Abstract:
Dynamics and numerical simulation of the mixing processes in the upper ocean have always been one of the key concerns of the oceanographers and meteorologists, the accuracy of the vertical mixing parameterization scheme can directly affect the skill of ocean models. The wind-driven waves play an extremely important role in the air-sea interaction and the internal mixing in upper ocean. In this paper, based on theoretical model of mixing coefficients of the wave-generated turbulence containing vertical stratification variation effect, analysis of the distribution and variation characteristics of the mixing coefficients under different stratification conditions is performed. One-dimensional ideal and quasi-global experiments are designed, and the results show that the mixed layer depths are negatively correlated with the mixing coefficients in upper ocean shallower than 100 m. The vertical mixing processes are strengthened when thermocline or mixed layer depth is deep, thus warmer water in surface later tends to be easily convected to deeper ocean, causing the simulated mixed layer depth deeper. This is because the stratification is relatively weak when thermocline is deeper, so the suppression to mixing processes become weaker. In addition, wave-generated turbulent mixing schemes are able to dramatically improve the simulation accuracy of the upper ocean temperature structure in the quasi-global experiments, and the accuracy of simulating the WOA13 multi-year monthly mean data in the thermocline regions can increased up to more than 60%.