A Total Turbulent Energy (TTE)-based Eddy-Diffusivity Mass-Flux (EDMF) Parameterization for Vertical Turbulent Mixing and its Impact on Hurricane Intensity and Track Forecasts

A total turbulent energy (TTE)-based eddy-diffusivity mass-flux (EDMF) vertical turbulent mixing scheme is developed for the National Centers for Environmental Prediction's (NCEP) Global Forecast System (GFS). The TTE is the sum of the turbulent kinetic energy (TKE) and turbulent potential energy (TPE) which is proportional to the potential temperature variance. Similar to the current GFS TKE-based EDMF planetary boundary layer (PBL) scheme, in the TTE-based EDMF scheme the nonlocal transport by large turbulent eddies in the PBL is represented by a mass-flux (MF) scheme and the local transport by small turbulent eddies is represented by an eddy-diffusivity (ED) scheme. While in the TKE-based EDMF scheme the ED is proportional to only a prognostic TKE, in the TTE-based EDMF scheme it is given by a function of TTE, TKE, and TPE. In this study, we test the TTE-based EDMF vertical turbulent mixing scheme in the NCEP GFS and present its impacts on hurricane intensity and track forecasts.