A harmonic analyzed parameterization of tide-induced mixing for ocean models

The tide-induced mixing plays an important role in the regulation of ocean circulation. Numerical simulation of continental shelf circulation is found to exhibit an unreasonable vertical thermohaline structure without consideration of tide effects. In this study, we establish a harmonic analyzed parameterization of tide-induced (HAT) mixing, by which means to derive time-depended function of mixing coefficient based on harmonic analysis of the vertical mixing coefficient. By employing HAT mixing parameterization scheme, a series of numerical experiments are conducted for the Yellow Sea. Numerical results show that an ocean circulation model with the HAT mixing involved is capable of reproducing the reasonable thermohaline structure of the Yellow Sea Cold Water Mass, similar to structures produced by explicit tidal forcing on the open boundary. The advantage of the HAT method is its faster computation time, compared with models that directly resolve explicit tidal motion. The HAT parameterization for the tide-induced mixing has potential to improve both the accuracy and efficiency of ocean circulation and climate models.