Parameterization of the eddy diffusivity due to double diffusive convection

The turbulent energy dissipation rates a in the western North Pacific Ocean were observed using a microstructure profiler at 49 casts, and the measured values were converted into diffusivities of heat K and salt K5. We obtained a new relationship between the Richardson number R and the buoyancy Reynolds number R5, which enables us to use K, instead of K5, as an indicator for distinguishing double diffusive convection from turbulence. We further obtained new relationships between K5, KT, K and the density ratio R by improving the parameterization proposed by KIMURA et al. (2011).