Large Eddy Simulation of Flow and Turbulence at the Steep Topography of Luzon Strait

TitleLarge Eddy Simulation of Flow and Turbulence at the Steep Topography of Luzon Strait
Publication TypeJournal Article
Year of Publication2017
AuthorsJalali M., Sarkar S.
JournalGeophysical Research Letters
Date Published2017/09
Type of ArticleArticle
ISBN Number0094-8276
Accession NumberWOS:000413148100040
Keywordsbreaking; conversion; dissipation; energetics; hawaii; Internal tide; kaena ridge; model; ocean modeling; ocean turbulence; topographic internal waves; waves

Steep generation sites for topographic internal gravity waves can also be sites of turbulence. The present work uses turbulence-resolving Large Eddy Simulation (LES) for tidal flow over multiscale, steep bathymetry patterned after a portion of the west ridge of Luzon Strait at 20.6 degrees N. Oceanic values of the slope criticality, Froude number, excursion number, and aspect ratio are matched. The amplitude and phasing of velocity, overturns, and dissipation are similar to observations made at a deep mooring. However a tidal phase is noted in which there is a discrepancy that could arise from the resonant interaction with waves generated at the east ridge that is not included in the model. Turbulent dissipation originates from several mechanisms including breaking lee waves during flow reversal, downslope jets, critical-slope boundary layer, high-mode internal wave beams, off-slope lee wave breaking and wave breaking in a valley between subridges. The model baroclinic energy budget is closed with negligible residual and the local turbulence loss of 23.5% is large.

Student Publication: