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Topographic height dependence of internal wave generation by tidal flow over random topography
Author(s) -
Zhao Jiajun,
Zhang Likun,
Swinney Harry L.
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl065650
Subject(s) - geology , flow (mathematics) , seafloor spreading , internal wave , tidal power , internal tide , geodesy , scale (ratio) , ocean surface topography , scaling , sea surface height , climatology , geophysics , geometry , oceanography , mechanics , altimeter , physics , ecology , mathematics , quantum mechanics , biology
Internal waves (IWs) generated by tidal flow over the seafloor play a critical role in ocean circulation and climate. We determine the dependence of the radiated IW power on topographic parameters in numerical simulations of tidal flow over two‐dimensional random topographic profiles that have the spectrum of oceanic abyssal hills. The IW power increases as the horizontal spatial resolution scale is decreased, but below a certain spatial scale the power saturates at a level less than the linear theory prediction. For increasing topographic RMS height H rms the emergent interference of the tide and the IWs from different generation sites leads to a transition in the IW power dependence on H rms from quadratic to linear. This transition in the scaling of the IW power depends on the slopes of a valley's nearest neighboring peaks. Our results should guide the modeling of IW generation by tidal flow over small‐scale ocean topography.