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Internal Tide Cycle and Topographic Scattering Over the North Mid‐Atlantic Ridge
Author(s) -
Lahaye Noé,
Gula Jonathan,
Roullet Guillaume
Publication year - 2020
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1029/2020jc016376
Subject(s) - baroclinity , internal tide , barotropic fluid , bathymetry , stratification (seeds) , geology , internal wave , ridge , dissipation , oceanography , climatology , scattering , geophysics , physics , paleontology , seed dormancy , botany , germination , dormancy , optics , biology , thermodynamics
Internal tides are a predominant source of high‐frequency variability and diapycnal mixing in the ocean. Understanding their dynamics and lifecycle is necessary to better understand their role in the ocean circulation. In this study, we describe and quantify internal tide generation, propagation, and dissipation in a sector of the North Mid‐Atlantic Ridge, using high‐resolution numerical simulations with realistic bathymetry and stratification. We show that the generation and dissipation of internal tides, as well as the distribution of internal tides among vertical modes, exhibit high spatial variability. We find that topographic scattering leads to a significant transfer of energy toward high vertical modes and thereby enhances internal tide dissipation. On average, and especially on the ridge, this mechanism is dominant over the conversion from the barotropic tide for transferring energy to high ( > 7) vertical modes. The magnitude of the scattering of the first baroclinic internal mode is found to be in good agreement with theoretical predictions.