Turbulence and Mixing in Deep-Water Stratified Tidal Bottom Boundary Layers

Abstract

Ocean currents flowing over the seabed produce a turbulent bottom boundary layer (BBL) which extracts energy from the overlying flow and mediates sedimentary, chemical, and biological processes at the seafloor. The role of the BBL is especially important in relatively shallow shelf seas where stratification, mean flow, and tidally-driven oscillating currents are typically strong. Despite this importance, the dynamics and even the height of the BBL formed under stratified, tidal conditions are not well understood. We address this knowledge gap by performing large-eddy simulations of the evolution of a tidally forced and stratified BBL, initialized from rest, over a range of geophysically rele..