Impact of Vertical Turbulence on Ocean Gravitational Potential Energy and the Tracer Mixing Process

Using a WOA09 (World Ocean Atlas 2009) data set of objectively analyzed in situ temperature and salinity, we calculate ocean gravitational potential energy (GPE) and investigate the relationships between the mixing coefficient, buoyancy frequency, and GPE. On that basis, we further explore the impact of energy conversion, caused by turbulent mixing, on turbulent parameterization. The research shows that ocean vertical turbulence is not only a kinetic energy sink but also an important way of external energy transformation to GPE. When the mixing coefficient is 0.1 cm² s^-1, GPE will increase 0.08 TW. Based on the results of other authors, we conclude that external energy can induce a global average mixing coefficient of up to 12 cm² s^-1. In general, the more stable the stratification of the ocean and the larger the mixing coefficient, the higher the GPE increase. Parameterization can obtain more realistic results with careful treatment of turbulent kinetic energy conversion to GPE.