

【 摘 要 】

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

【 授权许可】

CC BY