Large eddy simulation of the rotation effect on the ocean turbulence kinetic energy budget in the surface mixed layer

A non-hydrostatic, Boussinesq, and three-dimensional large eddy simulation (LES) model was used to study the impact of the Earth’s rotation on turbulence and the redistribution of energy in turbulence kinetic energy (TKE) budget. A set of numerical simulations was conducted, (1) with and without rotation, (2) at different latitudes (10°N, 30°N, 45°N, 60°N, and 80°N), (3) with wave breaking and with Langmuir circulation, and (4) under different wind speeds (5, 10, 20, and 30 m/s). The results show that eddy viscosity decreases when rotation is included, indicating that rotation weakens the turbulence strength. The TKE budget become tight with rotation and the effects of rotation grow with latitude. However, rotation become less important under Langmuir circulation since the transport term is strong in the vertical direction. Finally, simulations were conducted based on field data from the Boundary Layer and Air-Sea Transfer Low Wind (CBLAST-Low) experiment. The results, although more complex, are consistent with the results obtained from earlier simulations using ideal numerical conditions.