This paper proposes an energy-constrained profile parameterization of both turbulent kinetic energy dissipation rate ( ϵ ) and vertical diffusivity ( κ ), for shear instability-induced turbulence that is initiated in an initial unstable layer (IUL) where the gradient Richardson number R i ∈ ( 0 , 0.25 ) . Large-eddy simulation (LES) experiments provide the data of turbulent processes originating from Kelvin-Helmholtz instabili...