Journal of Oceanography and Marine Research
Open Access

Abstract

Turbulance Closure Models

Aqeel Piracha*

Internal tides are formed by the barotropic (surface) tides moving stratified water over sudden bathymetric changes. These phenomenon present an important control on climate dynamics, through the carbon cycle and the general ocean circulation and biological productivity in shelf seas. Turbulence closure schemes are used to model the effect of turbulence in a one dimensional water column. They are based on traditional boundary layer theory, which suggest that mixing is a result of boundary stresses. However, these schemes have been shown to be weak in simulating mixing in stratified water columns.

Three dimensional turbulence resolving models, such as Large Eddy Simulations (LES) have recently been applied to coastal regions. They allow for a much better understanding of turbulent processes as they directly derive each turbulent quantity. However, they often cannot be utilised due to their high computational cost. Although in recent years they have been used to improve turbulence closure schemes to better capture turbulent effects.

Three dimensional regional ocean model used by the MET office, presently cannot resolve the effect of internal tides. Once these regional models are able to resolve the phenomenon of internal tides, they will need turbulence closure models to capture the spatially varying mixing they induce. This literature review is written for the purposes of an MSc thesis project which aims to use LES to ‘tune’ a turbulence closure scheme to better capture the effect of internal tides. This work will further the understanding in this new area of research.

Published Date: 2024-06-28; Received Date: 2019-10-21