Estimation of turbulent kinetic energy dissipation rate in the bottom boundary layer of the Pearl River Estuary

A structure function approach is applied to estimate the turbulent kinetic energy (TKE) dissipation rate in the bottom boundary layer of the Pearl River Estuary (PRE). Simultaneous measurements with an acoustic Doppler velocimeter (ADV) supplied independent data for the verification of the structure function method. The results show that, 1) the structure function approach is reliable and successfully applied method to estimate the TKE dissipation rate. The observed dissipation rates range between 8.3×10⁻⁴ W/kg and 4.9×10⁻⁶ W/kg in YM01 and between 3.4×10⁻⁴ W/kg and 4.8×10⁻⁷ W/kg in YM03, respectively, while exhibiting a strong quarter-diurnal variation. 2) The balance between the shear production and viscous dissipation is better achieved in the straight river. This first-order balance is significantly broken in the estuary by non-shear production/dissipation due to wave-induced fluctuations.