GFS Scale-aware TKE-based Moist Eddy-Diffusion Mass-Flux (EDMF) PBL and Free Atmospheric Turbulence Scheme

Description

The current operational GFS Hybrid Eddy-Diffusivity Mass-Flux PBL and Free Atmospheric Turbulence Scheme uses a hybrid EDMF parameterization for the convective PBL (Han et al. 2016 [78]; Han et al. 2017 [79]), where the EDMF scheme is applied only for the strongly unstable PBL, while the eddy-diffusivity counter-gradient(EDCG) scheme is used for the weakly unstable PBL. The new TKE-EDMF is an extended version of GFS Hybrid Eddy-Diffusivity Mass-Flux PBL and Free Atmospheric Turbulence Scheme with below enhancement:

1. Eddy diffusivity (K) is now a function of TKE which is prognostically predicted
2. EDMF approach is applied for all the unstable PBL
3. EDMF approach is also applied to the stratocumulus-top-driven turbulence mixing
4. It includes a moist-adiabatic process when updraft thermal becomes saturated
5. Scale-aware capability
6. It includes interaction between TKE and cumulus convection

The CCPP-compliant subroutine satmedmfvdifq_run() computes subgrid vertical turbulence mixing using scale-aware TKE-based moist eddy-diffusion mass-flux paramterization (Han et al. 2019 [75])

• For the convective boundary layer, the scheme adopts EDMF parameterization (Siebesma et al. (2007)[163]) to take into account nonlocal transport by large eddies(mfpbltq.f)
• A new mass-flux paramterization for stratocumulus-top-induced turbulence mixing has been introduced (mfscuq.f; previously, it was an eddy diffusion form)
• For local turbulence mixing, a TKE closure model is used.

Intraphysics Communication

Argument Table

General Algorithm

GFS satmedmfvdifq General Algorithm