Near-Bottom Turbulence and Sediment Resuspension Induced by Nonlinear Internal Waves
Final technical rept. 11 Feb 2011-30 Sep 2014
CORNELL UNIV ITHACA NY
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The transition to fully turbulence under fully nonlinear internal solitary waves NLIWs has been investigated. Very well resolved Large Eddy Simulations LES of the separated bottom boundary layer BBL under a NLIW of depression have been conducted. Exploratory and production runs involving typically 1.5 billion grid points have been executed on state-of-the-art DoD Facilities accessible via a Frontier contract. NLIWs propagating into quiescent waters and against oncoming barotropic currents with their own BBL have been studied. In the former set-up, a 3-D near-bed vortex wake forms only when volumetric forcing is included, whereas in the former a self-sustained near-bed turbulent wake occurs in the NLIWs lee through a complex spontaneous transition to turbulence. Integral measures and the energetics of the NLIW-driven BBL have been quantified. Mechanisms of particulate resuspension have been investigated through Lagrangian Coherent Structure analysis and the quantification of wave and wake-driven pressure signals at the bed.
- Physical and Dynamic Oceanography