A New Moist Turbulence Parameterization in the Community Atmosphere Model

Abstract A new moist turbulence parameterization is presented and implemented in the Community Atmosphere Model (CAM). It is derived from Grenier and Bretherton but has been heavily modified to improve its numerical stability and efficiency with the long time steps used in climate models. A goal was to provide a more physically realistic treatment of marine stratocumulus-topped boundary layers than in the current CAM. Key features of the scheme include use of moist-conserved variables, an explicit entrainment closure for convective layers, diagnosis of turbulent kinetic energy (TKE) for computation of turbulent diffusivities, an efficient new formulation of TKE transport as a relaxation to layer-mean TKE, and…

• UD
  U.S. Department of Energy

  Awards: FG02-05ER63959, DE-FG02-, DE-FG02
• NA
  National Aeronautics and Space Administration

  Award: NNG05GA19G